WIP

bundles/org.eclipse.swt/Eclipse SWT Custom Widgets/common/org/eclipse/swt/custom/StyledText.java

@@ -3886,6 +3886,31 @@ public int getLinePixel(int lineIndex) {
 	}
 	return height + topMargin;
 }
+
+public float getLinePixelFloat(int lineIndex) {
+	checkWidget();
+	int zoom = DPIUtil.getZoomForAutoscaleProperty(nativeZoom);
+	int lineCount = content.getLineCount();
+	lineIndex = Math.max(0, Math.min(lineCount, lineIndex));
+	if (isFixedLineHeight()) {
+		int lineHeight = renderer.getLineHeight();
+		float lh = DPIUtil.scaleDown((float) DPIUtil.scaleUp(lineHeight, zoom), zoom);
+		return lineIndex * lh - getVerticalScrollOffset() + topMargin;
+	}
+	if (lineIndex == topIndex)
+		return topIndexY + topMargin;
+	int height = topIndexY;
+	if (lineIndex > topIndex) {
+		for (int i = topIndex; i < lineIndex; i++) {
+			height += DPIUtil.scaleDown((float) DPIUtil.scaleUp(renderer.getLineHeight(i), zoom), zoom);
+		}
+	} else {
+		for (int i = topIndex - 1; i >= lineIndex; i--) {
+			height -= DPIUtil.scaleDown((float) DPIUtil.scaleUp(renderer.getLineHeight(i), zoom), zoom);
+		}
+	}
+	return height + topMargin;
+}
 /**
  * Returns the line index for a y, relative to the client area.
  * The line index returned is always in the range 0..lineCount - 1.

bundles/org.eclipse.swt/Eclipse SWT Custom Widgets/common/org/eclipse/swt/custom/StyledTextRenderer.java

@@ -184,7 +184,7 @@ public LineInfo(LineInfo info) {
 		}
 	}
 
-	private record LineDrawInfo(int index, TextLayout layout, String text, int offset, int height) {
+	private record LineDrawInfo(int index, TextLayout layout, String text, int offset, float height) {
 
 	}
 
@@ -466,7 +466,7 @@ private LineDrawInfo makeLineDrawInfo(int lineIndex) {
 	TextLayout layout = getTextLayout(lineIndex);
 	String text = content.getLine(lineIndex);
 	int offset = content.getOffsetAtLine(lineIndex);
-	int height = layout.getBounds().height;
+	float height = layout.getBounds().getHeight();
 	return new LineDrawInfo(lineIndex, layout, text, offset, height);
 }
 
@@ -483,6 +483,11 @@ int drawLines(int startLine, int endLine, int begX, int begY, int endY, GC gc, C
 	// still, I'd rather stay safe.
 	final boolean drawBackBeforeFore = (fixedLineMetrics != null);
 
+
+//	Rectangle bounds = styledText.getClientArea();
+//	gc.setBackground(widgetBackground);
+//	styledText.drawBackground(gc, bounds.x, bounds.y, bounds.width, bounds.height);
+
 	if (drawBackBeforeFore) {
 		// Cache drawing information
 		final List<LineDrawInfo> drawInfos = new ArrayList<>();
@@ -515,18 +520,18 @@ int drawLines(int startLine, int endLine, int begX, int begY, int endY, GC gc, C
 		return y - begY;
 	}
 
-	int y = begY;
+	float y = begY;
 	for (int iLine = startLine; y < endY && iLine < endLine; iLine++) {
 		LineDrawInfo lineInfo = makeLineDrawInfo(iLine);
 		drawLineBackground(lineInfo, y, gc, widgetBackground);
-		drawLineForeground(lineInfo, begX, y, gc, widgetForeground);
+		drawLineForeground(lineInfo, begX, (int) y, gc, widgetForeground);
 		disposeTextLayout(lineInfo.layout);
-		y += lineInfo.height;
+		y += lineInfo.height;			// Culprit
 	}
-	return y - begY;
+	return (int) y - begY;
 }
 
