added raymarching

README.md

@@ -1,22 +1,23 @@
 # Metal
 
 Repository to accompany the following blog posts:
-- [Introducing the Metal framework](http://mhorga.org/2016/01/04/introducing-the-metal-framework.html)
-- [Using MetalKit part 1](http://mhorga.org/2016/01/11/using-metalkit-part-1.html)
-- [Using MetalKit part 2](http://mhorga.org/2016/01/18/using-metalkit-part-2.html)
-- [Using MetalKit part 3](http://mhorga.org/2016/01/25/using-metalkit-part-3.html)
-- [Using MetalKit part 4](http://mhorga.org/2016/02/01/using-metalkit-part-4.html)
-- [Using MetalKit part 5](http://mhorga.org/2016/02/08/using-metalkit-part-5.html)
-- [Using MetalKit part 6](http://mhorga.org/2016/02/15/using-metalkit-part-6.html)
-- [Using MetalKit part 7](http://mhorga.org/2016/02/29/using-metalkit-part-7.html)
-- [Using MetalKit part 8](http://mhorga.org/2016/03/07/using-metalkit-part-8.html)
-- [Using MetalKit part 9](http://mhorga.org/2016/04/18/using-metalkit-part-9.html)
-- [Using MetalKit part 10](http://mhorga.org/2016/05/02/using-metalkit-part-10.html)
-- [Using MetalKit part 11](http://mhorga.org/2016/05/10/using-metalkit-part-11.html)
-- [Using MetalKit part 12](http://mhorga.org/2016/05/18/using-metalkit-part-12.html)
-- [Using MetalKit part 13](http://mhorga.org/2016/05/25/using-metalkit-part-13.html)
-- [Using MetalKit part 14](http://mhorga.org/2016/06/01/using-metalkit-part-14.html)
-- [Using MetalKit part 15](http://mhorga.org/2016/06/23/using-metalkit-part-15.html)
-- [Using MetalKit part 16](http://mhorga.org/2016/07/06/using-metalkit-part-16.html)
-- [Using MetalKit part 17](http://mhorga.org/2016/09/24/using-metalkit-part-17.html)
-- [Using MetalKit part 18](http://mhorga.org/2016/09/30/using-metalkit-part-2-3-2.html)
+- [Introducing the Metal framework](http://metalkit.org/2016/01/04/introducing-the-metal-framework.html)
+- [Using MetalKit part 1](http://metalkit.org/2016/01/11/using-metalkit-part-1.html)
+- [Using MetalKit part 2](http://metalkit.org/2016/01/18/using-metalkit-part-2.html)
+- [Using MetalKit part 3](http://metalkit.org/2016/01/25/using-metalkit-part-3.html)
+- [Using MetalKit part 4](http://metalkit.org/2016/02/01/using-metalkit-part-4.html)
+- [Using MetalKit part 5](http://metalkit.org/2016/02/08/using-metalkit-part-5.html)
+- [Using MetalKit part 6](http://metalkit.org/2016/02/15/using-metalkit-part-6.html)
+- [Using MetalKit part 7](http://metalkit.org/2016/02/29/using-metalkit-part-7.html)
+- [Using MetalKit part 8](http://metalkit.org/2016/03/07/using-metalkit-part-8.html)
+- [Using MetalKit part 9](http://metalkit.org/2016/04/18/using-metalkit-part-9.html)
+- [Using MetalKit part 10](http://metalkit.org/2016/05/02/using-metalkit-part-10.html)
+- [Using MetalKit part 11](http://metalkit.org/2016/05/10/using-metalkit-part-11.html)
+- [Using MetalKit part 12](http://metalkit.org/2016/05/18/using-metalkit-part-12.html)
+- [Using MetalKit part 13](http://metalkit.org/2016/05/25/using-metalkit-part-13.html)
+- [Using MetalKit part 14](http://metalkit.org/2016/06/01/using-metalkit-part-14.html)
+- [Using MetalKit part 15](http://metalkit.org/2016/06/23/using-metalkit-part-15.html)
+- [Using MetalKit part 16](http://metalkit.org/2016/07/06/using-metalkit-part-16.html)
+- [Using MetalKit part 17](http://metalkit.org/2016/09/24/using-metalkit-part-17.html)
+- [Using MetalKit part 18](http://metalkit.org/2016/10/01/using-metalkit-part-2-3-2.html)
+- [Raymarching in Metal](http://metalkit.org/2016/12/29/raymarching-in-metal.html)

raymarching/raymarching.playground/Contents.swift

@@ -0,0 +1,9 @@
+
+import MetalKit
+import PlaygroundSupport
+
+let frame = NSRect(x: 0, y: 0, width: 300, height: 300)
+let delegate = MetalView()
+let view = MTKView(frame: frame, device: delegate.device)
+view.delegate = delegate
+PlaygroundPage.current.liveView = view

