src/gallium/auxiliary/draw/draw_prim_assembler.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2013 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 #include "draw_prim_assembler.h"
  29
  30 #include "draw_fs.h"
  31 #include "draw_gs.h"
  32
  33 #include "util/u_debug.h"
  34 #include "util/u_memory.h"
  35 #include "util/u_prim.h"
  36
  37 #include "pipe/p_defines.h"
  38
  39 struct draw_assembler
  40 {
  41    struct draw_context *draw;
  42
  43    struct draw_prim_info *output_prims;
  44    struct draw_vertex_info *output_verts;
  45
  46    const struct draw_prim_info *input_prims;
  47    const struct draw_vertex_info *input_verts;
  48
  49    boolean needs_primid;
  50    int primid_slot;
  51    unsigned primid;
  52
  53    boolean is_strip;
  54    boolean is_first_prim;
  55    unsigned num_prims;
  56 };
  57
  58
  59 static boolean
  60 needs_primid(const struct draw_context *draw)
  61 {
  62    const struct draw_fragment_shader *fs = draw->fs.fragment_shader;
  63    const struct draw_geometry_shader *gs = draw->gs.geometry_shader;
  64    if (fs && fs->info.uses_primid) {
  65       return !gs || !gs->info.uses_primid;
  66    }
  67    return FALSE;
  68 }
  69
  70 boolean
  71 draw_prim_assembler_is_required(const struct draw_context *draw,
  72                                 const struct draw_prim_info *prim_info,
  73                                 const struct draw_vertex_info *vert_info)
  74 {
  75    switch (prim_info->prim) {
  76    case PIPE_PRIM_LINES_ADJACENCY:
  77    case PIPE_PRIM_LINE_STRIP_ADJACENCY:
  78    case PIPE_PRIM_TRIANGLES_ADJACENCY:
  79    case PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY:
  80       return TRUE;
  81    default:
  82       return needs_primid(draw);
  83    }
  84 }
  85
  86 /*
  87  * Copy the vertex header along with its data from the current
  88  * vertex buffer into a buffer holding vertices arranged
  89  * into decomposed primitives (i.e. buffer without the
  90  * adjacency vertices)
  91  */
  92 static void
  93 copy_verts(struct draw_assembler *asmblr,
  94            unsigned *indices, unsigned num_indices)
  95 {
  96    unsigned i;
  97
  98    char *output = (char*)asmblr->output_verts->verts;
  99    const char *input = (const char*)asmblr->input_verts->verts;
 100
 101    for (i = 0; i < num_indices; ++i) {
 102       unsigned idx = indices[i];
 103       unsigned output_offset =
 104          asmblr->output_verts->count * asmblr->output_verts->stride;
 105       unsigned input_offset = asmblr->input_verts->stride * idx;
 106       memcpy(output + output_offset, input + input_offset,
 107              asmblr->input_verts->vertex_size);
 108       asmblr->output_verts->count += 1;
 109    }
 110    ++asmblr->num_prims;
 111 }
 112
 113
 114 static void
 115 inject_primid(struct draw_assembler *asmblr,
 116               unsigned idx,
 117               unsigned primid)
 118 {
 119    int slot = asmblr->primid_slot;
 120    char *input = (char*)asmblr->input_verts->verts;
 121    unsigned input_offset = asmblr->input_verts->stride * idx;
 122    struct vertex_header *v = (struct vertex_header*)(input + input_offset);
 123
 124    /* In case the backend doesn't care about it */
 125    if (slot < 0) {
 126       return;
 127    }
 128
 129    memcpy(&v->data[slot][0], &primid, sizeof(primid));
 130    memcpy(&v->data[slot][1], &primid, sizeof(primid));
 131    memcpy(&v->data[slot][2], &primid, sizeof(primid));
 132    memcpy(&v->data[slot][3], &primid, sizeof(primid));
 133 }
 134
 135
 136 static void
 137 prim_point(struct draw_assembler *asmblr,
 138            unsigned idx)
 139 {
 140    unsigned indices[1];
 141
 142    if (asmblr->needs_primid) {
 143       inject_primid(asmblr, idx, asmblr->primid++);
 144    }
 145    indices[0] = idx;
 146
 147    copy_verts(asmblr, indices, 1);
 148 }
 149
 150 static void
 151 prim_line(struct draw_assembler *asmblr,
 152           unsigned i0, unsigned i1)
 153 {
 154    unsigned indices[2];
 155
 156    if (asmblr->needs_primid) {
 157       if (asmblr->is_strip && asmblr->is_first_prim) {
 158          inject_primid(asmblr, i0, asmblr->primid++);
 159          inject_primid(asmblr, i1, asmblr->primid++);
 160          asmblr->is_first_prim = FALSE;
 161       } else if (asmblr->is_strip) {
 162             inject_primid(asmblr, i1, asmblr->primid++);
 163       } else {
 164          inject_primid(asmblr, i0, asmblr->primid);
 165          inject_primid(asmblr, i1, asmblr->primid++);
 166       }
 167    }
 168    indices[0] = i0;
 169    indices[1] = i1;
 170
 171    copy_verts(asmblr, indices, 2);
 172 }
 173
 174 static void
 175 prim_tri(struct draw_assembler *asmblr,
 176          unsigned i0, unsigned i1, unsigned i2)
 177 {
 178    unsigned indices[3];
 179
 180    if (asmblr->needs_primid) {
 181       if (asmblr->is_strip && asmblr->is_first_prim) {
 182          inject_primid(asmblr, i0, asmblr->primid++);
