1/*
2 * Mesa 3-D graphics library
3 *
4 * Copyright 2008 VMware, Inc.
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 OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25/**
26 * Code to convert compressed/paletted texture images to ordinary images.
27 * See the GL_OES_compressed_paletted_texture spec at
28 * http://khronos.org/registry/gles/extensions/OES/OES_compressed_paletted_texture.txt
29 *
30 * XXX this makes it impossible to add hardware support...
31 */
32
33
34#include "glheader.h"
35#include "context.h"
36#include "mtypes.h"
37
38#include "pixelstore.h"
39#include "texcompress_cpal.h"
40#include "teximage.h"
41#include "api_exec_decl.h"
42
43
44static 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 */
67static GLuint
68get_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 */
79static void
80paletted_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
108unsigned
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
144/**
145 * Convert a call to glCompressedTexImage2D() where internalFormat is a
146 *  compressed palette format into a regular GLubyte/RGBA glTexImage2D() call.
147 */
148void
149_mesa_cpal_compressed_teximage2d(GLenum target, GLint level,
150				 GLenum internalFormat,
151				 GLsizei width, GLsizei height,
152				 GLsizei imageSize, const void *palette)
153{
154   const struct cpal_format_info *info;
155   GLint lvl, num_levels;
156   const GLubyte *indices;
157   GLint saved_align, align;
158   GET_CURRENT_CONTEXT(ctx);
159
160   /* By this point, the internalFormat should have been validated.
161    */
162   assert(internalFormat >= GL_PALETTE4_RGB8_OES
163	  && internalFormat <= GL_PALETTE8_RGB5_A1_OES);
164
165   info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
166
167   num_levels = -level + 1;
168
169   /* first image follows the palette */
170   indices = (const GLubyte *) palette + info->palette_size * info->size;
171
172   saved_align = ctx->Unpack.Alignment;
173   align = saved_align;
174
175   for (lvl = 0; lvl < num_levels; lvl++) {
176      GLsizei w, h;
177      GLuint num_texels;
178      GLubyte *image = NULL;
179
180      w = width >> lvl;
181      if (!w)
182         w = 1;
183      h = height >> lvl;
184      if (!h)
185         h = 1;
186      num_texels = w * h;
187      if (w * info->size % align) {
188         _mesa_PixelStorei(GL_UNPACK_ALIGNMENT, 1);
189         align = 1;
190      }
191
192      /* allocate and fill dest image buffer */
193      if (palette) {
194         image = malloc(num_texels * info->size);
195         paletted_to_color(info, palette, indices, num_texels, image);
196      }
197
198      _mesa_TexImage2D(target, lvl, info->format, w, h, 0,
199                       info->format, info->type, image);
200      free(image);
201
202      /* advance index pointer to point to next src mipmap */
203      if (info->palette_size == 16)
204         indices += (num_texels + 1) / 2;
205      else
206         indices += num_texels;
207   }
208
209   if (saved_align != align)
210      _mesa_PixelStorei(GL_UNPACK_ALIGNMENT, saved_align);
211}
212