Get down an initial diamond-squares implementation

2018-11-10 09:53:37 -05:00 · 2018-11-10 09:53:37 -05:00 · cce59a45dc
commit cce59a45dc
parent a390cbc584
3 changed files with 244 additions and 14 deletions
--- a/Terrain.xcodeproj/project.pbxproj
+++ b/Terrain.xcodeproj/project.pbxproj
@ -8,6 +8,7 @@

 /* Begin PBXBuildFile section */
 		C018AD33219518080094BE3C /* Terrain2Tests.swift in Sources */ = {isa = PBXBuildFile; fileRef = C018AD32219518080094BE3C /* Terrain2Tests.swift */; };
+		C018AD3B219518480094BE3C /* AlgorithmsTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = C018AD3A219518480094BE3C /* AlgorithmsTests.swift */; };
 		C019C8512191CE7100EAD5BB /* Uniforms.m in Sources */ = {isa = PBXBuildFile; fileRef = C019C8502191CE7100EAD5BB /* Uniforms.m */; };
 		C08C58A0218F46F000EAFC2D /* Algorithms.swift in Sources */ = {isa = PBXBuildFile; fileRef = C08C589F218F46F000EAFC2D /* Algorithms.swift */; };
 		C08C58A2218F474E00EAFC2D /* TerrainAlgorithms.metal in Sources */ = {isa = PBXBuildFile; fileRef = C08C58A1218F474E00EAFC2D /* TerrainAlgorithms.metal */; };
@ -44,6 +45,7 @@
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 		C018AD32219518080094BE3C /* Terrain2Tests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Terrain2Tests.swift; sourceTree = "<group>"; };
 		C018AD34219518080094BE3C /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
+		C018AD3A219518480094BE3C /* AlgorithmsTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AlgorithmsTests.swift; sourceTree = "<group>"; };
 		C019C8502191CE7100EAD5BB /* Uniforms.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = Uniforms.m; sourceTree = "<group>"; };
 		C08C589F218F46F000EAFC2D /* Algorithms.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Algorithms.swift; sourceTree = "<group>"; };
 		C08C58A1218F474E00EAFC2D /* TerrainAlgorithms.metal */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.metal; path = TerrainAlgorithms.metal; sourceTree = "<group>"; };
@ -104,6 +106,7 @@
 			isa = PBXGroup;
 			children = (
 				C018AD32219518080094BE3C /* Terrain2Tests.swift */,
+				C018AD3A219518480094BE3C /* AlgorithmsTests.swift */,
 				C018AD34219518080094BE3C /* Info.plist */,
 			);
 			path = Terrain2Tests;
@ -307,6 +310,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				C018AD33219518080094BE3C /* Terrain2Tests.swift in Sources */,
+				C018AD3B219518480094BE3C /* AlgorithmsTests.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@ -372,9 +376,10 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				BUNDLE_LOADER = "$(TEST_HOST)";
-				CODE_SIGN_STYLE = Automatic;
+				CODE_SIGN_IDENTITY = "-";
+				CODE_SIGN_STYLE = Manual;
 				COMBINE_HIDPI_IMAGES = YES;
-				DEVELOPMENT_TEAM = 78372RE6B4;
+				DEVELOPMENT_TEAM = "";
 				INFOPLIST_FILE = Terrain2Tests/Info.plist;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
@ -383,6 +388,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = me.erynwells.Terrain2Tests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				PROVISIONING_PROFILE_SPECIFIER = "";
 				SWIFT_VERSION = 4.2;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/Terrain2.app/Contents/MacOS/Terrain2";
 			};
@ -392,9 +398,10 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				BUNDLE_LOADER = "$(TEST_HOST)";
-				CODE_SIGN_STYLE = Automatic;
+				CODE_SIGN_IDENTITY = "-";
+				CODE_SIGN_STYLE = Manual;
 				COMBINE_HIDPI_IMAGES = YES;
-				DEVELOPMENT_TEAM = 78372RE6B4;
+				DEVELOPMENT_TEAM = "";
 				INFOPLIST_FILE = Terrain2Tests/Info.plist;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
@ -403,6 +410,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = me.erynwells.Terrain2Tests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				PROVISIONING_PROFILE_SPECIFIER = "";
 				SWIFT_VERSION = 4.2;
 				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/Terrain2.app/Contents/MacOS/Terrain2";
 			};
@ -566,9 +574,10 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				CODE_SIGN_ENTITLEMENTS = Terrain2/Terrain2.entitlements;
-				CODE_SIGN_STYLE = Automatic;
+				CODE_SIGN_IDENTITY = "-";
+				CODE_SIGN_STYLE = Manual;
 				COMBINE_HIDPI_IMAGES = YES;
-				DEVELOPMENT_TEAM = 78372RE6B4;
+				DEVELOPMENT_TEAM = "";
 				INFOPLIST_FILE = Terrain2/Info.plist;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
@ -576,6 +585,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = me.erynwells.Terrain2;
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				PROVISIONING_PROFILE_SPECIFIER = "";
 				SWIFT_OBJC_BRIDGING_HEADER = Terrain2/ShaderTypes.h;
 				SWIFT_VERSION = 4.2;
 			};
@ -586,9 +596,10 @@
 			buildSettings = {
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				CODE_SIGN_ENTITLEMENTS = Terrain2/Terrain2.entitlements;
-				CODE_SIGN_STYLE = Automatic;
+				CODE_SIGN_IDENTITY = "-";
+				CODE_SIGN_STYLE = Manual;
 				COMBINE_HIDPI_IMAGES = YES;
-				DEVELOPMENT_TEAM = 78372RE6B4;
+				DEVELOPMENT_TEAM = "";
 				INFOPLIST_FILE = Terrain2/Info.plist;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
@ -596,6 +607,7 @@
 				);
 				PRODUCT_BUNDLE_IDENTIFIER = me.erynwells.Terrain2;
 				PRODUCT_NAME = "$(TARGET_NAME)";
+				PROVISIONING_PROFILE_SPECIFIER = "";
 				SWIFT_OBJC_BRIDGING_HEADER = Terrain2/ShaderTypes.h;
 				SWIFT_VERSION = 4.2;
 			};
--- a/Terrain2/Algorithms.swift
+++ b/Terrain2/Algorithms.swift
@ -23,7 +23,10 @@ protocol Algorithm {
 }

