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I20070227-0800 Enable ClearType fonts: - Right click on Desktop, select Properties - Go to Appearance - Click Effects.. - Select ClearType in the second drop down I also installed the Clear Type Tuning tool (http://www.microsoft.com/typography/ClearTypePowerToy.mspx) but I'm not sure if this matters. If I enable this, gc.drawString starts drawing before the x coordinate I give it. Here's a snippet: public static void main(String[] args) { final Display display = new Display(); Shell shell = new Shell(display); shell.setLayout(new FillLayout()); Canvas canvas = new Canvas(shell, SWT.NONE); canvas.addPaintListener(new PaintListener() { public void paintControl(PaintEvent e) { GC gc = e.gc; gc.setBackground(display.getSystemColor(SWT.COLOR_GREEN)); // draw the string gc.drawString("abc", 20, 20, false); // show the expected bounds Point extent = gc.textExtent("abc"); gc.drawRectangle(20, 20, extent.x, extent.y); } }); shell.pack(); shell.open(); while (!shell.isDisposed()) { if (!display.readAndDispatch()) display.sleep(); } display.dispose(); } I will attach a comparison screenshot, with and withough ClearType. Note: gc.drawText does not have this problem.
Created attachment 59927 [details] screenshot showing the problem
The ClearType bug also messed up FormText rendering. Pixels from inline images get cut off (see screenshot).
Created attachment 95673 [details] Screenshot showing correct rendering
Created attachment 95674 [details] Screenshot showing errorneous rendering
Not sure we can work around this bug in Windows.
*** Bug 194443 has been marked as a duplicate of this bug. ***
(In reply to comment #5) > Not sure we can work around this bug in Windows. ClearType is the default setting in Windows XP and this bug causes lots of glitches in FormText. If it can't be fixed than that makes me sad. Has a valiant effort been made? Is the problem that SWT cannot know if windows is using ClearType or not?
ExtTextOut() has a bug when ClearType is used and the string drawing is not transparent. There are a couple of solutions here: 1) SWT detects that ClearType is enabled, calculate and fill the background rect itself and then draw the string transparent. This solution would make every string drawing operation slower. It is also kind of late to change GC.drawString() for 3.4. 2) If the background is not required, the app code draws the string transparent (drawString("string", 0, 0, true)). It is not clear in the test code that the background drawing is necessary, but it seems it is not needed in the real eclipse screenshots. Is this an option for you?
It is worth to mention that the testcase is also wrong. If it draws with drawString(), it must measure with stringExtent() (not textExtent()).
Thanks for the quick response. I understand your hesitation to change GC.drawString() so late in 3.4 (particularly with a performance degradation involved). I tried out your suggested fix to draw the strings transparently and it does appear to fix the problem. In Forms we are actually drawing background colors ourselves anyway, so passing false was actually resulting in extra work being done for every rendered string.
This bug hasn't had any activity in quite some time. Maybe the problem got resolved, was a duplicate of something else, or became less pressing for some reason - or maybe it's still relevant but just hasn't been looked at yet. If you have further information on the current state of the bug, please add it. The information can be, for example, that the problem still occurs, that you still want the feature, that more information is needed, or that the bug is (for whatever reason) no longer relevant.
