GPUOperator
Metal is used for rendering graphics and performing parallel computations like image processing. But,
there are many boiler plates to use Metal normally.
- Creating Metal device
- Creating command queue
- Creating library, taking caring for which bundle includes it.
- PipelineState, CommandBuffer, Threadgroup .........
😱
This library simplifies these steps.
Examples
Shader: Thundershower
Implementation
- Reference: http://glslsandbox.com/
Realtime Video Processing: Edge Detection
Implementation
- Using Prewitt filter
- Same as this.
Image Processing: Two Images Difference
Implementation
| Before | After | Difference |
|---|---|---|
 |
 |
 |
This infers
- Bold font was changed to regular font.
- The last
processors.word was removed. - The border disappeared.
Getting Started
1. Define kernel function and kernel class
#include <metal_stdlib>
using namespace metal;
kernel void monochrome(texture2d<half, access::read_write> dest [[ texture(0) ]],
texture2d<half, access::read_write> source [[ texture(1) ]],
uint2 gid [[ thread_position_in_grid ]]) {
half3 color = source.read(gid).rgb;
half max_color = fmax3(color.r, color.g, color.b);
dest.write(half4(half3(max_color), 1), gid);
}import GPUOperator
final class Monochrome: Kernel {
static let functionName: String = "monochrome"
}2. Setup GPUOperator instance
let gpuOperator = try? GPUOperator()
try? gpuOperator?.install(kernel: Monochrome())3. Configure Rendering Process
let renderingView = RenderingView(frame: .zero)
renderingView.gpuOperator = gpuOperator
renderingView.run()The run() function just starts displaylink process inside RenderingView.
If you want to use MTLView (Metal Standard class), following example would be helpful.
import MetalKit
extension ViewController: MTKViewDelegate {
func mtkView(_ view: MTKView, drawableSizeWillChange size: CGSize) {}
func draw(in view: MTKView) {
autoreleasepool {
guard let drawable = view.currentDrawable else { return }
gpuOperator?.commit(drawable: drawable)
}
}
}Requirements
- Swift 5.0
- iOS 12.0+
- Any simulators are unsupported.
License
GPUOperator is available under the MIT license.