WebSVN - shark - Blame - Rev 96 - /shark/trunk/ports/png/pngwutil.c

Rev	Author	Line No.	Line
96	giacomo	1
		2	/* pngwutil.c - utilities to write a PNG file
		3	*
		4	* libpng 1.2.5 - October 3, 2002
		5	* For conditions of distribution and use, see copyright notice in png.h
		6	* Copyright (c) 1998-2002 Glenn Randers-Pehrson
		7	* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
		8	* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
		9	*/
		10
		11	#define PNG_INTERNAL
		12	#include "png.h"
		13	#ifdef PNG_WRITE_SUPPORTED
		14
		15	/* Place a 32-bit number into a buffer in PNG byte order. We work
		16	* with unsigned numbers for convenience, although one supported
		17	* ancillary chunk uses signed (two's complement) numbers.
		18	*/
		19	void /* PRIVATE */
		20	png_save_uint_32(png_bytep buf, png_uint_32 i)
		21	{
		22	buf[0] = (png_byte)((i >> 24) & 0xff);
		23	buf[1] = (png_byte)((i >> 16) & 0xff);
		24	buf[2] = (png_byte)((i >> 8) & 0xff);
		25	buf[3] = (png_byte)(i & 0xff);
		26	}
		27
		28	#if defined(PNG_WRITE_pCAL_SUPPORTED) \|\| defined(PNG_WRITE_oFFs_SUPPORTED)
		29	/* The png_save_int_32 function assumes integers are stored in two's
		30	* complement format. If this isn't the case, then this routine needs to
		31	* be modified to write data in two's complement format.
		32	*/
		33	void /* PRIVATE */
		34	png_save_int_32(png_bytep buf, png_int_32 i)
		35	{
		36	buf[0] = (png_byte)((i >> 24) & 0xff);
		37	buf[1] = (png_byte)((i >> 16) & 0xff);
		38	buf[2] = (png_byte)((i >> 8) & 0xff);
		39	buf[3] = (png_byte)(i & 0xff);
		40	}
		41	#endif
		42
		43	/* Place a 16-bit number into a buffer in PNG byte order.
		44	* The parameter is declared unsigned int, not png_uint_16,
		45	* just to avoid potential problems on pre-ANSI C compilers.
		46	*/
		47	void /* PRIVATE */
		48	png_save_uint_16(png_bytep buf, unsigned int i)
		49	{
		50	buf[0] = (png_byte)((i >> 8) & 0xff);
		51	buf[1] = (png_byte)(i & 0xff);
		52	}
		53
		54	/* Write a PNG chunk all at once. The type is an array of ASCII characters
		55	* representing the chunk name. The array must be at least 4 bytes in
		56	* length, and does not need to be null terminated. To be safe, pass the
		57	* pre-defined chunk names here, and if you need a new one, define it
		58	* where the others are defined. The length is the length of the data.
		59	* All the data must be present. If that is not possible, use the
		60	* png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
		61	* functions instead.
		62	*/
		63	void PNGAPI
		64	png_write_chunk(png_structp png_ptr, png_bytep chunk_name,
		65	png_bytep data, png_size_t length)
		66	{
		67	png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length);
		68	png_write_chunk_data(png_ptr, data, length);
		69	png_write_chunk_end(png_ptr);
		70	}
		71
		72	/* Write the start of a PNG chunk. The type is the chunk type.
		73	* The total_length is the sum of the lengths of all the data you will be
		74	* passing in png_write_chunk_data().
		75	*/
		76	void PNGAPI
		77	png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name,
		78	png_uint_32 length)
		79	{
		80	png_byte buf[4];
		81	png_debug2(0, "Writing %s chunk (%lu bytes)\n", chunk_name, length);
		82
		83	/* write the length */
		84	png_save_uint_32(buf, length);
		85	png_write_data(png_ptr, buf, (png_size_t)4);
		86
		87	/* write the chunk name */
		88	png_write_data(png_ptr, chunk_name, (png_size_t)4);
		89	/* reset the crc and run it over the chunk name */
		90	png_reset_crc(png_ptr);
		91	png_calculate_crc(png_ptr, chunk_name, (png_size_t)4);
		92	}
		93
		94	/* Write the data of a PNG chunk started with png_write_chunk_start().
		95	* Note that multiple calls to this function are allowed, and that the
		96	* sum of the lengths from these calls must add up to the total_length
		97	* given to png_write_chunk_start().
		98	*/
		99	void PNGAPI
		100	png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length)
		101	{
		102	/* write the data, and run the CRC over it */
		103	if (data != NULL && length > 0)
		104	{
		105	png_calculate_crc(png_ptr, data, length);
		106	png_write_data(png_ptr, data, length);
		107	}
		108	}
		109
		110	/* Finish a chunk started with png_write_chunk_start(). */
		111	void PNGAPI
		112	png_write_chunk_end(png_structp png_ptr)
		113	{
		114	png_byte buf[4];
		115
		116	/* write the crc */
		117	png_save_uint_32(buf, png_ptr->crc);
		118
		119	png_write_data(png_ptr, buf, (png_size_t)4);
		120	}
		121
		122	/* Simple function to write the signature. If we have already written
		123	* the magic bytes of the signature, or more likely, the PNG stream is
		124	* being embedded into another stream and doesn't need its own signature,
		125	* we should call png_set_sig_bytes() to tell libpng how many of the
		126	* bytes have already been written.
		127	*/
		128	void /* PRIVATE */
		129	png_write_sig(png_structp png_ptr)
		130	{
		131	png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
		132	/* write the rest of the 8 byte signature */
		133	png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
		134	(png_size_t)8 - png_ptr->sig_bytes);
		135	if(png_ptr->sig_bytes < 3)
		136	png_ptr->mode \|= PNG_HAVE_PNG_SIGNATURE;
		137	}
		138
		139	#if defined(PNG_WRITE_TEXT_SUPPORTED) \|\| defined(PNG_WRITE_iCCP_SUPPORTED)
		140	/*
		141	* This pair of functions encapsulates the operation of (a) compressing a
		142	* text string, and (b) issuing it later as a series of chunk data writes.
		143	* The compression_state structure is shared context for these functions
		144	* set up by the caller in order to make the whole mess thread-safe.
		145	*/
		146
		147	typedef struct
		148	{
		149	char input; / the uncompressed input data */
		150	int input_len; /* its length */
		151	int num_output_ptr; /* number of output pointers used */
		152	int max_output_ptr; /* size of output_ptr */
		153	png_charpp output_ptr; /* array of pointers to output */
		154	} compression_state;
		155
		156	/* compress given text into storage in the png_ptr structure */
		157	static int /* PRIVATE */
		158	png_text_compress(png_structp png_ptr,
		159	png_charp text, png_size_t text_len, int compression,
		160	compression_state *comp)
		161	{
		162	int ret;
		163
		164	comp->num_output_ptr = comp->max_output_ptr = 0;
		165	comp->output_ptr = NULL;
		166	comp->input = NULL;
		167
		168	/* we may just want to pass the text right through */
		169	if (compression == PNG_TEXT_COMPRESSION_NONE)
		170	{
		171	comp->input = text;
		172	comp->input_len = text_len;
		173	return((int)text_len);
		174	}
		175
		176	if (compression >= PNG_TEXT_COMPRESSION_LAST)
		177	{
		178	#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
		179	char msg[50];
		180	sprintf(msg, "Unknown compression type %d", compression);
		181	png_warning(png_ptr, msg);
		182	#else
		183	png_warning(png_ptr, "Unknown compression type");
		184	#endif
		185	}
		186
		187	/* We can't write the chunk until we find out how much data we have,
		188	* which means we need to run the compressor first and save the
		189	* output. This shouldn't be a problem, as the vast majority of
		190	* comments should be reasonable, but we will set up an array of
		191	* malloc'd pointers to be sure.
		192	*
		193	* If we knew the application was well behaved, we could simplify this
		194	* greatly by assuming we can always malloc an output buffer large
		195	* enough to hold the compressed text ((1001 * text_len / 1000) + 12)
		196	* and malloc this directly. The only time this would be a bad idea is
		197	* if we can't malloc more than 64K and we have 64K of random input
		198	* data, or if the input string is incredibly large (although this
		199	* wouldn't cause a failure, just a slowdown due to swapping).
		200	*/
		201
		202	/* set up the compression buffers */
		203	png_ptr->zstream.avail_in = (uInt)text_len;
		204	png_ptr->zstream.next_in = (Bytef *)text;
		205	png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
		206	png_ptr->zstream.next_out = (Bytef *)png_ptr->zbuf;
		207
		208	/* this is the same compression loop as in png_write_row() */
		209	do
		210	{
		211	/* compress the data */
		212	ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
		213	if (ret != Z_OK)
		214	{
		215	/* error */
		216	if (png_ptr->zstream.msg != NULL)
		217	png_error(png_ptr, png_ptr->zstream.msg);
		218	else
		219	png_error(png_ptr, "zlib error");
		220	}
		221	/* check to see if we need more room */
		222	if (!png_ptr->zstream.avail_out && png_ptr->zstream.avail_in)
		223	{
		224	/* make sure the output array has room */
		225	if (comp->num_output_ptr >= comp->max_output_ptr)
		226	{
		227	int old_max;
		228
		229	old_max = comp->max_output_ptr;
		230	comp->max_output_ptr = comp->num_output_ptr + 4;
		231	if (comp->output_ptr != NULL)
		232	{
		233	png_charpp old_ptr;
		234
		235	old_ptr = comp->output_ptr;
		236	comp->output_ptr = (png_charpp)png_malloc(png_ptr,
		237	(png_uint_32)(comp->max_output_ptr * sizeof (png_charpp)));
		238	png_memcpy(comp->output_ptr, old_ptr, old_max
		239	* sizeof (png_charp));
		240	png_free(png_ptr, old_ptr);
		241	}
		242	else
		243	comp->output_ptr = (png_charpp)png_malloc(png_ptr,
		244	(png_uint_32)(comp->max_output_ptr * sizeof (png_charp)));
		245	}
		246
		247	/* save the data */
		248	comp->output_ptr[comp->num_output_ptr] = (png_charp)png_malloc(png_ptr,
		249	(png_uint_32)png_ptr->zbuf_size);
		250	png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
		251	png_ptr->zbuf_size);
		252	comp->num_output_ptr++;
		253
		254	/* and reset the buffer */
		255	png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
		256	png_ptr->zstream.next_out = png_ptr->zbuf;
		257	}
		258	/* continue until we don't have any more to compress */
		259	} while (png_ptr->zstream.avail_in);
		260
		261	/* finish the compression */
		262	do
		263	{
		264	/* tell zlib we are finished */
		265	ret = deflate(&png_ptr->zstream, Z_FINISH);
		266
		267	if (ret == Z_OK)
		268	{
		269	/* check to see if we need more room */
		270	if (!(png_ptr->zstream.avail_out))
		271	{
		272	/* check to make sure our output array has room */
		273	if (comp->num_output_ptr >= comp->max_output_ptr)
		274	{
		275	int old_max;
		276
		277	old_max = comp->max_output_ptr;
		278	comp->max_output_ptr = comp->num_output_ptr + 4;
		279	if (comp->output_ptr != NULL)
		280	{
		281	png_charpp old_ptr;
		282
		283	old_ptr = comp->output_ptr;
		284	/* This could be optimized to realloc() */
		285	comp->output_ptr = (png_charpp)png_malloc(png_ptr,
		286	(png_uint_32)(comp->max_output_ptr * sizeof (png_charpp)));
		287	png_memcpy(comp->output_ptr, old_ptr,
		288	old_max * sizeof (png_charp));
		289	png_free(png_ptr, old_ptr);
		290	}
		291	else
		292	comp->output_ptr = (png_charpp)png_malloc(png_ptr,
		293	(png_uint_32)(comp->max_output_ptr * sizeof (png_charp)));
		294	}
		295
		296	/* save off the data */
		297	comp->output_ptr[comp->num_output_ptr] =
		298	(png_charp)png_malloc(png_ptr, (png_uint_32)png_ptr->zbuf_size);
		299	png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf,
		300	png_ptr->zbuf_size);
		301	comp->num_output_ptr++;
		302
		303	/* and reset the buffer pointers */
		304	png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
		305	png_ptr->zstream.next_out = png_ptr->zbuf;
		306	}
		307	}
		308	else if (ret != Z_STREAM_END)
		309	{
		310	/* we got an error */
		311	if (png_ptr->zstream.msg != NULL)
		312	png_error(png_ptr, png_ptr->zstream.msg);
		313	else
		314	png_error(png_ptr, "zlib error");
		315	}
		316	} while (ret != Z_STREAM_END);
		317
		318	/* text length is number of buffers plus last buffer */
		319	text_len = png_ptr->zbuf_size * comp->num_output_ptr;
		320	if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
		321	text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out;
		322
		323	return((int)text_len);
		324	}
		325
		326	/* ship the compressed text out via chunk writes */
		327	static void /* PRIVATE */
		328	png_write_compressed_data_out(png_structp png_ptr, compression_state *comp)
		329	{
		330	int i;
		331
		332	/* handle the no-compression case */
		333	if (comp->input)
		334	{
		335	png_write_chunk_data(png_ptr, (png_bytep)comp->input,
		336	(png_size_t)comp->input_len);
		337	return;
		338	}
		339
		340	/* write saved output buffers, if any */
		341	for (i = 0; i < comp->num_output_ptr; i++)
		342	{
		343	png_write_chunk_data(png_ptr,(png_bytep)comp->output_ptr[i],
		344	png_ptr->zbuf_size);
		345	png_free(png_ptr, comp->output_ptr[i]);
		346	comp->output_ptr[i]=NULL;
		347	}
		348	if (comp->max_output_ptr != 0)
		349	png_free(png_ptr, comp->output_ptr);
		350	comp->output_ptr=NULL;
		351	/* write anything left in zbuf */
		352	if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size)
		353	png_write_chunk_data(png_ptr, png_ptr->zbuf,
		354	png_ptr->zbuf_size - png_ptr->zstream.avail_out);
		355
		356	/* reset zlib for another zTXt/iTXt or the image data */
		357	deflateReset(&png_ptr->zstream);
		358
		359	}
		360	#endif
		361
		362	/* Write the IHDR chunk, and update the png_struct with the necessary
		363	* information. Note that the rest of this code depends upon this
		364	* information being correct.
