mesa: Move support for paletted textures to main/teximage.c

1 files changed, 204 insertions, 0 deletions

diff --git a/src/mesa/main/texpal.c b/src/mesa/main/texpal.c
new file mode 100644
index 0000000000..a25e7aa4ff
--- /dev/null
+++ b/src/mesa/main/texpal.c
@@ -0,0 +1,204 @@
+/**************************************************************************
+ *
+ * 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