delayed the creation of StableDiffusionPipeline until the first image generation.

.gitignore

@@ -3,6 +3,7 @@
 # gitignore contributors: remember to update Global/Xcode.gitignore, Objective-C.gitignore & Swift.gitignore
 
 # avoid checking CoreML models
+CoreMLModels
 merges.txt
 vocab.json
 *.mlmodelc

README.md

@@ -5,8 +5,8 @@
 A minimal iOS app that generates images using Stable Diffusion v2.
 You can create images specifying any prompt (text) such as "a photo of an astronaut riding a horse on mars".
 
-- macOS 13.1 beta 4 or newer, Xcode 14.1
-- iPhone 12+ / iOS 16.2 beta 4 or newer, iPad Pro with M1/M2 / iPadOS 16.2 beta 4 or newer
+- macOS 13.1 RC or newer, Xcode 14.2 or newer
+- iPhone 12+ / iOS 16.2 RC or newer, iPad Pro with M1/M2 / iPadOS 16.2 RC or newer
 
 You can run the app on above mobile devices.
 And you can run the app on Mac, building as a Designed for iPad app.
@@ -24,6 +24,16 @@ You can see how it works through the simple sample code.
 
 ![Image](images/ss0_1280.png)
 
+## Change Log
+
+- [1.0.1 (2)] - 2022-12-08 `[Changed]`
+    - Changed to delay creation of `StableDiffusionPipeline` until the first image 
+    generation and execute it in a background task.
+    - This eliminates the freeze when starting the app, but it takes time 
+    to generate the first image.
+    - Tested with Xcode 4.2 RC and macOS 13.1 RC.
+    - With the release of Xcode 14.2 RC, the correct Target OS 16.2 was specified.
+
 ## Convert CoreML models
 
 Convert the PyTorch SD2 model to CoreML models, following Apple's instructions.

imggensd2.xcodeproj/project.pbxproj

@@ -305,7 +305,7 @@
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = AccentColor;
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 1;
+				CURRENT_PROJECT_VERSION = 2;
 				DEVELOPMENT_ASSET_PATHS = "\"imggensd2/Preview Content\"";
 				DEVELOPMENT_TEAM = J5CY9Q9UP5;
 				ENABLE_PREVIEWS = YES;
@@ -320,7 +320,7 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				MARKETING_VERSION = 1.0;
+				MARKETING_VERSION = 1.0.1;
 				PRODUCT_BUNDLE_IDENTIFIER = com.atarayosd.imggensd2;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_EMIT_LOC_STRINGS = YES;
@@ -335,7 +335,7 @@
 				ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = AccentColor;
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 1;
+				CURRENT_PROJECT_VERSION = 2;
 				DEVELOPMENT_ASSET_PATHS = "\"imggensd2/Preview Content\"";
 				DEVELOPMENT_TEAM = J5CY9Q9UP5;
 				ENABLE_PREVIEWS = YES;
@@ -350,7 +350,7 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				MARKETING_VERSION = 1.0;
+				MARKETING_VERSION = 1.0.1;
 				PRODUCT_BUNDLE_IDENTIFIER = com.atarayosd.imggensd2;
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_EMIT_LOC_STRINGS = YES;

imggensd2/ImageGenerator.swift

@@ -49,25 +49,19 @@ final class ImageGenerator: ObservableObject {
 
     @Published var generationState: GenerationState = .idle
     @Published var generatedImages: GeneratedImages?
-    private let sdpipeline: StableDiffusionPipeline
+    private var sdPipeline: StableDiffusionPipeline?
 
     init() {
-        guard let path = Bundle.main.path(forResource: "CoreMLModels", ofType: nil, inDirectory: nil) else {
-            fatalError("Fatal error: failed to find the CoreML models.")
-        }
-        let resourceURL = URL(fileURLWithPath: path)
-        // TODO: move the pipeline creation to background task because it's heavy
-        if let pipeline = try? StableDiffusionPipeline(resourcesAt: resourceURL) {
-            sdpipeline = pipeline
-        } else {
-            fatalError("Fatal error: failed to create the Stable-Diffusion-Pipeline.")
-        }
     }
 
     func setState(_ state: GenerationState) { // for actor isolation
         generationState = state
     }
 