		365	*/
		366	void /* PRIVATE */
		367	png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height,
		368	int bit_depth, int color_type, int compression_type, int filter_type,
		369	int interlace_type)
		370	{
		371	#ifdef PNG_USE_LOCAL_ARRAYS
		372	PNG_IHDR;
		373	#endif
		374	png_byte buf[13]; /* buffer to store the IHDR info */
		375
		376	png_debug(1, "in png_write_IHDR\n");
		377	/* Check that we have valid input data from the application info */
		378	switch (color_type)
		379	{
		380	case PNG_COLOR_TYPE_GRAY:
		381	switch (bit_depth)
		382	{
		383	case 1:
		384	case 2:
		385	case 4:
		386	case 8:
		387	case 16: png_ptr->channels = 1; break;
		388	default: png_error(png_ptr,"Invalid bit depth for grayscale image");
		389	}
		390	break;
		391	case PNG_COLOR_TYPE_RGB:
		392	if (bit_depth != 8 && bit_depth != 16)
		393	png_error(png_ptr, "Invalid bit depth for RGB image");
		394	png_ptr->channels = 3;
		395	break;
		396	case PNG_COLOR_TYPE_PALETTE:
		397	switch (bit_depth)
		398	{
		399	case 1:
		400	case 2:
		401	case 4:
		402	case 8: png_ptr->channels = 1; break;
		403	default: png_error(png_ptr, "Invalid bit depth for paletted image");
		404	}
		405	break;
		406	case PNG_COLOR_TYPE_GRAY_ALPHA:
		407	if (bit_depth != 8 && bit_depth != 16)
		408	png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
		409	png_ptr->channels = 2;
		410	break;
		411	case PNG_COLOR_TYPE_RGB_ALPHA:
		412	if (bit_depth != 8 && bit_depth != 16)
		413	png_error(png_ptr, "Invalid bit depth for RGBA image");
		414	png_ptr->channels = 4;
		415	break;
		416	default:
		417	png_error(png_ptr, "Invalid image color type specified");
		418	}
		419
		420	if (compression_type != PNG_COMPRESSION_TYPE_BASE)
		421	{
		422	png_warning(png_ptr, "Invalid compression type specified");
		423	compression_type = PNG_COMPRESSION_TYPE_BASE;
		424	}
		425
		426	/* Write filter_method 64 (intrapixel differencing) only if
		427	* 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
		428	* 2. Libpng did not write a PNG signature (this filter_method is only
		429	* used in PNG datastreams that are embedded in MNG datastreams) and
		430	* 3. The application called png_permit_mng_features with a mask that
		431	* included PNG_FLAG_MNG_FILTER_64 and
		432	* 4. The filter_method is 64 and
		433	* 5. The color_type is RGB or RGBA
		434	*/
		435	if (
		436	#if defined(PNG_MNG_FEATURES_SUPPORTED)
		437	!((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) &&
		438	((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) &&
		439	(color_type == PNG_COLOR_TYPE_RGB \|\|
		440	color_type == PNG_COLOR_TYPE_RGB_ALPHA) &&
		441	(filter_type == PNG_INTRAPIXEL_DIFFERENCING)) &&
		442	#endif
		443	filter_type != PNG_FILTER_TYPE_BASE)
		444	{
		445	png_warning(png_ptr, "Invalid filter type specified");
		446	filter_type = PNG_FILTER_TYPE_BASE;
		447	}
		448
		449	#ifdef PNG_WRITE_INTERLACING_SUPPORTED
		450	if (interlace_type != PNG_INTERLACE_NONE &&
		451	interlace_type != PNG_INTERLACE_ADAM7)
		452	{
		453	png_warning(png_ptr, "Invalid interlace type specified");
		454	interlace_type = PNG_INTERLACE_ADAM7;
		455	}
		456	#else
		457	interlace_type=PNG_INTERLACE_NONE;
		458	#endif
		459
		460	/* save off the relevent information */
		461	png_ptr->bit_depth = (png_byte)bit_depth;
		462	png_ptr->color_type = (png_byte)color_type;
		463	png_ptr->interlaced = (png_byte)interlace_type;
		464	#if defined(PNG_MNG_FEATURES_SUPPORTED)
		465	png_ptr->filter_type = (png_byte)filter_type;
		466	#endif
		467	png_ptr->width = width;
		468	png_ptr->height = height;
		469
		470	png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
		471	png_ptr->rowbytes = ((width * (png_size_t)png_ptr->pixel_depth + 7) >> 3);
		472	/* set the usr info, so any transformations can modify it */
		473	png_ptr->usr_width = png_ptr->width;
		474	png_ptr->usr_bit_depth = png_ptr->bit_depth;
		475	png_ptr->usr_channels = png_ptr->channels;
		476
		477	/* pack the header information into the buffer */
		478	png_save_uint_32(buf, width);
		479	png_save_uint_32(buf + 4, height);
		480	buf[8] = (png_byte)bit_depth;
		481	buf[9] = (png_byte)color_type;
		482	buf[10] = (png_byte)compression_type;
		483	buf[11] = (png_byte)filter_type;
		484	buf[12] = (png_byte)interlace_type;
		485
		486	/* write the chunk */
		487	png_write_chunk(png_ptr, (png_bytep)png_IHDR, buf, (png_size_t)13);
		488
		489	/* initialize zlib with PNG info */
		490	png_ptr->zstream.zalloc = png_zalloc;
		491	png_ptr->zstream.zfree = png_zfree;
		492	png_ptr->zstream.opaque = (voidpf)png_ptr;
		493	if (!(png_ptr->do_filter))
		494	{
		495	if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE \|\|
		496	png_ptr->bit_depth < 8)
		497	png_ptr->do_filter = PNG_FILTER_NONE;
		498	else
		499	png_ptr->do_filter = PNG_ALL_FILTERS;
		500	}
		501	if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY))
		502	{
		503	if (png_ptr->do_filter != PNG_FILTER_NONE)
		504	png_ptr->zlib_strategy = Z_FILTERED;
		505	else
		506	png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY;
		507	}
		508	if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL))
		509	png_ptr->zlib_level = Z_DEFAULT_COMPRESSION;
		510	if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL))
		511	png_ptr->zlib_mem_level = 8;
		512	if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS))
		513	png_ptr->zlib_window_bits = 15;
		514	if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD))
		515	png_ptr->zlib_method = 8;
		516	deflateInit2(&png_ptr->zstream, png_ptr->zlib_level,
		517	png_ptr->zlib_method, png_ptr->zlib_window_bits,
		518	png_ptr->zlib_mem_level, png_ptr->zlib_strategy);
		519	png_ptr->zstream.next_out = png_ptr->zbuf;
		520	png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
		521
		522	png_ptr->mode = PNG_HAVE_IHDR;
		523	}
		524
		525	/* write the palette. We are careful not to trust png_color to be in the
		526	* correct order for PNG, so people can redefine it to any convenient
		527	* structure.
		528	*/
		529	void /* PRIVATE */
		530	png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal)
		531	{
		532	#ifdef PNG_USE_LOCAL_ARRAYS
		533	PNG_PLTE;
		534	#endif
		535	png_uint_32 i;
		536	png_colorp pal_ptr;
		537	png_byte buf[3];
		538
		539	png_debug(1, "in png_write_PLTE\n");
		540	if ((
		541	#if defined(PNG_MNG_FEATURES_SUPPORTED)
		542	!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) &&
		543	#endif
		544	num_pal == 0) \|\| num_pal > 256)
		545	{
		546	if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)
		547	{
		548	png_error(png_ptr, "Invalid number of colors in palette");
		549	}
		550	else
		551	{
		552	png_warning(png_ptr, "Invalid number of colors in palette");
		553	return;
		554	}
		555	}
		556
		557	if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR))
		558	{
		559	png_warning(png_ptr,
		560	"Ignoring request to write a PLTE chunk in grayscale PNG");
		561	return;
		562	}
		563
		564	png_ptr->num_palette = (png_uint_16)num_pal;
		565	png_debug1(3, "num_palette = %d\n", png_ptr->num_palette);
		566
		567	png_write_chunk_start(png_ptr, (png_bytep)png_PLTE, num_pal * 3);
		568	#ifndef PNG_NO_POINTER_INDEXING
		569	for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
		570	{
		571	buf[0] = pal_ptr->red;
		572	buf[1] = pal_ptr->green;
		573	buf[2] = pal_ptr->blue;
		574	png_write_chunk_data(png_ptr, buf, (png_size_t)3);
		575	}
		576	#else
		577	/* This is a little slower but some buggy compilers need to do this instead */
		578	pal_ptr=palette;
		579	for (i = 0; i < num_pal; i++)
		580	{
		581	buf[0] = pal_ptr[i].red;
		582	buf[1] = pal_ptr[i].green;
		583	buf[2] = pal_ptr[i].blue;
		584	png_write_chunk_data(png_ptr, buf, (png_size_t)3);
		585	}
		586	#endif
		587	png_write_chunk_end(png_ptr);
		588	png_ptr->mode \|= PNG_HAVE_PLTE;
		589	}
		590
		591	/* write an IDAT chunk */
		592	void /* PRIVATE */
		593	png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length)
		594	{
		595	#ifdef PNG_USE_LOCAL_ARRAYS
		596	PNG_IDAT;
		597	#endif
		598	png_debug(1, "in png_write_IDAT\n");
		599	png_write_chunk(png_ptr, (png_bytep)png_IDAT, data, length);
		600	png_ptr->mode \|= PNG_HAVE_IDAT;
		601	}
		602
		603	/* write an IEND chunk */
		604	void /* PRIVATE */
		605	png_write_IEND(png_structp png_ptr)
		606	{
		607	#ifdef PNG_USE_LOCAL_ARRAYS
		608	PNG_IEND;
		609	#endif
		610	png_debug(1, "in png_write_IEND\n");
		611	png_write_chunk(png_ptr, (png_bytep)png_IEND, png_bytep_NULL,
		612	(png_size_t)0);
		613	png_ptr->mode \|= PNG_HAVE_IEND;
		614	}
		615
		616	#if defined(PNG_WRITE_gAMA_SUPPORTED)
		617	/* write a gAMA chunk */
		618	#ifdef PNG_FLOATING_POINT_SUPPORTED
		619	void /* PRIVATE */
		620	png_write_gAMA(png_structp png_ptr, double file_gamma)
		621	{
		622	#ifdef PNG_USE_LOCAL_ARRAYS
		623	PNG_gAMA;
		624	#endif
		625	png_uint_32 igamma;
		626	png_byte buf[4];
		627
		628	png_debug(1, "in png_write_gAMA\n");
		629	/* file_gamma is saved in 1/100,000ths */
		630	igamma = (png_uint_32)(file_gamma * 100000.0 + 0.5);
		631	png_save_uint_32(buf, igamma);
		632	png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
		633	}
		634	#endif
		635	#ifdef PNG_FIXED_POINT_SUPPORTED
		636	void /* PRIVATE */
		637	png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma)
		638	{
		639	#ifdef PNG_USE_LOCAL_ARRAYS
		640	PNG_gAMA;
		641	#endif
		642	png_byte buf[4];
		643
		644	png_debug(1, "in png_write_gAMA\n");
		645	/* file_gamma is saved in 1/100,000ths */
		646	png_save_uint_32(buf, (png_uint_32)file_gamma);
		647	png_write_chunk(png_ptr, (png_bytep)png_gAMA, buf, (png_size_t)4);
		648	}
		649	#endif
		650	#endif
		651
		652	#if defined(PNG_WRITE_sRGB_SUPPORTED)
		653	/* write a sRGB chunk */
		654	void /* PRIVATE */
		655	png_write_sRGB(png_structp png_ptr, int srgb_intent)
		656	{
		657	#ifdef PNG_USE_LOCAL_ARRAYS
		658	PNG_sRGB;
		659	#endif
		660	png_byte buf[1];
		661
		662	png_debug(1, "in png_write_sRGB\n");
		663	if(srgb_intent >= PNG_sRGB_INTENT_LAST)
		664	png_warning(png_ptr,
		665	"Invalid sRGB rendering intent specified");
		666	buf[0]=(png_byte)srgb_intent;
