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| Rev | Author | Line No. | Line |
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| 56 | pj | 1 | /* $Id: t_vb_points.c,v 1.1 2003-02-28 11:48:07 pj Exp $ */ |
| 2 | |||
| 3 | /* |
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| 4 | * Mesa 3-D graphics library |
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| 5 | * Version: 4.1 |
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| 6 | * |
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| 7 | * Copyright (C) 1999-2002 Brian Paul All Rights Reserved. |
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| 8 | * |
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| 9 | * Permission is hereby granted, free of charge, to any person obtaining a |
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| 10 | * copy of this software and associated documentation files (the "Software"), |
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| 11 | * to deal in the Software without restriction, including without limitation |
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| 12 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
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| 13 | * and/or sell copies of the Software, and to permit persons to whom the |
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| 14 | * Software is furnished to do so, subject to the following conditions: |
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| 15 | * |
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| 16 | * The above copyright notice and this permission notice shall be included |
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| 17 | * in all copies or substantial portions of the Software. |
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| 18 | * |
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| 19 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
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| 20 | * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
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| 21 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
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| 22 | * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN |
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| 23 | * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN |
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| 24 | * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
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| 25 | * |
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| 26 | * Authors: |
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| 27 | * Brian Paul |
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| 28 | */ |
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| 29 | |||
| 30 | #include "mtypes.h" |
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| 31 | #include "imports.h" |
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| 32 | #include "t_context.h" |
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| 33 | #include "t_pipeline.h" |
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| 34 | |||
| 35 | |||
| 36 | struct point_stage_data { |
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| 37 | GLvector4f PointSize; |
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| 38 | }; |
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| 39 | |||
| 40 | #define POINT_STAGE_DATA(stage) ((struct point_stage_data *)stage->privatePtr) |
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| 41 | |||
| 42 | |||
| 43 | /* |
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| 44 | * Compute attenuated point sizes |
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| 45 | */ |
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| 46 | static GLboolean run_point_stage( GLcontext *ctx, |
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| 47 | struct gl_pipeline_stage *stage ) |
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| 48 | { |
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| 49 | struct point_stage_data *store = POINT_STAGE_DATA(stage); |
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| 50 | struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb; |
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| 51 | const GLfloat (*eye)[4] = (const GLfloat (*)[4]) VB->EyePtr->data; |
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| 52 | const GLfloat p0 = ctx->Point.Params[0]; |
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| 53 | const GLfloat p1 = ctx->Point.Params[1]; |
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| 54 | const GLfloat p2 = ctx->Point.Params[2]; |
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| 55 | const GLfloat pointSize = ctx->Point._Size; |
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| 56 | GLfloat (*size)[4] = store->PointSize.data; |
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| 57 | GLuint i; |
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| 58 | |||
| 59 | if (stage->changed_inputs) { |
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| 60 | /* XXX do threshold and min/max clamping here? */ |
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| 61 | for (i = 0; i < VB->Count; i++) { |
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| 62 | const GLfloat dist = -eye[i][2]; |
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| 63 | /* GLfloat dist = GL_SQRT(pos[0]*pos[0]+pos[1]*pos[1]+pos[2]*pos[2]);*/ |
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| 64 | size[i][0] = pointSize / (p0 + dist * (p1 + dist * p2)); |
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| 65 | } |
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| 66 | } |
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| 67 | |||
| 68 | VB->PointSizePtr = &store->PointSize; |
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| 69 | |||
| 70 | return GL_TRUE; |
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| 71 | } |
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| 72 | |||
| 73 | |||
| 74 | /* If point size attenuation is on we'll compute the point size for |
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| 75 | * each vertex in a special pipeline stage. |
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| 76 | */ |
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| 77 | static void check_point_size( GLcontext *ctx, struct gl_pipeline_stage *d ) |
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| 78 | { |
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| 79 | d->active = ctx->Point._Attenuated && !ctx->VertexProgram.Enabled; |
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| 80 | } |
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| 81 | |||
| 82 | static GLboolean alloc_point_data( GLcontext *ctx, |
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| 83 | struct gl_pipeline_stage *stage ) |
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| 84 | { |
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| 85 | struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb; |
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| 86 | struct point_stage_data *store; |
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| 87 | stage->privatePtr = MALLOC(sizeof(*store)); |
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| 88 | store = POINT_STAGE_DATA(stage); |
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| 89 | if (!store) |
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| 90 | return GL_FALSE; |
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| 91 | |||
| 92 | _mesa_vector4f_alloc( &store->PointSize, 0, VB->Size, 32 ); |
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| 93 | |||
| 94 | /* Now run the stage. |
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| 95 | */ |
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| 96 | stage->run = run_point_stage; |
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| 97 | return stage->run( ctx, stage ); |
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| 98 | } |
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| 99 | |||
| 100 | |||
| 101 | static void free_point_data( struct gl_pipeline_stage *stage ) |
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| 102 | { |
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| 103 | struct point_stage_data *store = POINT_STAGE_DATA(stage); |
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| 104 | if (store) { |
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| 105 | _mesa_vector4f_free( &store->PointSize ); |
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| 106 | FREE( store ); |
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| 107 | stage->privatePtr = 0; |
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| 108 | } |
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| 109 | } |
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| 110 | |||
| 111 | const struct gl_pipeline_stage _tnl_point_attenuation_stage = |
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| 112 | { |
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| 113 | "point size attenuation", /* name */ |
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| 114 | _NEW_POINT, /* build_state_change */ |
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| 115 | _NEW_POINT, /* run_state_change */ |
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| 116 | GL_FALSE, /* active */ |
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| 117 | VERT_BIT_EYE, /* inputs */ |
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| 118 | VERT_BIT_POINT_SIZE, /* outputs */ |
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| 119 | 0, /* changed_inputs (temporary value) */ |
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| 120 | NULL, /* stage private data */ |
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| 121 | free_point_data, /* destructor */ |
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| 122 | check_point_size, /* check */ |
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| 123 | alloc_point_data /* run -- initially set to alloc data */ |
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| 124 | }; |