src/gallium/auxiliary/draw/draw_pipe_unfilled.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 /**
  29  * \brief  Drawing stage for handling glPolygonMode(line/point).
  30  * Convert triangles to points or lines as needed.
  31  */
  32
  33 /* Authors:  Keith Whitwell <keith@tungstengraphics.com>
  34  */
  35
  36 #include "util/u_memory.h"
  37 #include "pipe/p_defines.h"
  38 #include "draw_private.h"
  39 #include "draw_pipe.h"
  40
  41
  42 struct unfilled_stage {
  43    struct draw_stage stage;
  44
  45    /** [0] = front face, [1] = back face.
  46     * legal values:  PIPE_POLYGON_MODE_FILL, PIPE_POLYGON_MODE_LINE,
  47     * and PIPE_POLYGON_MODE_POINT,
  48     */
  49    unsigned mode[2];
  50 };
  51
  52
  53 static INLINE struct unfilled_stage *unfilled_stage( struct draw_stage *stage )
  54 {
  55    return (struct unfilled_stage *)stage;
  56 }
  57
  58
  59
  60 static void point( struct draw_stage *stage,
  61                    struct vertex_header *v0 )
  62 {
  63    struct prim_header tmp;
  64    tmp.v[0] = v0;
  65    stage->next->point( stage->next, &tmp );
  66 }
  67
  68 static void line( struct draw_stage *stage,
  69                   struct vertex_header *v0,
  70                   struct vertex_header *v1 )
  71 {
  72    struct prim_header tmp;
  73    tmp.v[0] = v0;
  74    tmp.v[1] = v1;
  75    stage->next->line( stage->next, &tmp );
  76 }
  77
  78
  79 static void points( struct draw_stage *stage,
  80                     struct prim_header *header )
  81 {
  82    struct vertex_header *v0 = header->v[0];
  83    struct vertex_header *v1 = header->v[1];
  84    struct vertex_header *v2 = header->v[2];
  85
  86    if ((header->flags & DRAW_PIPE_EDGE_FLAG_0) && v0->edgeflag) point( stage, v0 );
  87    if ((header->flags & DRAW_PIPE_EDGE_FLAG_1) && v1->edgeflag) point( stage, v1 );
  88    if ((header->flags & DRAW_PIPE_EDGE_FLAG_2) && v2->edgeflag) point( stage, v2 );
  89 }
  90
  91
  92 static void lines( struct draw_stage *stage,
  93                    struct prim_header *header )
  94 {
  95    struct vertex_header *v0 = header->v[0];
  96    struct vertex_header *v1 = header->v[1];
  97    struct vertex_header *v2 = header->v[2];
  98
  99    if (header->flags & DRAW_PIPE_RESET_STIPPLE)
 100       stage->next->reset_stipple_counter( stage->next );
 101
 102    if ((header->flags & DRAW_PIPE_EDGE_FLAG_2) && v2->edgeflag) line( stage, v2, v0 );
 103    if ((header->flags & DRAW_PIPE_EDGE_FLAG_0) && v0->edgeflag) line( stage, v0, v1 );
 104    if ((header->flags & DRAW_PIPE_EDGE_FLAG_1) && v1->edgeflag) line( stage, v1, v2 );
 105 }
 106
 107
 108 /** For debugging */
 109 static void
 110 print_header_flags(unsigned flags)
 111 {
 112    debug_printf("header->flags = ");
 113    if (flags & DRAW_PIPE_RESET_STIPPLE)
 114       debug_printf("RESET_STIPPLE ");
 115    if (flags & DRAW_PIPE_EDGE_FLAG_0)
 116       debug_printf("EDGE_FLAG_0 ");
 117    if (flags & DRAW_PIPE_EDGE_FLAG_1)
 118       debug_printf("EDGE_FLAG_1 ");
 119    if (flags & DRAW_PIPE_EDGE_FLAG_2)
 120       debug_printf("EDGE_FLAG_2 ");
 121    debug_printf("\n");
 122 }
 123
 124
 125 /* Unfilled tri:
 126  *
 127  * Note edgeflags in the vertex struct is not sufficient as we will
 128  * need to manipulate them when decomposing primitives.
 129  *
 130  * We currently keep the vertex edgeflag and primitive edgeflag mask
 131  * separate until the last possible moment.
 132  */
 133 static void unfilled_tri( struct draw_stage *stage,
 134                           struct prim_header *header )
 135 {
 136    struct unfilled_stage *unfilled = unfilled_stage(stage);
 137    unsigned cw = header->det >= 0.0;
 138    unsigned mode = unfilled->mode[cw];
 139
 140    if (0)
 141       print_header_flags(header->flags);
 142
 143    switch (mode) {
 144    case PIPE_POLYGON_MODE_FILL:
 145       stage->next->tri( stage->next, header );
 146       break;
 147    case PIPE_POLYGON_MODE_LINE:
 148       lines( stage, header );
 149       break;
 150    case PIPE_POLYGON_MODE_POINT:
 151       points( stage, header );
 152       break;
 153    default:
 154       assert(0);
 155    }
 156 }
 157
 158
 159 static void unfilled_first_tri( struct draw_stage *stage,
 160                                 struct prim_header *header )
 161 {
 162    struct unfilled_stage *unfilled = unfilled_stage(stage);
 163    const struct pipe_rasterizer_state *rast = stage->draw->rasterizer;
 164
 165    unfilled->mode[0] = rast->front_ccw ? rast->fill_front : rast->fill_back;
 166    unfilled->mode[1] = rast->front_ccw ? rast->fill_back : rast->fill_front;
 167
 168    stage->tri = unfilled_tri;
 169    stage->tri( stage, header );
 170 }
 171
 172
 173
 174 static void unfilled_flush( struct draw_stage *stage,
 175                             unsigned flags )
 176 {
 177    stage->next->flush( stage->next, flags );
 178
 179    stage->tri = unfilled_first_tri;
 180 }
 181
 182
 183 static void unfilled_reset_stipple_counter( struct draw_stage *stage )
 184 {
 185    stage->next->reset_stipple_counter( stage->next );
 186 }
 187
 188
 189 static void unfilled_destroy( struct draw_stage *stage )
 190 {
 191    draw_free_temp_verts( stage );
 192    FREE( stage );
 193 }
 194
 195
 196 /**
 197  * Create unfilled triangle stage.
 198  */
 199 struct draw_stage *draw_unfilled_stage( struct draw_context *draw )
 200 {
 201    struct unfilled_stage *unfilled = CALLOC_STRUCT(unfilled_stage);
 202    if (unfilled == NULL)
 203       goto fail;
 204
 205    unfilled->stage.draw = draw;
 206    unfilled->stage.name = "unfilled";
 207    unfilled->stage.next = NULL;
 208    unfilled->stage.tmp = NULL;
 209    unfilled->stage.point = draw_pipe_passthrough_point;
 210    unfilled->stage.line = draw_pipe_passthrough_line;
 211    unfilled->stage.tri = unfilled_first_tri;
 212    unfilled->stage.flush = unfilled_flush;
 213    unfilled->stage.reset_stipple_counter = unfilled_reset_stipple_counter;
 214    unfilled->stage.destroy = unfilled_destroy;
 215
 216    if (!draw_alloc_temp_verts( &unfilled->stage, 0 ))
 217       goto fail;
 218
 219    return &unfilled->stage;
 220
 221  fail:
 222    if (unfilled)
 223       unfilled->stage.destroy( &unfilled->stage );
 224
 225    return NULL;
 226 }