		667	png_write_chunk(png_ptr, (png_bytep)png_sRGB, buf, (png_size_t)1);
		668	}
		669	#endif
		670
		671	#if defined(PNG_WRITE_iCCP_SUPPORTED)
		672	/* write an iCCP chunk */
		673	void /* PRIVATE */
		674	png_write_iCCP(png_structp png_ptr, png_charp name, int compression_type,
		675	png_charp profile, int profile_len)
		676	{
		677	#ifdef PNG_USE_LOCAL_ARRAYS
		678	PNG_iCCP;
		679	#endif
		680	png_size_t name_len;
		681	png_charp new_name;
		682	compression_state comp;
		683
		684	png_debug(1, "in png_write_iCCP\n");
		685	if (name == NULL \|\| (name_len = png_check_keyword(png_ptr, name,
		686	&new_name)) == 0)
		687	{
		688	png_warning(png_ptr, "Empty keyword in iCCP chunk");
		689	return;
		690	}
		691
		692	if (compression_type != PNG_COMPRESSION_TYPE_BASE)
		693	png_warning(png_ptr, "Unknown compression type in iCCP chunk");
		694
		695	if (profile == NULL)
		696	profile_len = 0;
		697
		698	if (profile_len)
		699	profile_len = png_text_compress(png_ptr, profile, (png_size_t)profile_len,
		700	PNG_COMPRESSION_TYPE_BASE, &comp);
		701
		702	/* make sure we include the NULL after the name and the compression type */
		703	png_write_chunk_start(png_ptr, (png_bytep)png_iCCP,
		704	(png_uint_32)name_len+profile_len+2);
		705	new_name[name_len+1]=0x00;
		706	png_write_chunk_data(png_ptr, (png_bytep)new_name, name_len + 2);
		707
		708	if (profile_len)
		709	png_write_compressed_data_out(png_ptr, &comp);
		710
		711	png_write_chunk_end(png_ptr);
		712	png_free(png_ptr, new_name);
		713	}
		714	#endif
		715
		716	#if defined(PNG_WRITE_sPLT_SUPPORTED)
		717	/* write a sPLT chunk */
		718	void /* PRIVATE */
		719	png_write_sPLT(png_structp png_ptr, png_sPLT_tp spalette)
		720	{
		721	#ifdef PNG_USE_LOCAL_ARRAYS
		722	PNG_sPLT;
		723	#endif
		724	png_size_t name_len;
		725	png_charp new_name;
		726	png_byte entrybuf[10];
		727	int entry_size = (spalette->depth == 8 ? 6 : 10);
		728	int palette_size = entry_size * spalette->nentries;
		729	png_sPLT_entryp ep;
		730	#ifdef PNG_NO_POINTER_INDEXING
		731	int i;
		732	#endif
		733
		734	png_debug(1, "in png_write_sPLT\n");
		735	if (spalette->name == NULL \|\| (name_len = png_check_keyword(png_ptr,
		736	spalette->name, &new_name))==0)
		737	{
		738	png_warning(png_ptr, "Empty keyword in sPLT chunk");
		739	return;
		740	}
		741
		742	/* make sure we include the NULL after the name */
		743	png_write_chunk_start(png_ptr, (png_bytep)png_sPLT,
		744	(png_uint_32)(name_len + 2 + palette_size));
		745	png_write_chunk_data(png_ptr, (png_bytep)new_name, name_len + 1);
		746	png_write_chunk_data(png_ptr, (png_bytep)&spalette->depth, 1);
		747
		748	/* loop through each palette entry, writing appropriately */
		749	#ifndef PNG_NO_POINTER_INDEXING
		750	for (ep = spalette->entries; ep<spalette->entries+spalette->nentries; ep++)
		751	{
		752	if (spalette->depth == 8)
		753	{
		754	entrybuf[0] = (png_byte)ep->red;
		755	entrybuf[1] = (png_byte)ep->green;
		756	entrybuf[2] = (png_byte)ep->blue;
		757	entrybuf[3] = (png_byte)ep->alpha;
		758	png_save_uint_16(entrybuf + 4, ep->frequency);
		759	}
		760	else
		761	{
		762	png_save_uint_16(entrybuf + 0, ep->red);
		763	png_save_uint_16(entrybuf + 2, ep->green);
		764	png_save_uint_16(entrybuf + 4, ep->blue);
		765	png_save_uint_16(entrybuf + 6, ep->alpha);
		766	png_save_uint_16(entrybuf + 8, ep->frequency);
		767	}
		768	png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size);
		769	}
		770	#else
		771	ep=spalette->entries;
		772	for (i=0; i>spalette->nentries; i++)
		773	{
		774	if (spalette->depth == 8)
		775	{
		776	entrybuf[0] = (png_byte)ep[i].red;
		777	entrybuf[1] = (png_byte)ep[i].green;
		778	entrybuf[2] = (png_byte)ep[i].blue;
		779	entrybuf[3] = (png_byte)ep[i].alpha;
		780	png_save_uint_16(entrybuf + 4, ep[i].frequency);
		781	}
		782	else
		783	{
		784	png_save_uint_16(entrybuf + 0, ep[i].red);
		785	png_save_uint_16(entrybuf + 2, ep[i].green);
		786	png_save_uint_16(entrybuf + 4, ep[i].blue);
		787	png_save_uint_16(entrybuf + 6, ep[i].alpha);
		788	png_save_uint_16(entrybuf + 8, ep[i].frequency);
		789	}
		790	png_write_chunk_data(png_ptr, entrybuf, entry_size);
		791	}
		792	#endif
		793
		794	png_write_chunk_end(png_ptr);
		795	png_free(png_ptr, new_name);
		796	}
		797	#endif
		798
		799	#if defined(PNG_WRITE_sBIT_SUPPORTED)
		800	/* write the sBIT chunk */
		801	void /* PRIVATE */
		802	png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type)
		803	{
		804	#ifdef PNG_USE_LOCAL_ARRAYS
		805	PNG_sBIT;
		806	#endif
		807	png_byte buf[4];
		808	png_size_t size;
		809
		810	png_debug(1, "in png_write_sBIT\n");
		811	/* make sure we don't depend upon the order of PNG_COLOR_8 */
		812	if (color_type & PNG_COLOR_MASK_COLOR)
		813	{
		814	png_byte maxbits;
		815
		816	maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 :
		817	png_ptr->usr_bit_depth);
		818	if (sbit->red == 0 \|\| sbit->red > maxbits \|\|
		819	sbit->green == 0 \|\| sbit->green > maxbits \|\|
		820	sbit->blue == 0 \|\| sbit->blue > maxbits)
		821	{
		822	png_warning(png_ptr, "Invalid sBIT depth specified");
		823	return;
		824	}
		825	buf[0] = sbit->red;
		826	buf[1] = sbit->green;
		827	buf[2] = sbit->blue;
		828	size = 3;
		829	}
		830	else
		831	{
		832	if (sbit->gray == 0 \|\| sbit->gray > png_ptr->usr_bit_depth)
		833	{
		834	png_warning(png_ptr, "Invalid sBIT depth specified");
		835	return;
		836	}
		837	buf[0] = sbit->gray;
		838	size = 1;
		839	}
		840
		841	if (color_type & PNG_COLOR_MASK_ALPHA)
		842	{
		843	if (sbit->alpha == 0 \|\| sbit->alpha > png_ptr->usr_bit_depth)
		844	{
		845	png_warning(png_ptr, "Invalid sBIT depth specified");
		846	return;
		847	}
		848	buf[size++] = sbit->alpha;
		849	}
		850
		851	png_write_chunk(png_ptr, (png_bytep)png_sBIT, buf, size);
		852	}
		853	#endif
		854
		855	#if defined(PNG_WRITE_cHRM_SUPPORTED)
		856	/* write the cHRM chunk */
		857	#ifdef PNG_FLOATING_POINT_SUPPORTED
		858	void /* PRIVATE */
		859	png_write_cHRM(png_structp png_ptr, double white_x, double white_y,
		860	double red_x, double red_y, double green_x, double green_y,
		861	double blue_x, double blue_y)
		862	{
		863	#ifdef PNG_USE_LOCAL_ARRAYS
		864	PNG_cHRM;
		865	#endif
		866	png_byte buf[32];
		867	png_uint_32 itemp;
		868
		869	png_debug(1, "in png_write_cHRM\n");
		870	/* each value is saved in 1/100,000ths */
		871	if (white_x < 0 \|\| white_x > 0.8 \|\| white_y < 0 \|\| white_y > 0.8 \|\|
		872	white_x + white_y > 1.0)
		873	{
		874	png_warning(png_ptr, "Invalid cHRM white point specified");
		875	#if !defined(PNG_NO_CONSOLE_IO)
		876	cprintf("white_x=%f, white_y=%f\n",white_x, white_y);
		877	#endif
		878	return;
		879	}
		880	itemp = (png_uint_32)(white_x * 100000.0 + 0.5);
		881	png_save_uint_32(buf, itemp);
		882	itemp = (png_uint_32)(white_y * 100000.0 + 0.5);
		883	png_save_uint_32(buf + 4, itemp);
		884
		885	if (red_x < 0 \|\| red_x > 0.8 \|\| red_y < 0 \|\| red_y > 0.8 \|\|
		886	red_x + red_y > 1.0)
		887	{
		888	png_warning(png_ptr, "Invalid cHRM red point specified");
		889	return;
		890	}
		891	itemp = (png_uint_32)(red_x * 100000.0 + 0.5);
		892	png_save_uint_32(buf + 8, itemp);
		893	itemp = (png_uint_32)(red_y * 100000.0 + 0.5);
		894	png_save_uint_32(buf + 12, itemp);
		895
		896	if (green_x < 0 \|\| green_x > 0.8 \|\| green_y < 0 \|\| green_y > 0.8 \|\|
		897	green_x + green_y > 1.0)
		898	{
		899	png_warning(png_ptr, "Invalid cHRM green point specified");
		900	return;
		901	}
		902	itemp = (png_uint_32)(green_x * 100000.0 + 0.5);
		903	png_save_uint_32(buf + 16, itemp);
		904	itemp = (png_uint_32)(green_y * 100000.0 + 0.5);
		905	png_save_uint_32(buf + 20, itemp);
		906
		907	if (blue_x < 0 \|\| blue_x > 0.8 \|\| blue_y < 0 \|\| blue_y > 0.8 \|\|
		908	blue_x + blue_y > 1.0)
		909	{
		910	png_warning(png_ptr, "Invalid cHRM blue point specified");
		911	return;
		912	}
		913	itemp = (png_uint_32)(blue_x * 100000.0 + 0.5);
		914	png_save_uint_32(buf + 24, itemp);
		915	itemp = (png_uint_32)(blue_y * 100000.0 + 0.5);
		916	png_save_uint_32(buf + 28, itemp);
		917
		918	png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
		919	}
		920	#endif
		921	#ifdef PNG_FIXED_POINT_SUPPORTED
		922	void /* PRIVATE */
		923	png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x,
		924	png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y,
		925	png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x,
		926	png_fixed_point blue_y)
		927	{
		928	#ifdef PNG_USE_LOCAL_ARRAYS
		929	PNG_cHRM;
		930	#endif
		931	png_byte buf[32];
		932
		933	png_debug(1, "in png_write_cHRM\n");
		934	/* each value is saved in 1/100,000ths */
		935	if (white_x > 80000L \|\| white_y > 80000L \|\| white_x + white_y > 100000L)
		936	{
		937	png_warning(png_ptr, "Invalid fixed cHRM white point specified");
		938	#if !defined(PNG_NO_CONSOLE_IO)
		939	cprintf("white_x=%ld, white_y=%ld\n",white_x, white_y);
		940	#endif
		941	return;
		942	}
		943	png_save_uint_32(buf, (png_uint_32)white_x);
		944	png_save_uint_32(buf + 4, (png_uint_32)white_y);
		945
		946	if (red_x > 80000L \|\| red_y > 80000L \|\| red_x + red_y > 100000L)
		947	{
		948	png_warning(png_ptr, "Invalid cHRM fixed red point specified");
		949	return;
		950	}
		951	png_save_uint_32(buf + 8, (png_uint_32)red_x);
		952	png_save_uint_32(buf + 12, (png_uint_32)red_y);
		953
		954	if (green_x > 80000L \|\| green_y > 80000L \|\| green_x + green_y > 100000L)
		955	{
		956	png_warning(png_ptr, "Invalid fixed cHRM green point specified");
		957	return;
		958	}
		959	png_save_uint_32(buf + 16, (png_uint_32)green_x);
		960	png_save_uint_32(buf + 20, (png_uint_32)green_y);
		961
		962	if (blue_x > 80000L \|\| blue_y > 80000L \|\| blue_x + blue_y > 100000L)
		963	{
		964	png_warning(png_ptr, "Invalid fixed cHRM blue point specified");
		965	return;
		966	}
		967	png_save_uint_32(buf + 24, (png_uint_32)blue_x);
		968	png_save_uint_32(buf + 28, (png_uint_32)blue_y);
		969
		970	png_write_chunk(png_ptr, (png_bytep)png_cHRM, buf, (png_size_t)32);
		971	}
		972	#endif
		973	#endif
		974
		975	#if defined(PNG_WRITE_tRNS_SUPPORTED)
