src/gallium/auxiliary/draw/draw_pt_vsplit.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright 2007-2008 VMware, Inc.
   5  * Copyright (C) 2010 LunarG Inc.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  22  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  23  * DEALINGS IN THE SOFTWARE.
  24  */
  25
  26 #include "util/u_math.h"
  27 #include "util/u_memory.h"
  28
  29 #include "draw/draw_context.h"
  30 #include "draw/draw_private.h"
  31 #include "draw/draw_pt.h"
  32
  33 #define SEGMENT_SIZE 1024
  34 #define MAP_SIZE     256
  35
  36 /* The largest possible index within an index buffer */
  37 #define MAX_ELT_IDX 0xffffffff
  38
  39 struct vsplit_frontend {
  40    struct draw_pt_front_end base;
  41    struct draw_context *draw;
  42
  43    unsigned prim;
  44
  45    struct draw_pt_middle_end *middle;
  46
  47    unsigned max_vertices;
  48    ushort segment_size;
  49
  50    /* buffers for splitting */
  51    unsigned fetch_elts[SEGMENT_SIZE];
  52    ushort draw_elts[SEGMENT_SIZE];
  53    ushort identity_draw_elts[SEGMENT_SIZE];
  54
  55    struct {
  56       /* map a fetch element to a draw element */
  57       unsigned fetches[MAP_SIZE];
  58       ushort draws[MAP_SIZE];
  59       boolean has_max_fetch;
  60
  61       ushort num_fetch_elts;
  62       ushort num_draw_elts;
  63    } cache;
  64 };
  65
  66
  67 static void
  68 vsplit_clear_cache(struct vsplit_frontend *vsplit)
  69 {
  70    memset(vsplit->cache.fetches, 0xff, sizeof(vsplit->cache.fetches));
  71    vsplit->cache.has_max_fetch = FALSE;
  72    vsplit->cache.num_fetch_elts = 0;
  73    vsplit->cache.num_draw_elts = 0;
  74 }
  75
  76 static void
  77 vsplit_flush_cache(struct vsplit_frontend *vsplit, unsigned flags)
  78 {
  79    vsplit->middle->run(vsplit->middle,
  80          vsplit->fetch_elts, vsplit->cache.num_fetch_elts,
  81          vsplit->draw_elts, vsplit->cache.num_draw_elts, flags);
  82 }
  83
  84 /**
  85  * Add a fetch element and add it to the draw elements.
  86  */
  87 static inline void
  88 vsplit_add_cache(struct vsplit_frontend *vsplit, unsigned fetch)
  89 {
  90    unsigned hash;
  91
  92    hash = fetch % MAP_SIZE;
  93
  94    /* If the value isn't in the cache or it's an overflow due to the
  95     * element bias */
  96    if (vsplit->cache.fetches[hash] != fetch) {
  97       /* update cache */
  98       vsplit->cache.fetches[hash] = fetch;
  99       vsplit->cache.draws[hash] = vsplit->cache.num_fetch_elts;
 100
 101       /* add fetch */
 102       assert(vsplit->cache.num_fetch_elts < vsplit->segment_size);
 103       vsplit->fetch_elts[vsplit->cache.num_fetch_elts++] = fetch;
 104    }
 105
 106    vsplit->draw_elts[vsplit->cache.num_draw_elts++] = vsplit->cache.draws[hash];
 107 }
 108
 109 /**
 110  * Returns the base index to the elements array.
 111  * The value is checked for integer overflow (not sure it can happen?).
 112  */
 113 static inline unsigned
 114 vsplit_get_base_idx(unsigned start, unsigned fetch)
 115 {
 116    return draw_overflow_uadd(start, fetch, MAX_ELT_IDX);
 117 }
 118
 119
 120 static inline void
 121 vsplit_add_cache_ubyte(struct vsplit_frontend *vsplit, const ubyte *elts,
 122                        unsigned start, unsigned fetch, int elt_bias)
 123 {
 124    struct draw_context *draw = vsplit->draw;
 125    unsigned elt_idx;
 126    elt_idx = vsplit_get_base_idx(start, fetch);
 127    elt_idx = (unsigned)((int)(DRAW_GET_IDX(elts, elt_idx)) + elt_bias);
 128    /* unlike the uint case this can only happen with elt_bias */
 129    if (elt_bias && elt_idx == DRAW_MAX_FETCH_IDX && !vsplit->cache.has_max_fetch) {
 130       unsigned hash = elt_idx % MAP_SIZE;
 131       vsplit->cache.fetches[hash] = 0;
 132       vsplit->cache.has_max_fetch = TRUE;
 133    }
 134    vsplit_add_cache(vsplit, elt_idx);
 135 }
 136
 137 static inline void
 138 vsplit_add_cache_ushort(struct vsplit_frontend *vsplit, const ushort *elts,
 139                        unsigned start, unsigned fetch, int elt_bias)
 140 {
 141    struct draw_context *draw = vsplit->draw;
 142    unsigned elt_idx;
 143    elt_idx = vsplit_get_base_idx(start, fetch);
 144    elt_idx = (unsigned)((int)(DRAW_GET_IDX(elts, elt_idx)) + elt_bias);
 145    /* unlike the uint case this can only happen with elt_bias */
 146    if (elt_bias && elt_idx == DRAW_MAX_FETCH_IDX && !vsplit->cache.has_max_fetch) {
 147       unsigned hash = elt_idx % MAP_SIZE;
 148       vsplit->cache.fetches[hash] = 0;
 149       vsplit->cache.has_max_fetch = TRUE;
 150    }
 151    vsplit_add_cache(vsplit, elt_idx);
 152 }
 153
 154
 155 /**
 156  * Add a fetch element and add it to the draw elements.  The fetch element is
 157  * in full range (uint).
