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-rw-r--r--src/mesa/main/texpal.c204
1 files changed, 204 insertions, 0 deletions
diff --git a/src/mesa/main/texpal.c b/src/mesa/main/texpal.c
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+/**************************************************************************
+ *
+ * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * All Rights Reserved.
+ *
+ **************************************************************************/
+
+
+/**
+ * Code to convert compressed/paletted texture images to ordinary images.
+ * See the GL_OES_compressed_paletted_texture spec at
+ * http://khronos.org/registry/gles/extensions/OES/OES_compressed_paletted_texture.txt
+ *
+ * XXX this makes it impossible to add hardware support...
+ */
+
+
+#include "glheader.h"
+#include "compiler.h" /* for ASSERT */
+#include "context.h"
+#include "mtypes.h"
+#include "imports.h"
+#include "pixelstore.h"
+#include "teximage.h"
+#include "texpal.h"
+
+#if FEATURE_ES
+
+
+static const struct cpal_format_info {
+ GLenum cpal_format;
+ GLenum format;
+ GLenum type;
+ GLuint palette_size;
+ GLuint size;
+} formats[] = {
+ { GL_PALETTE4_RGB8_OES, GL_RGB, GL_UNSIGNED_BYTE, 16, 3 },
+ { GL_PALETTE4_RGBA8_OES, GL_RGBA, GL_UNSIGNED_BYTE, 16, 4 },
+ { GL_PALETTE4_R5_G6_B5_OES, GL_RGB, GL_UNSIGNED_SHORT_5_6_5, 16, 2 },
+ { GL_PALETTE4_RGBA4_OES, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, 16, 2 },
+ { GL_PALETTE4_RGB5_A1_OES, GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1, 16, 2 },
+ { GL_PALETTE8_RGB8_OES, GL_RGB, GL_UNSIGNED_BYTE, 256, 3 },
+ { GL_PALETTE8_RGBA8_OES, GL_RGBA, GL_UNSIGNED_BYTE, 256, 4 },
+ { GL_PALETTE8_R5_G6_B5_OES, GL_RGB, GL_UNSIGNED_SHORT_5_6_5, 256, 2 },
+ { GL_PALETTE8_RGBA4_OES, GL_RGBA, GL_UNSIGNED_SHORT_4_4_4_4, 256, 2 },
+ { GL_PALETTE8_RGB5_A1_OES, GL_RGBA, GL_UNSIGNED_SHORT_5_5_5_1, 256, 2 }
+};
+
+
+/**
+ * Get a color/entry from the palette.
+ */
+static GLuint
+get_palette_entry(const struct cpal_format_info *info, const GLubyte *palette,
+ GLuint index, GLubyte *pixel)
+{
+ memcpy(pixel, palette + info->size * index, info->size);
+ return info->size;
+}
+
+
+/**
+ * Convert paletted texture to color texture.
+ */
+static void
+paletted_to_color(const struct cpal_format_info *info, const GLubyte *palette,
+ const void *indices, GLuint num_pixels, GLubyte *image)
+{
+ GLubyte *pix = image;
+ GLuint remain, i;
+
+ if (info->palette_size == 16) {
+ /* 4 bits per index */
+ const GLubyte *ind = (const GLubyte *) indices;
+
+ /* two pixels per iteration */
+ remain = num_pixels % 2;
+ for (i = 0; i < num_pixels / 2; i++) {
+ pix += get_palette_entry(info, palette, (ind[i] >> 4) & 0xf, pix);
+ pix += get_palette_entry(info, palette, ind[i] & 0xf, pix);
+ }
+ if (remain) {
+ get_palette_entry(info, palette, (ind[i] >> 4) & 0xf, pix);
+ }
+ }
+ else {
+ /* 8 bits per index */
+ const GLubyte *ind = (const GLubyte *) indices;
+ for (i = 0; i < num_pixels; i++)
+ pix += get_palette_entry(info, palette, ind[i], pix);
+ }
+}
+
+
+static const struct cpal_format_info *
+cpal_get_info(GLint level, GLenum internalFormat,
+ GLsizei width, GLsizei height, GLsizei imageSize)
+{
+ const struct cpal_format_info *info;
+ GLint lvl, num_levels;
+ GLsizei w, h, expect_size;
+
+ info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
+ ASSERT(info->cpal_format == internalFormat);
+
+ if (level > 0) {
+ _mesa_error(_mesa_get_current_context(), GL_INVALID_VALUE,
+ "glCompressedTexImage2D(level=%d)", level);
+ return NULL;
+ }
+
+ num_levels = -level + 1;
+ expect_size = info->palette_size * info->size;
+ for (lvl = 0; lvl < num_levels; lvl++) {
+ w = width >> lvl;
+ if (!w)
+ w = 1;
+ h = height >> lvl;
+ if (!h)
+ h = 1;
+
+ if (info->palette_size == 16)
+ expect_size += (w * h + 1) / 2;
+ else
+ expect_size += w * h;
+ }
+ if (expect_size > imageSize) {
+ _mesa_error(_mesa_get_current_context(), GL_INVALID_VALUE,
+ "glCompressedTexImage2D(imageSize=%d)", imageSize);
+ return NULL;
+ }
+ return info;
+}
+
+/**
+ * Convert a call to glCompressedTexImage2D() where internalFormat is a
+ * compressed palette format into a regular GLubyte/RGBA glTexImage2D() call.
+ */
+void
+_mesa_cpal_compressed_teximage2d(GLenum target, GLint level,
+ GLenum internalFormat,
+ GLsizei width, GLsizei height,
+ GLsizei imageSize, const void *palette)
+{
+ const struct cpal_format_info *info;
+ GLint lvl, num_levels;
+ const GLubyte *indices;
+ GLint saved_align, align;
+ GET_CURRENT_CONTEXT(ctx);
+
+ info = cpal_get_info(level, internalFormat, width, height, imageSize);
+ if (!info)
+ return;
+
+ info = &formats[internalFormat - GL_PALETTE4_RGB8_OES];
+ ASSERT(info->cpal_format == internalFormat);
+ num_levels = -level + 1;
+
+ /* first image follows the palette */
+ indices = (const GLubyte *) palette + info->palette_size * info->size;
+
+ saved_align = ctx->Unpack.Alignment;
+ align = saved_align;
+
+ for (lvl = 0; lvl < num_levels; lvl++) {
+ GLsizei w, h;
+ GLuint num_texels;
+ GLubyte *image = NULL;
+
+ w = width >> lvl;
+ if (!w)
+ w = 1;
+ h = height >> lvl;
+ if (!h)
+ h = 1;
+ num_texels = w * h;
+ if (w * info->size % align) {
+ _mesa_PixelStorei(GL_UNPACK_ALIGNMENT, 1);
+ align = 1;
+ }
+
+ /* allocate and fill dest image buffer */
+ if (palette) {
+ image = (GLubyte *) malloc(num_texels * info->size);
+ paletted_to_color(info, palette, indices, num_texels, image);
+ }
+
+ _mesa_TexImage2D(target, lvl, info->format, w, h, 0,
+ info->format, info->type, image);
+ if (image)
+ free(image);
+
+ /* advance index pointer to point to next src mipmap */
+ if (info->palette_size == 16)
+ indices += (num_texels + 1) / 2;
+ else
+ indices += num_texels;
+ }
+
+ if (saved_align != align)
+ _mesa_PixelStorei(GL_UNPACK_ALIGNMENT, saved_align);
+}
+
+#endif