src/gallium/auxiliary/draw/draw_pipe_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 "util/u_math.h"
  32 #include "util/u_memory.h"
  33
  34 #include "pipe/p_shader_tokens.h"
  35 #include "draw_vs.h"
  36 #include "draw_pipe.h"
  37
  38
  39 /** subclass of draw_stage */
  40 struct flat_stage
  41 {
  42    struct draw_stage stage;
  43
  44    uint num_color_attribs;
  45    uint color_attribs[2];  /* front/back primary colors */
  46
  47    uint num_spec_attribs;
  48    uint spec_attribs[2];  /* front/back secondary colors */
  49 };
  50
  51 #define COPY_3FV( DST, SRC )         \
  52 do {                                \
  53    (DST)[0] = (SRC)[0];             \
  54    (DST)[1] = (SRC)[1];             \
  55    (DST)[2] = (SRC)[2];             \
  56 } while (0)
  57
  58
  59 static INLINE struct flat_stage *
  60 flat_stage(struct draw_stage *stage)
  61 {
  62    return (struct flat_stage *) stage;
  63 }
  64
  65
  66 /** Copy all the color attributes from 'src' vertex to 'dst' vertex */
  67 static INLINE void copy_colors( struct draw_stage *stage,
  68                                 struct vertex_header *dst,
  69                                 const struct vertex_header *src )
  70 {
  71    const struct flat_stage *flat = flat_stage(stage);
  72    uint i;
  73
  74    for (i = 0; i < flat->num_color_attribs; i++) {
  75       const uint attr = flat->color_attribs[i];
  76       COPY_4FV(dst->data[attr], src->data[attr]);
  77    }
  78
  79    for (i = 0; i < flat->num_spec_attribs; i++) {
  80       const uint attr = flat->spec_attribs[i];
  81       COPY_3FV(dst->data[attr], src->data[attr]);
  82    }
  83 }
  84
  85
  86 /** Copy all the color attributes from src vertex to dst0 & dst1 vertices */
  87 static INLINE void copy_colors2( struct draw_stage *stage,
  88                                  struct vertex_header *dst0,
  89                                  struct vertex_header *dst1,
  90                                  const struct vertex_header *src )
  91 {
  92    const struct flat_stage *flat = flat_stage(stage);
  93    uint i;
  94    for (i = 0; i < flat->num_color_attribs; i++) {
  95       const uint attr = flat->color_attribs[i];
  96       COPY_4FV(dst0->data[attr], src->data[attr]);
  97       COPY_4FV(dst1->data[attr], src->data[attr]);
  98    }
  99
 100    for (i = 0; i < flat->num_spec_attribs; i++) {
 101       const uint attr = flat->spec_attribs[i];
 102       COPY_3FV(dst0->data[attr], src->data[attr]);
 103       COPY_3FV(dst1->data[attr], src->data[attr]);
 104    }
 105 }
 106
 107
 108 /**
 109  * Flatshade tri.  Required for clipping and when unfilled tris are
 110  * active, otherwise handled by hardware.
 111  */
 112 static void flatshade_tri_0( struct draw_stage *stage,
 113                              struct prim_header *header )
 114 {
 115    struct prim_header tmp;
 116
 117    tmp.det = header->det;
 118    tmp.flags = header->flags;
 119    tmp.pad = header->pad;
 120    tmp.v[0] = header->v[0];
 121    tmp.v[1] = dup_vert(stage, header->v[1], 0);
 122    tmp.v[2] = dup_vert(stage, header->v[2], 1);
 123
 124    copy_colors2(stage, tmp.v[1], tmp.v[2], tmp.v[0]);
 125
 126    stage->next->tri( stage->next, &tmp );
 127 }
 128
 129
 130 static void flatshade_tri_2( struct draw_stage *stage,
 131                              struct prim_header *header )
 132 {
 133    struct prim_header tmp;
 134
 135    tmp.det = header->det;
 136    tmp.flags = header->flags;
 137    tmp.pad = header->pad;
 138    tmp.v[0] = dup_vert(stage, header->v[0], 0);
 139    tmp.v[1] = dup_vert(stage, header->v[1], 1);
 140    tmp.v[2] = header->v[2];
 141
 142    copy_colors2(stage, tmp.v[0], tmp.v[1], tmp.v[2]);
 143
 144    stage->next->tri( stage->next, &tmp );
 145 }
 146
 147
 148
 149
 150
 151 /**
 152  * Flatshade line.  Required for clipping.
