How to Render two or more images on video frame in same draw call using metal

Question

I'm new bee to graphics programming and i have an existing code base which basically takes frame from video and passes it to metal shader where effects (like colour changes) happens.

Whats currently happening ?

I can use the existing method to send image as texture and it gets blended with the original frame and new frame is created .

what I want to achieve ?

I want to place multiple images on the original image in the same drawing call what would be the best way to achieve it? Should I change the existing render pipeline or shader can handle it.

Answer 1

It would help if you showed us some of your current code. But in general, you can add textures to your shader and then set them up in code by using -[MTLRenderCommandEncoder setFragmentTexture:atIndex:]. It may make sense to send them as a texture array, in which case you'd use -[MTLRenderCommandEncoder setFragmentTextures:withRange:].