+    func setPipeline(_ pipeline: StableDiffusionPipeline) { // for actor isolation
+        sdPipeline = pipeline
+    }
+
     func setGeneratedImages(_ images: GeneratedImages) { // for actor isolation
         generatedImages = images
     }
@@ -76,30 +70,49 @@ final class ImageGenerator: ObservableObject {
         guard generationState == .idle else { return }
         Task.detached(priority: .high) {
             await self.setState(.generating(progressStep: 0))
-            do {
-                //  generateImages(prompt: String, imageCount: Int = 1, stepCount: Int = 50, seed: Int = 0,
-                //  disableSafety: Bool = false,
-                //  progressHandler: (StableDiffusionPipeline.Progress) -> Bool = { _ in true }) throws -> [CGImage?]
-                // TODO: use the progressHandler
-                let cgImages = try self.sdpipeline.generateImages(prompt: parameter.prompt,
+
+            if await self.sdPipeline == nil {
+                guard let path = Bundle.main.path(forResource: "CoreMLModels", ofType: nil, inDirectory: nil) else {
+                    fatalError("Fatal error: failed to find the CoreML models.")
+                }
+                let resourceURL = URL(fileURLWithPath: path)
+
+                if let pipeline = try? StableDiffusionPipeline(resourcesAt: resourceURL) {
+                    await self.setPipeline(pipeline)
+                } else {
+                    fatalError("Fatal error: failed to create the Stable-Diffusion-Pipeline.")
+                }
+            }
+
+            if let sdPipeline = await self.sdPipeline {
+                do {
+                    //  API:
+                    //  generateImages(prompt: String, imageCount: Int = 1, stepCount: Int = 50, seed: Int = 0,
+                    //  disableSafety: Bool = false,
+                    //  progressHandler: (StableDiffusionPipeline.Progress) -> Bool = { _ in true })
+                    //  throws -> [CGImage?]
+                    //  TODO: use the progressHandler
+                    let cgImages = try sdPipeline.generateImages(prompt: parameter.prompt,
+                                                                 imageCount: parameter.imageCount,
+                                                                 stepCount: parameter.stepCount,
+                                                                 seed: parameter.seed,
+                                                                 disableSafety: parameter.disableSafety)
+                    print("images were generated.")
+                    let uiImages = cgImages.compactMap { image in
+                        if let cgImage = image { return UIImage(cgImage: cgImage)
+                        } else { return nil }
+                    }
+                    await self.setGeneratedImages(GeneratedImages(prompt: parameter.prompt,
                                                                   imageCount: parameter.imageCount,
                                                                   stepCount: parameter.stepCount,
                                                                   seed: parameter.seed,
-                                                                  disableSafety: parameter.disableSafety)
-                print("images were generated.")
-                let uiImages = cgImages.compactMap { image in
-                    if let cgImage = image { return UIImage(cgImage: cgImage)
-                    } else { return nil }
+                                                                  disableSafety: parameter.disableSafety,
+                                    images: uiImages.map { uiImage in GeneratedImage(uiImage: uiImage) }))
+                } catch {
+                    print("failed to generate images.")
                 }
-                await self.setGeneratedImages(GeneratedImages(prompt: parameter.prompt,
-                                                              imageCount: parameter.imageCount,
-                                                              stepCount: parameter.stepCount,
-                                                              seed: parameter.seed,
-                                                              disableSafety: parameter.disableSafety,
-                                           images: uiImages.map { uiImage in GeneratedImage(uiImage: uiImage) }))
-            } catch {
-                print("failed.")
             }
+
             await self.setState(.idle)
         }
     }