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-rwxr-xr-xsrc/classes/com/sun/opengl/util/texture/Texture.java22
1 files changed, 22 insertions, 0 deletions
diff --git a/src/classes/com/sun/opengl/util/texture/Texture.java b/src/classes/com/sun/opengl/util/texture/Texture.java
index d634f66fb..f4a0a8be2 100755
--- a/src/classes/com/sun/opengl/util/texture/Texture.java
+++ b/src/classes/com/sun/opengl/util/texture/Texture.java
@@ -112,6 +112,28 @@ import com.sun.opengl.util.texture.spi.*;
gl.glColor4f(r, g, b, a);
</pre>
*
+ * For reference, here is a list of the Porter-Duff compositing rules
+ * and the associated OpenGL blend functions (source and destination
+ * factors) to use in the face of premultiplied alpha:
+ *
+<CENTER>
+<TABLE WIDTH="75%">
+<TR> <TD> Rule <TD> Source <TD> Dest
+<TR> <TD> Clear <TD> GL_ZERO <TD> GL_ZERO
+<TR> <TD> Src <TD> GL_ONE <TD> GL_ZERO
+<TR> <TD> SrcOver <TD> GL_ONE <TD> GL_ONE_MINUS_SRC_ALPHA
+<TR> <TD> DstOver <TD> GL_ONE_MINUS_DST_ALPHA <TD> GL_ONE
+<TR> <TD> SrcIn <TD> GL_DST_ALPHA <TD> GL_ZERO
+<TR> <TD> DstIn <TD> GL_ZERO <TD> GL_SRC_ALPHA
+<TR> <TD> SrcOut <TD> GL_ONE_MINUS_DST_ALPHA <TD> GL_ZERO
+<TR> <TD> DstOut <TD> GL_ZERO <TD> GL_ONE_MINUS_SRC_ALPHA
+<TR> <TD> Dst <TD> GL_ZERO <TD> GL_ONE
+<TR> <TD> SrcAtop <TD> GL_DST_ALPHA <TD> GL_ONE_MINUS_SRC_ALPHA
+<TR> <TD> DstAtop <TD> GL_ONE_MINUS_DST_ALPHA <TD> GL_SRC_ALPHA
+<TR> <TD> AlphaXor <TD> GL_ONE_MINUS_DST_ALPHA <TD> GL_ONE_MINUS_SRC_ALPHA
+</TABLE>
+</CENTER>
+ *
* @author Chris Campbell
* @author Kenneth Russell
*/