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