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 uint *interp_mode = stage->draw->vertex_info.interp_mode;
  60    uint i;
  61
  62    /* Look for constant/flat attribs and duplicate from src to dst vertex */
  63    for (i = 1; i < num_attribs - 2; i++) {
  64       if (interp_mode[i + 2] == INTERP_CONSTANT) {
  65          copy_attr( i, dst, src );
  66       }
  67    }
  68 }
  69
  70
  71 /**
  72  * Flatshade tri.  Required for clipping and when unfilled tris are
  73  * active, otherwise handled by hardware.
  74  */
  75 static void flatshade_tri( struct draw_stage *stage,
  76                            struct prim_header *header )
  77 {
  78    struct prim_header tmp;
  79
  80    tmp.det = header->det;
  81    tmp.edgeflags = header->edgeflags;
  82    tmp.v[0] = dup_vert(stage, header->v[0], 0);
  83    tmp.v[1] = dup_vert(stage, header->v[1], 1);
  84    tmp.v[2] = header->v[2];
  85
  86    copy_colors(stage, tmp.v[0], tmp.v[2]);
  87    copy_colors(stage, tmp.v[1], tmp.v[2]);
  88
  89    stage->next->tri( stage->next, &tmp );
  90 }
  91
  92
  93 /**
  94  * Flatshade line.  Required for clipping.
  95  */
  96 static void flatshade_line( struct draw_stage *stage,
  97                             struct prim_header *header )
  98 {
  99    struct prim_header tmp;
 100
 101    tmp.v[0] = dup_vert(stage, header->v[0], 0);
 102    tmp.v[1] = header->v[1];
 103
 104    copy_colors(stage, tmp.v[0], tmp.v[1]);
 105
 106    stage->next->line( stage->next, &tmp );
 107 }
 108
 109
 110 static void flatshade_point( struct draw_stage *stage,
 111                              struct prim_header *header )
 112 {
 113    stage->next->point( stage->next, header );
 114 }
 115
 116
 117 static void flatshade_end( struct draw_stage *stage )
 118 {
 119    stage->next->end( stage->next );
 120 }
 121
 122
 123 static void flatshade_reset_stipple_counter( struct draw_stage *stage )
 124 {
 125    stage->next->reset_stipple_counter( stage->next );
 126 }
 127
 128
 129 /**
 130  * Create flatshading drawing stage.
 131  */
 132 struct draw_stage *draw_flatshade_stage( struct draw_context *draw )
 133 {
 134    struct draw_stage *flatshade = CALLOC_STRUCT(draw_stage);
 135
 136    draw_alloc_tmps( &flatshade->stage, 2 );
 137
 138    flatshade->draw = draw;
 139    flatshade->next = NULL;
 140    flatshade->begin = flatshade_begin;
 141    flatshade->point = flatshade_point;
 142    flatshade->line = flatshade_line;
 143    flatshade->tri = flatshade_tri;
 144    flatshade->end = flatshade_end;
 145    flatshade->reset_stipple_counter = flatshade_reset_stipple_counter;
 146
 147    return flatshade;
 148 }
 149
 150