		976	/* write the tRNS chunk */
		977	void /* PRIVATE */
		978	png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran,
		979	int num_trans, int color_type)
		980	{
		981	#ifdef PNG_USE_LOCAL_ARRAYS
		982	PNG_tRNS;
		983	#endif
		984	png_byte buf[6];
		985
		986	png_debug(1, "in png_write_tRNS\n");
		987	if (color_type == PNG_COLOR_TYPE_PALETTE)
		988	{
		989	if (num_trans <= 0 \|\| num_trans > (int)png_ptr->num_palette)
		990	{
		991	png_warning(png_ptr,"Invalid number of transparent colors specified");
		992	return;
		993	}
		994	/* write the chunk out as it is */
		995	png_write_chunk(png_ptr, (png_bytep)png_tRNS, trans, (png_size_t)num_trans);
		996	}
		997	else if (color_type == PNG_COLOR_TYPE_GRAY)
		998	{
		999	/* one 16 bit value */
		1000	if(tran->gray >= (1 << png_ptr->bit_depth))
		1001	{
		1002	png_warning(png_ptr,
		1003	"Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
		1004	return;
		1005	}
		1006	png_save_uint_16(buf, tran->gray);
		1007	png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)2);
		1008	}
		1009	else if (color_type == PNG_COLOR_TYPE_RGB)
		1010	{
		1011	/* three 16 bit values */
		1012	png_save_uint_16(buf, tran->red);
		1013	png_save_uint_16(buf + 2, tran->green);
		1014	png_save_uint_16(buf + 4, tran->blue);
		1015	if(png_ptr->bit_depth == 8 && (buf[0] \| buf[2] \| buf[4]))
		1016	{
		1017	png_warning(png_ptr,
		1018	"Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
		1019	return;
		1020	}
		1021	png_write_chunk(png_ptr, (png_bytep)png_tRNS, buf, (png_size_t)6);
		1022	}
		1023	else
		1024	{
		1025	png_warning(png_ptr, "Can't write tRNS with an alpha channel");
		1026	}
		1027	}
		1028	#endif
		1029
		1030	#if defined(PNG_WRITE_bKGD_SUPPORTED)
		1031	/* write the background chunk */
		1032	void /* PRIVATE */
		1033	png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type)
		1034	{
		1035	#ifdef PNG_USE_LOCAL_ARRAYS
		1036	PNG_bKGD;
		1037	#endif
		1038	png_byte buf[6];
		1039
		1040	png_debug(1, "in png_write_bKGD\n");
		1041	if (color_type == PNG_COLOR_TYPE_PALETTE)
		1042	{
		1043	if (
		1044	#if defined(PNG_MNG_FEATURES_SUPPORTED)
		1045	(png_ptr->num_palette \|\|
		1046	(!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) &&
		1047	#endif
		1048	back->index > png_ptr->num_palette)
		1049	{
		1050	png_warning(png_ptr, "Invalid background palette index");
		1051	return;
		1052	}
		1053	buf[0] = back->index;
		1054	png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)1);
		1055	}
		1056	else if (color_type & PNG_COLOR_MASK_COLOR)
		1057	{
		1058	png_save_uint_16(buf, back->red);
		1059	png_save_uint_16(buf + 2, back->green);
		1060	png_save_uint_16(buf + 4, back->blue);
		1061	if(png_ptr->bit_depth == 8 && (buf[0] \| buf[2] \| buf[4]))
		1062	{
		1063	png_warning(png_ptr,
		1064	"Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
		1065	return;
		1066	}
		1067	png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)6);
		1068	}
		1069	else
		1070	{
		1071	if(back->gray >= (1 << png_ptr->bit_depth))
		1072	{
		1073	png_warning(png_ptr,
		1074	"Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
		1075	return;
		1076	}
		1077	png_save_uint_16(buf, back->gray);
		1078	png_write_chunk(png_ptr, (png_bytep)png_bKGD, buf, (png_size_t)2);
		1079	}
		1080	}
		1081	#endif
		1082
		1083	#if defined(PNG_WRITE_hIST_SUPPORTED)
		1084	/* write the histogram */
		1085	void /* PRIVATE */
		1086	png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist)
		1087	{
		1088	#ifdef PNG_USE_LOCAL_ARRAYS
		1089	PNG_hIST;
		1090	#endif
		1091	int i;
		1092	png_byte buf[3];
		1093
		1094	png_debug(1, "in png_write_hIST\n");
		1095	if (num_hist > (int)png_ptr->num_palette)
		1096	{
		1097	png_debug2(3, "num_hist = %d, num_palette = %d\n", num_hist,
		1098	png_ptr->num_palette);
		1099	png_warning(png_ptr, "Invalid number of histogram entries specified");
		1100	return;
		1101	}
		1102
		1103	png_write_chunk_start(png_ptr, (png_bytep)png_hIST, (png_uint_32)(num_hist * 2));
		1104	for (i = 0; i < num_hist; i++)
		1105	{
		1106	png_save_uint_16(buf, hist[i]);
		1107	png_write_chunk_data(png_ptr, buf, (png_size_t)2);
		1108	}
		1109	png_write_chunk_end(png_ptr);
		1110	}
		1111	#endif
		1112
		1113	#if defined(PNG_WRITE_TEXT_SUPPORTED) \|\| defined(PNG_WRITE_pCAL_SUPPORTED) \|\| \
		1114	defined(PNG_WRITE_iCCP_SUPPORTED) \|\| defined(PNG_WRITE_sPLT_SUPPORTED)
		1115	/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
		1116	* and if invalid, correct the keyword rather than discarding the entire
		1117	* chunk. The PNG 1.0 specification requires keywords 1-79 characters in
		1118	* length, forbids leading or trailing whitespace, multiple internal spaces,
		1119	* and the non-break space (0x80) from ISO 8859-1. Returns keyword length.
		1120	*
		1121	* The new_key is allocated to hold the corrected keyword and must be freed
		1122	* by the calling routine. This avoids problems with trying to write to
		1123	* static keywords without having to have duplicate copies of the strings.
		1124	*/
		1125	png_size_t /* PRIVATE */
		1126	png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key)
		1127	{
		1128	png_size_t key_len;
		1129	png_charp kp, dp;
		1130	int kflag;
		1131	int kwarn=0;
		1132
		1133	png_debug(1, "in png_check_keyword\n");
		1134	*new_key = NULL;
		1135
		1136	if (key == NULL \|\| (key_len = png_strlen(key)) == 0)
		1137	{
		1138	png_warning(png_ptr, "zero length keyword");
		1139	return ((png_size_t)0);
		1140	}
		1141
		1142	png_debug1(2, "Keyword to be checked is '%s'\n", key);
		1143
		1144	*new_key = (png_charp)png_malloc(png_ptr, (png_uint_32)(key_len + 2));
		1145
		1146	/* Replace non-printing characters with a blank and print a warning */
		1147	for (kp = key, dp = new_key; kp != '\0'; kp++, dp++)
		1148	{
		1149	if (kp < 0x20 \|\| (kp > 0x7E && (png_byte)*kp < 0xA1))
		1150	{
		1151	#if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE)
		1152	char msg[40];
		1153
		1154	sprintf(msg, "invalid keyword character 0x%02X", *kp);
		1155	png_warning(png_ptr, msg);
		1156	#else
		1157	png_warning(png_ptr, "invalid character in keyword");
		1158	#endif
		1159	*dp = ' ';
		1160	}
		1161	else
		1162	{
		1163	dp = kp;
		1164	}
		1165	}
		1166	*dp = '\0';
		1167
		1168	/* Remove any trailing white space. */
		1169	kp = *new_key + key_len - 1;
		1170	if (*kp == ' ')
		1171	{
		1172	png_warning(png_ptr, "trailing spaces removed from keyword");
		1173
		1174	while (*kp == ' ')
		1175	{
		1176	*(kp--) = '\0';
		1177	key_len--;
		1178	}
		1179	}
		1180
		1181	/* Remove any leading white space. */
		1182	kp = *new_key;
		1183	if (*kp == ' ')
		1184	{
		1185	png_warning(png_ptr, "leading spaces removed from keyword");
		1186
		1187	while (*kp == ' ')
		1188	{
		1189	kp++;
		1190	key_len--;
		1191	}
		1192	}
		1193
		1194	png_debug1(2, "Checking for multiple internal spaces in '%s'\n", kp);
		1195
		1196	/* Remove multiple internal spaces. */
		1197	for (kflag = 0, dp = new_key; kp != '\0'; kp++)
		1198	{
		1199	if (*kp == ' ' && kflag == 0)
		1200	{
		1201	(dp++) = kp;
		1202	kflag = 1;
		1203	}
		1204	else if (*kp == ' ')
		1205	{
		1206	key_len--;
		1207	kwarn=1;
		1208	}
		1209	else
		1210	{
		1211	(dp++) = kp;
		1212	kflag = 0;
		1213	}
		1214	}
		1215	*dp = '\0';
		1216	if(kwarn)
		1217	png_warning(png_ptr, "extra interior spaces removed from keyword");
		1218
		1219	if (key_len == 0)
		1220	{
		1221	png_free(png_ptr, *new_key);
		1222	*new_key=NULL;
		1223	png_warning(png_ptr, "Zero length keyword");
		1224	}
		1225
		1226	if (key_len > 79)
		1227	{
		1228	png_warning(png_ptr, "keyword length must be 1 - 79 characters");
		1229	new_key[79] = '\0';
		1230	key_len = 79;
		1231	}
		1232
		1233	return (key_len);
		1234	}
		1235	#endif
		1236
		1237	#if defined(PNG_WRITE_tEXt_SUPPORTED)
		1238	/* write a tEXt chunk */
		1239	void /* PRIVATE */
		1240	png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text,
		1241	png_size_t text_len)
		1242	{
		1243	#ifdef PNG_USE_LOCAL_ARRAYS
		1244	PNG_tEXt;
		1245	#endif
		1246	png_size_t key_len;
		1247	png_charp new_key;
		1248
		1249	png_debug(1, "in png_write_tEXt\n");
		1250	if (key == NULL \|\| (key_len = png_check_keyword(png_ptr, key, &new_key))==0)
		1251	{
		1252	png_warning(png_ptr, "Empty keyword in tEXt chunk");
		1253	return;
		1254	}
		1255
		1256	if (text == NULL \|\| *text == '\0')
		1257	text_len = 0;
		1258	else
		1259	text_len = png_strlen(text);
		1260
		1261	/* make sure we include the 0 after the key */
		1262	png_write_chunk_start(png_ptr, (png_bytep)png_tEXt, (png_uint_32)key_len+text_len+1);
		1263	/*
		1264	* We leave it to the application to meet PNG-1.0 requirements on the
		1265	* contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
		1266	* any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
		1267	* The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
		1268	*/
		1269	png_write_chunk_data(png_ptr, (png_bytep)new_key, key_len + 1);
		1270	if (text_len)
		1271	png_write_chunk_data(png_ptr, (png_bytep)text, text_len);
		1272
		1273	png_write_chunk_end(png_ptr);
		1274	png_free(png_ptr, new_key);
		1275	}
		1276	#endif
		1277
		1278	#if defined(PNG_WRITE_zTXt_SUPPORTED)
		1279	/* write a compressed text chunk */
		1280	void /* PRIVATE */
		1281	png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text,
		1282	png_size_t text_len, int compression)
		1283	{
		1284	#ifdef PNG_USE_LOCAL_ARRAYS
		1285	PNG_zTXt;
		1286	#endif
		1287	png_size_t key_len;
		1288	char buf[1];
		1289	png_charp new_key;
		1290	compression_state comp;
		1291
		1292	png_debug(1, "in png_write_zTXt\n");
		1293
		1294	if (key == NULL \|\| (key_len = png_check_keyword(png_ptr, key, &new_key))==0)
		1295	{
		1296	png_warning(png_ptr, "Empty keyword in zTXt chunk");
		1297	return;
		1298	}
		1299
		1300	if (text == NULL \|\| *text == '\0' \|\| compression==PNG_TEXT_COMPRESSION_NONE)
		1301	{
		1302	png_write_tEXt(png_ptr, new_key, text, (png_size_t)0);
		1303	png_free(png_ptr, new_key);
		1304	return;
		1305	}
		1306
