reactos/dll/opengl/mesa/src/mesa/main/texpal.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
   5  *
   6  **************************************************************************/
   7
   8
   9 /**
  10  * Code to convert compressed/paletted texture images to ordinary images.
  11  * See the GL_OES_compressed_paletted_texture spec at
  12  * http://khronos.org/registry/gles/extensions/OES/OES_compressed_paletted_texture.txt
  13  *
  14  * XXX this makes it impossible to add hardware support...
  15  */
  16
  17
  18 #include "glheader.h"
  19 #include "compiler.h" /* for ASSERT */
  20 #include "context.h"
  21 #include "mfeatures.h"
  22 #include "mtypes.h"
  23 #include "imports.h"
  24 #include "pixelstore.h"
  25 #include "teximage.h"
  26 #include "texpal.h"
  27
  28 #if FEATURE_ES
  29
  30
  31 static const struct cpal_format_info {
  32    GLenum cpal_format;
  33    GLenum format;
  34    GLenum type;
  35    GLuint palette_size;
  36    GLuint size;
  37 } formats[] = {
  38    { GL_PALETTE4_RGB8_OES,     GL_RGB,  GL_UNSIGNED_BYTE,           16, 3 },
  39    { GL_PALETTE4_RGBA8_OES,    GL_RGBA, GL_UNSIGNED_BYTE,           16, 4 },
  40    { GL_PALETTE4_R5_G6_B5_OES, GL_RGB,  GL_UNSIGNED_SHORT_5_6_5,    16, 2 },
  41    { GL_PALETTE4_RGBA4_OES,    GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4,  16, 2 },
  42    { GL_PALETTE4_RGB5_A1_OES,  GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1,  16, 2 },
  43    { GL_PALETTE8_RGB8_OES,     GL_RGB,  GL_UNSIGNED_BYTE,          256, 3 },
  44    { GL_PALETTE8_RGBA8_OES,    GL_RGBA, GL_UNSIGNED_BYTE,          256, 4 },
  45    { GL_PALETTE8_R5_G6_B5_OES, GL_RGB,  GL_UNSIGNED_SHORT_5_6_5,   256, 2 },
  46    { GL_PALETTE8_RGBA4_OES,    GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, 256, 2 },
  47    { GL_PALETTE8_RGB5_A1_OES,  GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1, 256, 2 }
  48 };
  49
  50
  51 /**
  52  * Get a color/entry from the palette.
  53  */
  54 static GLuint
  55 get_palette_entry(const struct cpal_format_info *info, const GLubyte *palette,
  56                   GLuint index, GLubyte *pixel)
  57 {
  58    memcpy(pixel, palette + info->size * index, info->size);
  59    return info->size;
  60 }
  61
  62
  63 /**
  64  * Convert paletted texture to color texture.
  65  */
  66 static void
  67 paletted_to_color(const struct cpal_format_info *info, const GLubyte *palette,
  68                   const void *indices, GLuint num_pixels, GLubyte *image)
  69 {
  70    GLubyte *pix = image;
  71    GLuint remain, i;
  72
  73    if (info->palette_size == 16) {
  74       /* 4 bits per index */
  75       const GLubyte *ind = (const GLubyte *) indices;
  76
  77       /* two pixels per iteration */
  78       remain = num_pixels % 2;
  79       for (i = 0; i < num_pixels / 2; i++) {
  80          pix += get_palette_entry(info, palette, (ind[i] >> 4) & 0xf, pix);
  81          pix += get_palette_entry(info, palette, ind[i] & 0xf, pix);
  82       }
  83       if (remain) {
  84          get_palette_entry(info, palette, (ind[i] >> 4) & 0xf, pix);
  85       }
  86    }
  87    else {
  88       /* 8 bits per index */
  89       const GLubyte *ind = (const GLubyte *) indices;
  90       for (i = 0; i < num_pixels; i++)
  91          pix += get_palette_entry(info, palette, ind[i], pix);
  92    }
  93 }
  94
  95 unsigned
  96 _mesa_cpal_compressed_size(int level, GLenum internalFormat,
  97                            unsigned width, unsigned height)
  98 {
  99    const struct cpal_format_info *info;
 100    const int num_levels = -level + 1;
 101    int lvl;
