Htykuut

I have two transparent textures. First one is Source texture, Second one is Mask Texture. I want to mix two textures.

Scenario 1

• source texture having color and Alpha Mask Texture Having color and Alpha


• Resultant Color and alpha should be multiplied

Scenario 2

• source texture having color and Alpha Mask Texture alpha is Zero


• Resultant Color and alpha should be Source Texture Color and Alpha

Scenario 3

• source texture having Alpha zero Mask Texture alpha is having color and alpha


• Resultant Color and alpha should be Zero

How can I achieve this in metal Fragment shader.

fragment float4 fragmentShaderone(VertexOut params[[stage_in]],

                                                              texture2d<float, access::sample>srcTexture [[texture(0)]],

                                                              texture2d<float, access::sample> maskTexture [[texture(1)]])

{



    constexpr sampler defaultSampler;



    float  srcColor = float4(texture.sample(defaultSampler, float2(params.textureCoordinates)))  * float4(1,0,0,40.0/255.0);



    float4 maskColor = float4(texture4.sample(defaultSampler, float2(params.textureCoordinates))) ;



    return srcColor * maskColor



}

If I do like this Scenario 2 is missing. Anyway to solve in metal fragment shader. I need three scenarios to be satisfied.