		1307	text_len = png_strlen(text);
		1308
		1309	png_free(png_ptr, new_key);
		1310
		1311	/* compute the compressed data; do it now for the length */
		1312	text_len = png_text_compress(png_ptr, text, text_len, compression,
		1313	&comp);
		1314
		1315	/* write start of chunk */
		1316	png_write_chunk_start(png_ptr, (png_bytep)png_zTXt, (png_uint_32)
		1317	(key_len+text_len+2));
		1318	/* write key */
		1319	png_write_chunk_data(png_ptr, (png_bytep)key, key_len + 1);
		1320	buf[0] = (png_byte)compression;
		1321	/* write compression */
		1322	png_write_chunk_data(png_ptr, (png_bytep)buf, (png_size_t)1);
		1323	/* write the compressed data */
		1324	png_write_compressed_data_out(png_ptr, &comp);
		1325
		1326	/* close the chunk */
		1327	png_write_chunk_end(png_ptr);
		1328	}
		1329	#endif
		1330
		1331	#if defined(PNG_WRITE_iTXt_SUPPORTED)
		1332	/* write an iTXt chunk */
		1333	void /* PRIVATE */
		1334	png_write_iTXt(png_structp png_ptr, int compression, png_charp key,
		1335	png_charp lang, png_charp lang_key, png_charp text)
		1336	{
		1337	#ifdef PNG_USE_LOCAL_ARRAYS
		1338	PNG_iTXt;
		1339	#endif
		1340	png_size_t lang_len, key_len, lang_key_len, text_len;
		1341	png_charp new_lang, new_key;
		1342	png_byte cbuf[2];
		1343	compression_state comp;
		1344
		1345	png_debug(1, "in png_write_iTXt\n");
		1346
		1347	if (key == NULL \|\| (key_len = png_check_keyword(png_ptr, key, &new_key))==0)
		1348	{
		1349	png_warning(png_ptr, "Empty keyword in iTXt chunk");
		1350	return;
		1351	}
		1352	if (lang == NULL \|\| (lang_len = png_check_keyword(png_ptr, lang, &new_lang))==0)
		1353	{
		1354	png_warning(png_ptr, "Empty language field in iTXt chunk");
		1355	new_lang = NULL;
		1356	lang_len = 0;
		1357	}
		1358
		1359	if (lang_key == NULL)
		1360	lang_key_len = 0;
		1361	else
		1362	lang_key_len = png_strlen(lang_key);
		1363
		1364	if (text == NULL)
		1365	text_len = 0;
		1366	else
		1367	text_len = png_strlen(text);
		1368
		1369	/* compute the compressed data; do it now for the length */
		1370	text_len = png_text_compress(png_ptr, text, text_len, compression-2,
		1371	&comp);
		1372
		1373
		1374	/* make sure we include the compression flag, the compression byte,
		1375	* and the NULs after the key, lang, and lang_key parts */
		1376
		1377	png_write_chunk_start(png_ptr, (png_bytep)png_iTXt,
		1378	(png_uint_32)(
		1379	5 /* comp byte, comp flag, terminators for key, lang and lang_key */
		1380	+ key_len
		1381	+ lang_len
		1382	+ lang_key_len
		1383	+ text_len));
		1384
		1385	/*
		1386	* We leave it to the application to meet PNG-1.0 requirements on the
		1387	* contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
		1388	* any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
		1389	* The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
		1390	*/
		1391	png_write_chunk_data(png_ptr, (png_bytep)new_key, key_len + 1);
		1392
		1393	/* set the compression flag */
		1394	if (compression == PNG_ITXT_COMPRESSION_NONE \|\| \
		1395	compression == PNG_TEXT_COMPRESSION_NONE)
		1396	cbuf[0] = 0;
		1397	else /* compression == PNG_ITXT_COMPRESSION_zTXt */
		1398	cbuf[0] = 1;
		1399	/* set the compression method */
		1400	cbuf[1] = 0;
		1401	png_write_chunk_data(png_ptr, cbuf, 2);
		1402
		1403	cbuf[0] = 0;
		1404	png_write_chunk_data(png_ptr, (new_lang ? (png_bytep)new_lang : cbuf), lang_len + 1);
		1405	png_write_chunk_data(png_ptr, (lang_key ? (png_bytep)lang_key : cbuf), lang_key_len + 1);
		1406	png_write_compressed_data_out(png_ptr, &comp);
		1407
		1408	png_write_chunk_end(png_ptr);
		1409	png_free(png_ptr, new_key);
		1410	if (new_lang)
		1411	png_free(png_ptr, new_lang);
		1412	}
		1413	#endif
		1414
		1415	#if defined(PNG_WRITE_oFFs_SUPPORTED)
		1416	/* write the oFFs chunk */
		1417	void /* PRIVATE */
		1418	png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
		1419	int unit_type)
		1420	{
		1421	#ifdef PNG_USE_LOCAL_ARRAYS
		1422	PNG_oFFs;
		1423	#endif
		1424	png_byte buf[9];
		1425
		1426	png_debug(1, "in png_write_oFFs\n");
		1427	if (unit_type >= PNG_OFFSET_LAST)
		1428	png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
		1429
		1430	png_save_int_32(buf, x_offset);
		1431	png_save_int_32(buf + 4, y_offset);
		1432	buf[8] = (png_byte)unit_type;
		1433
		1434	png_write_chunk(png_ptr, (png_bytep)png_oFFs, buf, (png_size_t)9);
		1435	}
		1436	#endif
		1437
		1438	#if defined(PNG_WRITE_pCAL_SUPPORTED)
		1439	/* write the pCAL chunk (described in the PNG extensions document) */
		1440	void /* PRIVATE */
		1441	png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0,
		1442	png_int_32 X1, int type, int nparams, png_charp units, png_charpp params)
		1443	{
		1444	#ifdef PNG_USE_LOCAL_ARRAYS
		1445	PNG_pCAL;
		1446	#endif
		1447	png_size_t purpose_len, units_len, total_len;
		1448	png_uint_32p params_len;
		1449	png_byte buf[10];
		1450	png_charp new_purpose;
		1451	int i;
		1452
		1453	png_debug1(1, "in png_write_pCAL (%d parameters)\n", nparams);
		1454	if (type >= PNG_EQUATION_LAST)
		1455	png_warning(png_ptr, "Unrecognized equation type for pCAL chunk");
		1456
		1457	purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1;
		1458	png_debug1(3, "pCAL purpose length = %d\n", (int)purpose_len);
		1459	units_len = png_strlen(units) + (nparams == 0 ? 0 : 1);
		1460	png_debug1(3, "pCAL units length = %d\n", (int)units_len);
		1461	total_len = purpose_len + units_len + 10;
		1462
		1463	params_len = (png_uint_32p)png_malloc(png_ptr, (png_uint_32)(nparams
		1464	*sizeof(png_uint_32)));
		1465
		1466	/* Find the length of each parameter, making sure we don't count the
		1467	null terminator for the last parameter. */
		1468	for (i = 0; i < nparams; i++)
		1469	{
		1470	params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
		1471	png_debug2(3, "pCAL parameter %d length = %lu\n", i, params_len[i]);
		1472	total_len += (png_size_t)params_len[i];
		1473	}
		1474
		1475	png_debug1(3, "pCAL total length = %d\n", (int)total_len);
		1476	png_write_chunk_start(png_ptr, (png_bytep)png_pCAL, (png_uint_32)total_len);
		1477	png_write_chunk_data(png_ptr, (png_bytep)new_purpose, purpose_len);
		1478	png_save_int_32(buf, X0);
		1479	png_save_int_32(buf + 4, X1);
		1480	buf[8] = (png_byte)type;
		1481	buf[9] = (png_byte)nparams;
		1482	png_write_chunk_data(png_ptr, buf, (png_size_t)10);
		1483	png_write_chunk_data(png_ptr, (png_bytep)units, (png_size_t)units_len);
		1484
		1485	png_free(png_ptr, new_purpose);
		1486
		1487	for (i = 0; i < nparams; i++)
		1488	{
		1489	png_write_chunk_data(png_ptr, (png_bytep)params[i],
		1490	(png_size_t)params_len[i]);
		1491	}
		1492
		1493	png_free(png_ptr, params_len);
		1494	png_write_chunk_end(png_ptr);
		1495	}
		1496	#endif
		1497
		1498	#if defined(PNG_WRITE_sCAL_SUPPORTED)
		1499	/* write the sCAL chunk */
		1500	#if defined(PNG_FLOATING_POINT_SUPPORTED) && !defined(PNG_NO_STDIO)
		1501	void /* PRIVATE */
		1502	png_write_sCAL(png_structp png_ptr, int unit, double width,double height)
		1503	{
		1504	#ifdef PNG_USE_LOCAL_ARRAYS
		1505	PNG_sCAL;
		1506	#endif
		1507	png_size_t total_len;
		1508	char wbuf[32], hbuf[32];
		1509
		1510	png_debug(1, "in png_write_sCAL\n");
		1511
		1512	#if defined(_WIN32_WCE)
		1513	/* sprintf() function is not supported on WindowsCE */
		1514	{
		1515	wchar_t wc_buf[32];
		1516	swprintf(wc_buf, TEXT("%12.12e"), width);
		1517	WideCharToMultiByte(CP_ACP, 0, wc_buf, -1, wbuf, 32, NULL, NULL);
		1518	swprintf(wc_buf, TEXT("%12.12e"), height);
		1519	WideCharToMultiByte(CP_ACP, 0, wc_buf, -1, hbuf, 32, NULL, NULL);
		1520	}
		1521	#else
		1522	sprintf(wbuf, "%12.12e", width);
		1523	sprintf(hbuf, "%12.12e", height);
		1524	#endif
		1525	total_len = 1 + png_strlen(wbuf)+1 + png_strlen(hbuf);
		1526
		1527	png_debug1(3, "sCAL total length = %d\n", (int)total_len);
		1528	png_write_chunk_start(png_ptr, (png_bytep)png_sCAL, (png_uint_32)total_len);
		1529	png_write_chunk_data(png_ptr, (png_bytep)&unit, 1);
		1530	png_write_chunk_data(png_ptr, (png_bytep)wbuf, png_strlen(wbuf)+1);
		1531	png_write_chunk_data(png_ptr, (png_bytep)hbuf, png_strlen(hbuf));
		1532
		1533	png_write_chunk_end(png_ptr);
		1534	}
		1535	#else
		1536	#ifdef PNG_FIXED_POINT_SUPPORTED
		1537	void /* PRIVATE */
		1538	png_write_sCAL_s(png_structp png_ptr, int unit, png_charp width,
		1539	png_charp height)
		1540	{
		1541	#ifdef PNG_USE_LOCAL_ARRAYS
		1542	PNG_sCAL;
		1543	#endif
		1544	png_size_t total_len;
		1545	char wbuf[32], hbuf[32];
		1546
		1547	png_debug(1, "in png_write_sCAL_s\n");
		1548
		1549	png_strcpy(wbuf,(const char *)width);
		1550	png_strcpy(hbuf,(const char *)height);
		1551	total_len = 1 + png_strlen(wbuf)+1 + png_strlen(hbuf);
		1552
		1553	png_debug1(3, "sCAL total length = %d\n", total_len);
		1554	png_write_chunk_start(png_ptr, (png_bytep)png_sCAL, (png_uint_32)total_len);
		1555	png_write_chunk_data(png_ptr, (png_bytep)&unit, 1);
		1556	png_write_chunk_data(png_ptr, (png_bytep)wbuf, png_strlen(wbuf)+1);
		1557	png_write_chunk_data(png_ptr, (png_bytep)hbuf, png_strlen(hbuf));
		1558
		1559	png_write_chunk_end(png_ptr);
		1560	}
		1561	#endif
		1562	#endif
		1563	#endif
		1564
		1565	#if defined(PNG_WRITE_pHYs_SUPPORTED)
		1566	/* write the pHYs chunk */
		1567	void /* PRIVATE */
		1568	png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit,
		1569	png_uint_32 y_pixels_per_unit,
		1570	int unit_type)
		1571	{
		1572	#ifdef PNG_USE_LOCAL_ARRAYS
		1573	PNG_pHYs;
		1574	#endif
		1575	png_byte buf[9];
		1576
		1577	png_debug(1, "in png_write_pHYs\n");
		1578	if (unit_type >= PNG_RESOLUTION_LAST)
		1579	png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
		1580
		1581	png_save_uint_32(buf, x_pixels_per_unit);
		1582	png_save_uint_32(buf + 4, y_pixels_per_unit);
		1583	buf[8] = (png_byte)unit_type;
		1584
		1585	png_write_chunk(png_ptr, (png_bytep)png_pHYs, buf, (png_size_t)9);
		1586	}
		1587	#endif
		1588
		1589	#if defined(PNG_WRITE_tIME_SUPPORTED)
		1590	/* Write the tIME chunk. Use either png_convert_from_struct_tm()
		1591	* or png_convert_from_time_t(), or fill in the structure yourself.
