diff --git a/ui/cocoa/cocoa.go b/ui/cocoa/cocoa.go
index e10c9432a..673dec3d5 100644
--- a/ui/cocoa/cocoa.go
+++ b/ui/cocoa/cocoa.go
@@ -4,13 +4,13 @@ package cocoa
 // #cgo LDFLAGS: -framework Cocoa -framework OpenGL -framework QuartzCore
 //
 // #include <stdlib.h>
+// #include "input.h"
 //
 // void Run(size_t width, size_t height, size_t scale, const char* title);
 //
 import "C"
 import (
 	"github.com/hajimehoshi/go.ebiten"
-	// "github.com/hajimehoshi/go.ebiten/graphics"
 	"github.com/hajimehoshi/go.ebiten/graphics/opengl"
 	"time"
 	"unsafe"
@@ -55,8 +55,26 @@ func ebiten_EbitenOpenGLView_Updating() {
 }
 
 //export ebiten_EbitenOpenGLView_InputUpdated
-func ebiten_EbitenOpenGLView_InputUpdated(x, y C.int) {
-	currentUI.input <- ebiten.InputState{int(x), int(y)}
+func ebiten_EbitenOpenGLView_InputUpdated(inputType C.int, cx, cy C.int) {
+	if inputType == C.InputTypeMouseUp {
+		currentUI.input <- ebiten.InputState{-1, -1}
+		return
+	}
+
+	x, y := int(cx), int(cy)
+	x /= currentUI.screenScale
+	y /= currentUI.screenScale
+	if x < 0 {
+		x = 0
+	} else if currentUI.screenWidth <= x {
+		x = currentUI.screenWidth - 1
+	}
+	if y < 0 {
+		y = 0
+	} else if currentUI.screenHeight <= y {
+		y = currentUI.screenHeight - 1
+	}
+	currentUI.input <- ebiten.InputState{x, y}
 }
 
 func Run(game ebiten.Game, screenWidth, screenHeight, screenScale int,
diff --git a/ui/cocoa/ebiten_opengl_view.c b/ui/cocoa/ebiten_opengl_view.c
index 616448b07..6e429fa8d 100644
--- a/ui/cocoa/ebiten_opengl_view.c
+++ b/ui/cocoa/ebiten_opengl_view.c
@@ -1,10 +1,11 @@
 // -*- objc -*-
 
 #include "ebiten_opengl_view.h"
+#include "input.h"
 
 void ebiten_EbitenOpenGLView_Initialized(void);
 void ebiten_EbitenOpenGLView_Updating(void);
-void ebiten_EbitenOpenGLView_InputUpdated(int x, int y);
+void ebiten_EbitenOpenGLView_InputUpdated(enum InputType inputType, int x, int y);
 
 // Reference:
 //   http://developer.apple.com/library/mac/#qa/qa1385/_index.html
@@ -32,9 +33,6 @@ EbitenDisplayLinkCallback(CVDisplayLinkRef displayLink,
 @implementation EbitenOpenGLView {
 @private
   CVDisplayLinkRef displayLink_;
-  size_t screenWidth_;
-  size_t screenHeight_;
-  size_t screenScale_;
 }
 
 - (void)dealloc {
@@ -85,50 +83,26 @@ EbitenDisplayLinkCallback(CVDisplayLinkRef displayLink,
 - (void)mouseDown:(NSEvent*)theEvent {
   NSPoint location = [self convertPoint:[theEvent locationInWindow]
                                fromView:nil];
-  int x = location.x / self->screenScale_;
-  int y = location.y / self->screenScale_;
-  if (x < 0) {
-    x = 0;
-  } else if (self->screenWidth_<= x) {
-    x = self->screenWidth_ - 1;
-  }
-  if (y < 0) {
-    y = 0;
-  } else if (self->screenHeight_<= y) {
-    y = self->screenHeight_ - 1;
-  }
-  ebiten_EbitenOpenGLView_InputUpdated(x, y);
+  int x = location.x;
+  int y = location.y;
+  ebiten_EbitenOpenGLView_InputUpdated(InputTypeMouseDown, x, y);
 }
 
