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

src/nvimage/FloatImage.cpp

@@ -4,6 +4,7 @@
 #include <nvcore/Ptr.h>
 
 #include <nvmath/Color.h>
+#include <nvmath/Matrix.h>
 
 #include "FloatImage.h"
 #include "Filter.h"
@@ -240,6 +241,52 @@ void FloatImage::exponentiate(uint base_component, uint num, float power)
 	}
 }
 
+/// Apply linear transform.
+void FloatImage::transform(uint base_component, const Matrix & m)
+{
+	nvCheck(base_component + 4 <= m_componentNum);
+
+	const uint size = m_width * m_height;
+
+	float * r = this->channel(base_component + 0);
+	float * g = this->channel(base_component + 1);
+	float * b = this->channel(base_component + 2);
+	float * a = this->channel(base_component + 3);
+
+	for (uint i = 0; i < size; i++)
+	{
+		Vector4 color = nv::transform(m, Vector4(*r, *g, *b, *a));
+
+		*r++ = color.x();
+		*g++ = color.y();
+		*b++ = color.z();
+		*a++ = color.w();
+	}
+}
+
+void FloatImage::swizzle(uint base_component, uint r, uint g, uint b, uint a)
+{
+	nvCheck(base_component + 4 <= m_componentNum);
+
+	const uint size = m_width * m_height;
+
+	float * c[4];
+	c[0] = this->channel(base_component + 0);
+	c[1] = this->channel(base_component + 1);
+	c[2] = this->channel(base_component + 2);
+	c[3] = this->channel(base_component + 3);
+
+	for (uint i = 0; i < size; i++)
+	{
+		float tmp[4] = { c[r], c[g], c[b], c[a] };
+
+		*r++ = tmp[0];
+		*g++ = tmp[1];
+		*b++ = tmp[2];
+		*a++ = tmp[3];
+	}
+}
+
 float FloatImage::sampleNearest(const float x, const float y, const int c, const WrapMode wm) const
 {
 	if( wm == WrapMode_Clamp ) return sampleNearestClamp(x, y, c);

src/nvimage/FloatImage.h

@@ -11,6 +11,7 @@
 
 namespace nv
 {
+class Matrix;
 class Image;
 class Filter;
 class Kernel1;
@@ -62,6 +63,8 @@ public:
 	NVIMAGE_API void toGamma(uint base_component, uint num, float gamma = 2.2f);
 	NVIMAGE_API void exponentiate(uint base_component, uint num, float power);
 	
+	NVIMAGE_API void transform(uint base_component, const Matrix & m);
+	NVIMAGE_API void swizzle(uint base_component, uint r, uint g, uint b, uint a);
 	
 	NVIMAGE_API FloatImage * fastDownSample() const;
 	NVIMAGE_API FloatImage * downSample(const Filter & filter, WrapMode wm) const;

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.swizzleTransform[0] = x;
-	// m.yswizzle = y;
+	m.swizzleTransform[1] = y;
-	// m.zswizzle = z;
+	m.swizzleTransform[2] = z;
-	// m.wswizzle = w;
+	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;