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 "util/u_debug.h"
  31 #include "util/u_memory.h"
  32 #include "util/u_prim.h"
  33
  34 #include "pipe/p_defines.h"
  35
  36 struct draw_assembler
  37 {
  38    struct draw_context *draw;
  39
  40    struct draw_prim_info *output_prims;
  41    struct draw_vertex_info *output_verts;
  42
  43    const struct draw_prim_info *input_prims;
  44    const struct draw_vertex_info *input_verts;
  45 };
  46
  47 boolean
  48 draw_prim_assembler_is_required(const struct draw_context *draw,
  49                                 const struct draw_prim_info *prim_info,
  50                                 const struct draw_vertex_info *vert_info)
  51 {
  52    switch (prim_info->prim) {
  53    case PIPE_PRIM_LINES_ADJACENCY:
  54    case PIPE_PRIM_LINE_STRIP_ADJACENCY:
  55    case PIPE_PRIM_TRIANGLES_ADJACENCY:
  56    case PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY:
  57       return TRUE;
  58    default:
  59       return FALSE;
  60    }
  61 }
  62
  63 /*
  64  * Copy the vertex header along with its data from the current
  65  * vertex buffer into a buffer holding vertices arranged
  66  * into decomposed primitives (i.e. buffer without the
  67  * adjacency vertices)
  68  */
  69 static void
  70 copy_verts(struct draw_assembler *asmblr,
  71            unsigned *indices, unsigned num_indices)
  72 {
  73    unsigned i;
  74
  75    char *output = (char*)asmblr->output_verts->verts;
  76    const char *input = (const char*)asmblr->input_verts->verts;
  77
  78    for (i = 0; i < num_indices; ++i) {
  79       unsigned idx = indices[i];
  80       unsigned output_offset =
  81          asmblr->output_verts->count * asmblr->output_verts->stride;
  82       unsigned input_offset = asmblr->input_verts->stride * idx;
  83       memcpy(output + output_offset, input + input_offset,
  84              asmblr->input_verts->vertex_size);
  85       asmblr->output_verts->count += 1;
  86    }
  87 }
  88
  89 static void
  90 prim_point(struct draw_assembler *asmblr,
  91            unsigned idx)
  92 {
  93    unsigned indices[1];
  94
  95    indices[0] = idx;
  96
  97    copy_verts(asmblr, indices, 1);
  98 }
  99
 100 static void
 101 prim_line(struct draw_assembler *asmblr,
 102           unsigned i0, unsigned i1)
 103 {
 104    unsigned indices[2];
 105
 106    indices[0] = i0;
 107    indices[1] = i1;
 108
 109    copy_verts(asmblr, indices, 2);
 110 }
 111
 112 static void
 113 prim_line_adj(struct draw_assembler *asmblr,
 114               unsigned i0, unsigned i1, unsigned i2, unsigned i3)
 115 {
 116    unsigned indices[2];
 117
 118    indices[0] = i1;
 119    indices[1] = i2;
 120
 121    copy_verts(asmblr, indices, 2);
 122 }
 123
 124 static void
 125 prim_tri(struct draw_assembler *asmblr,
 126          unsigned i0, unsigned i1, unsigned i2)
 127 {
 128    unsigned indices[3];
 129
 130    indices[0] = i0;
 131    indices[1] = i1;
 132    indices[2] = i2;
 133
 134    copy_verts(asmblr, indices, 3);
 135 }
 136
 137 static void
 138 prim_tri_adj(struct draw_assembler *asmblr,
 139              unsigned i0, unsigned i1, unsigned i2,
 140              unsigned i3, unsigned i4, unsigned i5)
 141 {
 142    unsigned indices[3];
 143
 144    indices[0] = i0;
 145    indices[1] = i2;
 146    indices[2] = i4;
 147
 148    copy_verts(asmblr, indices, 3);
 149 }
 150
 151
 152
 153 #define FUNC assembler_run_linear
 154 #define GET_ELT(idx) (start + (idx))
 155 #include "draw_prim_assembler_tmp.h"
 156
 157 #define FUNC assembler_run_elts
 158 #define LOCAL_VARS   const ushort *elts = input_prims->elts;
 159 #define GET_ELT(idx) (elts[start + (idx)])
 160 #include "draw_prim_assembler_tmp.h"
 161
 162
 163
 164 /*
 165  * Primitive assembler breaks up adjacency primitives and assembles
 166  * the base primitives they represent, e.g. vertices forming
 167  * PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY
 168  * become vertices forming PIPE_PRIM_TRIANGLES
 169  * This is needed because specification says that the adjacency
 170  * primitives are only visible in the geometry shader so we need
 171  * to get rid of them so that the rest of the pipeline can
 172  * process the inputs.
 173  */
 174 void
 175 draw_prim_assembler_run(struct draw_context *draw,
 176                         const struct draw_prim_info *input_prims,
 177                         const struct draw_vertex_info *input_verts,
 178                         struct draw_prim_info *output_prims,
 179                         struct draw_vertex_info *output_verts)
 180 {
 181    struct draw_assembler asmblr;
 182    unsigned start, i;
 183    unsigned assembled_prim = u_assembled_prim(input_prims->prim);
 184    unsigned max_primitives = u_decomposed_prims_for_vertices(
 185       input_prims->prim, input_prims->count);
 186    unsigned max_verts = u_vertices_per_prim(assembled_prim) * max_primitives;
 187
 188    asmblr.draw = draw;
 189    asmblr.output_prims = output_prims;
 190    asmblr.output_verts = output_verts;
 191    asmblr.input_prims = input_prims;
 192    asmblr.input_verts = input_verts;
 193
 194    output_prims->linear = TRUE;
 195    output_prims->elts = NULL;
 196    output_prims->start = 0;
 197    output_prims->prim = u_assembled_prim(input_prims->prim);
 198    output_prims->flags = 0x0;
 199    output_prims->primitive_lengths = MALLOC(sizeof(unsigned));
 200    output_prims->primitive_lengths[0] = 0;
 201    output_prims->primitive_count = 1;
 202
 203    output_verts->vertex_size = input_verts->vertex_size;
 204    output_verts->stride = input_verts->stride;
 205    output_verts->verts = (struct vertex_header*)MALLOC(
 206       input_verts->vertex_size * max_verts);
 207    output_verts->count = 0;
 208
 209
 210    for (start = i = 0; i < input_prims->primitive_count;
 211         start += input_prims->primitive_lengths[i], i++)
 212    {
 213       unsigned count = input_prims->primitive_lengths[i];
 214       if (input_prims->linear) {
 215          assembler_run_linear(&asmblr, input_prims, input_verts,
 216                               start, count);
 217       } else {
 218          assembler_run_elts(&asmblr, input_prims, input_verts,
 219                             start, count);
 220       }
 221    }
 222
 223    output_prims->primitive_lengths[0] = output_verts->count;
 224    output_prims->count = output_verts->count;
 225 }