X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Fmesa%2Fmain%2Ftexcompress.c;h=4c6eaae4cf324272f5ab63e05788d500b6636480;hb=263581bba4d61291c54313648063a30c47106f0b;hp=81938854c277abe36f27a6333847c6c06ca7ec44;hpb=ee2b34215fc91b1c8b36b0b998df4ec9d9526fb8;p=mesa.git

diff --git a/src/mesa/main/texcompress.c b/src/mesa/main/texcompress.c
index 81938854c27..4c6eaae4cf3 100644
--- a/src/mesa/main/texcompress.c
+++ b/src/mesa/main/texcompress.c
@@ -1,4 +1,7 @@
-/* $Id: texcompress.c,v 1.4 2003/03/24 20:00:09 brianp Exp $ */
+/**
+ * \file texcompress.c
+ * Compressed textures functions.
+ */
 
 /*
  * Mesa 3-D graphics library
@@ -35,7 +38,10 @@
 
 /**
  * Get the list of supported internal compression formats.
- * \param formats - the results list (may be NULL)
+ * 
+ * \param ctx GL context.
+ * \param formats the resulting format list (may be NULL).
+ *
  * \return number of formats.
  */
 GLuint
@@ -52,18 +58,47 @@ _mesa_get_compressed_formats( GLcontext *ctx, GLint *formats )
             n += 2;
          }
       }
+      if (ctx->Extensions.EXT_texture_compression_s3tc) {
+         if (formats) {
+            formats[n++] = GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
+            /* Skip this one because it has a restriction (all transparent
+             * pixels become black).  See the texture compressions spec for
+             * a detailed explanation.  This is what NVIDIA does.
+            formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
+            */
+            formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT3_EXT;
+            formats[n++] = GL_COMPRESSED_RGBA_S3TC_DXT5_EXT;
+         }
+         else {
+            n += 3;
+         }
+      }
+      if (ctx->Extensions.S3_s3tc) {
+         if (formats) {
+            formats[n++] = GL_RGB_S3TC;
+            formats[n++] = GL_RGB4_S3TC;
+            formats[n++] = GL_RGBA_S3TC;
+            formats[n++] = GL_RGBA4_S3TC;
+         }
+         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
+ * Return bytes of storage needed for the given texture size and
+ * compressed format.
+ * 
+ * \param width texture width in texels.
+ * \param height texture height in texels.
+ * \param depth texture depth in texels.
+ * \param texFormat one of the compressed format enums
+ * 
+ * \return size in bytes, or zero if bad \p texFormat.
  */
 GLuint
 _mesa_compressed_texture_size( GLcontext *ctx,
@@ -72,11 +107,55 @@ _mesa_compressed_texture_size( GLcontext *ctx,
 {
    GLuint size;
 
+   if (ctx->Driver.CompressedTextureSize) {
+      return ctx->Driver.CompressedTextureSize(ctx, width, height, depth, format);
+   }
+
+   ASSERT(depth == 1);
+
    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;
+      /* round up width to next multiple of 8, height to next multiple of 4 */
+      width = (width + 7) & ~7;
+      height = (height + 3) & ~3;
+      /* 16 bytes per 8x4 tile of RGB[A] texels */
+      size = width * height / 2;
+      /* Textures smaller than 8x4 will effectively be made into 8x4 and
+       * take 16 bytes.
+       */
+      if (size < 16)
+         size = 16;
+      return size;
+   case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
+   case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
+   case GL_RGB_S3TC:
+   case GL_RGB4_S3TC:
+      /* round up width, height to next multiple of 4 */
+      width = (width + 3) & ~3;
+      height = (height + 3) & ~3;
+      /* 8 bytes per 4x4 tile of RGB[A] texels */
+      size = width * height / 2;
+      /* Textures smaller than 4x4 will effectively be made into 4x4 and
+       * take 8 bytes.
+       */
+      if (size < 8)
+         size = 8;
+      return size;
+   case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
+   case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
+   case GL_RGBA_S3TC:
+   case GL_RGBA4_S3TC:
+      /* round up width, height to next multiple of 4 */
+      width = (width + 3) & ~3;
+      height = (height + 3) & ~3;
+      /* 16 bytes per 4x4 tile of RGBA texels */
+      size = width * height; /* simple! */
+      /* Textures smaller than 4x4 will effectively be made into 4x4 and
+       * take 16 bytes.
+       */
+      if (size < 16)
+         size = 16;
       return size;
    default:
       _mesa_problem(ctx, "bad texformat in compressed_texture_size");
@@ -85,60 +164,100 @@ _mesa_compressed_texture_size( GLcontext *ctx,
 }
 
 
-/*
+/**
  * Compute the bytes per row in a compressed texture image.
+ * We use this for computing the destination address for sub-texture updates.
+ * \param format  one of the specific texture compression formats
+ * \param width  image width in pixels
+ * \return stride, in bytes, between rows for compressed image
  */
 GLint
 _mesa_compressed_row_stride(GLenum format, GLsizei width)
 {
-   GLint bytesPerTile, stride;
+   GLint stride;
 
    switch (format) {
+   case GL_COMPRESSED_RGB_FXT1_3DFX:
+   case GL_COMPRESSED_RGBA_FXT1_3DFX:
+      stride = ((width + 7) / 8) * 16; /* 16 bytes per 8x4 tile */
+      break;
+   case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
+   case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
+   case GL_RGB_S3TC:
+   case GL_RGB4_S3TC:
+      stride = ((width + 3) / 4) * 8; /* 8 bytes per 4x4 tile */
+      break;
+   case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
+   case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
+   case GL_RGBA_S3TC:
+   case GL_RGBA4_S3TC:
+      stride = ((width + 3) / 4) * 16; /* 16 bytes per 4x4 tile */
+      break;
    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)
+ * 
+ * \param col image position.
+ * \param row image position.
+ * \param img image position.
+ * \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;
 
+   /* We try to spot a "complete" subtexture "above" ROW, COL;
+    * this texture is given by appropriate rounding of WIDTH x ROW.
+    * Then we just add the amount left (usually on the left).
+    *
+    * Example for X*Y microtiles (Z bytes each)
+    * offset = Z * (((width + X - 1) / X) * (row / Y) + col / X);
+    */
+
    switch (format) {
+   case GL_COMPRESSED_RGB_FXT1_3DFX:
+   case GL_COMPRESSED_RGBA_FXT1_3DFX:
+      addr = (GLubyte *) image + 16 * (((width + 7) / 8) * (row / 4) + col / 8);
+      break;
+   case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
+   case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
+   case GL_RGB_S3TC:
+   case GL_RGB4_S3TC:
+      addr = (GLubyte *) image + 8 * (((width + 3) / 4) * (row / 4) + col / 4);
+      break;
+   case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
+   case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
+   case GL_RGBA_S3TC:
+   case GL_RGBA4_S3TC:
+      addr = (GLubyte *) image + 16 * (((width + 3) / 4) * (row / 4) + col / 4);
+      break;
    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
+/**
+ * \param srcRowStride source stride, in pixels
  */
 void
 _mesa_compress_teximage( GLcontext *ctx, GLsizei width, GLsizei height,