Implements a special case for temporary surface creation for DXT low mip levels.

TRAC #12908 The lowest mip levels for DXT textures will have dimensions < 4, so a D3D texture cannot be created to hold them offscreen directly. Instead, we must create a larger texture one of whose mip levels would be the desired dimension, and store the surface from that texture for later inclusion in the final texture. Signed-off-by: Daniel Koch Author: Shannon Woods git-svn-id: https://angleproject.googlecode.com/svn/trunk@398 736b8ea6-26fd-11df-bfd4-992fa37f6226

Implements a special case for temporary surface creation for DXT low mip levels.
1dcea9f8 · daniel@transgaming.com · 01868135 · 1dcea9f8
Commit 1dcea9f8 authored Aug 24, 2010 by daniel@transgaming.com
Hide whitespace changes
Inline Side-by-side

Showing with 23 additions and 2 deletions

Texture.cpp src/libGLESv2/Texture.cpp +23 -2

No files found.
--- a/src/libGLESv2/Texture.cpp
+++ b/src/libGLESv2/Texture.cpp
@@ -320,7 +320,28 @@ void Texture::createSurface(GLsizei width, GLsizei height, GLenum format, Image 

    if (width != 0 && height != 0)
    {
-        HRESULT result = getDevice()->CreateTexture(width, height, 1, NULL, selectFormat(format), D3DPOOL_SYSTEMMEM, &newTexture, NULL);
+        int levelToFetch = 0;
+        GLsizei requestWidth = width;
+        GLsizei requestHeight = height;
+        if (IsCompressed(format) && (width % 4 != 0 || height % 4 != 0))
+        {
+            bool isMult4 = false;
+            int upsampleCount = 0;
+            while (!isMult4)
+            {
+                requestWidth <<= 1;
+                requestHeight <<= 1;
+                upsampleCount++;
+                if (requestWidth % 4 == 0 && requestHeight % 4 == 0)
+                {
+                    isMult4 = true;
+                }
+            }
+            levelToFetch = upsampleCount;
+        }
+
+        HRESULT result = getDevice()->CreateTexture(requestWidth, requestHeight, levelToFetch + 1, NULL, selectFormat(format),
+                                                    D3DPOOL_SYSTEMMEM, &newTexture, NULL);

        if (FAILED(result))
        {
@@ -328,7 +349,7 @@ void Texture::createSurface(GLsizei width, GLsizei height, GLenum format, Image 
            return error(GL_OUT_OF_MEMORY);
        }

-        newTexture->GetSurfaceLevel(0, &newSurface);
+        newTexture->GetSurfaceLevel(levelToFetch, &newSurface);
        newTexture->Release();
    }