-private void drawLineBackground(LineDrawInfo lineInfo, int paintY, GC gc, Color widgetBackground) {
+private void drawLineBackground(LineDrawInfo lineInfo, float paintY, GC gc, Color widgetBackground) {
 	Rectangle client = styledText.getClientArea();
 	Color lineBackground = getLineBackground(lineInfo.index, null);
 	StyledTextEvent event = styledText.getLineBackgroundData(lineInfo.offset, lineInfo.text);
@@ -536,13 +541,13 @@ private void drawLineBackground(LineDrawInfo lineInfo, int paintY, GC gc, Color
 	if (lineBackground != null) {
 		if (verticalIndent > 0) {
 			gc.setBackground(widgetBackground);
-			gc.fillRectangle(client.x, paintY, client.width, verticalIndent);
+			gc.fillRectangle(new Rectangle.OfFloat(client.x, paintY, client.width, verticalIndent));
 		}
 		gc.setBackground(lineBackground);
-		gc.fillRectangle(client.x, paintY + verticalIndent, client.width, lineInfo.height - verticalIndent);
+		gc.fillRectangle(new Rectangle.OfFloat(client.x, paintY + verticalIndent, client.width, lineInfo.height - verticalIndent));
 	} else {
 		gc.setBackground(widgetBackground);
-		styledText.drawBackground(gc, client.x, paintY, client.width, lineInfo.height);
+		styledText.drawBackground(gc, new Rectangle.OfFloat(client.x, paintY, client.width, lineInfo.height));
 	}
 }
 

bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/graphics/Point.java

@@ -69,6 +69,16 @@ public Point (int x, int y) {
 	this.y = y;
 }
 
+public float getX() {
+	return x;
+}
+
+public float getY() {
+	return y;
+}
+
+
+
 /**
  * Compares the argument to the receiver, and returns true
  * if they represent the <em>same</em> object using a class
@@ -142,10 +152,12 @@ public OfFloat(float x, float y) {
 		this.residualY = y - this.y;
 	}
 
+	@Override
 	public float getX() {
 		return x + residualX;
 	}
 
+	@Override
 	public float getY() {
 		return y + residualY;
 	}

bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/graphics/Rectangle.java

@@ -87,6 +87,28 @@ public Rectangle (int x, int y, int width, int height) {
 	this.height = height;
 }
 
+
+
+public float getX() {
+	return x;
+}
+
+
+public float getY() {
+	return y;
+}
+
+
+public float getWidth() {
+	return width;
+}
+
+
+public float getHeight() {
+	return height;
+}
+
+
 /**
  * Destructively replaces the x, y, width and height values
  * in the receiver with ones which represent the union of the
@@ -424,18 +446,22 @@ public OfFloat(float x, float y, float width, float height) {
 		this.residualHeight = height - this.height;
 	}
 
+	@Override
 	public float getX() {
 		return x + residualX;
 	}
 
+	@Override
 	public float getY() {
 		return y + residualY;
 	}
 
+	@Override
 	public float getWidth() {
 		return width + residualWidth;
 	}
 
+	@Override
 	public float getHeight() {
 		return height + residualHeight;
 	}

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/GC.java

@@ -2405,6 +2405,13 @@ public void drawString (String string, int x, int y, boolean isTransparent) {
 	storeAndApplyOperationForExistingHandle(new DrawStringOperation(string, new Point(x, y), isTransparent));
 }
 
+public void drawString (String string, Point.OfFloat point, boolean isTransparent) {
+	checkNonDisposed();
+	if (string == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
+	if (string.isEmpty()) return;
+	storeAndApplyOperationForExistingHandle(new DrawStringOperation(string, point, isTransparent));
+}
+
 private class DrawStringOperation extends Operation {
 	private final String string;
 	private final Point location;

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/TextLayout.java

@@ -1799,7 +1799,8 @@ public Rectangle getBounds () {
 			width = Math.max(width, DPIUtil.scaleDown(lineWidthInPixels[line], getZoom()) + getLineIndent(line));
 		}
 	}
-	return new Rectangle (0, 0, width, lineY[lineY.length - 1] + getVerticalIndent());
+	float height = DPIUtil.scaleDown((float) Math.round(DPIUtil.scaleUp(lineY[lineY.length - 1] + getVerticalIndent(), getZoom())), getZoom());
+	return new Rectangle.OfFloat (0, 0, width, height);
 }
 
 /**

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Canvas.java

@@ -108,6 +108,12 @@ public void drawBackground (GC gc, int x, int y, int width, int height) {
 	drawBackgroundInPixels(gc, rectangle.x, rectangle.y, rectangle.width, rectangle.height, 0, 0);
 }
 
+public void drawBackground (GC gc, Rectangle rectangle) {
+	int zoom = getZoom();
+	Rectangle scaledRectangle = DPIUtil.scaleUp(rectangle, zoom);
+	drawBackgroundInPixels(gc, scaledRectangle.x, scaledRectangle.y, scaledRectangle.width, scaledRectangle.height, 0, 0);
+}
+
 /**
  * Returns the caret.
  * <p>