src/gallium/auxiliary/draw/draw_pipe_unfilled.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 VMware, Inc.
   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 VMWARE 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 <keithw@vmware.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 #include "draw_fs.h"
  41
  42
  43 struct unfilled_stage {
  44    struct draw_stage stage;
  45
  46    /** [0] = front face, [1] = back face.
  47     * legal values:  PIPE_POLYGON_MODE_FILL, PIPE_POLYGON_MODE_LINE,
  48     * and PIPE_POLYGON_MODE_POINT,
  49     */
  50    unsigned mode[2];
  51
  52    int face_slot;
  53 };
  54
  55
  56 static inline struct unfilled_stage *unfilled_stage( struct draw_stage *stage )
  57 {
  58    return (struct unfilled_stage *)stage;
  59 }
  60
  61 static void
  62 inject_front_face_info(struct draw_stage *stage,
  63                        struct prim_header *header)
  64 {
  65    struct unfilled_stage *unfilled = unfilled_stage(stage);
  66    unsigned ccw = header->det < 0.0;
  67    boolean is_front_face = (
  68       (stage->draw->rasterizer->front_ccw && ccw) ||
  69       (!stage->draw->rasterizer->front_ccw && !ccw));
  70    int slot = unfilled->face_slot;
  71    unsigned i;
  72
  73    /* In case the backend doesn't care about it */
  74    if (slot < 0) {
  75       return;
  76    }
  77
  78    for (i = 0; i < 3; ++i) {
  79       struct vertex_header *v = header->v[i];
  80       v->data[slot][0] = is_front_face;
  81       v->data[slot][1] = is_front_face;
  82       v->data[slot][2] = is_front_face;
  83       v->data[slot][3] = is_front_face;
  84       v->vertex_id = UNDEFINED_VERTEX_ID;
  85    }
  86 }
  87
  88
  89 static void point(struct draw_stage *stage,
  90                   struct prim_header *header,
  91                   struct vertex_header *v0)
  92 {
  93    struct prim_header tmp;
  94    tmp.det = header->det;
  95    tmp.flags = 0;
  96    tmp.v[0] = v0;
  97    stage->next->point(stage->next, &tmp);
  98 }
  99
 100 static void line(struct draw_stage *stage,
 101                  struct prim_header *header,
 102                  struct vertex_header *v0,
 103                  struct vertex_header *v1)
 104 {
 105    struct prim_header tmp;
 106    tmp.det = header->det;
 107    tmp.flags = 0;
 108    tmp.v[0] = v0;
 109    tmp.v[1] = v1;
 110    stage->next->line(stage->next, &tmp);
 111 }
 112
 113
 114 static void points(struct draw_stage *stage,
 115                    struct prim_header *header)
 116 {
 117    struct vertex_header *v0 = header->v[0];
 118    struct vertex_header *v1 = header->v[1];
 119    struct vertex_header *v2 = header->v[2];
 120
 121    inject_front_face_info(stage, header);
 122
 123    if ((header->flags & DRAW_PIPE_EDGE_FLAG_0) && v0->edgeflag)
 124       point(stage, header, v0);
 125    if ((header->flags & DRAW_PIPE_EDGE_FLAG_1) && v1->edgeflag)
 126       point(stage, header, v1);
 127    if ((header->flags & DRAW_PIPE_EDGE_FLAG_2) && v2->edgeflag)
 128       point(stage, header, v2);
 129 }
 130
 131
 132 static void lines(struct draw_stage *stage,
 133                   struct prim_header *header)
 134 {
 135    struct vertex_header *v0 = header->v[0];
 136    struct vertex_header *v1 = header->v[1];
 137    struct vertex_header *v2 = header->v[2];
 138
 139    if (header->flags & DRAW_PIPE_RESET_STIPPLE)
 140       /*
 141        * XXX could revisit this. The only stage which cares is the line
 142        * stipple stage. Could just emit correct reset flags here and not
 143        * bother about all the calling through reset_stipple_counter
 144        * stages. Though technically it is necessary if line stipple is
 145        * handled by the driver, but this is not actually hooked up when
 146        * using vbuf (vbuf stage reset_stipple_counter does nothing).
 147        */
 148       stage->next->reset_stipple_counter(stage->next);
 149
 150    inject_front_face_info(stage, header);
 151
 152    if ((header->flags & DRAW_PIPE_EDGE_FLAG_2) && v2->edgeflag)
 153       line(stage, header, v2, v0);
 154    if ((header->flags & DRAW_PIPE_EDGE_FLAG_0) && v0->edgeflag)
 155       line(stage, header, v0, v1);
 156    if ((header->flags & DRAW_PIPE_EDGE_FLAG_1) && v1->edgeflag)
 157       line(stage, header, v1, v2);
 158 }
 159
 160
 161 /** For debugging */
 162 static void
 163 print_header_flags(unsigned flags)
 164 {
 165    debug_printf("header->flags = ");
 166    if (flags & DRAW_PIPE_RESET_STIPPLE)
 167       debug_printf("RESET_STIPPLE ");
 168    if (flags & DRAW_PIPE_EDGE_FLAG_0)
 169       debug_printf("EDGE_FLAG_0 ");
 170    if (flags & DRAW_PIPE_EDGE_FLAG_1)
 171       debug_printf("EDGE_FLAG_1 ");
 172    if (flags & DRAW_PIPE_EDGE_FLAG_2)
 173       debug_printf("EDGE_FLAG_2 ");
 174    debug_printf("\n");
 175 }
 176
 177
 178 /* Unfilled tri:
 179  *
 180  * Note edgeflags in the vertex struct is not sufficient as we will
 181  * need to manipulate them when decomposing primitives.
