src/gallium/auxiliary/draw/draw_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 "pipe/p_util.h"
  37 #include "pipe/p_defines.h"
  38 #include "draw_private.h"
  39
  40
  41 struct unfilled_stage {
  42    struct draw_stage stage;
  43
  44    /** [0] = front face, [1] = back face.
  45     * legal values:  PIPE_POLYGON_MODE_FILL, PIPE_POLYGON_MODE_LINE,
  46     * and PIPE_POLYGON_MODE_POINT,
  47     */
  48    unsigned mode[2];
  49 };
  50
  51
  52 static INLINE struct unfilled_stage *unfilled_stage( struct draw_stage *stage )
  53 {
  54    return (struct unfilled_stage *)stage;
  55 }
  56
  57
  58
  59 static void point( struct draw_stage *stage,
  60                    struct vertex_header *v0 )
  61 {
  62    struct prim_header tmp;
  63    tmp.v[0] = v0;
  64    stage->next->point( stage->next, &tmp );
  65 }
  66
  67 static void line( struct draw_stage *stage,
  68                   struct vertex_header *v0,
  69                   struct vertex_header *v1 )
  70 {
  71    struct prim_header tmp;
  72    tmp.v[0] = v0;
  73    tmp.v[1] = v1;
  74    stage->next->line( stage->next, &tmp );
  75 }
  76
  77
  78 static void points( struct draw_stage *stage,
  79                     struct prim_header *header )
  80 {
  81    struct vertex_header *v0 = header->v[0];
  82    struct vertex_header *v1 = header->v[1];
  83    struct vertex_header *v2 = header->v[2];
  84
  85    if (header->edgeflags & 0x1) point( stage, v0 );
  86    if (header->edgeflags & 0x2) point( stage, v1 );
  87    if (header->edgeflags & 0x4) point( stage, v2 );
  88 }
  89
  90
  91 static void lines( struct draw_stage *stage,
  92                    struct prim_header *header )
  93 {
  94    struct vertex_header *v0 = header->v[0];
  95    struct vertex_header *v1 = header->v[1];
  96    struct vertex_header *v2 = header->v[2];
  97
  98 #if 0
  99    assert(((header->edgeflags & 0x1) >> 0) == header->v[0]->edgeflag);
 100    assert(((header->edgeflags & 0x2) >> 1) == header->v[1]->edgeflag);
 101    assert(((header->edgeflags & 0x4) >> 2) == header->v[2]->edgeflag);
 102 #endif
 103
 104    if (header->edgeflags & 0x4) line( stage, v2, v0 );
 105    if (header->edgeflags & 0x1) line( stage, v0, v1 );
 106    if (header->edgeflags & 0x2) line( stage, v1, v2 );
 107 }
 108
 109
 110 /* Unfilled tri:
 111  *
 112  * Note edgeflags in the vertex struct is not sufficient as we will
 113  * need to manipulate them when decomposing primitives???
 114  */
 115 static void unfilled_tri( struct draw_stage *stage,
 116                           struct prim_header *header )
 117 {
 118    struct unfilled_stage *unfilled = unfilled_stage(stage);
 119    unsigned mode = unfilled->mode[header->det >= 0.0];
 120
 121    switch (mode) {
 122    case PIPE_POLYGON_MODE_FILL:
 123       stage->next->tri( stage->next, header );
 124       break;
 125    case PIPE_POLYGON_MODE_LINE:
 126       lines( stage, header );
 127       break;
 128    case PIPE_POLYGON_MODE_POINT:
 129       points( stage, header );
 130       break;
 131    default:
 132       assert(0);
 133    }
 134 }
 135
 136
 137 static void unfilled_first_tri( struct draw_stage *stage,
 138                                 struct prim_header *header )
 139 {
 140    struct unfilled_stage *unfilled = unfilled_stage(stage);
 141
 142    unfilled->mode[0] = stage->draw->rasterizer->fill_ccw; /* front */
 143    unfilled->mode[1] = stage->draw->rasterizer->fill_cw;  /* back */
 144
 145    stage->tri = unfilled_tri;
 146    stage->tri( stage, header );
 147 }
 148
 149
 150 static void unfilled_line( struct draw_stage *stage,
 151                            struct prim_header *header )
 152 {
 153    stage->next->line( stage->next, header );
 154 }
 155
 156
 157 static void unfilled_point( struct draw_stage *stage,
 158                             struct prim_header *header )
 159 {
 160    stage->next->point( stage->next, header );
 161 }
 162
 163
 164 static void unfilled_flush( struct draw_stage *stage,
 165                             unsigned flags )
 166 {
 167    stage->next->flush( stage->next, flags );
 168
 169    stage->tri = unfilled_first_tri;
 170 }
 171
 172
 173 static void unfilled_reset_stipple_counter( struct draw_stage *stage )
 174 {
 175    stage->next->reset_stipple_counter( stage->next );
 176 }
 177
 178
 179 static void unfilled_destroy( struct draw_stage *stage )
 180 {
 181    draw_free_temp_verts( stage );
 182    FREE( stage );
 183 }
 184
 185
 186 /**
 187  * Create unfilled triangle stage.
 188  */
 189 struct draw_stage *draw_unfilled_stage( struct draw_context *draw )
 190 {
 191    struct unfilled_stage *unfilled = CALLOC_STRUCT(unfilled_stage);
 192
 193    draw_alloc_temp_verts( &unfilled->stage, 0 );
 194
 195    unfilled->stage.draw = draw;
 196    unfilled->stage.next = NULL;
 197    unfilled->stage.tmp = NULL;
 198    unfilled->stage.point = unfilled_point;
 199    unfilled->stage.line = unfilled_line;
 200    unfilled->stage.tri = unfilled_first_tri;
 201    unfilled->stage.flush = unfilled_flush;
 202    unfilled->stage.reset_stipple_counter = unfilled_reset_stipple_counter;
 203    unfilled->stage.destroy = unfilled_destroy;
 204
 205    return &unfilled->stage;
 206 }