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