public void copyFramebuffer(IFramebuffer source, IFramebuffer target, bool fromLowres)
{
//Bind shader
LowLevelRenderer.shader = HighLevelRenderer.shaderDrawSprite;
target.bind();
//Set target size uniforms
var tmatrix = fromLowres ? Util.Maths.matrixFitRectIntoScreen(lowResWidth, lowResHeight, highResWidth, highResHeight)
: Matrix4.Identity;
HighLevelRenderer.shaderDrawSprite["transformMatrix"].SetValue(tmatrix);
float yflip = fromLowres ? -1 : 1;
HighLevelRenderer.shaderDrawSprite["uvMatrix"].SetValue(new Matrix4(new float[] {1,0,0,0,
0,yflip,0,0,
0,0,0,0,
0,0,0,1}));
//Bind source texture
Gl.BindTexture(TextureTarget.Texture2D, source.textures()[0]);
LowLevelRenderer.geometry = LowLevelRenderer.quad;
LowLevelRenderer.draw();
}