Add guidance scale.

Diffusion-macOS/ControlsView.swift

@@ -54,6 +54,7 @@ struct ControlsView: View {
     @State private var model = Settings.shared.currentModel.modelVersion
     @State private var disclosedModel = true
     @State private var disclosedPrompt = true
+    @State private var disclosedGuidance = false
     @State private var disclosedSteps = false
     @State private var disclosedSeed = false
 
@@ -134,6 +135,17 @@ struct ControlsView: View {
                     
                     Divider()
 
+                    DisclosureGroup(isExpanded: $disclosedGuidance) {
+                        CompactSlider(value: $generation.guidanceScale, in: 0...20, step: 0.5) {
+                            Text("Guidance Scale")
+                            Spacer()
+                            Text(generation.guidanceScale.formatted("%.1f"))
+                        }.padding(.leading, 10)
+                    } label: {
+                        Label("Guidance Scale", systemImage: "scalemass").foregroundColor(.secondary)
+                    }
+                    Divider()
+
                     DisclosureGroup(isExpanded: $disclosedSteps) {
                         CompactSlider(value: $generation.steps, in: 0...150, step: 5) {
                             Text("Steps")

Diffusion/Pipeline/Pipeline.swift

@@ -29,7 +29,15 @@ class Pipeline {
         self.pipeline = pipeline
     }
     
-    func generate(prompt: String, negativePrompt: String = "", scheduler: StableDiffusionScheduler, numInferenceSteps stepCount: Int = 50, seed: UInt32? = nil) throws -> (CGImage, TimeInterval) {
+    func generate(
+        prompt: String,
+        negativePrompt: String = "",
+        scheduler: StableDiffusionScheduler,
+        numInferenceSteps stepCount: Int = 50,
+        seed: UInt32? = nil,
+        guidanceScale: Float = 7.5,
+        disableSafety: Bool = false
+    ) throws -> (CGImage, TimeInterval) {
         let beginDate = Date()
         print("Generating...")
         let theSeed = seed ?? UInt32.random(in: 0..<UInt32.max)
@@ -39,6 +47,8 @@ class Pipeline {
             imageCount: 1,
             stepCount: stepCount,
             seed: theSeed,
+            guidanceScale: guidanceScale,
+            disableSafety: disableSafety,
             scheduler: scheduler
         ) { progress in
             handleProgress(progress)

Diffusion/State.swift

@@ -44,13 +44,23 @@ class GenerationContext: ObservableObject {
     @Published var steps = 25.0
     @Published var numImages = 1.0
     @Published var seed = -1.0
+    @Published var guidanceScale = 7.5
+    @Published var disableSafety = false
 
     private var progressSubscriber: Cancellable?
 
     func generate() async -> (CGImage, TimeInterval)? {
         guard let pipeline = pipeline else { return nil }
         let seed = self.seed >= 0 ? UInt32(self.seed) : nil
-        return try? pipeline.generate(prompt: positivePrompt, negativePrompt: negativePrompt, scheduler: scheduler, numInferenceSteps: Int(steps), seed: seed)
+        return try? pipeline.generate(
+            prompt: positivePrompt,
+            negativePrompt: negativePrompt,
+            scheduler: scheduler,
+            numInferenceSteps: Int(steps),
+            seed: seed,
+            guidanceScale: Float(guidanceScale),
+            disableSafety: disableSafety
+        )
     }
 }
 

Diffusion/Utils.swift

@@ -9,3 +9,9 @@
 import Foundation
 
 extension String: Error {}
+
+extension Double {
+    func formatted(_ format: String) -> String {
+        return String(format: "\(format)", self)
+    }
+}