		1592	*/
		1593	void /* PRIVATE */
		1594	png_write_tIME(png_structp png_ptr, png_timep mod_time)
		1595	{
		1596	#ifdef PNG_USE_LOCAL_ARRAYS
		1597	PNG_tIME;
		1598	#endif
		1599	png_byte buf[7];
		1600
		1601	png_debug(1, "in png_write_tIME\n");
		1602	if (mod_time->month > 12 \|\| mod_time->month < 1 \|\|
		1603	mod_time->day > 31 \|\| mod_time->day < 1 \|\|
		1604	mod_time->hour > 23 \|\| mod_time->second > 60)
		1605	{
		1606	png_warning(png_ptr, "Invalid time specified for tIME chunk");
		1607	return;
		1608	}
		1609
		1610	png_save_uint_16(buf, mod_time->year);
		1611	buf[2] = mod_time->month;
		1612	buf[3] = mod_time->day;
		1613	buf[4] = mod_time->hour;
		1614	buf[5] = mod_time->minute;
		1615	buf[6] = mod_time->second;
		1616
		1617	png_write_chunk(png_ptr, (png_bytep)png_tIME, buf, (png_size_t)7);
		1618	}
		1619	#endif
		1620
		1621	/* initializes the row writing capability of libpng */
		1622	void /* PRIVATE */
		1623	png_write_start_row(png_structp png_ptr)
		1624	{
		1625	#ifdef PNG_USE_LOCAL_ARRAYS
		1626	/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
		1627
		1628	/* start of interlace block */
		1629	int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
		1630
		1631	/* offset to next interlace block */
		1632	int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
		1633
		1634	/* start of interlace block in the y direction */
		1635	int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
		1636
		1637	/* offset to next interlace block in the y direction */
		1638	int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
		1639	#endif
		1640
		1641	png_size_t buf_size;
		1642
		1643	png_debug(1, "in png_write_start_row\n");
		1644	buf_size = (png_size_t)(((png_ptr->width * png_ptr->usr_channels *
		1645	png_ptr->usr_bit_depth + 7) >> 3) + 1);
		1646
		1647	/* set up row buffer */
		1648	png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, (png_uint_32)buf_size);
		1649	png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
		1650
		1651	/* set up filtering buffer, if using this filter */
		1652	if (png_ptr->do_filter & PNG_FILTER_SUB)
		1653	{
		1654	png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
		1655	(png_ptr->rowbytes + 1));
		1656	png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
		1657	}
		1658
		1659	/* We only need to keep the previous row if we are using one of these. */
		1660	if (png_ptr->do_filter & (PNG_FILTER_AVG \| PNG_FILTER_UP \| PNG_FILTER_PAETH))
		1661	{
		1662	/* set up previous row buffer */
		1663	png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)buf_size);
		1664	png_memset(png_ptr->prev_row, 0, buf_size);
		1665
		1666	if (png_ptr->do_filter & PNG_FILTER_UP)
		1667	{
		1668	png_ptr->up_row = (png_bytep )png_malloc(png_ptr,
		1669	(png_ptr->rowbytes + 1));
		1670	png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
		1671	}
		1672
		1673	if (png_ptr->do_filter & PNG_FILTER_AVG)
		1674	{
		1675	png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
		1676	(png_ptr->rowbytes + 1));
		1677	png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
		1678	}
		1679
		1680	if (png_ptr->do_filter & PNG_FILTER_PAETH)
		1681	{
		1682	png_ptr->paeth_row = (png_bytep )png_malloc(png_ptr,
		1683	(png_ptr->rowbytes + 1));
		1684	png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
		1685	}
		1686	}
		1687
		1688	#ifdef PNG_WRITE_INTERLACING_SUPPORTED
		1689	/* if interlaced, we need to set up width and height of pass */
		1690	if (png_ptr->interlaced)
		1691	{
		1692	if (!(png_ptr->transformations & PNG_INTERLACE))
		1693	{
		1694	png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 -
		1695	png_pass_ystart[0]) / png_pass_yinc[0];
		1696	png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
		1697	png_pass_start[0]) / png_pass_inc[0];
		1698	}
		1699	else
		1700	{
		1701	png_ptr->num_rows = png_ptr->height;
		1702	png_ptr->usr_width = png_ptr->width;
		1703	}
		1704	}
		1705	else
		1706	#endif
		1707	{
		1708	png_ptr->num_rows = png_ptr->height;
		1709	png_ptr->usr_width = png_ptr->width;
		1710	}
		1711	png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
		1712	png_ptr->zstream.next_out = png_ptr->zbuf;
		1713	}
		1714
		1715	/* Internal use only. Called when finished processing a row of data. */
		1716	void /* PRIVATE */
		1717	png_write_finish_row(png_structp png_ptr)
		1718	{
		1719	#ifdef PNG_USE_LOCAL_ARRAYS
		1720	/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
		1721
		1722	/* start of interlace block */
		1723	int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
		1724
		1725	/* offset to next interlace block */
		1726	int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
		1727
		1728	/* start of interlace block in the y direction */
		1729	int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
		1730
		1731	/* offset to next interlace block in the y direction */
		1732	int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
		1733	#endif
		1734
		1735	int ret;
		1736
		1737	png_debug(1, "in png_write_finish_row\n");
		1738	/* next row */
		1739	png_ptr->row_number++;
		1740
		1741	/* see if we are done */
		1742	if (png_ptr->row_number < png_ptr->num_rows)
		1743	return;
		1744
		1745	#ifdef PNG_WRITE_INTERLACING_SUPPORTED
		1746	/* if interlaced, go to next pass */
		1747	if (png_ptr->interlaced)
		1748	{
		1749	png_ptr->row_number = 0;
		1750	if (png_ptr->transformations & PNG_INTERLACE)
		1751	{
		1752	png_ptr->pass++;
		1753	}
		1754	else
		1755	{
		1756	/* loop until we find a non-zero width or height pass */
		1757	do
		1758	{
		1759	png_ptr->pass++;
		1760	if (png_ptr->pass >= 7)
		1761	break;
		1762	png_ptr->usr_width = (png_ptr->width +
		1763	png_pass_inc[png_ptr->pass] - 1 -
		1764	png_pass_start[png_ptr->pass]) /
		1765	png_pass_inc[png_ptr->pass];
		1766	png_ptr->num_rows = (png_ptr->height +
		1767	png_pass_yinc[png_ptr->pass] - 1 -
		1768	png_pass_ystart[png_ptr->pass]) /
		1769	png_pass_yinc[png_ptr->pass];
		1770	if (png_ptr->transformations & PNG_INTERLACE)
		1771	break;
		1772	} while (png_ptr->usr_width == 0 \|\| png_ptr->num_rows == 0);
		1773
		1774	}
		1775
		1776	/* reset the row above the image for the next pass */
		1777	if (png_ptr->pass < 7)
		1778	{
		1779	if (png_ptr->prev_row != NULL)
		1780	png_memset(png_ptr->prev_row, 0,
		1781	(png_size_t) (((png_uint_32)png_ptr->usr_channels *
		1782	(png_uint_32)png_ptr->usr_bit_depth *
		1783	png_ptr->width + 7) >> 3) + 1);
		1784	return;
		1785	}
		1786	}
		1787	#endif
		1788
		1789	/* if we get here, we've just written the last row, so we need
		1790	to flush the compressor */
		1791	do
		1792	{
		1793	/* tell the compressor we are done */
		1794	ret = deflate(&png_ptr->zstream, Z_FINISH);
		1795	/* check for an error */
		1796	if (ret == Z_OK)
		1797	{
		1798	/* check to see if we need more room */
		1799	if (!(png_ptr->zstream.avail_out))
		1800	{
		1801	png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
		1802	png_ptr->zstream.next_out = png_ptr->zbuf;
		1803	png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
		1804	}
		1805	}
		1806	else if (ret != Z_STREAM_END)
		1807	{
		1808	if (png_ptr->zstream.msg != NULL)
		1809	png_error(png_ptr, png_ptr->zstream.msg);
		1810	else
		1811	png_error(png_ptr, "zlib error");
		1812	}
		1813	} while (ret != Z_STREAM_END);
		1814
		1815	/* write any extra space */
		1816	if (png_ptr->zstream.avail_out < png_ptr->zbuf_size)
		1817	{
		1818	png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size -
		1819	png_ptr->zstream.avail_out);
		1820	}
		1821
		1822	deflateReset(&png_ptr->zstream);
		1823	}
		1824
		1825	#if defined(PNG_WRITE_INTERLACING_SUPPORTED)
		1826	/* Pick out the correct pixels for the interlace pass.
		1827	* The basic idea here is to go through the row with a source
		1828	* pointer and a destination pointer (sp and dp), and copy the
		1829	* correct pixels for the pass. As the row gets compacted,
		1830	* sp will always be >= dp, so we should never overwrite anything.
		1831	* See the default: case for the easiest code to understand.
		1832	*/
		1833	void /* PRIVATE */
		1834	png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
		1835	{
		1836	#ifdef PNG_USE_LOCAL_ARRAYS
		1837	/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
		1838
		1839	/* start of interlace block */
		1840	int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
		1841
		1842	/* offset to next interlace block */
		1843	int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
		1844	#endif
		1845
		1846	png_debug(1, "in png_do_write_interlace\n");
		1847	/* we don't have to do anything on the last pass (6) */
		1848	#if defined(PNG_USELESS_TESTS_SUPPORTED)
		1849	if (row != NULL && row_info != NULL && pass < 6)
		1850	#else
		1851	if (pass < 6)
		1852	#endif
		1853	{
		1854	/* each pixel depth is handled separately */
		1855	switch (row_info->pixel_depth)
		1856	{
		1857	case 1:
		1858	{
		1859	png_bytep sp;
		1860	png_bytep dp;
		1861	int shift;
		1862	int d;
		1863	int value;
		1864	png_uint_32 i;
		1865	png_uint_32 row_width = row_info->width;
		1866
		1867	dp = row;
		1868	d = 0;
		1869	shift = 7;
		1870	for (i = png_pass_start[pass]; i < row_width;
		1871	i += png_pass_inc[pass])
		1872	{
		1873	sp = row + (png_size_t)(i >> 3);
		1874	value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01;
		1875	d \|= (value << shift);
		1876
		1877	if (shift == 0)
		1878	{
		1879	shift = 7;
		1880	*dp++ = (png_byte)d;
		1881	d = 0;
		1882	}
		1883	else
		1884	shift--;
		1885
		1886	}
		1887	if (shift != 7)
		1888	*dp = (png_byte)d;
		1889	break;
		1890	}
		1891	case 2:
		1892	{
		1893	png_bytep sp;
		1894	png_bytep dp;
		1895	int shift;
		1896	int d;
		1897	int value;
		1898	png_uint_32 i;
		1899	png_uint_32 row_width = row_info->width;
		1900
		1901	dp = row;
		1902	shift = 6;
		1903	d = 0;
		1904	for (i = png_pass_start[pass]; i < row_width;
		1905	i += png_pass_inc[pass])
		1906	{
		1907	sp = row + (png_size_t)(i >> 2);
		1908	value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03;
		1909	d \|= (value << shift);
		1910
		1911	if (shift == 0)
		1912	{
		1913	shift = 6;
		1914	*dp++ = (png_byte)d;
		1915	d = 0;
		1916	}
		1917	else
		1918	shift -= 2;
		1919	}
		1920	if (shift != 6)
		1921	*dp = (png_byte)d;
		1922	break;
		1923	}
		1924	case 4:
		1925	{
		1926	png_bytep sp;
		1927	png_bytep dp;
		1928	int shift;
		1929	int d;
		1930	int value;
		1931	png_uint_32 i;
		1932	png_uint_32 row_width = row_info->width;
		1933
		1934	dp = row;
		1935	shift = 4;
		1936	d = 0;
		1937	for (i = png_pass_start[pass]; i < row_width;
		1938	i += png_pass_inc[pass])
		1939	{
		1940	sp = row + (png_size_t)(i >> 1);
		1941	value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
		1942	d \|= (value << shift);
		1943
		1944	if (shift == 0)
		1945	{
		1946	shift = 4;
		1947	*dp++ = (png_byte)d;
		1948	d = 0;
		1949	}
		1950	else
		1951	shift -= 4;
		1952	}
		1953	if (shift != 4)
		1954	*dp = (png_byte)d;
		1955	break;
		1956	}
		1957	default:
		1958	{
		1959	png_bytep sp;
		1960	png_bytep dp;
		1961	png_uint_32 i;
		1962	png_uint_32 row_width = row_info->width;
		1963	png_size_t pixel_bytes;
		1964
		1965	/* start at the beginning */
		1966	dp = row;
		1967	/* find out how many bytes each pixel takes up */
		1968	pixel_bytes = (row_info->pixel_depth >> 3);
		1969	/* loop through the row, only looking at the pixels that
		1970	matter */
		1971	for (i = png_pass_start[pass]; i < row_width;
		1972	i += png_pass_inc[pass])
		1973	{
		1974	/* find out where the original pixel is */
		1975	sp = row + (png_size_t)i * pixel_bytes;
		1976	/* move the pixel */
		1977	if (dp != sp)
		1978	png_memcpy(dp, sp, pixel_bytes);
		1979	/* next pixel */
		1980	dp += pixel_bytes;
		1981	}
		1982	break;
		1983	}
		1984	}
		1985	/* set new row width */
		1986	row_info->width = (row_info->width +
		1987	png_pass_inc[pass] - 1 -
		1988	png_pass_start[pass]) /
		1989	png_pass_inc[pass];
		1990	row_info->rowbytes = ((row_info->width *
		1991	row_info->pixel_depth + 7) >> 3);
		1992	}
		1993	}
		1994	#endif
		1995
		1996	/* This filters the row, chooses which filter to use, if it has not already
		1997	* been specified by the application, and then writes the row out with the
		1998	* chosen filter.
