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 "pipe/p_util.h"
  32 #include "pipe/p_shader_tokens.h"
  33 #include "draw_vs.h"
  34 #include "draw_pipe.h"
  35
  36
  37 /** subclass of draw_stage */
  38 struct flat_stage
  39 {
  40    struct draw_stage stage;
  41
  42    uint num_color_attribs;
  43    uint color_attribs[4];  /* front/back primary/secondary colors */
  44 };
  45
  46
  47 static INLINE struct flat_stage *
  48 flat_stage(struct draw_stage *stage)
  49 {
  50    return (struct flat_stage *) stage;
  51 }
  52
  53
  54 /** Copy all the color attributes from 'src' vertex to 'dst' vertex */
  55 static INLINE void copy_colors( struct draw_stage *stage,
  56                                 struct vertex_header *dst,
  57                                 const struct vertex_header *src )
  58 {
  59    const struct flat_stage *flat = flat_stage(stage);
  60    uint i;
  61    for (i = 0; i < flat->num_color_attribs; i++) {
  62       const uint attr = flat->color_attribs[i];
  63       COPY_4FV(dst->data[attr], src->data[attr]);
  64    }
  65 }
  66
  67
  68 /** Copy all the color attributes from src vertex to dst0 & dst1 vertices */
  69 static INLINE void copy_colors2( struct draw_stage *stage,
  70                                  struct vertex_header *dst0,
  71                                  struct vertex_header *dst1,
  72                                  const struct vertex_header *src )
  73 {
  74    const struct flat_stage *flat = flat_stage(stage);
  75    uint i;
  76    for (i = 0; i < flat->num_color_attribs; i++) {
  77       const uint attr = flat->color_attribs[i];
  78       COPY_4FV(dst0->data[attr], src->data[attr]);
  79       COPY_4FV(dst1->data[attr], src->data[attr]);
  80    }
  81 }
  82
  83
  84 /**
  85  * Flatshade tri.  Required for clipping and when unfilled tris are
  86  * active, otherwise handled by hardware.
  87  */
  88 static void flatshade_tri_0( struct draw_stage *stage,
  89                              struct prim_header *header )
  90 {
  91    struct prim_header tmp;
  92
  93    tmp.det = header->det;
  94    tmp.flags = header->flags;
  95    tmp.pad = header->pad;
  96    tmp.v[0] = header->v[0];
  97    tmp.v[1] = dup_vert(stage, header->v[1], 0);
  98    tmp.v[2] = dup_vert(stage, header->v[2], 1);
  99
 100    copy_colors2(stage, tmp.v[1], tmp.v[2], tmp.v[0]);
 101
 102    stage->next->tri( stage->next, &tmp );
 103 }
 104
 105
 106 static void flatshade_tri_2( struct draw_stage *stage,
 107                              struct prim_header *header )
 108 {
 109    struct prim_header tmp;
 110
 111    tmp.det = header->det;
 112    tmp.flags = header->flags;
 113    tmp.pad = header->pad;
 114    tmp.v[0] = dup_vert(stage, header->v[0], 0);
 115    tmp.v[1] = dup_vert(stage, header->v[1], 1);
 116    tmp.v[2] = header->v[2];
 117
 118    copy_colors2(stage, tmp.v[0], tmp.v[1], tmp.v[2]);
 119
 120    stage->next->tri( stage->next, &tmp );
 121 }
 122
 123
 124
 125
 126
 127 /**
 128  * Flatshade line.  Required for clipping.
 129  */
 130 static void flatshade_line_0( struct draw_stage *stage,
 131                               struct prim_header *header )
 132 {
 133    struct prim_header tmp;
 134
 135    tmp.v[0] = header->v[0];
 136    tmp.v[1] = dup_vert(stage, header->v[1], 0);
 137
 138    copy_colors(stage, tmp.v[1], tmp.v[0]);
 139
 140    stage->next->line( stage->next, &tmp );
 141 }
 142
 143 static void flatshade_line_1( struct draw_stage *stage,
 144                               struct prim_header *header )
 145 {
 146    struct prim_header tmp;
 147
 148    tmp.v[0] = dup_vert(stage, header->v[0], 0);
 149    tmp.v[1] = header->v[1];
 150
 151    copy_colors(stage, tmp.v[0], tmp.v[1]);
 152
 153    stage->next->line( stage->next, &tmp );
 154 }
 155
 156
 157
 158
 159 static void flatshade_init_state( struct draw_stage *stage )
 160 {
 161    struct flat_stage *flat = flat_stage(stage);
 162    const struct draw_vertex_shader *vs = stage->draw->vertex_shader;
 163    uint i;
 164
 165    /* Find which vertex shader outputs are colors, make a list */
 166    flat->num_color_attribs = 0;
 167    for (i = 0; i < vs->info.num_outputs; i++) {
 168       if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_COLOR ||
 169           vs->info.output_semantic_name[i] == TGSI_SEMANTIC_BCOLOR) {
 170          flat->color_attribs[flat->num_color_attribs++] = i;
 171       }
 172    }
 173
 174    /* Choose flatshade routine according to provoking vertex:
 175     */
 176    if (stage->draw->rasterizer->flatshade_first) {
 177       stage->line = flatshade_line_0;
 178       stage->tri = flatshade_tri_0;
 179    }
 180    else {
 181       stage->line = flatshade_line_1;
 182       stage->tri = flatshade_tri_2;
 183    }
 184 }
 185
 186 static void flatshade_first_tri( struct draw_stage *stage,
 187                                  struct prim_header *header )
 188 {
 189    flatshade_init_state( stage );
 190    stage->tri( stage, header );
 191 }
 192
 193 static void flatshade_first_line( struct draw_stage *stage,
 194                                   struct prim_header *header )
 195 {
 196    flatshade_init_state( stage );
 197    stage->line( stage, header );
 198 }
 199
 200
 201 static void flatshade_flush( struct draw_stage *stage,
 202                              unsigned flags )
 203 {
 204    stage->tri = flatshade_first_tri;
 205    stage->line = flatshade_first_line;
 206    stage->next->flush( stage->next, flags );
 207 }
 208
 209
 210 static void flatshade_reset_stipple_counter( struct draw_stage *stage )
 211 {
 212    stage->next->reset_stipple_counter( stage->next );
 213 }
 214
 215
 216 static void flatshade_destroy( struct draw_stage *stage )
 217 {
 218    draw_free_temp_verts( stage );
 219    FREE( stage );
 220 }
 221
 222
 223 /**
 224  * Create flatshading drawing stage.
 225  */
 226 struct draw_stage *draw_flatshade_stage( struct draw_context *draw )
 227 {
 228    struct flat_stage *flatshade = CALLOC_STRUCT(flat_stage);
 229    if (flatshade == NULL)
 230       goto fail;
 231
 232    if (!draw_alloc_temp_verts( &flatshade->stage, 2 ))
 233       goto fail;
 234
 235    flatshade->stage.draw = draw;
 236    flatshade->stage.next = NULL;
 237    flatshade->stage.point = draw_pipe_passthrough_point;
 238    flatshade->stage.line = flatshade_first_line;
 239    flatshade->stage.tri = flatshade_first_tri;
 240    flatshade->stage.flush = flatshade_flush;
 241    flatshade->stage.reset_stipple_counter = flatshade_reset_stipple_counter;
 242    flatshade->stage.destroy = flatshade_destroy;
 243
 244    return &flatshade->stage;
 245
 246  fail:
 247    if (flatshade)
 248       flatshade->stage.destroy( &flatshade->stage );
 249
 250    return NULL;
 251 }
 252
 253