 102    unsigned w, h, expect_size;
 103
 104    if (internalFormat < GL_PALETTE4_RGB8_OES
 105        || internalFormat > GL_PALETTE8_RGB5_A1_OES) {
 106       return 0;
 107    }
 108
 109    info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
 110    ASSERT(info->cpal_format == internalFormat);
 111
 112    expect_size = info->palette_size * info->size;
 113    for (lvl = 0; lvl < num_levels; lvl++) {
 114       w = width >> lvl;
 115       if (!w)
 116          w = 1;
 117       h = height >> lvl;
 118       if (!h)
 119          h = 1;
 120
 121       if (info->palette_size == 16)
 122          expect_size += (w * h  + 1) / 2;
 123       else
 124          expect_size += w * h;
 125    }
 126
 127    return expect_size;
 128 }
 129
 130 void
 131 _mesa_cpal_compressed_format_type(GLenum internalFormat, GLenum *format,
 132                                   GLenum *type)
 133 {
 134    const struct cpal_format_info *info;
 135
 136    if (internalFormat < GL_PALETTE4_RGB8_OES
 137        || internalFormat > GL_PALETTE8_RGB5_A1_OES) {
 138       return;
 139    }
 140
 141    info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
 142    *format = info->format;
 143    *type = info->type;
 144 }
 145
 146 /**
 147  * Convert a call to glCompressedTexImage2D() where internalFormat is a
 148  *  compressed palette format into a regular GLubyte/RGBA glTexImage2D() call.
 149  */
 150 void
 151 _mesa_cpal_compressed_teximage2d(GLenum target, GLint level,
 152                                  GLenum internalFormat,
 153                                  GLsizei width, GLsizei height,
 154                                  GLsizei imageSize, const void *palette)
 155 {
 156    const struct cpal_format_info *info;
 157    GLint lvl, num_levels;
 158    const GLubyte *indices;
 159    GLint saved_align, align;
 160    GET_CURRENT_CONTEXT(ctx);
 161
 162    /* By this point, the internalFormat should have been validated.
 163     */
 164    assert(internalFormat >= GL_PALETTE4_RGB8_OES
 165           && internalFormat <= GL_PALETTE8_RGB5_A1_OES);
 166
 167    info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
 168
 169    num_levels = -level + 1;
 170
 171    /* first image follows the palette */
 172    indices = (const GLubyte *) palette + info->palette_size * info->size;
 173
 174    saved_align = ctx->Unpack.Alignment;
 175    align = saved_align;
 176
 177    for (lvl = 0; lvl < num_levels; lvl++) {
 178       GLsizei w, h;
 179       GLuint num_texels;
 180       GLubyte *image = NULL;
 181
 182       w = width >> lvl;
 183       if (!w)
 184          w = 1;
 185       h = height >> lvl;
 186       if (!h)
 187          h = 1;
 188       num_texels = w * h;
 189       if (w * info->size % align) {
 190          _mesa_PixelStorei(GL_UNPACK_ALIGNMENT, 1);
 191          align = 1;
 192       }
 193
 194       /* allocate and fill dest image buffer */
 195       if (palette) {
 196          image = (GLubyte *) malloc(num_texels * info->size);
 197          paletted_to_color(info, palette, indices, num_texels, image);
 198       }
 199
 200       _mesa_TexImage2D(target, lvl, info->format, w, h, 0,
 201                        info->format, info->type, image);
 202       if (image)
 203          free(image);
 204
 205       /* advance index pointer to point to next src mipmap */
 206       if (info->palette_size == 16)
 207          indices += (num_texels + 1) / 2;
 208       else
 209          indices += num_texels;
 210    }
 211
 212    if (saved_align != align)
 213       _mesa_PixelStorei(GL_UNPACK_ALIGNMENT, saved_align);
 214 }
 215
 216 #endif