src/gallium/auxiliary/indices/u_unfilled_indices.c

   1 /*
   2  * Copyright 2009 VMware, Inc.
   3  * All Rights Reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * on the rights to use, copy, modify, merge, publish, distribute, sub
   9  * license, and/or sell copies of the Software, and to permit persons to whom
  10  * the Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
  19  * VMWARE AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
  20  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  21  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  22  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 #include "u_indices.h"
  26 #include "u_indices_priv.h"
  27
  28
  29 static void translate_ubyte_ushort( const void *in,
  30                                     unsigned start,
  31                                     unsigned nr,
  32                                     void *out )
  33 {
  34    const ubyte *in_ub = (const ubyte *)in;
  35    ushort *out_us = (ushort *)out;
  36    unsigned i;
  37    for (i = 0; i < nr; i++)
  38       out_us[i] = (ushort) in_ub[i+start];
  39 }
  40
  41 static void translate_memcpy_ushort( const void *in,
  42                                      unsigned start,
  43                                      unsigned nr,
  44                                      void *out )
  45 {
  46    memcpy(out, &((short *)in)[start], nr*sizeof(short));
  47 }
  48
  49 static void translate_memcpy_uint( const void *in,
  50                                    unsigned start,
  51                                    unsigned nr,
  52                                    void *out )
  53 {
  54    memcpy(out, &((int *)in)[start], nr*sizeof(int));
  55 }
  56
  57
  58 static void generate_linear_ushort( unsigned start,
  59                                     unsigned nr,
  60                                     void *out )
  61 {
  62    ushort *out_us = (ushort *)out;
  63    unsigned i;
  64    for (i = 0; i < nr; i++)
  65       out_us[i] = (ushort)(i + start);
  66 }
  67
  68 static void generate_linear_uint( unsigned start,
  69                                   unsigned nr,
  70                                   void *out )
  71 {
  72    unsigned *out_ui = (unsigned *)out;
  73    unsigned i;
  74    for (i = 0; i < nr; i++)
  75       out_ui[i] = i + start;
  76 }
  77
  78
  79 /**
  80  * Given a primitive type and number of vertices, return the number of vertices
  81  * needed to draw the primitive with fill mode = PIPE_POLYGON_MODE_LINE using
  82  * separate lines (PIPE_PRIM_LINES).
  83  */
  84 static unsigned nr_lines( unsigned prim,
  85                           unsigned nr )
  86 {
  87    switch (prim) {
  88    case PIPE_PRIM_TRIANGLES:
  89       return (nr / 3) * 6;
  90    case PIPE_PRIM_TRIANGLE_STRIP:
  91       return (nr - 2) * 6;
  92    case PIPE_PRIM_TRIANGLE_FAN:
  93       return (nr - 2)  * 6;
  94    case PIPE_PRIM_QUADS:
  95       return (nr / 4) * 8;
  96    case PIPE_PRIM_QUAD_STRIP:
  97       return (nr - 2) / 2 * 8;
  98    case PIPE_PRIM_POLYGON:
  99       return 2 * nr; /* a line (two verts) for each polygon edge */
 100    default:
 101       assert(0);
 102       return 0;
 103    }
 104 }
 105
 106
 107
 108 int u_unfilled_translator( unsigned prim,
 109                         unsigned in_index_size,
 110                         unsigned nr,
 111                         unsigned unfilled_mode,
 112                         unsigned *out_prim,
 113                         unsigned *out_index_size,
 114                         unsigned *out_nr,
 115                         u_translate_func *out_translate )
 116 {
 117    unsigned in_idx;
 118    unsigned out_idx;
 119
 120    u_unfilled_init();
 121
 122    in_idx = in_size_idx(in_index_size);
 123    *out_index_size = (in_index_size == 4) ? 4 : 2;
 124    out_idx = out_size_idx(*out_index_size);
 125
 126    if (unfilled_mode == PIPE_POLYGON_MODE_POINT)
 127    {
 128       *out_prim = PIPE_PRIM_POINTS;
 129       *out_nr = nr;
 130
 131       switch (in_index_size)
 132       {
 133       case 1:
 134          *out_translate = translate_ubyte_ushort;
 135          return U_TRANSLATE_NORMAL;
 136       case 2:
 137          *out_translate = translate_memcpy_uint;
 138          return U_TRANSLATE_MEMCPY;
 139       case 4:
 140          *out_translate = translate_memcpy_ushort;
 141          return U_TRANSLATE_MEMCPY;
 142       default:
 143          *out_translate = translate_memcpy_uint;
 144          *out_nr = 0;
 145          assert(0);
 146          return U_TRANSLATE_ERROR;
 147       }
 148    }
 149    else {
 150       assert(unfilled_mode == PIPE_POLYGON_MODE_LINE);
 151       *out_prim = PIPE_PRIM_LINES;
 152       *out_translate = translate_line[in_idx][out_idx][prim];
 153       *out_nr = nr_lines( prim, nr );
 154       return U_TRANSLATE_NORMAL;
 155    }
 156 }
 157
 158
 159 /**
 160  * Utility for converting unfilled polygons into points, lines, triangles.
 161  * Few drivers have direct support for OpenGL's glPolygonMode.
 162  * This function helps with converting triangles into points or lines
 163  * when the front and back fill modes are the same.  When there's
 164  * different front/back fill modes, that can be handled with the
 165  * 'draw' module.
 166  */
 167 int u_unfilled_generator( unsigned prim,
 168                           unsigned start,
 169                           unsigned nr,
 170                           unsigned unfilled_mode,
 171                           unsigned *out_prim,
 172                           unsigned *out_index_size,
 173                           unsigned *out_nr,
 174                           u_generate_func *out_generate )
 175 {
 176    unsigned out_idx;
 177
 178    u_unfilled_init();
 179
 180    *out_index_size = ((start + nr) > 0xfffe) ? 4 : 2;
 181    out_idx = out_size_idx(*out_index_size);
 182
 183    if (unfilled_mode == PIPE_POLYGON_MODE_POINT) {
 184
 185       if (*out_index_size == 4)
 186          *out_generate = generate_linear_uint;
 187       else
 188          *out_generate = generate_linear_ushort;
 189
 190       *out_prim = PIPE_PRIM_POINTS;
 191       *out_nr = nr;
 192       return U_GENERATE_LINEAR;
 193    }
 194    else {
 195       assert(unfilled_mode == PIPE_POLYGON_MODE_LINE);
 196       *out_prim = PIPE_PRIM_LINES;
 197       *out_generate = generate_line[out_idx][prim];
 198       *out_nr = nr_lines( prim, nr );
 199
 200       return U_GENERATE_REUSABLE;
 201    }
 202 }
 203