godot/thirdparty/squish/patches/decompress_bc4_bc5.patch

diff --git a/thirdparty/squish/colourblock.cpp b/thirdparty/squish/colourblock.cpp
index af8b980365..f14c9362bd 100644
--- a/thirdparty/squish/colourblock.cpp
+++ b/thirdparty/squish/colourblock.cpp
@@ -24,6 +24,9 @@
    -------------------------------------------------------------------------- */
 
 #include "colourblock.h"
+// -- GODOT start --
+#include "alpha.h"
+// -- GODOT end --
 
 namespace squish {
 
@@ -211,4 +214,34 @@ void DecompressColour( u8* rgba, void const* block, bool isDxt1 )
     }
 }
 
+// -- GODOT start --
+void DecompressColourBc4( u8* rgba, void const* block)
+{
+    DecompressAlphaDxt5(rgba,block);
+    for ( int i = 0; i < 16; ++i ) {
+        rgba[i*4] = rgba[i*4 + 3];
+		rgba[i*4 + 1] = 0;
+		rgba[i*4 + 2] = 0;
+        rgba[i*4 + 3] = 255;
+    }
+}
+
+void DecompressColourBc5( u8* rgba, void const* block)
+{
+    void const* rblock = block;
+    void const* gblock = reinterpret_cast< u8 const* >( block ) + 8;
+    DecompressAlphaDxt5(rgba,rblock);
+    for ( int i = 0; i < 16; ++i ) {
+        rgba[i*4] = rgba[i*4 + 3];
+    }
+    DecompressAlphaDxt5(rgba,gblock);
+    for ( int i = 0; i < 16; ++i ) {
+        rgba[i*4+1] = rgba[i*4 + 3];
+        rgba[i*4 + 2] = 0;
+        rgba[i*4 + 3] = 255;
+    }
+}
+// -- GODOT end --
+
+
 } // namespace squish
diff --git a/thirdparty/squish/colourblock.h b/thirdparty/squish/colourblock.h
index fee2cd7c5d..e1eb9e4917 100644
--- a/thirdparty/squish/colourblock.h
+++ b/thirdparty/squish/colourblock.h
@@ -35,6 +35,10 @@ void WriteColourBlock3( Vec3::Arg start, Vec3::Arg end, u8 const* indices, void*
 void WriteColourBlock4( Vec3::Arg start, Vec3::Arg end, u8 const* indices, void* block );
 
 void DecompressColour( u8* rgba, void const* block, bool isDxt1 );
+// -- GODOT start --
+void DecompressColourBc4( u8* rgba, void const* block );
+void DecompressColourBc5( u8* rgba, void const* block );
+// -- GODOT end --
 
 } // namespace squish
 
diff --git a/thirdparty/squish/squish.cpp b/thirdparty/squish/squish.cpp
index 1d22a64ad6..086ba11cd0 100644
--- a/thirdparty/squish/squish.cpp
+++ b/thirdparty/squish/squish.cpp
@@ -135,7 +135,15 @@ void Decompress( u8* rgba, void const* block, int flags )
         colourBlock = reinterpret_cast< u8 const* >( block ) + 8;
 
     // decompress colour
-    DecompressColour( rgba, colourBlock, ( flags & kDxt1 ) != 0 );
+    // -- GODOT start --
+    //DecompressColour( rgba, colourBlock, ( flags & kDxt1 ) != 0 );
+    if(( flags & ( kBc4 ) ) != 0)
+        DecompressColourBc4( rgba, colourBlock);
+    else if(( flags & ( kBc5 ) ) != 0)
+        DecompressColourBc5( rgba, colourBlock);
+    else
+        DecompressColour( rgba, colourBlock, ( flags & kDxt1 ) != 0 );
+    // -- GODOT end --
 
     // decompress alpha separately if necessary
     if( ( flags & kDxt3 ) != 0 )