Add support for linear and swizzle transforms. Fixes issue 4.

src/nvtt/Compressor.cpp

@@ -651,9 +651,20 @@ void Compressor::Private::processInputImage(Mipmap & mipmap, const InputOptions:
 		{
 			mipmap.toFloatImage(inputOptions);
 		}
-	}
 
-	// @@ Linear and swizzle color transforms should be done here.
+		// Apply linear transforms in linear space.
+		FloatImage * image = mipmap.asFloatImage();
+		nvDebugCheck(image != NULL);
+
+		if (inputOptions.colorTransform == ColorTransform_Linear)
+		{
+			image->transform(0, inputOptions.linearTransform);
+		}
+		else if (inputOptions.colorTransform == ColorTransform_Swizzle)
+		{
+			image->swizzle(0, input.swizzleTransform[0], input.swizzleTransform[1], input.swizzleTransform[2], input.swizzleTransform[3]);
+		}
+	}
 }
 
 

src/nvtt/InputOptions.cpp

@@ -316,10 +316,10 @@ void InputOptions::setSwizzleTransform(int x, int y, int z, int w)
 	nvCheck(z >= 0 && z < 3);
 	nvCheck(w >= 0 && w < 3);
 	
-	// m.xswizzle = x;
-	// m.yswizzle = y;
-	// m.zswizzle = z;
-	// m.wswizzle = w;
+	m.swizzleTransform[0] = x;
+	m.swizzleTransform[1] = y;
+	m.swizzleTransform[2] = z;
+	m.swizzleTransform[3] = w;
 }
 
 void InputOptions::setMaxExtents(int e)

src/nvtt/InputOptions.h

@@ -56,6 +56,7 @@ namespace nvtt
 		// Color transform.
 		ColorTransform colorTransform;
 		nv::Matrix linearTransform;
+		uint swizzleTransform[4];
 		
 		// Mipmap generation options.
 		bool generateMipmaps;