src/mesa/main/texcompress_cpal.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  20  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 /**
  25  * Code to convert compressed/paletted texture images to ordinary images.
  26  * See the GL_OES_compressed_paletted_texture spec at
  27  * http://khronos.org/registry/gles/extensions/OES/OES_compressed_paletted_texture.txt
  28  *
  29  * XXX this makes it impossible to add hardware support...
  30  */
  31
  32
  33 #include "glheader.h"
  34 #include "compiler.h" /* for ASSERT */
  35 #include "context.h"
  36 #include "mfeatures.h"
  37 #include "mtypes.h"
  38 #include "imports.h"
  39 #include "pixelstore.h"
  40 #include "texcompress_cpal.h"
  41 #include "teximage.h"
  42
  43
  44 static const struct cpal_format_info {
  45    GLenum cpal_format;
  46    GLenum format;
  47    GLenum type;
  48    GLuint palette_size;
  49    GLuint size;
  50 } formats[] = {
  51    { GL_PALETTE4_RGB8_OES,     GL_RGB,  GL_UNSIGNED_BYTE,           16, 3 },
  52    { GL_PALETTE4_RGBA8_OES,    GL_RGBA, GL_UNSIGNED_BYTE,           16, 4 },
  53    { GL_PALETTE4_R5_G6_B5_OES, GL_RGB,  GL_UNSIGNED_SHORT_5_6_5,    16, 2 },
  54    { GL_PALETTE4_RGBA4_OES,    GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4,  16, 2 },
  55    { GL_PALETTE4_RGB5_A1_OES,  GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1,  16, 2 },
  56    { GL_PALETTE8_RGB8_OES,     GL_RGB,  GL_UNSIGNED_BYTE,          256, 3 },
  57    { GL_PALETTE8_RGBA8_OES,    GL_RGBA, GL_UNSIGNED_BYTE,          256, 4 },
  58    { GL_PALETTE8_R5_G6_B5_OES, GL_RGB,  GL_UNSIGNED_SHORT_5_6_5,   256, 2 },
  59    { GL_PALETTE8_RGBA4_OES,    GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, 256, 2 },
  60    { GL_PALETTE8_RGB5_A1_OES,  GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1, 256, 2 }
  61 };
  62
  63
  64 /**
  65  * Get a color/entry from the palette.
  66  */
  67 static GLuint
  68 get_palette_entry(const struct cpal_format_info *info, const GLubyte *palette,
  69                   GLuint index, GLubyte *pixel)
  70 {
  71    memcpy(pixel, palette + info->size * index, info->size);
  72    return info->size;
  73 }
  74
  75
  76 /**
  77  * Convert paletted texture to color texture.
  78  */
  79 static void
  80 paletted_to_color(const struct cpal_format_info *info, const GLubyte *palette,
  81                   const void *indices, GLuint num_pixels, GLubyte *image)
  82 {
  83    GLubyte *pix = image;
  84    GLuint remain, i;
  85
  86    if (info->palette_size == 16) {
  87       /* 4 bits per index */
  88       const GLubyte *ind = (const GLubyte *) indices;
  89
  90       /* two pixels per iteration */
  91       remain = num_pixels % 2;
  92       for (i = 0; i < num_pixels / 2; i++) {
  93          pix += get_palette_entry(info, palette, (ind[i] >> 4) & 0xf, pix);
  94          pix += get_palette_entry(info, palette, ind[i] & 0xf, pix);
  95       }
  96       if (remain) {
  97          get_palette_entry(info, palette, (ind[i] >> 4) & 0xf, pix);
  98       }
  99    }
 100    else {
 101       /* 8 bits per index */
 102       const GLubyte *ind = (const GLubyte *) indices;
 103       for (i = 0; i < num_pixels; i++)
 104          pix += get_palette_entry(info, palette, ind[i], pix);
 105    }
 106 }
 107
 108 unsigned
 109 _mesa_cpal_compressed_size(int level, GLenum internalFormat,
 110                            unsigned width, unsigned height)
 111 {
 112    const struct cpal_format_info *info;
 113    const int num_levels = -level + 1;
 114    int lvl;
