src/mesa/pipe/draw/draw_flatshade.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28 /* Authors:  Keith Whitwell <keith@tungstengraphics.com>
  29  */
  30
  31 #include "pipe/p_util.h"
  32 #include "draw_private.h"
  33
  34
  35 static void flatshade_begin( struct draw_stage *stage )
  36 {
  37    stage->next->begin( stage->next );
  38 }
  39
  40
  41
  42 static INLINE void copy_attr( unsigned attr,
  43                               struct vertex_header *dst,
  44                               const struct vertex_header *src )
  45 {
  46    if (attr) {
  47       memcpy( dst->data[attr],
  48               src->data[attr],
  49               sizeof(src->data[0]) );
  50    }
  51 }
  52
  53
  54 static INLINE void copy_colors( struct draw_stage *stage,
  55                                 struct vertex_header *dst,
  56                                 const struct vertex_header *src )
  57 {
  58    const uint num_attribs = stage->draw->vertex_info.num_attribs;
  59    const enum interp_mode *interp = stage->draw->vertex_info.interp_mode;
  60    uint i;
  61
  62    /* Look for constant/flat attribs and duplicate from src to dst vertex */
  63    /* skip attrib[0] which is vert pos */
  64    for (i = 1; i < num_attribs; i++) {
  65       if (interp[i] == INTERP_CONSTANT) {
  66          copy_attr( i, dst, src );
  67       }
  68    }
  69 }
  70
  71
  72 /**
  73  * Flatshade tri.  Required for clipping and when unfilled tris are
  74  * active, otherwise handled by hardware.
  75  */
  76 static void flatshade_tri( struct draw_stage *stage,
  77                            struct prim_header *header )
  78 {
  79    struct prim_header tmp;
  80
  81    tmp.det = header->det;
  82    tmp.edgeflags = header->edgeflags;
  83    tmp.v[0] = dup_vert(stage, header->v[0], 0);
  84    tmp.v[1] = dup_vert(stage, header->v[1], 1);
  85    tmp.v[2] = header->v[2];
  86
  87    copy_colors(stage, tmp.v[0], tmp.v[2]);
  88    copy_colors(stage, tmp.v[1], tmp.v[2]);
  89
  90    stage->next->tri( stage->next, &tmp );
  91 }
  92
  93
  94 /**
  95  * Flatshade line.  Required for clipping.
  96  */
  97 static void flatshade_line( struct draw_stage *stage,
  98                             struct prim_header *header )
  99 {
 100    struct prim_header tmp;
 101
 102    tmp.v[0] = dup_vert(stage, header->v[0], 0);
 103    tmp.v[1] = header->v[1];
 104
 105    copy_colors(stage, tmp.v[0], tmp.v[1]);
 106
 107    stage->next->line( stage->next, &tmp );
 108 }
 109
 110
 111 static void flatshade_point( struct draw_stage *stage,
 112                              struct prim_header *header )
 113 {
 114    stage->next->point( stage->next, header );
 115 }
 116
 117
 118 static void flatshade_end( struct draw_stage *stage )
 119 {
 120    stage->next->end( stage->next );
 121 }
 122
 123
 124 static void flatshade_reset_stipple_counter( struct draw_stage *stage )
 125 {
 126    stage->next->reset_stipple_counter( stage->next );
 127 }
 128
 129
 130 /**
 131  * Create flatshading drawing stage.
 132  */
 133 struct draw_stage *draw_flatshade_stage( struct draw_context *draw )
 134 {
 135    struct draw_stage *flatshade = CALLOC_STRUCT(draw_stage);
 136
 137    draw_alloc_tmps( flatshade, 2 );
 138
 139    flatshade->draw = draw;
 140    flatshade->next = NULL;
 141    flatshade->begin = flatshade_begin;
 142    flatshade->point = flatshade_point;
 143    flatshade->line = flatshade_line;
 144    flatshade->tri = flatshade_tri;
 145    flatshade->end = flatshade_end;
 146    flatshade->reset_stipple_counter = flatshade_reset_stipple_counter;
 147
 148    return flatshade;
 149 }
 150
 151