Prototype

terrain.js

@@ -0,0 +1,20 @@
+import {createCanvas, drawRect, clipCanvas} from './gfx.js';
+
+export function createTerrain(width, height) {
+  const terrain = createCanvas(width, height);
+  generateTerrain(terrain, width, height);
+  return terrain;
+}
+
+export function generateTerrain(ctx, width, height) {
+  drawRect(ctx, 0, height-80, width, 80, 'burlywood');
+}
+
+export function isTerrain(ctx, x, y) {
+  const imageData = ctx.getImageData(x, y, 1, 1);
+  return imageData.data[3] > 0;
+}
+
+export function clipTerrain(ctx, fn) {
+  return clipCanvas(ctx, fn);
+}