src/gallium/aux/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 "pipe/p_shader_tokens.h"
  33 #include "draw_private.h"
  34
  35
  36 /** subclass of draw_stage */
  37 struct flat_stage
  38 {
  39    struct draw_stage stage;
  40
  41    uint num_color_attribs;
  42    uint color_attribs[4];  /* front/back primary/secondary colors */
  43 };
  44
  45
  46 static INLINE struct flat_stage *
  47 flat_stage(struct draw_stage *stage)
  48 {
  49    return (struct flat_stage *) stage;
  50 }
  51
  52
  53 /** Copy all the color attributes from 'src' vertex to 'dst' vertex */
  54 static INLINE void copy_colors( struct draw_stage *stage,
  55                                 struct vertex_header *dst,
  56                                 const struct vertex_header *src )
  57 {
  58    const struct flat_stage *flat = flat_stage(stage);
  59    uint i;
  60    for (i = 0; i < flat->num_color_attribs; i++) {
  61       const uint attr = flat->color_attribs[i];
  62       COPY_4FV(dst->data[attr], src->data[attr]);
  63    }
  64 }
  65
  66
  67 /** Copy all the color attributes from src vertex to dst0 & dst1 vertices */
  68 static INLINE void copy_colors2( struct draw_stage *stage,
  69                                  struct vertex_header *dst0,
  70                                  struct vertex_header *dst1,
  71                                  const struct vertex_header *src )
  72 {
  73    const struct flat_stage *flat = flat_stage(stage);
  74    uint i;
  75    for (i = 0; i < flat->num_color_attribs; i++) {
  76       const uint attr = flat->color_attribs[i];
  77       COPY_4FV(dst0->data[attr], src->data[attr]);
  78       COPY_4FV(dst1->data[attr], src->data[attr]);
  79    }
  80 }
  81
  82
  83 /**
  84  * Flatshade tri.  Required for clipping and when unfilled tris are
  85  * active, otherwise handled by hardware.
  86  */
  87 static void flatshade_tri( struct draw_stage *stage,
  88                            struct prim_header *header )
  89 {
  90    struct prim_header tmp;
  91
  92    tmp.det = header->det;
  93    tmp.edgeflags = header->edgeflags;
  94    tmp.v[0] = dup_vert(stage, header->v[0], 0);
  95    tmp.v[1] = dup_vert(stage, header->v[1], 1);
  96    tmp.v[2] = header->v[2];
  97
  98    copy_colors2(stage, tmp.v[0], tmp.v[1], tmp.v[2]);
  99
 100    stage->next->tri( stage->next, &tmp );
 101 }
 102
 103
 104 /**
 105  * Flatshade line.  Required for clipping.
 106  */
 107 static void flatshade_line( struct draw_stage *stage,
 108                             struct prim_header *header )
 109 {
 110    struct prim_header tmp;
 111
 112    tmp.v[0] = dup_vert(stage, header->v[0], 0);
 113    tmp.v[1] = header->v[1];
 114
 115    copy_colors(stage, tmp.v[0], tmp.v[1]);
 116
 117    stage->next->line( stage->next, &tmp );
 118 }
 119
 120
 121 static void flatshade_point( struct draw_stage *stage,
 122                              struct prim_header *header )
 123 {
 124    stage->next->point( stage->next, header );
 125 }
 126
 127
 128 static void flatshade_init_state( struct draw_stage *stage )
 129 {
 130    struct flat_stage *flat = flat_stage(stage);
 131    const struct pipe_shader_state *vs = stage->draw->vertex_shader->state;
 132    uint i;
 133
 134    /* Find which vertex shader outputs are colors, make a list */
 135    flat->num_color_attribs = 0;
 136    for (i = 0; i < vs->num_outputs; i++) {
 137       if (vs->output_semantic_name[i] == TGSI_SEMANTIC_COLOR ||
 138           vs->output_semantic_name[i] == TGSI_SEMANTIC_BCOLOR) {
 139          flat->color_attribs[flat->num_color_attribs++] = i;
 140       }
 141    }
 142
 143    stage->line = flatshade_line;
 144    stage->tri = flatshade_tri;
 145 }
 146
 147 static void flatshade_first_tri( struct draw_stage *stage,
 148                                  struct prim_header *header )
 149 {
 150    flatshade_init_state( stage );
 151    stage->tri( stage, header );
 152 }
 153
 154 static void flatshade_first_line( struct draw_stage *stage,
 155                                   struct prim_header *header )
 156 {
 157    flatshade_init_state( stage );
 158    stage->line( stage, header );
 159 }
 160
 161
 162 static void flatshade_flush( struct draw_stage *stage,
 163                              unsigned flags )
 164 {
 165    stage->tri = flatshade_first_tri;
 166    stage->line = flatshade_first_line;
 167    stage->next->flush( stage->next, flags );
 168 }
 169
 170
 171 static void flatshade_reset_stipple_counter( struct draw_stage *stage )
 172 {
 173    stage->next->reset_stipple_counter( stage->next );
 174 }
 175
 176
 177 static void flatshade_destroy( struct draw_stage *stage )
 178 {
 179    draw_free_temp_verts( stage );
 180    FREE( stage );
 181 }
 182
 183
 184 /**
 185  * Create flatshading drawing stage.
 186  */
 187 struct draw_stage *draw_flatshade_stage( struct draw_context *draw )
 188 {
 189    struct flat_stage *flatshade = CALLOC_STRUCT(flat_stage);
 190
 191    draw_alloc_temp_verts( &flatshade->stage, 2 );
 192
 193    flatshade->stage.draw = draw;
 194    flatshade->stage.next = NULL;
 195    flatshade->stage.point = flatshade_point;
 196    flatshade->stage.line = flatshade_first_line;
 197    flatshade->stage.tri = flatshade_first_tri;
 198    flatshade->stage.flush = flatshade_flush;
 199    flatshade->stage.reset_stipple_counter = flatshade_reset_stipple_counter;
 200    flatshade->stage.destroy = flatshade_destroy;
 201
 202    return &flatshade->stage;
 203 }
 204
 205