Rotate landscape 180 degrees

assets/index.html

@@ -37,6 +37,15 @@
             height = canvas.height = window.innerHeight;
         }
 
+        function rotatePoint(point, angle) {
+            const cos = Math.cos(angle);
+            const sin = Math.sin(angle);
+            return {
+                x: point.x * cos - point.z * sin,
+                z: point.x * sin + point.z * cos
+            };
+        }
+
         window.addEventListener('resize', resize);
         resize();
 
@@ -52,9 +61,10 @@
             }
 
             project() {
+                const rotated = rotatePoint(this, Math.PI);
                 const scale = camera.fov / (camera.fov + this.z);
-                const xIso = this.x - this.z;
-                const yIso = (this.x + this.z) * 0.5;
+                const xIso = rotated.x - rotated.z;
+                const yIso = (rotated.x + rotated.z) * 0.5;
                 const x2d = xIso * scale + width / 2;
                 const y2d = yIso * scale + height / 2;
                 return { x: x2d, y: y2d, scale: scale };