src/gallium/auxiliary/draw/draw_split_tmp.h

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.9
   4  *
   5  * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
   6  * Copyright (C) 2010 LunarG Inc.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included
  16  * in all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  24  * DEALINGS IN THE SOFTWARE.
  25  */
  26
  27 static void
  28 FUNC(FUNC_VARS)
  29 {
  30    unsigned first, incr;
  31    LOCAL_VARS
  32
  33    /*
  34     * prim, start, count, and max_count_{simple,loop,fan} should have been
  35     * defined
  36     */
  37    if (0) {
  38       debug_printf("%s: prim 0x%x, start %d, count %d, max_count_simple %d, "
  39                    "max_count_loop %d, max_count_fan %d\n",
  40                    __FUNCTION__, prim, start, count, max_count_simple,
  41                    max_count_loop, max_count_fan);
  42    }
  43
  44    draw_pt_split_prim(prim, &first, &incr);
  45    /* sanitize primitive length */
  46    count = draw_pt_trim_count(count, first, incr);
  47    if (count < first)
  48       return;
  49
  50    /* try flushing the entire primitive */
  51    if (PRIMITIVE(start, count))
  52       return;
  53
  54    /* must be able to at least flush two complete primitives */
  55    assert(max_count_simple >= first + incr &&
  56           max_count_loop >= first + incr &&
  57           max_count_fan >= first + incr);
  58
  59    /* no splitting required */
  60    if (count <= max_count_simple) {
  61       SEGMENT_SIMPLE(0x0, start, count);
  62    }
  63    else {
  64       const unsigned rollback = first - incr;
  65       unsigned flags = DRAW_SPLIT_AFTER, seg_start = 0, seg_max;
  66
  67       /*
  68        * Both count and seg_max below are explicitly trimmed.  Because
  69        *
  70        *   seg_start = N * (seg_max - rollback) = N' * incr,
  71        *
  72        * we have
  73        *
  74        *   remaining = count - seg_start = first + N'' * incr.
  75        *
  76        * That is, remaining is implicitly trimmed.
  77        */
  78       switch (prim) {
  79       case PIPE_PRIM_POINTS:
  80       case PIPE_PRIM_LINES:
  81       case PIPE_PRIM_LINE_STRIP:
  82       case PIPE_PRIM_TRIANGLES:
  83       case PIPE_PRIM_TRIANGLE_STRIP:
  84       case PIPE_PRIM_QUADS:
  85       case PIPE_PRIM_QUAD_STRIP:
  86       case PIPE_PRIM_LINES_ADJACENCY:
  87       case PIPE_PRIM_LINE_STRIP_ADJACENCY:
  88       case PIPE_PRIM_TRIANGLES_ADJACENCY:
  89       case PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY:
  90          seg_max =
  91             draw_pt_trim_count(MIN2(max_count_simple, count), first, incr);
  92          if (prim == PIPE_PRIM_TRIANGLE_STRIP ||
  93              prim == PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY) {
  94             /* make sure we flush even number of triangles at a time */
  95             if (seg_max < count && !(((seg_max - first) / incr) & 1))
  96                seg_max -= incr;
  97          }
  98
  99          do {
 100             const unsigned remaining = count - seg_start;
 101
 102             if (remaining > seg_max) {
 103                SEGMENT_SIMPLE(flags, start + seg_start, seg_max);
 104                seg_start += seg_max - rollback;
 105
 106                flags |= DRAW_SPLIT_BEFORE;
 107             }
 108             else {
 109                flags &= ~DRAW_SPLIT_AFTER;
 110
 111                SEGMENT_SIMPLE(flags, start + seg_start, remaining);
 112                seg_start += remaining;
 113             }
 114          } while (seg_start < count);
 115          break;
 116
 117       case PIPE_PRIM_LINE_LOOP:
 118          seg_max =
 119             draw_pt_trim_count(MIN2(max_count_loop, count), first, incr);
 120
 121          do {
 122             const unsigned remaining = count - seg_start;
 123
 124             if (remaining > seg_max) {
 125                SEGMENT_LOOP(flags, start + seg_start, seg_max, start);
 126                seg_start += seg_max - rollback;
 127
 128                flags |= DRAW_SPLIT_BEFORE;
 129             }
 130             else {
 131                flags &= ~DRAW_SPLIT_AFTER;
 132
 133                SEGMENT_LOOP(flags, start + seg_start, remaining, start);
 134                seg_start += remaining;
 135             }
 136          } while (seg_start < count);
 137          break;
 138
 139       case PIPE_PRIM_TRIANGLE_FAN:
 140       case PIPE_PRIM_POLYGON:
 141          seg_max =
 142             draw_pt_trim_count(MIN2(max_count_fan, count), first, incr);
 143
 144          do {
 145             const unsigned remaining = count - seg_start;
 146
 147             if (remaining > seg_max) {
 148                SEGMENT_FAN(flags, start + seg_start, seg_max, start);
 149                seg_start += seg_max - rollback;
 150
 151                flags |= DRAW_SPLIT_BEFORE;
 152             }
 153             else {
 154                flags &= ~DRAW_SPLIT_AFTER;
 155
 156                SEGMENT_FAN(flags, start + seg_start, remaining, start);
 157                seg_start += remaining;
 158             }
 159          } while (seg_start < count);
 160          break;
 161
 162       default:
 163          assert(0);
 164          break;
 165       }
 166    }
 167 }
 168
 169 #undef FUNC
 170 #undef FUNC_VARS
 171 #undef LOCAL_VARS
 172
 173 #undef PRIMITIVE
 174 #undef SEGMENT_SIMPLE
 175 #undef SEGMENT_LOOP
 176 #undef SEGMENT_FAN