added memory

memory/memory.playground/Contents.swift

@@ -0,0 +1,50 @@
+
+import MetalKit
+
+let device = MTLCreateSystemDefaultDevice()!
+let queue = device.makeCommandQueue()
+let count = 1500
+var myVector = [Float](repeating: 0, count: count)
+var length = count * MemoryLayout<Float>.size
+//print(length)
+var outBuffer = device.makeBuffer(bytes: myVector, length: length, options: [])
+for (index, value) in myVector.enumerated() { myVector[index] = Float(index) }
+var inBuffer = device.makeBuffer(bytes: myVector, length: length, options: [])
+
+let path = Bundle.main.path(forResource: "memory", ofType: "metal")
+let input = try String(contentsOfFile: path!, encoding: String.Encoding.utf8)
+let library = try device.makeLibrary(source: input, options: nil)
+let function = library.makeFunction(name: "compute")!
+let computePipelineState = try! device.makeComputePipelineState(function: function)
+
+let commandBuffer = queue.makeCommandBuffer()
+let encoder = commandBuffer.makeComputeCommandEncoder()
+encoder.setComputePipelineState(computePipelineState)
+encoder.setBuffer(inBuffer, offset: 0, at: 0)
+encoder.setBuffer(outBuffer, offset: 0, at: 1)
+let size = MTLSize(width: count, height: 1, depth: 1)
+encoder.dispatchThreadgroups(size, threadsPerThreadgroup: size)
+encoder.endEncoding()
+commandBuffer.commit()
+
+let result = outBuffer.contents().bindMemory(to: Float.self, capacity: count)
+var data = [Float](repeating:0, count: count)
+for i in 0 ..< count { data[i] = result[i] }
+data.map { $0 }
+
+import ModelIO
+
+guard let url = Bundle.main.url(forResource: "teapot", withExtension: "obj") else { fatalError() }
+let asset = MDLAsset(url: url)
+let voxelArray = MDLVoxelArray(asset: asset, divisions: 10, patchRadius: 0)
+if let data = voxelArray.voxelIndices() {
+    data.withUnsafeBytes { (voxels: UnsafePointer<MDLVoxelIndex>) -> Void in
+        let count = data.count / MemoryLayout<MDLVoxelIndex>.size
+        var voxelIndex = voxels
+        for _ in 0..<count {
+            let position = voxelArray.spatialLocation(ofIndex: voxelIndex.pointee)
+            print(position)
+            voxelIndex = voxelIndex.successor()
+        }
+    }
+}

memory/memory.playground/Resources/memory.metal

@@ -0,0 +1,10 @@
+
+#include <metal_stdlib>
+using namespace metal;
+
+kernel void compute(const device float *inVector [[ buffer(0) ]],
+                    device float *outVector [[ buffer(1) ]],
+                    uint id [[ thread_position_in_grid ]])
+{
+    outVector[id] = 1.0 / (1.0 + exp(-inVector[id]));
+}