Initial Commit

src/lib/platforms.js

@@ -0,0 +1,48 @@
+import { WORLD, VIEWPORT } from "./config.js";
+
+export function createPlatforms() {
+    const result = [];
+    const count = 16;
+    const spacing = 145;
+
+    for (let index = 0; index < count; index += 1) {
+        const width = index === 0 ? 220 : 150 + (index % 4) * 34;
+        const x = index === 0 ? (WORLD.width - width) / 2 : 40 + ((index * 173) % (WORLD.width - width - 80));
+        const y = WORLD.height - 70 - index * spacing;
+
+        result.push({
+            id: index + 1,
+            x,
+            y,
+            width,
+            height: 22,
+        });
+    }
+
+    return result;
+}
+
+export function getVisiblePlatforms(platforms, camera) {
+    return platforms
+        .filter((platform) => isPlatformVisible(platform, camera))
+        .map((platform) => ({
+            ...platform,
+            local: worldToViewport(platform, camera),
+        }));
+}
+
+export function isPlatformVisible(platform, camera) {
+    return (
+        platform.x + platform.width >= camera.x &&
+        platform.x <= camera.x + VIEWPORT.width &&
+        platform.y + platform.height >= camera.y &&
+        platform.y <= camera.y + VIEWPORT.height
+    );
+}
+
+export function worldToViewport(point, camera) {
+    return {
+        x: point.x - camera.x,
+        y: point.y - camera.y,
+    };
+}