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 #if FEATURE_ES
44 
45 
46 static const struct cpal_format_info {
47    GLenum cpal_format;
48    GLenum format;
49    GLenum type;
50    GLuint palette_size;
51    GLuint size;
52 } formats[] = {
53    { GL_PALETTE4_RGB8_OES,     GL_RGB,  GL_UNSIGNED_BYTE,           16, 3 },
54    { GL_PALETTE4_RGBA8_OES,    GL_RGBA, GL_UNSIGNED_BYTE,           16, 4 },
55    { GL_PALETTE4_R5_G6_B5_OES, GL_RGB,  GL_UNSIGNED_SHORT_5_6_5,    16, 2 },
56    { GL_PALETTE4_RGBA4_OES,    GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4,  16, 2 },
57    { GL_PALETTE4_RGB5_A1_OES,  GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1,  16, 2 },
58    { GL_PALETTE8_RGB8_OES,     GL_RGB,  GL_UNSIGNED_BYTE,          256, 3 },
59    { GL_PALETTE8_RGBA8_OES,    GL_RGBA, GL_UNSIGNED_BYTE,          256, 4 },
60    { GL_PALETTE8_R5_G6_B5_OES, GL_RGB,  GL_UNSIGNED_SHORT_5_6_5,   256, 2 },
61    { GL_PALETTE8_RGBA4_OES,    GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, 256, 2 },
62    { GL_PALETTE8_RGB5_A1_OES,  GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1, 256, 2 }
63 };
64 
65 
66 /**
67  * Get a color/entry from the palette.
68  */
69 static GLuint
get_palette_entry(const struct cpal_format_info * info,const GLubyte * palette,GLuint index,GLubyte * pixel)70 get_palette_entry(const struct cpal_format_info *info, const GLubyte *palette,
71                   GLuint index, GLubyte *pixel)
72 {
73    memcpy(pixel, palette + info->size * index, info->size);
74    return info->size;
75 }
76 
77 
78 /**
79  * Convert paletted texture to color texture.
80  */
81 static void
paletted_to_color(const struct cpal_format_info * info,const GLubyte * palette,const void * indices,GLuint num_pixels,GLubyte * image)82 paletted_to_color(const struct cpal_format_info *info, const GLubyte *palette,
83                   const void *indices, GLuint num_pixels, GLubyte *image)
84 {
85    GLubyte *pix = image;
86    GLuint remain, i;
87 
88    if (info->palette_size == 16) {
89       /* 4 bits per index */
90       const GLubyte *ind = (const GLubyte *) indices;
91 
92       /* two pixels per iteration */
93       remain = num_pixels % 2;
94       for (i = 0; i < num_pixels / 2; i++) {
95          pix += get_palette_entry(info, palette, (ind[i] >> 4) & 0xf, pix);
96          pix += get_palette_entry(info, palette, ind[i] & 0xf, pix);
97       }
98       if (remain) {
99          get_palette_entry(info, palette, (ind[i] >> 4) & 0xf, pix);
100       }
101    }
102    else {
103       /* 8 bits per index */
104       const GLubyte *ind = (const GLubyte *) indices;
105       for (i = 0; i < num_pixels; i++)
106          pix += get_palette_entry(info, palette, ind[i], pix);
107    }
108 }
109 
110 unsigned
_mesa_cpal_compressed_size(int level,GLenum internalFormat,unsigned width,unsigned height)111 _mesa_cpal_compressed_size(int level, GLenum internalFormat,
112 			   unsigned width, unsigned height)
113 {
114    const struct cpal_format_info *info;
115    const int num_levels = -level + 1;
116    int lvl;
117    unsigned w, h, expect_size;
118 
119    if (internalFormat < GL_PALETTE4_RGB8_OES
120        || internalFormat > GL_PALETTE8_RGB5_A1_OES) {
121       return 0;
122    }
123 
124    info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
125    ASSERT(info->cpal_format == internalFormat);
126 
127    expect_size = info->palette_size * info->size;
128    for (lvl = 0; lvl < num_levels; lvl++) {
129       w = width >> lvl;
130       if (!w)
131          w = 1;
132       h = height >> lvl;
133       if (!h)
134          h = 1;
135 
136       if (info->palette_size == 16)
137          expect_size += (w * h  + 1) / 2;
138       else
139          expect_size += w * h;
140    }
141 
142    return expect_size;
143 }
144 
145 void
_mesa_cpal_compressed_format_type(GLenum internalFormat,GLenum * format,GLenum * type)146 _mesa_cpal_compressed_format_type(GLenum internalFormat, GLenum *format,
147 				  GLenum *type)
148 {
149    const struct cpal_format_info *info;
150 
151    if (internalFormat < GL_PALETTE4_RGB8_OES
152        || internalFormat > GL_PALETTE8_RGB5_A1_OES) {
153       return;
154    }
155 
156    info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
157    *format = info->format;
158    *type = info->type;
159 }
160 
161 /**
162  * Convert a call to glCompressedTexImage2D() where internalFormat is a
163  *  compressed palette format into a regular GLubyte/RGBA glTexImage2D() call.
164  */
165 void
_mesa_cpal_compressed_teximage2d(GLenum target,GLint level,GLenum internalFormat,GLsizei width,GLsizei height,GLsizei imageSize,const void * palette)166 _mesa_cpal_compressed_teximage2d(GLenum target, GLint level,
167 				 GLenum internalFormat,
168 				 GLsizei width, GLsizei height,
169 				 GLsizei imageSize, const void *palette)
170 {
171    const struct cpal_format_info *info;
172    GLint lvl, num_levels;
173    const GLubyte *indices;
174    GLint saved_align, align;
175    GET_CURRENT_CONTEXT(ctx);
176 
177    /* By this point, the internalFormat should have been validated.
178     */
179    assert(internalFormat >= GL_PALETTE4_RGB8_OES
180 	  && internalFormat <= GL_PALETTE8_RGB5_A1_OES);
181 
182    info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
183 
184    num_levels = -level + 1;
185 
186    /* first image follows the palette */
187    indices = (const GLubyte *) palette + info->palette_size * info->size;
188 
189    saved_align = ctx->Unpack.Alignment;
190    align = saved_align;
191 
192    for (lvl = 0; lvl < num_levels; lvl++) {
193       GLsizei w, h;
194       GLuint num_texels;
195       GLubyte *image = NULL;
196 
197       w = width >> lvl;
198       if (!w)
199          w = 1;
200       h = height >> lvl;
201       if (!h)
202          h = 1;
203       num_texels = w * h;
204       if (w * info->size % align) {
205          _mesa_PixelStorei(GL_UNPACK_ALIGNMENT, 1);
206          align = 1;
207       }
208 
209       /* allocate and fill dest image buffer */
210       if (palette) {
211          image = (GLubyte *) malloc(num_texels * info->size);
212          paletted_to_color(info, palette, indices, num_texels, image);
213       }
214 
215       _mesa_TexImage2D(target, lvl, info->format, w, h, 0,
216                        info->format, info->type, image);
217       if (image)
218          free(image);
219 
220       /* advance index pointer to point to next src mipmap */
221       if (info->palette_size == 16)
222          indices += (num_texels + 1) / 2;
223       else
224          indices += num_texels;
225    }
226 
227    if (saved_align != align)
228       _mesa_PixelStorei(GL_UNPACK_ALIGNMENT, saved_align);
229 }
230 
231 #endif
232