 182  *
 183  * We currently keep the vertex edgeflag and primitive edgeflag mask
 184  * separate until the last possible moment.
 185  */
 186 static void unfilled_tri( struct draw_stage *stage,
 187                           struct prim_header *header )
 188 {
 189    struct unfilled_stage *unfilled = unfilled_stage(stage);
 190    unsigned cw = header->det >= 0.0;
 191    unsigned mode = unfilled->mode[cw];
 192
 193    if (0)
 194       print_header_flags(header->flags);
 195
 196    switch (mode) {
 197    case PIPE_POLYGON_MODE_FILL:
 198       stage->next->tri( stage->next, header );
 199       break;
 200    case PIPE_POLYGON_MODE_LINE:
 201       lines( stage, header );
 202       break;
 203    case PIPE_POLYGON_MODE_POINT:
 204       points( stage, header );
 205       break;
 206    default:
 207       assert(0);
 208    }
 209 }
 210
 211
 212 static void unfilled_first_tri( struct draw_stage *stage,
 213                                 struct prim_header *header )
 214 {
 215    struct unfilled_stage *unfilled = unfilled_stage(stage);
 216    const struct pipe_rasterizer_state *rast = stage->draw->rasterizer;
 217
 218    unfilled->mode[0] = rast->front_ccw ? rast->fill_front : rast->fill_back;
 219    unfilled->mode[1] = rast->front_ccw ? rast->fill_back : rast->fill_front;
 220
 221    stage->tri = unfilled_tri;
 222    stage->tri( stage, header );
 223 }
 224
 225
 226
 227 static void unfilled_flush( struct draw_stage *stage,
 228                             unsigned flags )
 229 {
 230    stage->next->flush( stage->next, flags );
 231
 232    stage->tri = unfilled_first_tri;
 233 }
 234
 235
 236 static void unfilled_reset_stipple_counter( struct draw_stage *stage )
 237 {
 238    stage->next->reset_stipple_counter( stage->next );
 239 }
 240
 241
 242 static void unfilled_destroy( struct draw_stage *stage )
 243 {
 244    draw_free_temp_verts( stage );
 245    FREE( stage );
 246 }
 247
 248 /*
 249  * Try to allocate an output slot which we can use
 250  * to preserve the front face information.
 251  */
 252 void
 253 draw_unfilled_prepare_outputs( struct draw_context *draw,
 254                                struct draw_stage *stage )
 255 {
 256    struct unfilled_stage *unfilled = unfilled_stage(stage);
 257    const struct pipe_rasterizer_state *rast = draw ? draw->rasterizer : 0;
 258    boolean is_unfilled = (rast &&
 259                           (rast->fill_front != PIPE_POLYGON_MODE_FILL ||
 260                            rast->fill_back != PIPE_POLYGON_MODE_FILL));
 261    const struct draw_fragment_shader *fs = draw ? draw->fs.fragment_shader : 0;
 262
 263    if (is_unfilled && fs && fs->info.uses_frontface)  {
 264       unfilled->face_slot = draw_alloc_extra_vertex_attrib(
 265          stage->draw, TGSI_SEMANTIC_FACE, 0);
 266    } else {
 267       unfilled->face_slot = -1;
 268    }
 269 }
 270
 271
 272 /**
 273  * Create unfilled triangle stage.
 274  */
 275 struct draw_stage *draw_unfilled_stage( struct draw_context *draw )
 276 {
 277    struct unfilled_stage *unfilled = CALLOC_STRUCT(unfilled_stage);
 278    if (!unfilled)
 279       goto fail;
 280
 281    unfilled->stage.draw = draw;
 282    unfilled->stage.name = "unfilled";
 283    unfilled->stage.next = NULL;
 284    unfilled->stage.tmp = NULL;
 285    unfilled->stage.point = draw_pipe_passthrough_point;
 286    unfilled->stage.line = draw_pipe_passthrough_line;
 287    unfilled->stage.tri = unfilled_first_tri;
 288    unfilled->stage.flush = unfilled_flush;
 289    unfilled->stage.reset_stipple_counter = unfilled_reset_stipple_counter;
 290    unfilled->stage.destroy = unfilled_destroy;
 291
 292    unfilled->face_slot = -1;
 293
 294    if (!draw_alloc_temp_verts( &unfilled->stage, 0 ))
 295       goto fail;
 296
 297    return &unfilled->stage;
 298
 299  fail:
 300    if (unfilled)
 301       unfilled->stage.destroy( &unfilled->stage );
 302
 303    return NULL;
 304 }