		1999	*/
		2000	#define PNG_MAXSUM (~((png_uint_32)0) >> 1)
		2001	#define PNG_HISHIFT 10
		2002	#define PNG_LOMASK ((png_uint_32)0xffffL)
		2003	#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT))
		2004	void /* PRIVATE */
		2005	png_write_find_filter(png_structp png_ptr, png_row_infop row_info)
		2006	{
		2007	png_bytep prev_row, best_row, row_buf;
		2008	png_uint_32 mins, bpp;
		2009	png_byte filter_to_do = png_ptr->do_filter;
		2010	png_uint_32 row_bytes = row_info->rowbytes;
		2011	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
		2012	int num_p_filters = (int)png_ptr->num_prev_filters;
		2013	#endif
		2014
		2015	png_debug(1, "in png_write_find_filter\n");
		2016	/* find out how many bytes offset each pixel is */
		2017	bpp = (row_info->pixel_depth + 7) / 8;
		2018
		2019	prev_row = png_ptr->prev_row;
		2020	best_row = row_buf = png_ptr->row_buf;
		2021	mins = PNG_MAXSUM;
		2022
		2023	/* The prediction method we use is to find which method provides the
		2024	* smallest value when summing the absolute values of the distances
		2025	* from zero, using anything >= 128 as negative numbers. This is known
		2026	* as the "minimum sum of absolute differences" heuristic. Other
		2027	* heuristics are the "weighted minimum sum of absolute differences"
		2028	* (experimental and can in theory improve compression), and the "zlib
		2029	* predictive" method (not implemented yet), which does test compressions
		2030	* of lines using different filter methods, and then chooses the
		2031	* (series of) filter(s) that give minimum compressed data size (VERY
		2032	* computationally expensive).
		2033	*
		2034	* GRR 980525: consider also
		2035	* (1) minimum sum of absolute differences from running average (i.e.,
		2036	* keep running sum of non-absolute differences & count of bytes)
		2037	* [track dispersion, too? restart average if dispersion too large?]
		2038	* (1b) minimum sum of absolute differences from sliding average, probably
		2039	* with window size <= deflate window (usually 32K)
		2040	* (2) minimum sum of squared differences from zero or running average
		2041	* (i.e., ~ root-mean-square approach)
		2042	*/
		2043
		2044
		2045	/* We don't need to test the 'no filter' case if this is the only filter
		2046	* that has been chosen, as it doesn't actually do anything to the data.
		2047	*/
		2048	if ((filter_to_do & PNG_FILTER_NONE) &&
		2049	filter_to_do != PNG_FILTER_NONE)
		2050	{
		2051	png_bytep rp;
		2052	png_uint_32 sum = 0;
		2053	png_uint_32 i;
		2054	int v;
		2055
		2056	for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
		2057	{
		2058	v = *rp;
		2059	sum += (v < 128) ? v : 256 - v;
		2060	}
		2061
		2062	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
		2063	if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
		2064	{
		2065	png_uint_32 sumhi, sumlo;
		2066	int j;
		2067	sumlo = sum & PNG_LOMASK;
		2068	sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */
		2069
		2070	/* Reduce the sum if we match any of the previous rows */
		2071	for (j = 0; j < num_p_filters; j++)
		2072	{
		2073	if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
		2074	{
		2075	sumlo = (sumlo * png_ptr->filter_weights[j]) >>
		2076	PNG_WEIGHT_SHIFT;
		2077	sumhi = (sumhi * png_ptr->filter_weights[j]) >>
		2078	PNG_WEIGHT_SHIFT;
		2079	}
		2080	}
		2081
		2082	/* Factor in the cost of this filter (this is here for completeness,
		2083	* but it makes no sense to have a "cost" for the NONE filter, as
		2084	* it has the minimum possible computational cost - none).
		2085	*/
		2086	sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
		2087	PNG_COST_SHIFT;
		2088	sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >>
		2089	PNG_COST_SHIFT;
		2090
		2091	if (sumhi > PNG_HIMASK)
		2092	sum = PNG_MAXSUM;
		2093	else
		2094	sum = (sumhi << PNG_HISHIFT) + sumlo;
		2095	}
		2096	#endif
		2097	mins = sum;
		2098	}
		2099
		2100	/* sub filter */
		2101	if (filter_to_do == PNG_FILTER_SUB)
		2102	/* it's the only filter so no testing is needed */
		2103	{
		2104	png_bytep rp, lp, dp;
		2105	png_uint_32 i;
		2106	for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
		2107	i++, rp++, dp++)
		2108	{
		2109	dp = rp;
		2110	}
		2111	for (lp = row_buf + 1; i < row_bytes;
		2112	i++, rp++, lp++, dp++)
		2113	{
		2114	dp = (png_byte)(((int)rp - (int)*lp) & 0xff);
		2115	}
		2116	best_row = png_ptr->sub_row;
		2117	}
		2118
		2119	else if (filter_to_do & PNG_FILTER_SUB)
		2120	{
		2121	png_bytep rp, dp, lp;
		2122	png_uint_32 sum = 0, lmins = mins;
		2123	png_uint_32 i;
		2124	int v;
		2125
		2126	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
		2127	/* We temporarily increase the "minimum sum" by the factor we
		2128	* would reduce the sum of this filter, so that we can do the
		2129	* early exit comparison without scaling the sum each time.
		2130	*/
		2131	if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
		2132	{
		2133	int j;
		2134	png_uint_32 lmhi, lmlo;
		2135	lmlo = lmins & PNG_LOMASK;
		2136	lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
		2137
		2138	for (j = 0; j < num_p_filters; j++)
		2139	{
		2140	if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
		2141	{
		2142	lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
		2143	PNG_WEIGHT_SHIFT;
		2144	lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
		2145	PNG_WEIGHT_SHIFT;
		2146	}
		2147	}
		2148
		2149	lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
		2150	PNG_COST_SHIFT;
		2151	lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
		2152	PNG_COST_SHIFT;
		2153
		2154	if (lmhi > PNG_HIMASK)
		2155	lmins = PNG_MAXSUM;
		2156	else
		2157	lmins = (lmhi << PNG_HISHIFT) + lmlo;
		2158	}
		2159	#endif
		2160
		2161	for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp;
		2162	i++, rp++, dp++)
		2163	{
		2164	v = dp = rp;
		2165
		2166	sum += (v < 128) ? v : 256 - v;
		2167	}
		2168	for (lp = row_buf + 1; i < row_info->rowbytes;
		2169	i++, rp++, lp++, dp++)
		2170	{
		2171	v = dp = (png_byte)(((int)rp - (int)*lp) & 0xff);
		2172
		2173	sum += (v < 128) ? v : 256 - v;
		2174
		2175	if (sum > lmins) /* We are already worse, don't continue. */
		2176	break;
		2177	}
		2178
		2179	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
		2180	if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
		2181	{
		2182	int j;
		2183	png_uint_32 sumhi, sumlo;
		2184	sumlo = sum & PNG_LOMASK;
		2185	sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
		2186
		2187	for (j = 0; j < num_p_filters; j++)
		2188	{
		2189	if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB)
		2190	{
		2191	sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >>
		2192	PNG_WEIGHT_SHIFT;
		2193	sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >>
		2194	PNG_WEIGHT_SHIFT;
		2195	}
		2196	}
		2197
		2198	sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
		2199	PNG_COST_SHIFT;
		2200	sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >>
		2201	PNG_COST_SHIFT;
		2202
		2203	if (sumhi > PNG_HIMASK)
		2204	sum = PNG_MAXSUM;
		2205	else
		2206	sum = (sumhi << PNG_HISHIFT) + sumlo;
		2207	}
		2208	#endif
		2209
		2210	if (sum < mins)
		2211	{
		2212	mins = sum;
		2213	best_row = png_ptr->sub_row;
		2214	}
		2215	}
		2216
		2217	/* up filter */
		2218	if (filter_to_do == PNG_FILTER_UP)
		2219	{
		2220	png_bytep rp, dp, pp;
		2221	png_uint_32 i;
		2222
		2223	for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
		2224	pp = prev_row + 1; i < row_bytes;
		2225	i++, rp++, pp++, dp++)
		2226	{
		2227	dp = (png_byte)(((int)rp - (int)*pp) & 0xff);
		2228	}
		2229	best_row = png_ptr->up_row;
		2230	}
		2231
		2232	else if (filter_to_do & PNG_FILTER_UP)
		2233	{
		2234	png_bytep rp, dp, pp;
		2235	png_uint_32 sum = 0, lmins = mins;
		2236	png_uint_32 i;
		2237	int v;
		2238
		2239
		2240	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
		2241	if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
		2242	{
		2243	int j;
		2244	png_uint_32 lmhi, lmlo;
		2245	lmlo = lmins & PNG_LOMASK;
		2246	lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
		2247
		2248	for (j = 0; j < num_p_filters; j++)
		2249	{
		2250	if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
		2251	{
		2252	lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
		2253	PNG_WEIGHT_SHIFT;
		2254	lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
		2255	PNG_WEIGHT_SHIFT;
		2256	}
		2257	}
		2258
		2259	lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
		2260	PNG_COST_SHIFT;
		2261	lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >>
		2262	PNG_COST_SHIFT;
		2263
		2264	if (lmhi > PNG_HIMASK)
		2265	lmins = PNG_MAXSUM;
		2266	else
		2267	lmins = (lmhi << PNG_HISHIFT) + lmlo;
		2268	}
		2269	#endif
		2270
		2271	for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1,
		2272	pp = prev_row + 1; i < row_bytes; i++)
		2273	{
		2274	v = dp++ = (png_byte)(((int)rp++ - (int)*pp++) & 0xff);
		2275
		2276	sum += (v < 128) ? v : 256 - v;
		2277
		2278	if (sum > lmins) /* We are already worse, don't continue. */
		2279	break;
		2280	}
		2281
		2282	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
		2283	if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
		2284	{
		2285	int j;
		2286	png_uint_32 sumhi, sumlo;
		2287	sumlo = sum & PNG_LOMASK;
		2288	sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
		2289
		2290	for (j = 0; j < num_p_filters; j++)
		2291	{
		2292	if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP)
		2293	{
		2294	sumlo = (sumlo * png_ptr->filter_weights[j]) >>
		2295	PNG_WEIGHT_SHIFT;
		2296	sumhi = (sumhi * png_ptr->filter_weights[j]) >>
		2297	PNG_WEIGHT_SHIFT;
		2298	}
		2299	}
		2300
		2301	sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
		2302	PNG_COST_SHIFT;
		2303	sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >>
		2304	PNG_COST_SHIFT;
		2305
		2306	if (sumhi > PNG_HIMASK)
		2307	sum = PNG_MAXSUM;
		2308	else
		2309	sum = (sumhi << PNG_HISHIFT) + sumlo;
		2310	}
		2311	#endif
		2312
		2313	if (sum < mins)
		2314	{
		2315	mins = sum;
		2316	best_row = png_ptr->up_row;
		2317	}
		2318	}
		2319
		2320	/* avg filter */
		2321	if (filter_to_do == PNG_FILTER_AVG)
