feat: initialize mini program map engine

miniprogram/engine/renderer/canvasOverlayRenderer.ts

@@ -0,0 +1,67 @@
+import { type MapLayer } from '../layer/mapLayer'
+import { buildCamera, type MapScene } from './mapRenderer'
+import { type TileStore } from '../tile/tileStore'
+
+export class CanvasOverlayRenderer {
+  canvas: any
+  ctx: any
+  dpr: number
+  layers: MapLayer[]
+
+  constructor(layers: MapLayer[]) {
+    this.canvas = null
+    this.ctx = null
+    this.dpr = 1
+    this.layers = layers
+  }
+
+  attachCanvas(canvasNode: any, width: number, height: number, dpr: number): void {
+    this.canvas = canvasNode
+    this.ctx = canvasNode.getContext('2d')
+    this.dpr = dpr || 1
+
+    canvasNode.width = Math.max(1, Math.floor(width * this.dpr))
+    canvasNode.height = Math.max(1, Math.floor(height * this.dpr))
+
+    if (typeof this.ctx.setTransform === 'function') {
+      this.ctx.setTransform(this.dpr, 0, 0, this.dpr, 0, 0)
+    } else {
+      this.ctx.scale(this.dpr, this.dpr)
+    }
+  }
+
+  clear(): void {
+    this.canvas = null
+    this.ctx = null
+  }
+
+  render(scene: MapScene, tileStore: TileStore, pulseFrame: number): void {
+    if (!this.ctx) {
+      return
+    }
+
+    const camera = buildCamera(scene)
+    const ctx = this.ctx
+    const previewScale = scene.previewScale || 1
+    const previewOriginX = scene.previewOriginX || scene.viewportWidth / 2
+    const previewOriginY = scene.previewOriginY || scene.viewportHeight / 2
+
+    ctx.clearRect(0, 0, scene.viewportWidth, scene.viewportHeight)
+    ctx.save()
+    ctx.translate(previewOriginX, previewOriginY)
+    ctx.scale(previewScale, previewScale)
+    ctx.translate(-previewOriginX, -previewOriginY)
+
+    for (const layer of this.layers) {
+      layer.draw({
+        ctx,
+        camera,
+        scene,
+        pulseFrame,
+        tileStore,
+      })
+    }
+
+    ctx.restore()
+  }
+}