 115    unsigned w, h, expect_size;
 116
 117    if (internalFormat < GL_PALETTE4_RGB8_OES
 118        || internalFormat > GL_PALETTE8_RGB5_A1_OES) {
 119       return 0;
 120    }
 121
 122    info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
 123    ASSERT(info->cpal_format == internalFormat);
 124
 125    expect_size = info->palette_size * info->size;
 126    for (lvl = 0; lvl < num_levels; lvl++) {
 127       w = width >> lvl;
 128       if (!w)
 129          w = 1;
 130       h = height >> lvl;
 131       if (!h)
 132          h = 1;
 133
 134       if (info->palette_size == 16)
 135          expect_size += (w * h  + 1) / 2;
 136       else
 137          expect_size += w * h;
 138    }
 139
 140    return expect_size;
 141 }
 142
 143 void
 144 _mesa_cpal_compressed_format_type(GLenum internalFormat, GLenum *format,
 145                                   GLenum *type)
 146 {
 147    const struct cpal_format_info *info;
 148
 149    if (internalFormat < GL_PALETTE4_RGB8_OES
 150        || internalFormat > GL_PALETTE8_RGB5_A1_OES) {
 151       return;
 152    }
 153
 154    info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
 155    *format = info->format;
 156    *type = info->type;
 157 }
 158
 159 /**
 160  * Convert a call to glCompressedTexImage2D() where internalFormat is a
 161  *  compressed palette format into a regular GLubyte/RGBA glTexImage2D() call.
 162  */
 163 void
 164 _mesa_cpal_compressed_teximage2d(GLenum target, GLint level,
 165                                  GLenum internalFormat,
 166                                  GLsizei width, GLsizei height,
 167                                  GLsizei imageSize, const void *palette)
 168 {
 169    const struct cpal_format_info *info;
 170    GLint lvl, num_levels;
 171    const GLubyte *indices;
 172    GLint saved_align, align;
 173    GET_CURRENT_CONTEXT(ctx);
 174
 175    /* By this point, the internalFormat should have been validated.
 176     */
 177    assert(internalFormat >= GL_PALETTE4_RGB8_OES
 178           && internalFormat <= GL_PALETTE8_RGB5_A1_OES);
 179
 180    info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
 181
 182    num_levels = -level + 1;
 183
 184    /* first image follows the palette */
 185    indices = (const GLubyte *) palette + info->palette_size * info->size;
 186
 187    saved_align = ctx->Unpack.Alignment;
 188    align = saved_align;
 189
 190    for (lvl = 0; lvl < num_levels; lvl++) {
 191       GLsizei w, h;
 192       GLuint num_texels;
 193       GLubyte *image = NULL;
 194
 195       w = width >> lvl;
 196       if (!w)
 197          w = 1;
 198       h = height >> lvl;
 199       if (!h)
 200          h = 1;
 201       num_texels = w * h;
 202       if (w * info->size % align) {
 203          _mesa_PixelStorei(GL_UNPACK_ALIGNMENT, 1);
 204          align = 1;
 205       }
 206
 207       /* allocate and fill dest image buffer */
 208       if (palette) {
 209          image = malloc(num_texels * info->size);
 210          paletted_to_color(info, palette, indices, num_texels, image);
 211       }
 212
 213       _mesa_TexImage2D(target, lvl, info->format, w, h, 0,
 214                        info->format, info->type, image);
 215       free(image);
 216
 217       /* advance index pointer to point to next src mipmap */
 218       if (info->palette_size == 16)
 219          indices += (num_texels + 1) / 2;
 220       else
 221          indices += num_texels;
 222    }
 223
 224    if (saved_align != align)
 225       _mesa_PixelStorei(GL_UNPACK_ALIGNMENT, saved_align);
 226 }