HLSL - Combining textures
- by b34r
Hi All,
I'm trying to combine two textures in HLSL - specifically, I want to take the alpha values from a base image, and the color data from an overlay image.
My pixel shader for this looks like this:
float4 PixelShaderFunction(VertexOut input) : COLOR0
{
float4 baseColor = tex2D( BaseSampler, input.baseCoords.xy ).rgba;
float4 overlayColor = tex2D( OverlaySampler, input.overlayCoords.xy ).rgba;
float4 color;
color.r = overlayColor.r;
color.g = overlayColor.g;
color.b = overlayColor.b;
color.a = baseColor.a;
return color.rgba;
}
and my blend state looks like this:
BlendState bs = new BlendState();
bs.AlphaSourceBlend = Blend.SourceAlpha;
bs.AlphaDestinationBlend = Blend.DestinationAlpha;
bs.ColorSourceBlend = Blend.SourceColor;
bs.ColorDestinationBlend = Blend.DestinationColor;
What this leaves me with is a washed out version of what should be the overlay color.
I've tried numerous permutations of the BlendState settings, and played with the pixel shader math quite a bit, but to no avail.
Can anyone point me in the right direction?
Thanks in advance =)
