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/* $Id: s_zoom.c,v 1.1 2003-02-28 11:49:43 pj Exp $ */
/*
* Mesa 3-D graphics library
* Version: 4.1
*
* Copyright (C) 1999-2002 Brian Paul All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "glheader.h"
#include "macros.h"
#include "imports.h"
#include "colormac.h"
#include "s_context.h"
#include "s_span.h"
#include "s_stencil.h"
#include "s_zoom.h"
/*
* Helper function called from _mesa_write_zoomed_rgba/rgb/index_span().
*/
static void
zoom_span( GLcontext *ctx, const struct sw_span *span,
const GLvoid *src, GLint y0, GLenum format )
{
GLint r0, r1, row;
GLint c0, c1, skipCol;
GLint i, j;
const GLuint maxWidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
GLchan rgbaSave[MAX_WIDTH][4];
GLuint indexSave[MAX_WIDTH];
const GLchan (*rgba)[4] = (const GLchan (*)[4]) src;
const GLchan (*rgb)[3] = (const GLchan (*)[3]) src;
const GLuint *indexes = (const GLuint *) src;
struct sw_span zoomed;
struct span_arrays zoomed_arrays; /* this is big! */
/* no pixel arrays! */
ASSERT((span->arrayMask & SPAN_XY) == 0);
ASSERT(span->primitive == GL_BITMAP);
INIT_SPAN(zoomed, GL_BITMAP, 0, 0, 0);
zoomed.array = &zoomed_arrays;
if (format == GL_RGBA || format == GL_RGB) {
zoomed.z = span->z;
zoomed.zStep = span->z;
zoomed.fog = span->fog;
zoomed.fogStep = span->fogStep;
zoomed.interpMask = span->interpMask & ~SPAN_RGBA;
zoomed.arrayMask |= SPAN_RGBA;
}
else if (format == GL_COLOR_INDEX) {
zoomed.z = span->z;
zoomed.zStep = span->z;
zoomed.fog = span->fog;
zoomed.fogStep = span->fogStep;
zoomed.interpMask = span->interpMask & ~SPAN_INDEX;
zoomed.arrayMask |= SPAN_INDEX;
}
/*
* Compute which columns to draw: [c0, c1)
*/
c0 = (GLint) span->x;
c1 = (GLint) (span->x + span->end * ctx->Pixel.ZoomX);
if (c0 == c1) {
return;
}
else if (c1 < c0) {
/* swap */
GLint ctmp = c1;
c1 = c0;
c0 = ctmp;
}
if (c0 < 0) {
zoomed.x = 0;
zoomed.start = 0;
zoomed.end = c1;
skipCol = -c0;
}
else {
zoomed.x = c0;
zoomed.start = 0;
zoomed.end = c1 - c0;
skipCol = 0;
}
if (zoomed.end > maxWidth)
zoomed.end = maxWidth;
/*
* Compute which rows to draw: [r0, r1)
*/
row = span->y - y0;
r0 = y0 + (GLint) (row * ctx->Pixel.ZoomY);
r1 = y0 + (GLint) ((row+1) * ctx->Pixel.ZoomY);
if (r0 == r1) {
return;
}
else if (r1 < r0) {
/* swap */
GLint rtmp = r1;
r1 = r0;
r0 = rtmp;
}
ASSERT(r0 < r1);
ASSERT(c0 < c1);
/*
* Trivial clip rejection testing.
*/
if (r1 < 0) /* below window */
return;
if (r0 >= (GLint) ctx->DrawBuffer->Height) /* above window */
return;
if (c1 < 0) /* left of window */
return;
if (c0 >= (GLint) ctx->DrawBuffer->Width) /* right of window */
return;
/* zoom the span horizontally */
if (format == GL_RGBA) {
if (ctx->Pixel.ZoomX == -1.0F) {
/* common case */
for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
i = span->end - (j + skipCol) - 1;
COPY_CHAN4(zoomed.array->rgba[j], rgba[i]);
}
}
else {
/* general solution */
const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
i = (GLint) ((j + skipCol) * xscale);
if (i < 0)
i = span->end + i - 1;
COPY_CHAN4(zoomed.array->rgba[j], rgba[i]);
}
}
}
else if (format == GL_RGB) {
if (ctx->Pixel.ZoomX == -1.0F) {
/* common case */
for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
i = span->end - (j + skipCol) - 1;
zoomed.array->rgba[j][0] = rgb[i][0];
zoomed.array->rgba[j][1] = rgb[i][1];
zoomed.array->rgba[j][2] = rgb[i][2];
zoomed.array->rgba[j][3] = CHAN_MAX;
}
}
else {
/* general solution */
const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
i = (GLint) ((j + skipCol) * xscale);
if (i < 0)
i = span->end + i - 1;
zoomed.array->rgba[j][0] = rgb[i][0];
zoomed.array->rgba[j][1] = rgb[i][1];
zoomed.array->rgba[j][2] = rgb[i][2];
zoomed.array->rgba[j][3] = CHAN_MAX;
}
}
}
else if (format == GL_COLOR_INDEX) {
if (ctx->Pixel.ZoomX == -1.0F) {
/* common case */
for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
i = span->end - (j + skipCol) - 1;
zoomed.array->index[j] = indexes[i];
}
}
else {
/* general solution */
const GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
for (j = (GLint) zoomed.start; j < (GLint) zoomed.end; j++) {
i = (GLint) ((j + skipCol) * xscale);
if (i < 0)
i = span->end + i - 1;
zoomed.array->index[j] = indexes[i];
}
}
}
/* write the span in rows [r0, r1) */
if (format == GL_RGBA || format == GL_RGB) {
/* Writing the span may modify the colors, so make a backup now if we're
* going to call _mesa_write_zoomed_span() more than once.