 183          inject_primid(asmblr, i1, asmblr->primid++);
 184          inject_primid(asmblr, i2, asmblr->primid++);
 185          asmblr->is_first_prim = FALSE;
 186       } else if (asmblr->is_strip) {
 187          if (asmblr->num_prims & 1) {
 188             inject_primid(asmblr, i1, asmblr->primid++);
 189          } else {
 190             inject_primid(asmblr, i2, asmblr->primid++);
 191          }
 192       } else {
 193          inject_primid(asmblr, i0, asmblr->primid);
 194          inject_primid(asmblr, i1, asmblr->primid);
 195          inject_primid(asmblr, i2, asmblr->primid++);
 196       }
 197    }
 198    indices[0] = i0;
 199    indices[1] = i1;
 200    indices[2] = i2;
 201
 202    copy_verts(asmblr, indices, 3);
 203 }
 204
 205 void
 206 draw_prim_assembler_prepare_outputs(struct draw_assembler *ia)
 207 {
 208    struct draw_context *draw = ia->draw;
 209    if (needs_primid(draw)) {
 210       ia->primid_slot = draw_alloc_extra_vertex_attrib(
 211          ia->draw, TGSI_SEMANTIC_PRIMID, 0);
 212    } else {
 213       ia->primid_slot = -1;
 214    }
 215    ia->primid = 0;
 216 }
 217
 218
 219 #define FUNC assembler_run_linear
 220 #define GET_ELT(idx) (start + (idx))
 221 #include "draw_prim_assembler_tmp.h"
 222
 223 #define FUNC assembler_run_elts
 224 #define LOCAL_VARS   const ushort *elts = input_prims->elts;
 225 #define GET_ELT(idx) (elts[start + (idx)])
 226 #include "draw_prim_assembler_tmp.h"
 227
 228
 229
 230 /*
 231  * Primitive assembler breaks up adjacency primitives and assembles
 232  * the base primitives they represent, e.g. vertices forming
 233  * PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY
 234  * become vertices forming PIPE_PRIM_TRIANGLES
 235  * This is needed because specification says that the adjacency
 236  * primitives are only visible in the geometry shader so we need
 237  * to get rid of them so that the rest of the pipeline can
 238  * process the inputs.
 239  */
 240 void
 241 draw_prim_assembler_run(struct draw_context *draw,
 242                         const struct draw_prim_info *input_prims,
 243                         const struct draw_vertex_info *input_verts,
 244                         struct draw_prim_info *output_prims,
 245                         struct draw_vertex_info *output_verts)
 246 {
 247    struct draw_assembler *asmblr = draw->ia;
 248    unsigned start, i;
 249    unsigned assembled_prim = u_reduced_prim(input_prims->prim);
 250    unsigned max_primitives = u_decomposed_prims_for_vertices(
 251       input_prims->prim, input_prims->count);
 252    unsigned max_verts = u_vertices_per_prim(assembled_prim) * max_primitives;
 253
 254    asmblr->output_prims = output_prims;
 255    asmblr->output_verts = output_verts;
 256    asmblr->input_prims = input_prims;
 257    asmblr->input_verts = input_verts;
 258    asmblr->is_strip =
 259       (input_prims->prim == PIPE_PRIM_TRIANGLE_STRIP ||
 260        input_prims->prim == PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY) ||
 261       (input_prims->prim == PIPE_PRIM_LINE_STRIP ||
 262        input_prims->prim == PIPE_PRIM_LINE_STRIP_ADJACENCY);
 263    asmblr->needs_primid = needs_primid(asmblr->draw);
 264    asmblr->is_first_prim = asmblr->is_strip;
 265    asmblr->primid = 0;
 266    asmblr->num_prims = 0;
 267
 268    output_prims->linear = TRUE;
 269    output_prims->elts = NULL;
 270    output_prims->start = 0;
 271    output_prims->prim = assembled_prim;
 272    output_prims->flags = 0x0;
 273    output_prims->primitive_lengths = MALLOC(sizeof(unsigned));
 274    output_prims->primitive_lengths[0] = 0;
 275    output_prims->primitive_count = 1;
 276
 277    output_verts->vertex_size = input_verts->vertex_size;
 278    output_verts->stride = input_verts->stride;
 279    output_verts->verts = (struct vertex_header*)MALLOC(
 280       input_verts->vertex_size * max_verts);
 281    output_verts->count = 0;
 282
 283
 284    for (start = i = 0; i < input_prims->primitive_count;
 285         start += input_prims->primitive_lengths[i], i++)
 286    {
 287       unsigned count = input_prims->primitive_lengths[i];
 288       if (input_prims->linear) {
 289          assembler_run_linear(asmblr, input_prims, input_verts,
 290                               start, count);
 291       } else {
 292          assembler_run_elts(asmblr, input_prims, input_verts,
 293                             start, count);
 294       }
 295    }
 296
 297    output_prims->primitive_lengths[0] = output_verts->count;
 298    output_prims->count = output_verts->count;
 299 }
 300
 301 struct draw_assembler *
 302 draw_prim_assembler_create(struct draw_context *draw)
 303 {
 304    struct draw_assembler *ia = CALLOC_STRUCT( draw_assembler );
 305
 306    ia->draw = draw;
 307
 308    return ia;
 309 }
 310
 311 void
 312 draw_prim_assembler_destroy(struct draw_assembler *ia)
 313 {
 314    FREE(ia);
 315 }