src/mesa/tnl/t_vb_points.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.1
   4  *
   5  * Copyright (C) 1999-2004  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  *
  24  * Authors:
  25  *    Brian Paul
  26  */
  27
  28 #include "mtypes.h"
  29 #include "imports.h"
  30 #include "t_context.h"
  31 #include "t_pipeline.h"
  32
  33
  34 struct point_stage_data {
  35    GLvector4f PointSize;
  36 };
  37
  38 #define POINT_STAGE_DATA(stage) ((struct point_stage_data *)stage->privatePtr)
  39
  40
  41 /*
  42  * Compute attenuated point sizes
  43  */
  44 static GLboolean run_point_stage( GLcontext *ctx,
  45                                   struct tnl_pipeline_stage *stage )
  46 {
  47    if (ctx->Point._Attenuated && !ctx->VertexProgram._Enabled) {
  48       struct point_stage_data *store = POINT_STAGE_DATA(stage);
  49       struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
  50       const GLfloat (*eye)[4] = (const GLfloat (*)[4]) VB->EyePtr->data;
  51       const GLfloat p0 = ctx->Point.Params[0];
  52       const GLfloat p1 = ctx->Point.Params[1];
  53       const GLfloat p2 = ctx->Point.Params[2];
  54       const GLfloat pointSize = ctx->Point._Size;
  55       GLfloat (*size)[4] = store->PointSize.data;
  56       GLuint i;
  57
  58       for (i = 0; i < VB->Count; i++) {
  59          const GLfloat dist = -eye[i][2];
  60          /* GLfloat dist = SQRTF(pos[0]*pos[0]+pos[1]*pos[1]+pos[2]*pos[2]);*/
  61          size[i][0] = pointSize / (p0 + dist * (p1 + dist * p2));
  62       }
  63
  64       VB->PointSizePtr = &store->PointSize;
  65       VB->AttribPtr[_TNL_ATTRIB_POINTSIZE] = &store->PointSize;
  66    }
  67
  68    return GL_TRUE;
  69 }
  70
  71
  72
  73 static GLboolean alloc_point_data( GLcontext *ctx,
  74                                    struct tnl_pipeline_stage *stage )
  75 {
  76    struct vertex_buffer *VB = &TNL_CONTEXT(ctx)->vb;
  77    struct point_stage_data *store;
  78    stage->privatePtr = MALLOC(sizeof(*store));
  79    store = POINT_STAGE_DATA(stage);
  80    if (!store)
  81       return GL_FALSE;
  82
  83    _mesa_vector4f_alloc( &store->PointSize, 0, VB->Size, 32 );
  84    return GL_TRUE;
  85 }
  86
  87
  88 static void free_point_data( struct tnl_pipeline_stage *stage )
  89 {
  90    struct point_stage_data *store = POINT_STAGE_DATA(stage);
  91    if (store) {
  92       _mesa_vector4f_free( &store->PointSize );
  93       FREE( store );
  94       stage->privatePtr = NULL;
  95    }
  96 }
  97
  98 const struct tnl_pipeline_stage _tnl_point_attenuation_stage =
  99 {
 100    "point size attenuation",    /* name */
 101    NULL,                        /* stage private data */
 102    alloc_point_data,            /* alloc data */
 103    free_point_data,             /* destructor */
 104    NULL,
 105    run_point_stage              /* run */
 106 };