Wsrtjtyk

my target is to render 2 image spontaneously.First image or texture is my camera image which comes from live video and for second one I want to load image from gif where some position of the gif has alpha = 0 so that I can see my back image also.my draw method looks like below.

    public func draw(in: MTKView) {



    autoreleasepool {

        guard let texture = texture else {

            print("Error : camera stream failed to create texture")

            return

        }

        guard let device = self.device else {

            print("Error : Metal Device is nil")

            return

        }

        guard let commandBuffer = commandQueue?.makeCommandBuffer() else {

            print("Error : Command encoder is nil")

            return

        }





        // resposible to create metal camera effect in camera raw image and output will be written to

        // internalTexture, if success, internal texture will be present to the screen using encoder



        self.createMetalEffect(texture, inputCommandBuffer: commandBuffer)



        guard let commandGifBuffer = commandQueue?.makeCommandBuffer() else{

            print("Error : Command encoder is nil")

            return

        }



        // rendering the effect output texture (writen to internalTexture via kernel) on screen

        // so the self.internalTexture must not be nil!

        render(texture: self.internalTexture!, withCommandBuffer: commandBuffer, device: device)



        // for loading gif here

        if isGifEnable{

            if count == self.imageArray.count - 1{

                count = 0

            }else{

                count += 1

            }

            if let giftexture = self.loadImageFrame(img: self.imageArray[count]){

                self.createGifMetalEffect(giftexture, inputCommandBuffer: commandGifBuffer)

                render(texture: self.gifInternalTexture!, withCommandBuffer: commandGifBuffer, device: device)

            }

        }



        /// ------------------------- end gif loading ------------------------------





    }

}

and for presenting images my render method looks like this.

        private func render(texture: MTLTexture,

                        withCommandBuffer commandBuffer: MTLCommandBuffer,

                        device: MTLDevice) {





        guard let renderPassDescriptor = metalView.currentRenderPassDescriptor else {

            print("Error : Render pass descriptor is nil")

            return

        }

        guard let drawable = metalView.currentDrawable else {

            print("Error : drawable from metal view is nil")

            return

        }

        guard let pipelineState = self.pipelineState else {

            print("Error : pipelineState is nil")

            return

        }

//        guard let animation = self.animationDescriptor else {

//            print("Error : animation is nil")

//            return

//        }

        guard let encoder = commandBuffer.makeRenderCommandEncoder(descriptor: renderPassDescriptor) else {

            print("Error : Fail to create screen render encoder from command buffer!")

                return

        }

        encoder.pushDebugGroup("RenderFrame")

        encoder.setRenderPipelineState(pipelineState)

        encoder.setFragmentTexture(texture, index: 0)

        encoder.drawPrimitives(type: .triangleStrip, vertexStart: 0,

                                vertexCount: 4, instanceCount: 1)



        encoder.popDebugGroup()

        encoder.endEncoding()



        commandBuffer.present(drawable)



        commandBuffer.commit()

        commandBuffer.waitUntilCompleted()

        self.metalTexture = texture



//        self.metalWriteQueue.async {

//            self.writeTexture(texture)

//        }



    }

I have renderGif method also which looks same as render method but with different parameter name self.gifInternalTexture! and commandGifBuffer.So the question is when I render my video without gif it works fine but when I apply gif which I expect to render in top are not showing and also video is frizzing maybe because of this command commandBuffer.waitUntilCompleted()
the warning message which it give is

should not be called after already presenting this drawable. Get a nextDrawable instead.

maybe because it already present currentdrawable in render function. so how can I render tow image independently and show one under the another?? What should be my architecture?