 153  */
 154 static void flatshade_line_0( struct draw_stage *stage,
 155                               struct prim_header *header )
 156 {
 157    struct prim_header tmp;
 158
 159    tmp.v[0] = header->v[0];
 160    tmp.v[1] = dup_vert(stage, header->v[1], 0);
 161
 162    copy_colors(stage, tmp.v[1], tmp.v[0]);
 163
 164    stage->next->line( stage->next, &tmp );
 165 }
 166
 167 static void flatshade_line_1( struct draw_stage *stage,
 168                               struct prim_header *header )
 169 {
 170    struct prim_header tmp;
 171
 172    tmp.v[0] = dup_vert(stage, header->v[0], 0);
 173    tmp.v[1] = header->v[1];
 174
 175    copy_colors(stage, tmp.v[0], tmp.v[1]);
 176
 177    stage->next->line( stage->next, &tmp );
 178 }
 179
 180
 181
 182
 183 static void flatshade_init_state( struct draw_stage *stage )
 184 {
 185    struct flat_stage *flat = flat_stage(stage);
 186    const struct draw_vertex_shader *vs = stage->draw->vs.vertex_shader;
 187    uint i;
 188
 189    /* Find which vertex shader outputs are colors, make a list */
 190    flat->num_color_attribs = 0;
 191    flat->num_spec_attribs = 0;
 192    for (i = 0; i < vs->info.num_outputs; i++) {
 193       if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_COLOR ||
 194           vs->info.output_semantic_name[i] == TGSI_SEMANTIC_BCOLOR) {
 195          if (vs->info.output_semantic_index[i] == 0)
 196             flat->color_attribs[flat->num_color_attribs++] = i;
 197          else
 198             flat->spec_attribs[flat->num_spec_attribs++] = i;
 199       }
 200    }
 201
 202    /* Choose flatshade routine according to provoking vertex:
 203     */
 204    if (stage->draw->rasterizer->flatshade_first) {
 205       stage->line = flatshade_line_0;
 206       stage->tri = flatshade_tri_0;
 207    }
 208    else {
 209       stage->line = flatshade_line_1;
 210       stage->tri = flatshade_tri_2;
 211    }
 212 }
 213
 214 static void flatshade_first_tri( struct draw_stage *stage,
 215                                  struct prim_header *header )
 216 {
 217    flatshade_init_state( stage );
 218    stage->tri( stage, header );
 219 }
 220
 221 static void flatshade_first_line( struct draw_stage *stage,
 222                                   struct prim_header *header )
 223 {
 224    flatshade_init_state( stage );
 225    stage->line( stage, header );
 226 }
 227
 228
 229 static void flatshade_flush( struct draw_stage *stage,
 230                              unsigned flags )
 231 {
 232    stage->tri = flatshade_first_tri;
 233    stage->line = flatshade_first_line;
 234    stage->next->flush( stage->next, flags );
 235 }
 236
 237
 238 static void flatshade_reset_stipple_counter( struct draw_stage *stage )
 239 {
 240    stage->next->reset_stipple_counter( stage->next );
 241 }
 242
 243
 244 static void flatshade_destroy( struct draw_stage *stage )
 245 {
 246    draw_free_temp_verts( stage );
 247    FREE( stage );
 248 }
 249
 250
 251 /**
 252  * Create flatshading drawing stage.
 253  */
 254 struct draw_stage *draw_flatshade_stage( struct draw_context *draw )
 255 {
 256    struct flat_stage *flatshade = CALLOC_STRUCT(flat_stage);
 257    if (flatshade == NULL)
 258       goto fail;
 259
 260    flatshade->stage.draw = draw;
 261    flatshade->stage.name = "flatshade";
 262    flatshade->stage.next = NULL;
 263    flatshade->stage.point = draw_pipe_passthrough_point;
 264    flatshade->stage.line = flatshade_first_line;
 265    flatshade->stage.tri = flatshade_first_tri;
 266    flatshade->stage.flush = flatshade_flush;
 267    flatshade->stage.reset_stipple_counter = flatshade_reset_stipple_counter;
 268    flatshade->stage.destroy = flatshade_destroy;
 269
 270    if (!draw_alloc_temp_verts( &flatshade->stage, 2 ))
 271       goto fail;
 272
 273    return &flatshade->stage;
 274
 275  fail:
 276    if (flatshade)
 277       flatshade->stage.destroy( &flatshade->stage );
 278
 279    return NULL;
 280 }
 281
 282