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.edgeflags = header->edgeflags;
  95    tmp.v[0] = header->v[0];
  96    tmp.v[1] = dup_vert(stage, header->v[1], 0);
  97    tmp.v[2] = dup_vert(stage, header->v[2], 1);
  98
  99    copy_colors2(stage, tmp.v[1], tmp.v[2], tmp.v[0]);
 100
 101    stage->next->tri( stage->next, &tmp );
 102 }
 103
 104
 105 static void flatshade_tri_2( struct draw_stage *stage,
 106                              struct prim_header *header )
 107 {
 108    struct prim_header tmp;
 109
 110    tmp.det = header->det;
 111    tmp.edgeflags = header->edgeflags;
 112    tmp.v[0] = dup_vert(stage, header->v[0], 0);
 113    tmp.v[1] = dup_vert(stage, header->v[1], 1);
 114    tmp.v[2] = header->v[2];
 115
 116    copy_colors2(stage, tmp.v[0], tmp.v[1], tmp.v[2]);
 117
 118    stage->next->tri( stage->next, &tmp );
 119 }
 120
 121
 122
 123
 124
 125 /**
 126  * Flatshade line.  Required for clipping.
 127  */
 128 static void flatshade_line_0( struct draw_stage *stage,
 129                               struct prim_header *header )
 130 {
 131    struct prim_header tmp;
 132
 133    tmp.v[0] = header->v[0];
 134    tmp.v[1] = dup_vert(stage, header->v[1], 0);
 135
 136    copy_colors(stage, tmp.v[1], tmp.v[0]);
 137
 138    stage->next->line( stage->next, &tmp );
 139 }
 140
 141 static void flatshade_line_1( struct draw_stage *stage,
 142                               struct prim_header *header )
 143 {
 144    struct prim_header tmp;
 145
 146    tmp.v[0] = dup_vert(stage, header->v[0], 0);
 147    tmp.v[1] = header->v[1];
 148
 149    copy_colors(stage, tmp.v[0], tmp.v[1]);
 150
 151    stage->next->line( stage->next, &tmp );
 152 }
 153
 154
 155
 156
 157 static void flatshade_init_state( struct draw_stage *stage )
 158 {
 159    struct flat_stage *flat = flat_stage(stage);
 160    const struct draw_vertex_shader *vs = stage->draw->vertex_shader;
 161    uint i;
 162
 163    /* Find which vertex shader outputs are colors, make a list */
 164    flat->num_color_attribs = 0;
 165    for (i = 0; i < vs->info.num_outputs; i++) {
 166       if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_COLOR ||
 167           vs->info.output_semantic_name[i] == TGSI_SEMANTIC_BCOLOR) {
 168          flat->color_attribs[flat->num_color_attribs++] = i;
 169       }
 170    }
 171
 172    /* Choose flatshade routine according to provoking vertex:
 173     */
 174    if (stage->draw->rasterizer->flatshade_first) {
 175       stage->line = flatshade_line_0;
 176       stage->tri = flatshade_tri_0;
 177    }
 178    else {
 179       stage->line = flatshade_line_1;
 180       stage->tri = flatshade_tri_2;
 181    }
 182 }
 183
 184 static void flatshade_first_tri( struct draw_stage *stage,
 185                                  struct prim_header *header )
 186 {
 187    flatshade_init_state( stage );
 188    stage->tri( stage, header );
 189 }
 190
 191 static void flatshade_first_line( struct draw_stage *stage,
 192                                   struct prim_header *header )
 193 {
 194    flatshade_init_state( stage );
 195    stage->line( stage, header );
 196 }
 197
 198
 199 static void flatshade_flush( struct draw_stage *stage,
 200                              unsigned flags )
 201 {
 202    stage->tri = flatshade_first_tri;
 203    stage->line = flatshade_first_line;
 204    stage->next->flush( stage->next, flags );
 205 }
 206
 207
 208 static void flatshade_reset_stipple_counter( struct draw_stage *stage )
 209 {
 210    stage->next->reset_stipple_counter( stage->next );
 211 }
 212
 213
 214 static void flatshade_destroy( struct draw_stage *stage )
 215 {
 216    draw_free_temp_verts( stage );
 217    FREE( stage );
 218 }
 219
 220
 221 /**
 222  * Create flatshading drawing stage.
 223  */
 224 struct draw_stage *draw_flatshade_stage( struct draw_context *draw )
 225 {
 226    struct flat_stage *flatshade = CALLOC_STRUCT(flat_stage);
 227    if (flatshade == NULL)
 228       goto fail;
 229
 230    if (!draw_alloc_temp_verts( &flatshade->stage, 2 ))
 231       goto fail;
 232
 233    flatshade->stage.draw = draw;
 234    flatshade->stage.next = NULL;
 235    flatshade->stage.point = draw_pipe_passthrough_point;
 236    flatshade->stage.line = flatshade_first_line;
 237    flatshade->stage.tri = flatshade_first_tri;
 238    flatshade->stage.flush = flatshade_flush;
 239    flatshade->stage.reset_stipple_counter = flatshade_reset_stipple_counter;
 240    flatshade->stage.destroy = flatshade_destroy;
 241
 242    return &flatshade->stage;
 243
 244  fail:
 245    if (flatshade)
 246       flatshade->stage.destroy( &flatshade->stage );
 247
 248    return NULL;
 249 }
 250
 251