 158  */
 159 static inline void
 160 vsplit_add_cache_uint(struct vsplit_frontend *vsplit, const uint *elts,
 161                       unsigned start, unsigned fetch, int elt_bias)
 162 {
 163    struct draw_context *draw = vsplit->draw;
 164    unsigned elt_idx;
 165    /*
 166     * The final element index is just element index plus element bias.
 167     */
 168    elt_idx = vsplit_get_base_idx(start, fetch);
 169    elt_idx = (unsigned)((int)(DRAW_GET_IDX(elts, elt_idx)) + elt_bias);
 170    /* Take care for DRAW_MAX_FETCH_IDX (since cache is initialized to -1). */
 171    if (elt_idx == DRAW_MAX_FETCH_IDX && !vsplit->cache.has_max_fetch) {
 172       unsigned hash = elt_idx % MAP_SIZE;
 173       /* force update - any value will do except DRAW_MAX_FETCH_IDX */
 174       vsplit->cache.fetches[hash] = 0;
 175       vsplit->cache.has_max_fetch = TRUE;
 176    }
 177    vsplit_add_cache(vsplit, elt_idx);
 178 }
 179
 180
 181 #define FUNC vsplit_run_linear
 182 #include "draw_pt_vsplit_tmp.h"
 183
 184 #define FUNC vsplit_run_ubyte
 185 #define ELT_TYPE ubyte
 186 #define ADD_CACHE(vsplit, ib, start, fetch, bias) vsplit_add_cache_ubyte(vsplit,ib,start,fetch,bias)
 187 #include "draw_pt_vsplit_tmp.h"
 188
 189 #define FUNC vsplit_run_ushort
 190 #define ELT_TYPE ushort
 191 #define ADD_CACHE(vsplit, ib, start, fetch, bias) vsplit_add_cache_ushort(vsplit,ib,start,fetch, bias)
 192 #include "draw_pt_vsplit_tmp.h"
 193
 194 #define FUNC vsplit_run_uint
 195 #define ELT_TYPE uint
 196 #define ADD_CACHE(vsplit, ib, start, fetch, bias) vsplit_add_cache_uint(vsplit, ib, start, fetch, bias)
 197 #include "draw_pt_vsplit_tmp.h"
 198
 199
 200 static void vsplit_prepare(struct draw_pt_front_end *frontend,
 201                            unsigned in_prim,
 202                            struct draw_pt_middle_end *middle,
 203                            unsigned opt)
 204 {
 205    struct vsplit_frontend *vsplit = (struct vsplit_frontend *) frontend;
 206
 207    switch (vsplit->draw->pt.user.eltSize) {
 208    case 0:
 209       vsplit->base.run = vsplit_run_linear;
 210       break;
 211    case 1:
 212       vsplit->base.run = vsplit_run_ubyte;
 213       break;
 214    case 2:
 215       vsplit->base.run = vsplit_run_ushort;
 216       break;
 217    case 4:
 218       vsplit->base.run = vsplit_run_uint;
 219       break;
 220    default:
 221       assert(0);
 222       break;
 223    }
 224
 225    /* split only */
 226    vsplit->prim = in_prim;
 227
 228    vsplit->middle = middle;
 229    middle->prepare(middle, vsplit->prim, opt, &vsplit->max_vertices);
 230
 231    vsplit->segment_size = MIN2(SEGMENT_SIZE, vsplit->max_vertices);
 232 }
 233
 234
 235 static void vsplit_flush(struct draw_pt_front_end *frontend, unsigned flags)
 236 {
 237    struct vsplit_frontend *vsplit = (struct vsplit_frontend *) frontend;
 238
 239    if (flags & DRAW_FLUSH_STATE_CHANGE) {
 240       vsplit->middle->finish(vsplit->middle);
 241       vsplit->middle = NULL;
 242    }
 243 }
 244
 245
 246 static void vsplit_destroy(struct draw_pt_front_end *frontend)
 247 {
 248    FREE(frontend);
 249 }
 250
 251
 252 struct draw_pt_front_end *draw_pt_vsplit(struct draw_context *draw)
 253 {
 254    struct vsplit_frontend *vsplit = CALLOC_STRUCT(vsplit_frontend);
 255    ushort i;
 256
 257    if (!vsplit)
 258       return NULL;
 259
 260    vsplit->base.prepare = vsplit_prepare;
 261    vsplit->base.run     = NULL;
 262    vsplit->base.flush   = vsplit_flush;
 263    vsplit->base.destroy = vsplit_destroy;
 264    vsplit->draw = draw;
 265
 266    for (i = 0; i < SEGMENT_SIZE; i++)
 267       vsplit->identity_draw_elts[i] = i;
 268
 269    return &vsplit->base;
 270 }