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 struct flatshade_stage {
  36    struct draw_stage stage;
  37
  38    const unsigned *lookup;
  39 };
  40
  41
  42
  43 static INLINE struct flatshade_stage *flatshade_stage( struct draw_stage *stage )
  44 {
  45    return (struct flatshade_stage *)stage;
  46 }
  47
  48
  49 static void flatshade_begin( struct draw_stage *stage )
  50 {
  51    stage->next->begin( stage->next );
  52 }
  53
  54
  55
  56 static INLINE void copy_attr( unsigned attr,
  57                               struct vertex_header *dst,
  58                               const struct vertex_header *src )
  59 {
  60    if (attr) {
  61       memcpy( dst->data[attr],
  62               src->data[attr],
  63               sizeof(src->data[0]) );
  64    }
  65 }
  66
  67
  68 static INLINE void copy_colors( struct draw_stage *stage,
  69                                 struct vertex_header *dst,
  70                                 const struct vertex_header *src )
  71 {
  72    const struct flatshade_stage *flatshade = flatshade_stage(stage);
  73    const unsigned *lookup = flatshade->lookup;
  74
  75    copy_attr( lookup[VF_ATTRIB_COLOR0], dst, src );
  76    copy_attr( lookup[VF_ATTRIB_COLOR1], dst, src );
  77    copy_attr( lookup[VF_ATTRIB_BFC0], dst, src );
  78    copy_attr( lookup[VF_ATTRIB_BFC1], dst, src );
  79 }
  80
  81
  82 /**
  83  * Flatshade tri.  Required for clipping and when unfilled tris are
  84  * active, otherwise handled by hardware.
  85  */
  86 static void flatshade_tri( struct draw_stage *stage,
  87                            struct prim_header *header )
  88 {
  89    struct prim_header tmp;
  90
  91    tmp.det = header->det;
  92    tmp.v[0] = dup_vert(stage, header->v[0], 0);
  93    tmp.v[1] = dup_vert(stage, header->v[1], 1);
  94    tmp.v[2] = header->v[2];
  95
  96    copy_colors(stage, tmp.v[0], tmp.v[2]);
  97    copy_colors(stage, tmp.v[1], tmp.v[2]);
  98
  99    stage->next->tri( stage->next, &tmp );
 100 }
 101
 102
 103 /**
 104  * Flatshade line.  Required for clipping.
 105  */
 106 static void flatshade_line( struct draw_stage *stage,
 107                             struct prim_header *header )
 108 {
 109    struct prim_header tmp;
 110
 111    tmp.v[0] = dup_vert(stage, header->v[0], 0);
 112    tmp.v[1] = header->v[1];
 113
 114    copy_colors(stage, tmp.v[0], tmp.v[1]);
 115
 116    stage->next->line( stage->next, &tmp );
 117 }
 118
 119
 120 static void flatshade_point( struct draw_stage *stage,
 121                              struct prim_header *header )
 122 {
 123    stage->next->point( stage->next, header );
 124 }
 125
 126
 127 static void flatshade_end( struct draw_stage *stage )
 128 {
 129    stage->next->end( stage->next );
 130 }
 131
 132
 133 static void flatshade_reset_stipple_counter( struct draw_stage *stage )
 134 {
 135    stage->next->reset_stipple_counter( stage->next );
 136 }
 137
 138
 139 /**
 140  * Create flatshading drawing stage.
 141  */
 142 struct draw_stage *draw_flatshade_stage( struct draw_context *draw )
 143 {
 144    struct flatshade_stage *flatshade = CALLOC_STRUCT(flatshade_stage);
 145
 146    draw_alloc_tmps( &flatshade->stage, 2 );
 147
 148    flatshade->stage.draw = draw;
 149    flatshade->stage.next = NULL;
 150    flatshade->stage.begin = flatshade_begin;
 151    flatshade->stage.point = flatshade_point;
 152    flatshade->stage.line = flatshade_line;
 153    flatshade->stage.tri = flatshade_tri;
 154    flatshade->stage.end = flatshade_end;
 155    flatshade->stage.reset_stipple_counter = flatshade_reset_stipple_counter;
 156
 157    flatshade->lookup = draw->vertex_info.attrib_to_slot;
 158
 159    return &flatshade->stage;
 160 }
 161
 162