raymarching/raymarching.playground/Resources/Shaders.metal

@@ -0,0 +1,54 @@
+
+#include <metal_stdlib>
+using namespace metal;
+
+struct Ray {
+    float3 origin;
+    float3 direction;
+    Ray(float3 o, float3 d) {
+        origin = o;
+        direction = d;
+    }
+};
+
+struct Sphere {
+    float3 center;
+    float radius;
+    Sphere(float3 c, float r) {
+        center = c;
+        radius = r;
+    }
+};
+
+float distToSphere(Ray ray, Sphere s) {
+    return length(ray.origin - s.center) - s.radius;
+}
+
+float distToScene(Ray r) {
+    Sphere s = Sphere(float3(1.), 0.5);
+    Ray repeatRay = r;
+    repeatRay.origin = fmod(r.origin, 2.0);
+    return distToSphere(repeatRay, s);
+}
+
+kernel void compute(texture2d<float, access::write> output [[texture(0)]],
+                    constant float &time [[buffer(0)]],
+                    uint2 gid [[thread_position_in_grid]]) {
+    int width = output.get_width();
+    int height = output.get_height();
+    float2 uv = float2(gid) / float2(width, height);
+    uv = uv * 2.0 - 1.0;
+    float3 camPos = float3(1000. + sin(time) + 1., 1000. + cos(time) + 1., time);
+    Ray ray = Ray(camPos, normalize(float3(uv, 1.)));
+    float3 col = float3(0.);
+    for (int i=0.; i<100.; i++) {
+        float dist = distToScene(ray);
+        if (dist < 0.001) {
+            col = float3(1.);
+            break;
+        }
+        ray.origin += ray.direction * dist;
+    }
+    float3 posRelativeToCamera = ray.origin - camPos;
+    output.write(float4(col * abs((posRelativeToCamera) / 10.0), 1.), gid);
+}

raymarching/raymarching.playground/Sources/MetalView.swift

@@ -0,0 +1,52 @@
+
+import MetalKit
+
+public class MetalView: NSObject, MTKViewDelegate {
+    
+    public var device: MTLDevice!
+    var queue: MTLCommandQueue!
+    var cps: MTLComputePipelineState!
+    var time: Float = 0
+    var timeBuffer: MTLBuffer!
+    
+    override public init() {
+        super.init()
+        registerShaders()
+    }
+    
+    func registerShaders() {
+        device = MTLCreateSystemDefaultDevice()!
+        queue = device.makeCommandQueue()
+        let path = Bundle.main.path(forResource: "Shaders", ofType: "metal")
+        do {
+            let input = try String(contentsOfFile: path!, encoding: String.Encoding.utf8)
+            let library = try device.makeLibrary(source: input, options: nil)
+            let kernel = library.makeFunction(name: "compute")!
+            cps = try device.makeComputePipelineState(function: kernel)
+        } catch let e {
+            Swift.print("\(e)")
+        }
+        timeBuffer = device!.makeBuffer(length: MemoryLayout<Float>.size, options: [])
+    }
+
+    public func mtkView(_ view: MTKView, drawableSizeWillChange size: CGSize) {}
+    
+    public func draw(in view: MTKView) {
+        if let drawable = view.currentDrawable {
+            let commandBuffer = queue.makeCommandBuffer()
+            let commandEncoder = commandBuffer.makeComputeCommandEncoder()
+            commandEncoder.setComputePipelineState(cps)
+            commandEncoder.setTexture(drawable.texture, at: 0)
+            commandEncoder.setBuffer(timeBuffer, offset: 0, at: 0)
+            time += 0.01
+            let bufferPointer = timeBuffer.contents()
+            memcpy(bufferPointer, &time, MemoryLayout<Float>.size)
+            let threadGroupCount = MTLSizeMake(8, 8, 1)
+            let threadGroups = MTLSizeMake(drawable.texture.width / threadGroupCount.width, drawable.texture.height / threadGroupCount.height, 1)
+            commandEncoder.dispatchThreadgroups(threadGroups, threadsPerThreadgroup: threadGroupCount)
+            commandEncoder.endEncoding()
+            commandBuffer.present(drawable)
+            commandBuffer.commit()
+        }
+    }
+}

raymarching/raymarching.playground/contents.xcplayground

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<playground version='5.0' target-platform='osx' executeOnSourceChanges='false'>
+    <timeline fileName='timeline.xctimeline'/>
+</playground>

raymarching/raymarching.playground/playground.xcworkspace/contents.xcworkspacedata

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "self:">
+   </FileRef>
+</Workspace>

raymarching/raymarching.playground/timeline.xctimeline

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Timeline
+   version = "3.0">
+   <TimelineItems>
+   </TimelineItems>
+</Timeline>