 class Kernel {
-    static let textureSize = MTLSize(width: 512, height: 512, depth: 1)
+
+    class var textureSize: MTLSize {
+        return MTLSize(width: 512, height: 512, depth: 1)
+    }

    class func buildTexture(device: MTLDevice, size: MTLSize) -> MTLTexture? {
        let desc = MTLTextureDescriptor.texture2DDescriptor(pixelFormat: .r32Float, width: size.width, height: size.height, mipmapped: false)
@ -51,7 +54,7 @@ class Kernel {
        // Create our input and output textures
        var textures = [MTLTexture]()
        for i in 0..<2 {
-            guard let tex = Kernel.buildTexture(device: device, size: Kernel.textureSize) else {
+            guard let tex = Kernel.buildTexture(device: device, size: type(of: self).textureSize) else {
                print("Couldn't create heights texture i=\(i)")
                throw KernelError.textureCreationFailed
            }
@ -67,7 +70,7 @@ class Kernel {
        encoder.setTexture(textures[textureIndexes.in], index: textureIndexes.in)
        encoder.setTexture(textures[textureIndexes.out], index: textureIndexes.out)
        encoder.setBuffer(uniformBuffer, offset: 0, index: 0)
-        encoder.dispatchThreads(Kernel.textureSize, threadsPerThreadgroup: MTLSize(width: 8, height: 8, depth: 1))
+        encoder.dispatchThreads(type(of: self).textureSize, threadsPerThreadgroup: MTLSize(width: 8, height: 8, depth: 1))
    }
 }

