At higher scaling, font gets unusually bigger and alignment also got distorted

[deepika-u]

Describe the bug
I see 2 minor problems.

• the alignment got distorted in section 3.
• the font became unusually bigger from 175% and above resolution.
  reference screenshots are attached indetail in the doc =>

Hi-DPI_changes.docx

To Reproduce
Run the Snippet367 at 175% or 200% resolution, you see the 2 problems reported.

Expected behavior
Behavior should be same as 100% or 125% or 150%.

Screenshots
Attached in the doc.

Environment:

1. Select the platform(s) on which the behavior is seen:

• • All OS
• • Windows
• • Linux
• • macOS

Version since
Tried on this version
Eclipse SDK
Version: 2025-03 (4.35)
Build id: I20250209-1800
OS: Windows 11, v.10.0, x86_64 / win32
Java vendor: Eclipse Adoptium
Java runtime version: 22.0.2+9
Java version: 22.0.2

Workaround (or) Additional context
Not aware of.

[HeikoKlare]

At least the font size is expected behavior when running SWT with default settings (i.e., swt.autoScale=integer200), isn't it? When you start the snippet with -Dswt.autoScale=quarter, it will probably show the results you expect, but that's not how SWT behaves by default.

[akoch-yatta]

I'm not sure. Didn't have a look at the snippet yet, but shouldn't be there font still everywhere the same size? I will have a short look later to get in impression about it.

[HeikoKlare]

Taking a look at the screenshots, the font size is only changed in line "4. Painted image (multi-res, zoomed paint)". And this "zoomed paint" explicitly changes the font size:

eclipse.platform.swt/examples/org.eclipse.swt.snippets/src/org/eclipse/swt/snippets/Snippet367.java

Lines 214 to 218 in df1c412

	FontData fontData = gc.getFont ().getFontData ()[0];
	fontData.setHeight (fontData.getHeight ()*f);
	Font font = new Font (gc.getDevice (), fontData);
	try {
	gc.setFont (font);

The scale factor used here will be 1 for 100%-150% and 2 for 175% and above. That's why I would expect this behavior. But maybe I miss something.