		2322	{
		2323	png_bytep rp, dp, pp, lp;
		2324	png_uint_32 i;
		2325	for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
		2326	pp = prev_row + 1; i < bpp; i++)
		2327	{
		2328	dp++ = (png_byte)(((int)rp++ - ((int)*pp++ / 2)) & 0xff);
		2329	}
		2330	for (lp = row_buf + 1; i < row_bytes; i++)
		2331	{
		2332	dp++ = (png_byte)(((int)rp++ - (((int)pp++ + (int)lp++) / 2))
		2333	& 0xff);
		2334	}
		2335	best_row = png_ptr->avg_row;
		2336	}
		2337
		2338	else if (filter_to_do & PNG_FILTER_AVG)
		2339	{
		2340	png_bytep rp, dp, pp, lp;
		2341	png_uint_32 sum = 0, lmins = mins;
		2342	png_uint_32 i;
		2343	int v;
		2344
		2345	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
		2346	if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
		2347	{
		2348	int j;
		2349	png_uint_32 lmhi, lmlo;
		2350	lmlo = lmins & PNG_LOMASK;
		2351	lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
		2352
		2353	for (j = 0; j < num_p_filters; j++)
		2354	{
		2355	if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG)
		2356	{
		2357	lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
		2358	PNG_WEIGHT_SHIFT;
		2359	lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
		2360	PNG_WEIGHT_SHIFT;
		2361	}
		2362	}
		2363
		2364	lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
		2365	PNG_COST_SHIFT;
		2366	lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >>
		2367	PNG_COST_SHIFT;
		2368
		2369	if (lmhi > PNG_HIMASK)
		2370	lmins = PNG_MAXSUM;
		2371	else
		2372	lmins = (lmhi << PNG_HISHIFT) + lmlo;
		2373	}
		2374	#endif
		2375
		2376	for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1,
		2377	pp = prev_row + 1; i < bpp; i++)
		2378	{
		2379	v = dp++ = (png_byte)(((int)rp++ - ((int)*pp++ / 2)) & 0xff);
		2380
		2381	sum += (v < 128) ? v : 256 - v;
		2382	}
		2383	for (lp = row_buf + 1; i < row_bytes; i++)
		2384	{
		2385	v = *dp++ =
		2386	(png_byte)(((int)rp++ - (((int)pp++ + (int)*lp++) / 2)) & 0xff);
		2387
		2388	sum += (v < 128) ? v : 256 - v;
		2389
		2390	if (sum > lmins) /* We are already worse, don't continue. */
		2391	break;
		2392	}
		2393
		2394	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
		2395	if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
		2396	{
		2397	int j;
		2398	png_uint_32 sumhi, sumlo;
		2399	sumlo = sum & PNG_LOMASK;
		2400	sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
		2401
		2402	for (j = 0; j < num_p_filters; j++)
		2403	{
		2404	if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE)
		2405	{
		2406	sumlo = (sumlo * png_ptr->filter_weights[j]) >>
		2407	PNG_WEIGHT_SHIFT;
		2408	sumhi = (sumhi * png_ptr->filter_weights[j]) >>
		2409	PNG_WEIGHT_SHIFT;
		2410	}
		2411	}
		2412
		2413	sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
		2414	PNG_COST_SHIFT;
		2415	sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >>
		2416	PNG_COST_SHIFT;
		2417
		2418	if (sumhi > PNG_HIMASK)
		2419	sum = PNG_MAXSUM;
		2420	else
		2421	sum = (sumhi << PNG_HISHIFT) + sumlo;
		2422	}
		2423	#endif
		2424
		2425	if (sum < mins)
		2426	{
		2427	mins = sum;
		2428	best_row = png_ptr->avg_row;
		2429	}
		2430	}
		2431
		2432	/* Paeth filter */
		2433	if (filter_to_do == PNG_FILTER_PAETH)
		2434	{
		2435	png_bytep rp, dp, pp, cp, lp;
		2436	png_uint_32 i;
		2437	for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
		2438	pp = prev_row + 1; i < bpp; i++)
		2439	{
		2440	dp++ = (png_byte)(((int)rp++ - (int)*pp++) & 0xff);
		2441	}
		2442
		2443	for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
		2444	{
		2445	int a, b, c, pa, pb, pc, p;
		2446
		2447	b = *pp++;
		2448	c = *cp++;
		2449	a = *lp++;
		2450
		2451	p = b - c;
		2452	pc = a - c;
		2453
		2454	#ifdef PNG_USE_ABS
		2455	pa = abs(p);
		2456	pb = abs(pc);
		2457	pc = abs(p + pc);
		2458	#else
		2459	pa = p < 0 ? -p : p;
		2460	pb = pc < 0 ? -pc : pc;
		2461	pc = (p + pc) < 0 ? -(p + pc) : p + pc;
		2462	#endif
		2463
		2464	p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
		2465
		2466	dp++ = (png_byte)(((int)rp++ - p) & 0xff);
		2467	}
		2468	best_row = png_ptr->paeth_row;
		2469	}
		2470
		2471	else if (filter_to_do & PNG_FILTER_PAETH)
		2472	{
		2473	png_bytep rp, dp, pp, cp, lp;
		2474	png_uint_32 sum = 0, lmins = mins;
		2475	png_uint_32 i;
		2476	int v;
		2477
		2478	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
		2479	if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
		2480	{
		2481	int j;
		2482	png_uint_32 lmhi, lmlo;
		2483	lmlo = lmins & PNG_LOMASK;
		2484	lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK;
		2485
		2486	for (j = 0; j < num_p_filters; j++)
		2487	{
		2488	if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
		2489	{
		2490	lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >>
		2491	PNG_WEIGHT_SHIFT;
		2492	lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >>
		2493	PNG_WEIGHT_SHIFT;
		2494	}
		2495	}
		2496
		2497	lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
		2498	PNG_COST_SHIFT;
		2499	lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >>
		2500	PNG_COST_SHIFT;
		2501
		2502	if (lmhi > PNG_HIMASK)
		2503	lmins = PNG_MAXSUM;
		2504	else
		2505	lmins = (lmhi << PNG_HISHIFT) + lmlo;
		2506	}
		2507	#endif
		2508
		2509	for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1,
		2510	pp = prev_row + 1; i < bpp; i++)
		2511	{
		2512	v = dp++ = (png_byte)(((int)rp++ - (int)*pp++) & 0xff);
		2513
		2514	sum += (v < 128) ? v : 256 - v;
		2515	}
		2516
		2517	for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++)
		2518	{
		2519	int a, b, c, pa, pb, pc, p;
		2520
		2521	b = *pp++;
		2522	c = *cp++;
		2523	a = *lp++;
		2524
		2525	#ifndef PNG_SLOW_PAETH
		2526	p = b - c;
		2527	pc = a - c;
		2528	#ifdef PNG_USE_ABS
		2529	pa = abs(p);
		2530	pb = abs(pc);
		2531	pc = abs(p + pc);
		2532	#else
		2533	pa = p < 0 ? -p : p;
		2534	pb = pc < 0 ? -pc : pc;
		2535	pc = (p + pc) < 0 ? -(p + pc) : p + pc;
		2536	#endif
		2537	p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c;
		2538	#else /* PNG_SLOW_PAETH */
		2539	p = a + b - c;
		2540	pa = abs(p - a);
		2541	pb = abs(p - b);
		2542	pc = abs(p - c);
		2543	if (pa <= pb && pa <= pc)
		2544	p = a;
		2545	else if (pb <= pc)
		2546	p = b;
		2547	else
		2548	p = c;
		2549	#endif /* PNG_SLOW_PAETH */
		2550
		2551	v = dp++ = (png_byte)(((int)rp++ - p) & 0xff);
		2552
		2553	sum += (v < 128) ? v : 256 - v;
		2554
		2555	if (sum > lmins) /* We are already worse, don't continue. */
		2556	break;
		2557	}
		2558
		2559	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
		2560	if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED)
		2561	{
		2562	int j;
		2563	png_uint_32 sumhi, sumlo;
		2564	sumlo = sum & PNG_LOMASK;
		2565	sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK;
		2566
		2567	for (j = 0; j < num_p_filters; j++)
		2568	{
		2569	if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH)
		2570	{
		2571	sumlo = (sumlo * png_ptr->filter_weights[j]) >>
		2572	PNG_WEIGHT_SHIFT;
		2573	sumhi = (sumhi * png_ptr->filter_weights[j]) >>
		2574	PNG_WEIGHT_SHIFT;
		2575	}
		2576	}
		2577
		2578	sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
		2579	PNG_COST_SHIFT;
		2580	sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >>
		2581	PNG_COST_SHIFT;
		2582
		2583	if (sumhi > PNG_HIMASK)
		2584	sum = PNG_MAXSUM;
		2585	else
		2586	sum = (sumhi << PNG_HISHIFT) + sumlo;
		2587	}
		2588	#endif
		2589
		2590	if (sum < mins)
		2591	{
		2592	best_row = png_ptr->paeth_row;
		2593	}
		2594	}
		2595
		2596	/* Do the actual writing of the filtered row data from the chosen filter. */
		2597
		2598	png_write_filtered_row(png_ptr, best_row);
		2599
		2600	#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
		2601	/* Save the type of filter we picked this time for future calculations */
		2602	if (png_ptr->num_prev_filters > 0)
		2603	{
		2604	int j;
		2605	for (j = 1; j < num_p_filters; j++)
		2606	{
		2607	png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1];
		2608	}
		2609	png_ptr->prev_filters[j] = best_row[0];
		2610	}
		2611	#endif
		2612	}
		2613
		2614
		2615	/* Do the actual writing of a previously filtered row. */
		2616	void /* PRIVATE */
		2617	png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row)
		2618	{
		2619	png_debug(1, "in png_write_filtered_row\n");
		2620	png_debug1(2, "filter = %d\n", filtered_row[0]);
		2621	/* set up the zlib input buffer */
		2622
		2623	png_ptr->zstream.next_in = filtered_row;
		2624	png_ptr->zstream.avail_in = (uInt)png_ptr->row_info.rowbytes + 1;
		2625	/* repeat until we have compressed all the data */
		2626	do
		2627	{
		2628	int ret; /* return of zlib */
		2629
		2630	/* compress the data */
		2631	ret = deflate(&png_ptr->zstream, Z_NO_FLUSH);
		2632	/* check for compression errors */
		2633	if (ret != Z_OK)
		2634	{
		2635	if (png_ptr->zstream.msg != NULL)
		2636	png_error(png_ptr, png_ptr->zstream.msg);
		2637	else
		2638	png_error(png_ptr, "zlib error");
		2639	}
		2640
		2641	/* see if it is time to write another IDAT */
		2642	if (!(png_ptr->zstream.avail_out))
		2643	{
		2644	/* write the IDAT and reset the zlib output buffer */
		2645	png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size);
		2646	png_ptr->zstream.next_out = png_ptr->zbuf;
		2647	png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;
		2648	}
		2649	/* repeat until all data has been compressed */
		2650	} while (png_ptr->zstream.avail_in);
		2651
		2652	/* swap the current and previous rows */
		2653	if (png_ptr->prev_row != NULL)
		2654	{
		2655	png_bytep tptr;
		2656
		2657	tptr = png_ptr->prev_row;
		2658	png_ptr->prev_row = png_ptr->row_buf;
		2659	png_ptr->row_buf = tptr;
		2660	}
		2661
		2662	/* finish row - updates counters and flushes zlib if last row */
		2663	png_write_finish_row(png_ptr);
		2664
		2665	#if defined(PNG_WRITE_FLUSH_SUPPORTED)
		2666	png_ptr->flush_rows++;
		2667
		2668	if (png_ptr->flush_dist > 0 &&
		2669	png_ptr->flush_rows >= png_ptr->flush_dist)
		2670	{
		2671	png_write_flush(png_ptr);
		2672	}
		2673	#endif
		2674	}
		2675	#endif /* PNG_WRITE_SUPPORTED */

Subversion Repositories shark

(root)/shark/trunk/ports/png/pngwutil.c @ 706 - Rev 96