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