@ -121,9 +124,172 @@ class RandomAlgorithm: Kernel, Algorithm {

 /// Implementation of the Diamond-Squares algorithm.
 /// - https://en.wikipedia.org/wiki/Diamond-square_algorithm
-//class DiamondSquareAlgorithm: Algorithm {
-//    static let name = "Diamond-Square"
-//}
+public class DiamondSquareAlgorithm: Algorithm {
+    public struct Box {
+        public typealias Point = (x: Int, y: Int)
+        public typealias Size = (w: Int, h: Int)
+
+        let origin: Point
+        let size: Size
+
+        public init(origin o: Point, size s: Size) {
+            origin = o
+            size = s
+        }
+
+        public var corners: [Point] {
+            return [northwest, southwest, northeast, northwest]
+        }
+
+        public var sideMidpoints: [Point] {
+            return [north, west, south, east]
+        }
+
+        public var north: Point {
+            return (x: origin.x + (size.w / 2 + 1), y: origin.y)
+        }
+
+        public var west: Point {
+            return (x: origin.x, y: origin.y + (size.h / 2 + 1))
+        }
+
+        public var south: Point {
+            return (x: origin.x + (size.w / 2 + 1), y: origin.y + size.h)
+        }
+
+        public var east: Point {
+            return (x: origin.x + size.w, y: origin.y + (size.h / 2 + 1))
+        }
+
+        public var northwest: Point {
+            return origin
+        }
+
+        public var southwest: Point {
+            return (x: origin.x, y: origin.y + size.h)
+        }
+
+        public var northeast: Point {
+            return (x: origin.x + size.w, y: origin.y)
+        }
+
+        public var southeast: Point {
+            return (x: origin.x + size.w, y: origin.y + size.h)
+        }
+
+        public var midpoint: Point {
+            return (x: origin.x + (size.w / 2 + 1), y: origin.y + (size.h / 2 + 1))
+        }
+    }
+    
+    let name = "Diamond-Square"
+
+    class var textureSize: MTLSize {
+        // Needs to 2n + 1 on each side.
+        return MTLSize(width: 513, height: 513, depth: 1)
+    }
+
+    let texture: MTLTexture
+    let textureSemaphore = DispatchSemaphore(value: 1)
+
+    init?(device: MTLDevice) {
+        let size = DiamondSquareAlgorithm.textureSize
+        let desc = MTLTextureDescriptor.texture2DDescriptor(pixelFormat: .r32Float, width: size.width, height: size.height, mipmapped: false)
+        desc.usage = [.shaderRead, .shaderWrite]
+        desc.resourceOptions = .storageModeShared
+        guard let tex = device.makeTexture(descriptor: desc) else {
+            print("Couldn't create texture for Diamond-Squares algorithm.")
+            return nil
+        }
+        texture = tex
+    }
+
+    func render() {
+        let size = DiamondSquareAlgorithm.textureSize
+
+        func ptToIndex(_ pt: Box.Point) -> Int {
+            return pt.y * size.width + pt.x
+        }
+
+        var heightMap = [Float](repeating: 0, count: size.width * size.height)
+        var queue: [Box] = [Box(origin: (0, 0), size: (size.width, size.height))]
+
+        // 0. Set the corners to initial values if they haven't been set yet.
+        for p in queue.first!.corners {
+            let idx = ptToIndex(p)
+            if heightMap[idx] == 0.0 {
+                heightMap[idx] = Float.random(in: 0...1)
+            }
+        }
+
+        while queue.count > 0 {
+            let box = queue.removeFirst()
+            let halfSize = (w: box.size.w / 2 + 1, h: box.size.h / 2 + 1)
+
+            // 1. Diamond. Average the corners, add a random value. Set the midpoint.
+            let midpoint = box.midpoint
+            let cornerAverage = Float.random(in: 0...1) + 0.25 * box.corners.reduce(0.0) { (acc, pt) -> Float in
+                let index = ptToIndex(pt)
+                let value = heightMap[index]
+                return acc + value
+            }
+            let midptIdx = ptToIndex(midpoint)
+            heightMap[midptIdx] = cornerAverage
+
+            // 2. Square. Find the midpoints of the sides of this box. These four points are the origins of the new subdivided boxes.
+            for p in box.sideMidpoints {
+                // Find our diamond's corners, wrapping around the grid if needed.
+                let diamondCorners = [
+                    (x: p.x, y: p.y - halfSize.h), // North
+                    (x: p.x - halfSize.w, y: p.y), // West
+                    (x: p.x, y: (p.y + halfSize.h) % size.height), // South
+                    (x: (p.x + halfSize.w) % size.width, y: p.y), // West
+                ].map { (p: Box.Point) -> Box.Point in
+                    if p.x < 0 {
+                        return (x: p.x + size.width, y: p.y)
+                    } else if p.y < 0 {
+                        return (x: p.x, y: p.y + size.height)
+                    } else {
+                        return p
+                    }
+                }
+
+                let idx = ptToIndex(p)
+                let value = Float.random(in: 0...1) + 0.25 * diamondCorners.reduce(0) { (acc, pt) -> Float in
+                    let idx = ptToIndex(pt)
+                    let value = heightMap[idx]
+                    return acc + value
+                }
+                heightMap[idx] = value
+            }
+
+            // 3. Base case for this recursion is boxes of size 1. Subdivide this box into 4 and push them onto the queue.
+            if box.size.w > 1 || box.size.h > 1 {
+                let newSize = (w: midpoint.x - box.origin.x, h: midpoint.y - box.origin.y)
+                let newBoxes = [Box(origin: box.origin, size: newSize),
+                                Box(origin: midpoint, size: newSize),
+                                Box(origin: (box.origin.x, box.origin.1 + newSize.1), size: newSize),
+                                Box(origin: (box.origin.x + newSize.w, box.origin.y + newSize.h), size: newSize)]
+                queue.append(contentsOf: newBoxes)
+            }
+        }
+
+        let region = MTLRegion(origin: MTLOrigin(), size: size)
+        texture.replace(region: region, mipmapLevel: 0, withBytes: heightMap, bytesPerRow: MemoryLayout<Float>.stride * size.width)
+    }
+
+    // MARK: Algorithm
+
+    var outTexture: MTLTexture {
+        return texture
+    }
+
+    func encode(in encoder: MTLComputeCommandEncoder) {
+    }
+
+    func updateUniforms() {
+    }
+}

