Re: Implement GdiGetCharDimensions

[Alexandre Julliard]

Robert Shearman <rob(a)codeweavers.com> writes:
> +LONG WINAPI GdiGetCharDimensions(HDC hdc, LPTEXTMETRICW lptm, LONG *height)
> +{
> +    SIZE sz;
> +    static const WCHAR alphabet[] = {
> +        'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q',
> +        'r','s','t','u','v','w','x','y','z','A','B','C','D','E','F','G','H',
> +        'I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z',0};
> +
> +    if(lptm && !GetTextMetricsW(hdc, lptm)) return 0;
> +
> +    if(!GetTextExtentPointW(hdc, alphabet, 52, &sz)) return 0;
> +
> +    if (height) *height = sz.cy;
> +    return (sz.cx / 26 + 1) / 2;
> +}

Again I think you should be using tmHeight instead of sz.cy for the
height. Some fonts may well have characters larger than the alphabet
ones, and the current behavior is always to use tmHeight.

-- 
Alexandre Julliard
julliard(a)winehq.org

Implement GdiGetCharDimensions

[Huw D M Davies]

On Mon, Jul 18, 2005 at 05:03:49PM +0200, Alexandre Julliard wrote:
> Robert Shearman <rob(a)codeweavers.com> writes:
> > +LONG WINAPI GdiGetCharDimensions(HDC hdc, LPTEXTMETRICW lptm, LONG *height)
> > +{
> > +    SIZE sz;
> > +    static const WCHAR alphabet[] = {
> > +        'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q',
> > +        'r','s','t','u','v','w','x','y','z','A','B','C','D','E','F','G','H',
> > +        'I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z',0};
> > +
> > +    if(lptm && !GetTextMetricsW(hdc, lptm)) return 0;
> > +
> > +    if(!GetTextExtentPointW(hdc, alphabet, 52, &sz)) return 0;
> > +
> > +    if (height) *height = sz.cy;
> > +    return (sz.cx / 26 + 1) / 2;
> > +}
>
> Again I think you should be using tmHeight instead of sz.cy for the
> height. Some fonts may well have characters larger than the alphabet
> ones, and the current behavior is always to use tmHeight.

Actually GetTextExtentPoint returns tm.tmHeight for cy, so there
shouldn't be any difference.

Huw.
-- 
Huw Davies
huw(a)codeweavers.com

Implement GdiGetCharDimensions

[Alexandre Julliard]

Huw D M Davies <h.davies1(a)physics.ox.ac.uk> writes:
> Actually GetTextExtentPoint returns tm.tmHeight for cy, so there
> shouldn't be any difference.

Ah right, in that case of course it makes no difference. But is that
really the correct behavior for GetTextExtentPoint?

-- 
Alexandre Julliard
julliard(a)winehq.org

Implement GdiGetCharDimensions

[Huw D M Davies]

On Mon, Jul 18, 2005 at 05:24:42PM +0200, Alexandre Julliard wrote:
> Huw D M Davies <h.davies1(a)physics.ox.ac.uk> writes:
> > Actually GetTextExtentPoint returns tm.tmHeight for cy, so there
> > shouldn't be any difference.
>
> Ah right, in that case of course it makes no difference. But is that
> really the correct behavior for GetTextExtentPoint?

Yup.  Here's a test.

Huw Davies <huw(a)codeweavers.com>
Test to show that the height returned by GetTextExtentPoint is
the same as tmHeight.
-- 
Huw Davies
huw(a)codeweavers.com
Index: dlls/gdi/tests/gdiobj.c
===================================================================
RCS file: /home/wine/wine/dlls/gdi/tests/gdiobj.c,v
retrieving revision 1.6
diff -u -p -r1.6 gdiobj.c
--- dlls/gdi/tests/gdiobj.c	20 May 2005 18:58:19 -0000	1.6
+++ dlls/gdi/tests/gdiobj.c	18 Jul 2005 15:41:06 -0000
@@ -266,9 +266,34 @@ static void test_gdi_objects(void)
     ReleaseDC(NULL, hdc);
 }
 
+static void test_text_extents(void)
+{
+    LOGFONTA lf;
+    TEXTMETRICA tm;
+    HDC hdc;
+    HFONT hfont;
+    SIZE sz;
+
+    memset(&lf, 0, sizeof(lf));
+    strcpy(lf.lfFaceName, "Arial");
+    lf.lfHeight = 20;
+
+    hfont = CreateFontIndirectA(&lf);
+    hdc = GetDC(0);
+    hfont = SelectObject(hdc, hfont);
+    GetTextMetricsA(hdc, &tm);
+    GetTextExtentPointA(hdc, "o", 1, &sz);
+    ok(sz.cy == tm.tmHeight, "cy %ld tmHeight %ld\n", sz.cy, tm.tmHeight);
+
+    SelectObject(hdc, hfont);
+    DeleteObject(hfont);
+    ReleaseDC(NULL, hdc);
+}
+
 START_TEST(gdiobj)
 {
     test_logfont();
     test_bitmap_font();
     test_gdi_objects();
+    test_text_extents();
 }