*/
if (r1 - r0 > 1) {
MEMCPY(rgbaSave, zoomed.array->rgba, zoomed.end * 4 * sizeof(GLchan));
}
for (zoomed.y = r0; zoomed.y < r1; zoomed.y++) {
_mesa_write_rgba_span(ctx, &zoomed);
if (r1 - r0 > 1) {
/* restore the colors */
MEMCPY(zoomed.array->rgba, rgbaSave, zoomed.end*4 * sizeof(GLchan));
}
}
}
else if (format == GL_COLOR_INDEX) {
if (r1 - r0 > 1) {
MEMCPY(indexSave, zoomed.array->index, zoomed.end * sizeof(GLuint));
}
for (zoomed.y = r0; zoomed.y < r1; zoomed.y++) {
_mesa_write_index_span(ctx, &zoomed);
if (r1 - r0 > 1) {
/* restore the colors */
MEMCPY(zoomed.array->index, indexSave, zoomed.end * sizeof(GLuint));
}
}
}
}
void
_mesa_write_zoomed_rgba_span( GLcontext *ctx, const struct sw_span *span,
CONST GLchan rgba[][4], GLint y0 )
{
zoom_span(ctx, span, (const GLvoid *) rgba, y0, GL_RGBA);
}
void
_mesa_write_zoomed_rgb_span( GLcontext *ctx, const struct sw_span *span,
CONST GLchan rgb[][3], GLint y0 )
{
zoom_span(ctx, span, (const GLvoid *) rgb, y0, GL_RGB);
}
void
_mesa_write_zoomed_index_span( GLcontext *ctx, const struct sw_span *span,
GLint y0 )
{
zoom_span(ctx, span, (const GLvoid *) span->array->index, y0, GL_COLOR_INDEX);
}
/*
* As above, but write stencil values.
*/
void
_mesa_write_zoomed_stencil_span( GLcontext *ctx,
GLuint n, GLint x, GLint y,
const GLstencil stencil[], GLint y0 )
{
GLint m;
GLint r0, r1, row, r;
GLint i, j, skipcol;
GLstencil zstencil[MAX_WIDTH]; /* zoomed stencil values */
GLint maxwidth = MIN2( ctx->DrawBuffer->Width, MAX_WIDTH );
/* compute width of output row */
m = (GLint) ABSF( n * ctx->Pixel.ZoomX );
if (m==0) {
return;
}
if (ctx->Pixel.ZoomX<0.0) {
/* adjust x coordinate for left/right mirroring */
x = x - m;
}
/* compute which rows to draw */
row = y-y0;
r0 = y0 + (GLint) (row * ctx->Pixel.ZoomY);
r1 = y0 + (GLint) ((row+1) * ctx->Pixel.ZoomY);
if (r0==r1) {
return;
}
else if (r1<r0) {
GLint rtmp = r1;
r1 = r0;
r0 = rtmp;
}
/* return early if r0...r1 is above or below window */
if (r0<0 && r1<0) {
/* below window */
return;
}
if (r0 >= (GLint) ctx->DrawBuffer->Height &&
r1 >= (GLint) ctx->DrawBuffer->Height) {
/* above window */
return;
}
/* check if left edge is outside window */
skipcol = 0;
if (x<0) {
skipcol = -x;
m += x;
}
/* make sure span isn't too long or short */
if (m>maxwidth) {
m = maxwidth;
}
else if (m<=0) {
return;
}
ASSERT( m <= MAX_WIDTH );
/* zoom the span horizontally */
if (ctx->Pixel.ZoomX==-1.0F) {
/* n==m */
for (j=0;j<m;j++) {
i = n - (j+skipcol) - 1;
zstencil[j] = stencil[i];
}
}
else {
GLfloat xscale = 1.0F / ctx->Pixel.ZoomX;
for (j=0;j<m;j++) {
i = (GLint) ((j+skipcol) * xscale);
if (i<0) i = n + i - 1;
zstencil[j] = stencil[i];
}
}
/* write the span */
for (r=r0; r<r1; r++) {
_mesa_write_stencil_span( ctx, m, x+skipcol, r, zstencil );
}
}