iOS retina support (#1185)

examples/common/entry/entry_ios.mm

@@ -247,6 +247,8 @@ static	void* m_device = NULL;
 	BX_UNUSED(touches);
 	UITouch *touch = [[event allTouches] anyObject];
 	CGPoint touchLocation = [touch locationInView:self];
+	touchLocation.x *= self.contentScaleFactor;
+	touchLocation.y *= self.contentScaleFactor;
 
 	s_ctx->m_eventQueue.postMouseEvent(s_defaultWindow, touchLocation.x, touchLocation.y, 0);
 	s_ctx->m_eventQueue.postMouseEvent(s_defaultWindow, touchLocation.x, touchLocation.y, 0, MouseButton::Left, true);
@@ -257,6 +259,9 @@ static	void* m_device = NULL;
 	BX_UNUSED(touches);
 	UITouch *touch = [[event allTouches] anyObject];
 	CGPoint touchLocation = [touch locationInView:self];
+	touchLocation.x *= self.contentScaleFactor;
+	touchLocation.y *= self.contentScaleFactor;
+	
 	s_ctx->m_eventQueue.postMouseEvent(s_defaultWindow, touchLocation.x, touchLocation.y, 0, MouseButton::Left, false);
 }
 
@@ -265,6 +270,9 @@ static	void* m_device = NULL;
 	BX_UNUSED(touches);
 	UITouch *touch = [[event allTouches] anyObject];
 	CGPoint touchLocation = [touch locationInView:self];
+	touchLocation.x *= self.contentScaleFactor;
+	touchLocation.y *= self.contentScaleFactor;
+
 	s_ctx->m_eventQueue.postMouseEvent(s_defaultWindow, touchLocation.x, touchLocation.y, 0);
 }
 
@@ -273,6 +281,9 @@ static	void* m_device = NULL;
 	BX_UNUSED(touches);
 	UITouch *touch = [[event allTouches] anyObject];
 	CGPoint touchLocation = [touch locationInView:self];
+	touchLocation.x *= self.contentScaleFactor;
+	touchLocation.y *= self.contentScaleFactor;
+	
 	s_ctx->m_eventQueue.postMouseEvent(s_defaultWindow, touchLocation.x, touchLocation.y, 0, MouseButton::Left, false);
 }
 
@@ -312,8 +323,7 @@ static	void* m_device = NULL;
 
 	[m_window makeKeyAndVisible];
 
-	//float scaleFactor = [[UIScreen mainScreen] scale]; // should use this, but needs to further pass the value to the `nvgBeginFrame()` call's `devicePixelRatio` parameter in `ExampleNanoVG` class' `update()` method so it can actually work properly.
-	float scaleFactor = 1.0f;
+	float scaleFactor = [[UIScreen mainScreen] scale];
 	[m_view setContentScaleFactor: scaleFactor ];
 
 	s_ctx = new Context((uint32_t)(scaleFactor*rect.size.width), (uint32_t)(scaleFactor*rect.size.height));