feat: implement canvas

2026-05-20 22:57:07 +02:00 · 2024-05-04 13:58:47 +07:00
parent 4c2cff3e7f
commit fb66b38230
54 changed files with 3035 additions and 1 deletions
@@ -0,0 +1,87 @@
+//
+//  CacheRenderPass.swift
+//  Memola
+//
+//  Created by Dscyre Scotti on 5/4/24.
+//
+
+import MetalKit
+import Foundation
+
+class CacheRenderPass: RenderPass {
+    var label: String = "Cache Render Pass"
+
+    var descriptor: MTLRenderPassDescriptor?
+
+    var cachePipelineState: MTLComputePipelineState?
+    var graphicPipelineState: MTLRenderPipelineState?
+
+    weak var graphicTexture: MTLTexture?
+    var cacheTexture: MTLTexture?
+
+    weak var strokeRenderPass: StrokeRenderPass?
+    weak var eraserRenderPass: EraserRenderPass?
+    var clearsTexture: Bool = true
+
+    init(renderer: Renderer) {
+        descriptor = MTLRenderPassDescriptor()
+        cachePipelineState = PipelineStates.createCachePipelineState(from: renderer)
+    }
+
+    func resize(on view: MTKView, to size: CGSize, with renderer: Renderer) {
+        guard size != .zero else { return }
+        cacheTexture = Textures.createCacheTexture(from: renderer, size: size, pixelFormat: view.colorPixelFormat)
+    }
+
+    func draw(on canvas: Canvas, with renderer: Renderer) {
+        guard let descriptor, let strokeRenderPass, let eraserRenderPass else { return }
+
+        copyTexture(on: canvas, with: renderer)
+
+        guard let graphicPipelineState else { return }
+        descriptor.colorAttachments[0].texture = cacheTexture
+        descriptor.colorAttachments[0].clearColor = MTLClearColor(red: 1, green: 1, blue: 1, alpha: 0)
+        descriptor.colorAttachments[0].loadAction = clearsTexture ? .clear : .load
+        descriptor.colorAttachments[0].storeAction = .store
+
+        if let stroke = canvas.graphicContext.currentStroke {
+            if stroke.isEraserPenStyle {
+                eraserRenderPass.stroke = stroke
+                eraserRenderPass.descriptor = descriptor
+                eraserRenderPass.draw(on: canvas, with: renderer)
+            } else {
+                canvas.setGraphicRenderType(.inProgress)
+                strokeRenderPass.stroke = stroke
+                strokeRenderPass.graphicDescriptor = descriptor
+                strokeRenderPass.graphicPipelineState = graphicPipelineState
+                strokeRenderPass.draw(on: canvas, with: renderer)
+            }
+            clearsTexture = false
+        }
+    }
+
+    private func copyTexture(on canvas: Canvas, with renderer: Renderer) {
+        guard let graphicTexture, let cacheTexture else { return }
+        guard let cachePipelineState else { return }
+        guard let copyCommandBuffer = renderer.commandQueue.makeCommandBuffer() else {
+            return
+        }
+        guard let computeEncoder = copyCommandBuffer.makeComputeCommandEncoder() else {
+            return
+        }
+        computeEncoder.label = label
+
+        computeEncoder.setComputePipelineState(cachePipelineState)
+        computeEncoder.setTexture(graphicTexture, index: 0)
+        computeEncoder.setTexture(cacheTexture, index: 1)
+        let threadgroupSize = MTLSize(width: 8, height: 8, depth: 1)
+        let threadgroupCount = MTLSize(
+            width: (graphicTexture.width + threadgroupSize.width - 1) / threadgroupSize.width,
+            height: (graphicTexture.height + threadgroupSize.height - 1) / threadgroupSize.height,
+            depth: 1
+        )
+        computeEncoder.dispatchThreadgroups(threadgroupCount, threadsPerThreadgroup: threadgroupSize)
+        computeEncoder.endEncoding()
+        copyCommandBuffer.commit()
+    }
+}