 - (void)mouseUp:(NSEvent*)theEvent {
   (void)theEvent;
-  ebiten_EbitenOpenGLView_InputUpdated(-1, -1);
+  NSPoint location = [self convertPoint:[theEvent locationInWindow]
+                               fromView:nil];
+  int x = location.x;
+  int y = location.y;
+  ebiten_EbitenOpenGLView_InputUpdated(InputTypeMouseUp, x, y);
 }
 
 - (void)mouseDragged:(NSEvent*)theEvent {
   NSPoint location = [self convertPoint:[theEvent locationInWindow]
                                fromView:nil];
-  int x = location.x / self->screenScale_;
-  int y = location.y / self->screenScale_;
-  if (x < 0) {
-    x = 0;
-  } else if (self->screenWidth_<= x) {
-    x = self->screenWidth_ - 1;
-  }
-  if (y < 0) {
-    y = 0;
-  } else if (self->screenHeight_<= y) {
-    y = self->screenHeight_ - 1;
-  }
-  ebiten_EbitenOpenGLView_InputUpdated(x, y);
-}
-
-- (void)setScreenWidth:(size_t)screenWidth
-          screenHeight:(size_t)screenHeight
-           screenScale:(size_t)screenScale {
-  self->screenWidth_ = screenWidth;
-  self->screenHeight_ = screenHeight;
-  self->screenScale_ = screenScale;
+  int x = location.x;
+  int y = location.y;
+  ebiten_EbitenOpenGLView_InputUpdated(InputTypeMouseDragged, x, y);
 }
 
 @end
diff --git a/ui/cocoa/ebiten_opengl_view.h b/ui/cocoa/ebiten_opengl_view.h
index a4f6b98da..802065c0a 100644
--- a/ui/cocoa/ebiten_opengl_view.h
+++ b/ui/cocoa/ebiten_opengl_view.h
@@ -9,9 +9,6 @@
 @interface EbitenOpenGLView : NSOpenGLView
 
 - (CVReturn)getFrameForTime:(CVTimeStamp const*)outputTime;
-- (void)setScreenWidth:(size_t)screenWidth
-          screenHeight:(size_t)screenHeight
-           screenScale:(size_t)screenScale;
 
 @end
 
diff --git a/ui/cocoa/input.h b/ui/cocoa/input.h
new file mode 100644
index 000000000..3042a5bca
--- /dev/null
+++ b/ui/cocoa/input.h
@@ -0,0 +1,10 @@
+#ifndef GO_EBITEN_UI_COCOA_INPUT_H_
+#define GO_EBITEN_UI_COCOA_INPUT_H_
+
+enum InputType {
+  InputTypeMouseUp,
+  InputTypeMouseDragged,
+  InputTypeMouseDown,
+};
+
+#endif
diff --git a/ui/cocoa/run.c b/ui/cocoa/run.c
index 9689b2697..cc8dd34ba 100644
--- a/ui/cocoa/run.c
+++ b/ui/cocoa/run.c
@@ -24,9 +24,6 @@ static NSWindow* generateWindow(size_t width, size_t height, size_t scale, const
   EbitenOpenGLView* glView =
     [[EbitenOpenGLView alloc] initWithFrame:rect
                                 pixelFormat:format];
-  [glView setScreenWidth:width
-            screenHeight:height
-             screenScale:scale];
   [window setContentView:glView];
   [window setTitle: [[NSString alloc] initWithUTF8String:title]];
   //[window makeFirstResponder:glView];
diff --git a/ui/glut/glut.go b/ui/glut/glut.go
index d5cab77f7..6384fe583 100644
--- a/ui/glut/glut.go
+++ b/ui/glut/glut.go
@@ -117,7 +117,7 @@ func Run(game ebiten.Game, screenWidth, screenHeight, screenScale int, title str
 		screenWidth, screenHeight, screenScale)
 	ui.graphicsDevice = graphicsDevice
 	graphicsDevice.Init()
-	
+
 	game.Init(ui.graphicsDevice.TextureFactory())
 
 	input := make(chan ebiten.InputState)
@@ -169,7 +169,7 @@ func Run(game ebiten.Game, screenWidth, screenHeight, screenScale int, title str
 
 	// Set the callbacks
 	C.setGlutFuncs()
-	
+
 	C.glutMainLoop()
 }