Enable support for DXT3 and DXT5 accelerated compressors.

src/nvimage/nvtt/dxtlib.cpp

@@ -186,15 +186,15 @@ static bool compressMipmap(const Image * image, const OutputOptions & outputOpti
 		}
 		else
 #endif
-		if (compressionOptions.useCuda && nv::cuda::isHardwarePresent())
+		if (compressionOptions.quality == Quality_Fastest)
 		{
-			cudaCompressDXT1(image, outputOptions, compressionOptions);
+			fastCompressDXT1(image, outputOptions);
 		}
 		else
 		{
-			if (compressionOptions.quality == Quality_Fastest)
+			if (compressionOptions.useCuda && nv::cuda::isHardwarePresent())
 			{
-				fastCompressDXT1(image, outputOptions);
+				cudaCompressDXT1(image, outputOptions, compressionOptions);
 			}
 			else
 			{
@@ -209,10 +209,17 @@ static bool compressMipmap(const Image * image, const OutputOptions & outputOpti
 			fastCompressDXT3(image, outputOptions);
 		}
 		else
+		{
+			if (compressionOptions.useCuda && nv::cuda::isHardwarePresent())
+			{
+				cudaCompressDXT3(image, outputOptions, compressionOptions);
+			}
+			else
 			{
 				compressDXT3(image, outputOptions, compressionOptions);
 			}
 		}
+	}
 	else if (compressionOptions.format == Format_DXT5)
 	{
 		if (compressionOptions.quality == Quality_Fastest)
@@ -220,10 +227,17 @@ static bool compressMipmap(const Image * image, const OutputOptions & outputOpti
 			fastCompressDXT5(image, outputOptions);
 		}
 		else
+		{
+			if (compressionOptions.useCuda && nv::cuda::isHardwarePresent())
+			{
+				cudaCompressDXT5(image, outputOptions, compressionOptions);
+			}
+			else
 			{
 				compressDXT5(image, outputOptions, compressionOptions);
 			}
 		}
+	}
 	else if (compressionOptions.format == Format_DXT5n)
 	{
 		if (compressionOptions.quality == Quality_Fastest)