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 /* Unfilled tri:
 109  *
 110  * Note edgeflags in the vertex struct is not sufficient as we will
 111  * need to manipulate them when decomposing primitives.
 112  *
 113  * We currently keep the vertex edgeflag and primitive edgeflag mask
 114  * separate until the last possible moment.
 115  */
 116 static void unfilled_tri( struct draw_stage *stage,
 117                           struct prim_header *header )
 118 {
 119    struct unfilled_stage *unfilled = unfilled_stage(stage);
 120    unsigned mode = unfilled->mode[header->det >= 0.0];
 121
 122    switch (mode) {
 123    case PIPE_POLYGON_MODE_FILL:
 124       stage->next->tri( stage->next, header );
 125       break;
 126    case PIPE_POLYGON_MODE_LINE:
 127       lines( stage, header );
 128       break;
 129    case PIPE_POLYGON_MODE_POINT:
 130       points( stage, header );
 131       break;
 132    default:
 133       assert(0);
 134    }
 135 }
 136
 137
 138 static void unfilled_first_tri( struct draw_stage *stage,
 139                                 struct prim_header *header )
 140 {
 141    struct unfilled_stage *unfilled = unfilled_stage(stage);
 142
 143    unfilled->mode[0] = stage->draw->rasterizer->fill_ccw; /* front */
 144    unfilled->mode[1] = stage->draw->rasterizer->fill_cw;  /* back */
 145
 146    stage->tri = unfilled_tri;
 147    stage->tri( stage, header );
 148 }
 149
 150
 151
 152 static void unfilled_flush( struct draw_stage *stage,
 153                             unsigned flags )
 154 {
 155    stage->next->flush( stage->next, flags );
 156
 157    stage->tri = unfilled_first_tri;
 158 }
 159
 160
 161 static void unfilled_reset_stipple_counter( struct draw_stage *stage )
 162 {
 163    stage->next->reset_stipple_counter( stage->next );
 164 }
 165
 166
 167 static void unfilled_destroy( struct draw_stage *stage )
 168 {
 169    draw_free_temp_verts( stage );
 170    FREE( stage );
 171 }
 172
 173
 174 /**
 175  * Create unfilled triangle stage.
 176  */
 177 struct draw_stage *draw_unfilled_stage( struct draw_context *draw )
 178 {
 179    struct unfilled_stage *unfilled = CALLOC_STRUCT(unfilled_stage);
 180    if (unfilled == NULL)
 181       goto fail;
 182
 183    if (!draw_alloc_temp_verts( &unfilled->stage, 0 ))
 184       goto fail;
 185
 186    unfilled->stage.draw = draw;
 187    unfilled->stage.name = "unfilled";
 188    unfilled->stage.next = NULL;
 189    unfilled->stage.tmp = NULL;
 190    unfilled->stage.point = draw_pipe_passthrough_point;
 191    unfilled->stage.line = draw_pipe_passthrough_line;
 192    unfilled->stage.tri = unfilled_first_tri;
 193    unfilled->stage.flush = unfilled_flush;
 194    unfilled->stage.reset_stipple_counter = unfilled_reset_stipple_counter;
 195    unfilled->stage.destroy = unfilled_destroy;
 196
 197    return &unfilled->stage;
 198
 199  fail:
 200    if (unfilled)
 201       unfilled->stage.destroy( &unfilled->stage );
 202
 203    return NULL;
 204 }