Add support for Capcon's DXT trick by setting the red channel to 1 in the DXT5n mode.

src/nvimage/ColorBlock.cpp

@@ -88,7 +88,7 @@ void ColorBlock::swizzleDXT5n()
 	for(int i = 0; i < 16; i++)
 	{
 		Color32 c = m_color[i];
-		m_color[i] = Color32(0, c.g, 0, c.r);
+		m_color[i] = Color32(0xFF, c.g, 0, c.r);
 	}
 }
 

src/nvtt/QuickCompressDXT.cpp

@@ -506,10 +506,12 @@ void QuickCompress::compressDXT1G(const ColorBlock & rgba, BlockDXT1 * block)
 		maxg = max(maxg, green);
 	}
 
-	block->col0.u = 0;
-	block->col1.u = 0;
+	block->col0.r = 0xFF;
+	block->col1.r = 0xFF;
 	block->col0.g = maxg;
 	block->col1.g = ming;
+	block->col0.b = 0;
+	block->col1.b = 0;
 
 	if (maxg - ming > 4)
 	{