From 89fb06fcc11cbe3f23521312155d6c55d869f526 Mon Sep 17 00:00:00 2001
From: Brian Paul <brian.paul@tungstengraphics.com>
Date: Fri, 27 Sep 2002 02:45:37 +0000
Subject: new texture compression infrastructure

---
 src/mesa/main/texcompress.c | 159 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 159 insertions(+)
 create mode 100644 src/mesa/main/texcompress.c

(limited to 'src/mesa/main/texcompress.c')

diff --git a/src/mesa/main/texcompress.c b/src/mesa/main/texcompress.c
new file mode 100644
index 0000000000..0ba9aa9a4c
--- /dev/null
+++ b/src/mesa/main/texcompress.c
@@ -0,0 +1,159 @@
+/* $Id: texcompress.c,v 1.1 2002/09/27 02:45:38 brianp Exp $ */
+
+/*
+ * Mesa 3-D graphics library
+ * Version:  4.1
+ *
+ * Copyright (C) 1999-2002  Brian Paul   All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+#include "glheader.h"
+#include "context.h"
+#include "image.h"
+#include "mem.h"
+#include "texcompress.h"
+#include "texformat.h"
+
+
+/**
+ * Get the list of supported internal compression formats.
+ * \param formats - the results list (may be NULL)
+ * \return number of formats.
+ */
+GLuint
+_mesa_get_compressed_formats( GLcontext *ctx, GLint *formats )
+{
+   GLuint n = 0;
+   if (ctx->Extensions.ARB_texture_compression) {
+      if (ctx->Extensions.TDFX_texture_compression_FXT1) {
+         if (formats) {
+            formats[n++] = GL_COMPRESSED_RGB_FXT1_3DFX;
+            formats[n++] = GL_COMPRESSED_RGBA_FXT1_3DFX;
+         }
+         else {
+            n += 4;
+         }
+      }
+   }
+   return n;
+}
+
+
+
+/**
+ * Return bytes of storage needed for the given texture size and compressed
+ * format.
+ * \param width, height, depth - texture size in texels
+ * \param texFormat - one of the compressed format enums
+ * \return size in bytes, or zero if bad texFormat
+ */
+GLuint
+_mesa_compressed_texture_size( GLcontext *ctx,
+                               GLsizei width, GLsizei height, GLsizei depth,
+                               GLenum format )
+{
+   GLuint size;
+
+   switch (format) {
+   case GL_COMPRESSED_RGB_FXT1_3DFX:
+   case GL_COMPRESSED_RGBA_FXT1_3DFX:
+      /* round up to multiple of 4 */
+      size = ((width + 7) / 8) * ((height + 3) / 4) * 16;
+      return size;
+   default:
+      _mesa_problem(ctx, "bad texformat in compressed_texture_size");
+      return 0;
+   }
+}
+
+
+/*
+ * Compute the bytes per row in a compressed texture image.
+ */
+GLint
+_mesa_compressed_row_stride(GLenum format, GLsizei width)
+{
+   GLint bytesPerTile, stride;
+
+   switch (format) {
+   default:
+      return 0;
+   }
+
+   stride = ((width + 3) / 4) * bytesPerTile;
+   return stride;
+}
+
+
+/*
+ * Return the address of the pixel at (col, row, img) in a
+ * compressed texture image.
+ * \param col, row, img - image position (3D)
+ * \param format - compressed image format
+ * \param width - image width
+ * \param image - the image address
+ * \return address of pixel at (row, col)
+ */
+GLubyte *
+_mesa_compressed_image_address(GLint col, GLint row, GLint img,
+                               GLenum format,
+                               GLsizei width, const GLubyte *image)
+{
+   GLint bytesPerTile, stride;
+   GLubyte *addr;
+
+   ASSERT((row & 3) == 0);
+   ASSERT((col & 3) == 0);
+   (void) img;
+
+   switch (format) {
+   default:
+      return 0;
+   }
+
+   stride = ((width + 3) / 4) * bytesPerTile;
+
+   addr = (GLubyte *) image + (row / 4) * stride + (col / 4) * bytesPerTile;
+   return addr;
+}
+
+
+
+/*
+ * \param srcRowStride - source stride, in pixels
+ */
+void
+_mesa_compress_teximage( GLcontext *ctx, GLsizei width, GLsizei height,
+                   GLenum srcFormat, const GLchan *source, GLint srcRowStride,
+                   GLenum dstFormat, GLubyte *dest, GLint dstRowStride )
+{
+   GLuint len = 0;
+
+   switch (dstFormat) {
+   default:
+      _mesa_problem(ctx, "Bad dstFormat in _mesa_compress_teximage()");
+      return;
+   }
+
+   /* sanity check */
+   ASSERT(len == _mesa_compressed_texture_size(ctx, width, height,
+                                               1, dstFormat));
+}
-- 
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