feat: add collision check on shape drop.

main.go

@@ -48,7 +48,13 @@ func main() {
 
 	for !rl.WindowShouldClose() {
 		if dropTimer.UpdateReset(rl.GetFrameTime()) {
-			shape_pos.Y += 1
+			new_pos := shape_pos
+			new_pos.Y += 1
+
+			// Update position if it does not collide
+			if !game.CheckShapeCollision(new_pos, &shape, &grid) {
+				shape_pos = new_pos
+			}
 		}
 
 		render.Begin(r.Theme.GridBackground)