Method createTextureCubeMapImpl

src/cinder/gl/Texture.cpp:1946–1981

template<typename T>
TextureCubeMapRef TextureCubeMap::createTextureCubeMapImpl( const ImageSourceRef &imageSource, const Format &format )
{
	std::vector<CubeMapFaceRegion> faceRegions;

	// Infer the layout based on image aspect ratio
	ivec2 imageSize( imageSource->getWidth(), imageSource->getHeight() );
	float minDim = (float)std::min( imageSize.x, imageSize.y );
	float maxDim = (float)std::max( imageSize.x, imageSize.y );
	float aspect = minDim / maxDim;
	if( abs( aspect - 1 / 6.0f ) < abs( aspect - 3 / 4.0f ) ) { // closer to 1:6 than to 4:3, so row or column
		faceRegions = ( imageSize.x > imageSize.y ) ? calcCubeMapHorizontalRegions( imageSource ) : calcCubeMapVerticalRegions( imageSource );
	}
	else { // else, horizontal or vertical cross
		faceRegions = ( imageSize.x > imageSize.y ) ? calcCubeMapHorizontalCrossRegions( imageSource ) : calcCubeMapVerticalCrossRegions( imageSource );
	}

	Area faceArea = faceRegions.front().mArea;
	ivec2 faceSize = faceArea.getSize();

	SurfaceT<T> masterSurface( imageSource, SurfaceConstraintsDefault() );
	SurfaceT<T> images[6];

	for( uint8_t f = 0; f < 6; ++f ) {
		images[f] = SurfaceT<T>( faceSize.x, faceSize.y, masterSurface.hasAlpha(), SurfaceConstraints() );
		images[f].copyFrom( masterSurface, faceRegions[f].mArea, faceRegions[f].mOffset );
		if( faceRegions[f].mFlip ) {
			ip::flipVertical( &images[f] );
			ip::flipHorizontal( &images[f] );
		}
	}

	if( format.mDeleter )
		return TextureCubeMapRef( new TextureCubeMap( images, format ), format.mDeleter );
	else
		return TextureCubeMapRef( new TextureCubeMap( images, format ) );
}

TextureCubeMapRef TextureCubeMap::create( const ImageSourceRef images[6], const Format &format )
{