texturec: Added BC4/5 compression.

3rdparty/.editorconfig

@@ -11,3 +11,5 @@ indent_size  = 4
 [remotery/*]
 indent_style = space
 indent_size  = 4
+
+[libsquish/*]

3rdparty/libsquish/squish.cpp

@@ -37,13 +37,18 @@ namespace squish {
 static int FixFlags( int flags )
 {
 	// grab the flag bits
-	int method = flags & ( kDxt1 | kDxt3 | kDxt5 );
+	int method = flags & ( kDxt1 | kDxt3 | kDxt5 | kBc4 | kBc5 );
 	int fit = flags & ( kColourIterativeClusterFit | kColourClusterFit | kColourRangeFit );
 	int extra = flags & kWeightColourByAlpha;
 	
 	// set defaults
-	if( method != kDxt3 && method != kDxt5 )
+	if ( method != kDxt3
+	&&   method != kDxt5
+	&&   method != kBc4
+	&&   method != kBc5 )
+	{
 		method = kDxt1;
+	}
 	if( fit != kColourRangeFit && fit != kColourIterativeClusterFit )
 		fit = kColourClusterFit;
 		
@@ -56,9 +61,34 @@ void CompressMasked( u8 const* rgba, int mask, void* block, int flags, float* me
 	// fix any bad flags
 	flags = FixFlags( flags );
 
+	if ( ( flags & ( kBc4 | kBc5 ) ) != 0 )
+	{
+		u8 alpha[16*4];
+		for( int i = 0; i < 16; ++i )
+		{
+			alpha[i*4 + 3] = rgba[i*4 + 0]; // copy R to A
+		}
+
+		u8* rBlock = reinterpret_cast< u8* >( block );
+		CompressAlphaDxt5( alpha, mask, rBlock );
+
+		if ( ( flags & ( kBc5 ) ) != 0 )
+		{
+			for( int i = 0; i < 16; ++i )
+			{
+				alpha[i*4 + 3] = rgba[i*4 + 1]; // copy G to A
+			}
+
+			u8* gBlock = reinterpret_cast< u8* >( block ) + 8;
+			CompressAlphaDxt5( alpha, mask, gBlock );
+		}
+
+		return;
+	}
+
 	// get the block locations
 	void* colourBlock = block;
-	void* alphaBock = block;
+	void* alphaBlock = block;
 	if( ( flags & ( kDxt3 | kDxt5 ) ) != 0 )
 		colourBlock = reinterpret_cast< u8* >( block ) + 8;
 
@@ -87,9 +117,9 @@ void CompressMasked( u8 const* rgba, int mask, void* block, int flags, float* me
 	
 	// compress alpha separately if necessary
 	if( ( flags & kDxt3 ) != 0 )
-		CompressAlphaDxt3( rgba, mask, alphaBock );
+		CompressAlphaDxt3( rgba, mask, alphaBlock );
 	else if( ( flags & kDxt5 ) != 0 )
-		CompressAlphaDxt5( rgba, mask, alphaBock );
+		CompressAlphaDxt5( rgba, mask, alphaBlock );
 }
 
 void Decompress( u8* rgba, void const* block, int flags )
@@ -120,7 +150,7 @@ int GetStorageRequirements( int width, int height, int flags )
 	
 	// compute the storage requirements
 	int blockcount = ( ( width + 3 )/4 ) * ( ( height + 3 )/4 );
-	int blocksize = ( ( flags & kDxt1 ) != 0 ) ? 8 : 16;
+	int blocksize = ( ( flags & ( kDxt1 | kBc4 ) ) != 0 ) ? 8 : 16;
 	return blockcount*blocksize;	
 }
 
@@ -131,7 +161,7 @@ void CompressImage( u8 const* rgba, int width, int height, void* blocks, int fla
 
 	// initialise the block output
 	u8* targetBlock = reinterpret_cast< u8* >( blocks );
-	int bytesPerBlock = ( ( flags & kDxt1 ) != 0 ) ? 8 : 16;
+	int bytesPerBlock = ( ( flags & ( kDxt1 | kBc4 ) ) != 0 ) ? 8 : 16;
 
 	// loop over blocks
 	for( int y = 0; y < height; y += 4 )
@@ -185,7 +215,7 @@ void DecompressImage( u8* rgba, int width, int height, void const* blocks, int f
 
 	// initialise the block input
 	u8 const* sourceBlock = reinterpret_cast< u8 const* >( blocks );
-	int bytesPerBlock = ( ( flags & kDxt1 ) != 0 ) ? 8 : 16;
+	int bytesPerBlock = ( ( flags & ( kDxt1 | kBc4 ) ) != 0 ) ? 8 : 16;
 
 	// loop over blocks
 	for( int y = 0; y < height; y += 4 )

3rdparty/libsquish/squish.h

@@ -39,23 +39,29 @@ typedef unsigned char u8;
 enum
 {
 	//! Use DXT1 compression.
-	kDxt1 = ( 1 << 0 ), 
-	
+	kDxt1 = ( 1 << 0 ),
+
 	//! Use DXT3 compression.
-	kDxt3 = ( 1 << 1 ), 
-	
+	kDxt3 = ( 1 << 1 ),
+
 	//! Use DXT5 compression.
-	kDxt5 = ( 1 << 2 ), 
-	
+	kDxt5 = ( 1 << 2 ),
+
+	//! Use BC4 compression.
+	kBc4 = ( 1 << 3 ),
+
+	//! Use BC5 compression.
+	kBc5 = ( 1 << 4 ),
+
 	//! Use a very slow but very high quality colour compressor.
 	kColourIterativeClusterFit = ( 1 << 8 ),	
-	
+
 	//! Use a slow but high quality colour compressor (the default).
 	kColourClusterFit = ( 1 << 3 ),	
-	
+
 	//! Use a fast but low quality colour compressor.
 	kColourRangeFit	= ( 1 << 4 ),
-	
+
 	//! Weight the colour by alpha during cluster fit (disabled by default).
 	kWeightColourByAlpha = ( 1 << 7 )
 };