 /// Implementation of the Circles algorithm.
 //class CirclesAlgorithm: Algorithm {
--- a/Terrain2Tests/AlgorithmsTests.swift
+++ b/Terrain2Tests/AlgorithmsTests.swift
@ -0,0 +1,52 @@
+//
+//  AlgorithmsTests.swift
+//  Terrain2Tests
+//
+//  Created by Eryn Wells on 11/8/18.
+//  Copyright © 2018 Eryn Wells. All rights reserved.
+//
+
+import XCTest
+import Terrain2
+
+class DiamondSquareBoxTests: XCTestCase {
+    func testNorthwest() {
+        let box = DiamondSquareAlgorithm.Box(origin: DiamondSquareAlgorithm.Box.Point(x: 3, y: 4),
+                                             size: DiamondSquareAlgorithm.Box.Size(w: 5, h: 5))
+        let pt = box.northwest
+        XCTAssertEqual(pt.x, 3)
+        XCTAssertEqual(pt.y, 4)
+    }
+
+    func testNortheast() {
+        let box = DiamondSquareAlgorithm.Box(origin: DiamondSquareAlgorithm.Box.Point(x: 3, y: 4),
+                                             size: DiamondSquareAlgorithm.Box.Size(w: 5, h: 5))
+        let pt = box.northeast
+        XCTAssertEqual(pt.x, 8)
+        XCTAssertEqual(pt.y, 4)
+    }
+
+    func testSouthwest() {
+        let box = DiamondSquareAlgorithm.Box(origin: DiamondSquareAlgorithm.Box.Point(x: 3, y: 4),
+                                             size: DiamondSquareAlgorithm.Box.Size(w: 5, h: 5))
+        let pt = box.southwest
+        XCTAssertEqual(pt.x, 3)
+        XCTAssertEqual(pt.y, 9)
+    }
+
+    func testSoutheast() {
+        let box = DiamondSquareAlgorithm.Box(origin: DiamondSquareAlgorithm.Box.Point(x: 3, y: 4),
+                                             size: DiamondSquareAlgorithm.Box.Size(w: 5, h: 5))
+        let pt = box.southeast
+        XCTAssertEqual(pt.x, 8)
+        XCTAssertEqual(pt.y, 9)
+    }
+
+    func testMidpoint() {
+        let box = DiamondSquareAlgorithm.Box(origin: DiamondSquareAlgorithm.Box.Point(x: 3, y: 4),
+                                             size: DiamondSquareAlgorithm.Box.Size(w: 5, h: 5))
+        let midpoint = box.midpoint
+        XCTAssertEqual(midpoint.x, 6)
+        XCTAssertEqual(midpoint.y, 7)
+    }
+}