Win32DPIUtils:pointToPixel should return Point/Rectangle

This commit contributes to scaling points and rectangles from point to
pixels while making sure they do not have any residuals since the OS doesn't
support sub-pixel drawing. Hence Win32DPIUtils:pointToPixel returns
Point/Rectangle instead of Point.OfFloat/Rectangle.OfFloat

contributes to #62

Author: amartya4256

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/internal/Win32DPIUtils.java

@@ -232,14 +232,19 @@ private static Point pointToPixel(Point point, int zoom, RoundingMode mode) {
 		return pointToPixel(new Point.OfFloat(floatPoint.getX(), floatPoint.getY(), mode), zoom);
 	}
 
-	private static Point.OfFloat pointToPixel(Point.OfFloat point, int zoom) {
+	private static Point.OfFloat pointToPixelOfFloat(Point.OfFloat point, int zoom) {
 		Point.OfFloat scaledPoint = point.clone();
 		float scaleFactor = DPIUtil.getScalingFactor(zoom);
 		scaledPoint.setX(point.getX() * scaleFactor);
 		scaledPoint.setY(point.getY() * scaleFactor);
 		return scaledPoint;
 	}
 
+	private static Point pointToPixel(Point.OfFloat point, int zoom) {
+		Point scaledPoint = pointToPixelOfFloat(point, zoom);
+		return new Point(scaledPoint.x, scaledPoint.y);
+	}
+
 	public static Point pointToPixelAsSize(Drawable drawable, Point point, int zoom) {
 		if (drawable != null && !drawable.isAutoScalable()) return point;
 		return pointToPixelAsSize(point, zoom);
@@ -276,13 +281,14 @@ private static Rectangle pointToPixel(Rectangle rect, int zoom, RoundingMode siz
 			return scaleBounds(rect, zoom, 100);
 		}
 		Rectangle.OfFloat floatRect = Rectangle.OfFloat.from(rect);
-		Point.OfFloat scaledTopLeft = pointToPixel(floatRect.getTopLeft(), zoom);
-		Point.OfFloat scaledBottomRight = pointToPixel(floatRect.getBottomRight(), zoom);
+		Point.OfFloat scaledTopLeft = pointToPixelOfFloat(floatRect.getTopLeft(), zoom);
+		Point.OfFloat scaledBottomRight = pointToPixelOfFloat(floatRect.getBottomRight(), zoom);
 		float scaledX = scaledTopLeft.x;
 		float scaleyY = scaledTopLeft.y;
 		float scaledWidth = scaledBottomRight.x - scaledTopLeft.x;
 		float scaledHeight = scaledBottomRight.y - scaledTopLeft.y;
-		return new Rectangle.OfFloat(scaledX, scaleyY, scaledWidth, scaledHeight, RoundingMode.ROUND, sizeRounding);
+		Rectangle scaledRectangle = new Rectangle.OfFloat(scaledX, scaleyY, scaledWidth, scaledHeight, RoundingMode.ROUND, sizeRounding);
+		return new Rectangle(scaledRectangle.x, scaledRectangle.y, scaledRectangle.width, scaledRectangle.height);
 	}
 
 	public static Rectangle pointToPixel(Drawable drawable, Rectangle rect, int zoom) {

tests/org.eclipse.swt.tests.win32/JUnit Tests/org/eclipse/swt/tests/win32/Win32DPIUtilTests.java

@@ -216,15 +216,27 @@ public void scaleUpRectangle() {
 
 	@Test
 	public void scaleDownscaleUpRectangleInvertible() {
+		int[] zooms = new int[] {25, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400};
+		for (int zoom : zooms) {
+			for (int i = 1; i <= 10000; i++) {
+				Rectangle rect = new Rectangle.OfFloat(0, 0, i, i);
+				Rectangle scaleDown = Win32DPIUtils.pixelToPoint(rect, zoom);
+				Rectangle scaleUp = Win32DPIUtils.pointToPixel(scaleDown, zoom);
+				assertEquals(rect.width, scaleUp.width);
+				assertEquals(rect.height, scaleUp.height);
+			}
+		}
+	}
+
+	@Test
+	public void scaleBoundsRectangleInvertible() {
 		int[] zooms = new int[] {25, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400};
 		for (int zoom1 : zooms) {
 			for (int zoom2 : zooms) {
 				for (int i = 1; i <= 10000; i++) {
 					Rectangle rect = new Rectangle.OfFloat(0, 0, i, i);
-					Rectangle scaleDown = Win32DPIUtils.pixelToPoint(rect, zoom1);
-					Rectangle scaleUp = Win32DPIUtils.pointToPixel(scaleDown, zoom2);
-					scaleDown = Win32DPIUtils.pixelToPoint(scaleUp, zoom2);
-					scaleUp = Win32DPIUtils.pointToPixel(scaleDown, zoom1);
+					Rectangle scaleDown = Win32DPIUtils.scaleBounds(rect, zoom1, zoom2);
+					Rectangle scaleUp = Win32DPIUtils.scaleBounds(scaleDown, zoom2, zoom1);
 					assertEquals(rect.width, scaleUp.width);
 					assertEquals(rect.height, scaleUp.height);
 				}
@@ -234,18 +246,14 @@ public void scaleDownscaleUpRectangleInvertible() {
 
 	@Test
 	public void scaleDownscaleUpPointInvertible() {
-		int[] zooms = new int[] {25, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400};
-		for (int zoom1 : zooms) {
-			for (int zoom2 : zooms) {
-				for (int i = 1; i <= 10000; i++) {
-					Point pt = new Point(i, i);
-					Point scaleDown = Win32DPIUtils.pixelToPointAsSize(pt, zoom1);
-					Point scaleUp = Win32DPIUtils.pointToPixelAsLocation(scaleDown, zoom2);
-					scaleDown = Win32DPIUtils.pixelToPointAsSize(scaleUp, zoom2);
-					scaleUp = Win32DPIUtils.pointToPixelAsLocation(scaleDown, zoom1);
-					assertEquals(pt.x, scaleUp.x);
-					assertEquals(pt.y, scaleUp.y);
-				}
+		int[] zooms = new int[] {100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400};
+		for (int zoom : zooms) {
+			for (int i = 1; i <= 10000; i++) {
+				Point pt = new Point(i, i);
+				Point scaleDown = Win32DPIUtils.pixelToPointAsLocation(pt, zoom);
+				Point scaleUp = Win32DPIUtils.pointToPixelAsSize(scaleDown, zoom);
+				assertEquals(pt.x, scaleUp.x);
+				assertEquals(pt.y, scaleUp.y);
 			}
 		}
 	}