[update] Implemented clamping an actor's position.

sjplayer/src/sjplayer/Actor.d

@@ -12,6 +12,9 @@ class Actor {
     speed = vec2(0, 0);
     color = vec4(0, 0, 0, 0);
 
+    clip_lefttop     = vec2(0, 0);
+    clip_rightbottom = vec2(0, 0);
+
     program_ = program;
   }
 
@@ -20,10 +23,18 @@ class Actor {
     program_.Draw(pos, speed, color);
   }
 
+  ///
   vec2 pos;
+  ///
   vec2 speed;
+  ///
   vec4 color;
 
+  ///
+  vec2 clip_lefttop;
+  ///
+  vec2 clip_rightbottom;
+
  private:
   ActorProgram program_;
 }

sjplayer/src/sjplayer/ActorController.d

@@ -50,7 +50,13 @@ class ActorController : ActorScheduledController, ActorControllerInterface {
     }
 
     actor_.pos += actor_.speed;
-    // TODO: clamping the actor position
+
+    const left_edge   = -1 + actor_.clip_lefttop.x;
+    const right_edge  = 1 - actor_.clip_rightbottom.x;
+    const top_edge    = 1 - actor_.clip_lefttop.y;
+    const bottom_edge = -1 + actor_.clip_rightbottom.y;
+    actor_.pos.x = actor_.pos.x.clamp(left_edge, right_edge);
+    actor_.pos.y = actor_.pos.y.clamp(bottom_edge, top_edge);
 
     actor_.speed *= 1-SpeedAttenuation;
   }
@@ -72,6 +78,11 @@ private alias ActorScheduledController = ScheduledController!(
       "color_g": "color.g",
       "color_b": "color.b",
       "color_a": "color.a",
+
+      "clip_left":   "clip_lefttop.x",
+      "clip_top":    "clip_lefttop.y",
+      "clip_right":  "clip_rightbottom.x",
+      "clip_bottom": "clip_rightbottom.y",
     ]
   );