dirty initial commit

game/CanvasAdapter.js

@@ -0,0 +1,58 @@
+import BoundingRectangle from './BoundingRectangle.js'
+
+export default class CanvasAdapter {
+  constructor(canvas) {
+    this._canvas = canvas
+    this._ctx = this._canvas.getContext('2d')
+    this._w = this._canvas.width
+    this._h = this._canvas.height
+    this._boundingRect = new BoundingRectangle(0, this._w - 1, 0, this._h - 1)
+
+    this._imageData = this._ctx.createImageData(this._w, this._h)
+    this._data = this._imageData.data
+
+    this.width = this._w
+    this.height = this._h
+  }
+
+  clear() {
+    this._imageData = this._ctx.createImageData(this._w, this._h)
+    this._data = this._imageData.data
+    this.apply()
+  }
+
+  getPix(x, y, out) {
+    if (x < 0 || y < 0 || x >= this._w || y >= this._h) {
+      return false;
+    }
+    x = Math.round(x)
+    y = Math.round(y)
+    const idx = (y * 4 * this._w) + (x * 4)
+    out[0] = this._data[idx]
+    out[1] = this._data[idx + 1]
+    out[2] = this._data[idx + 2]
+    out[3] = this._data[idx + 3]
+    return true
+  }
+
+  putPix(x, y, rgba) {
+    if (x < 0 || y < 0 || x >= this._w || y >= this._h) {
+      return null;
+    }
+    x = Math.round(x)
+    y = Math.round(y)
+    const idx = (y * 4 * this._w) + (x * 4)
+    this._data[idx] = rgba[0]
+    this._data[idx + 1] = rgba[1]
+    this._data[idx + 2] = rgba[2]
+    this._data[idx + 3] = rgba[3]
+  }
+
+  getBoundingRect() {
+    return this._boundingRect
+  }
+
+  apply() {
+    this._ctx.putImageData(this._imageData, 0, 0)
+  }
+}