Cleanup color rounding and expansion.

src/nvtt/cuda/CompressKernel.cu

@@ -305,7 +305,6 @@ __device__ void loadColorBlock(const uint * image, float2 colors[16], float2 sum
 ////////////////////////////////////////////////////////////////////////////////
 inline __device__ float3 roundAndExpand565(float3 v, ushort * w)
 {
-#if 0
 	uint x = __float2uint_rn(__saturatef(v.x) * 31.0f);
 	uint y = __float2uint_rn(__saturatef(v.y) * 63.0f);
 	uint z = __float2uint_rn(__saturatef(v.z) * 31.0f);
@@ -313,35 +312,26 @@ inline __device__ float3 roundAndExpand565(float3 v, ushort * w)
 	v.x = __uint2float_rn(x) * 1.0f / 31.0f;
 	v.y = __uint2float_rn(y) * 1.0f / 63.0f;
 	v.z = __uint2float_rn(z) * 1.0f / 31.0f;
-#else
-	v.x = rintf(__saturatef(v.x) * 31.0f);
-	v.y = rintf(__saturatef(v.y) * 63.0f);
-	v.z = rintf(__saturatef(v.z) * 31.0f);
-	*w = ((ushort)v.x << 11) | ((ushort)v.y << 5) | (ushort)v.z;
-	v.x *= 1.0f / 31.0f;
-	v.y *= 1.0f / 63.0f;
-	v.z *= 1.0f / 31.0f;
-#endif
 	return v;
 }
 
 inline __device__ float2 roundAndExpand56(float2 v, ushort * w)
 {
-	v.x = rintf(__saturatef(v.x) * 31.0f);
-	v.y = rintf(__saturatef(v.y) * 63.0f);
-	*w = ((ushort)v.x << 11) | ((ushort)v.y << 5);
-	v.x *= 1.0f / 31.0f;
-	v.y *= 1.0f / 63.0f;
+	uint x = __float2uint_rn(__saturatef(v.x) * 31.0f);
+	uint y = __float2uint_rn(__saturatef(v.y) * 63.0f);
+	*w = (x << 11) | (y << 5);
+	v.x = __uint2float_rn(x) * 1.0f / 31.0f;
+	v.y = __uint2float_rn(y) * 1.0f / 63.0f;
 	return v;
 }
 
 inline __device__ float2 roundAndExpand88(float2 v, ushort * w)
 {
-	v.x = rintf(__saturatef(v.x) * 255.0f);
-	v.y = rintf(__saturatef(v.y) * 255.0f);
-	*w = ((ushort)v.x << 8) | ((ushort)v.y);
-	v.x *= 1.0f / 255.0f;
-	v.y *= 1.0f / 255.0f;
+	uint x = __float2uint_rn(__saturatef(v.x) * 255.0f);
+	uint y = __float2uint_rn(__saturatef(v.y) * 255.0f);
+	*w = (x << 8) | y;
+	v.x = __uint2float_rn(x) * 1.0f / 255.0f;
+	v.y = __uint2float_rn(y) * 1.0f / 255.0f;
 	return v;
 }