[ wxwindows-Bugs-1910313 ] GetTextExtent wrong results for JP font

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Bugs item #1910313, was opened at 2008-03-09 01:54
Message generated for change (Comment added) made by nusi
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Category: wxMac specific
Group: Platform specific
Status: Open
Resolution: None
Priority: 5
Private: No
Submitted By: David Whetstone (dwhetstone)
Assigned to: Stefan Csomor (csomor)
Summary: GetTextExtent wrong results for JP font

Initial Comment:
GetTextExtent() on wxMac 2.8.7 returns incorrect results for japanese and other similar fonts.  The following code draws two strings, one in roman characters and another in japanese characters.  Each string has a red rectangle drawn to its text extent. While the roman string is neatly encompassed by its rectangle, the rectangle for the japanese string falls far short.  An image of the result is attached.

#include "wx/wx.h"

class TestFrame : public wxFrame
    {
    public:
        TestFrame() : wxFrame(NULL, wxID_ANY, wxT("Test"))
        {
        }
        
        void DrawString(wxDC& dc, const wxString & txt, int vOffset)
        {
            wxSize sz = GetClientSize();
            wxSize ext = dc.GetTextExtent(txt);
            
            int x = wxMax(0, (sz.x-ext.x)/2);
            int y = wxMax(0, (sz.y-ext.y)/2) + vOffset;
            
            dc.SetPen(*wxRED_PEN);
            dc.DrawRectangle(x, y, ext.x, ext.y);
            dc.SetPen(*wxBLACK_PEN);
            dc.DrawText(txt, x, y);
        }
        
        void OnPaint(wxPaintEvent& event)
        {
            wxPaintDC dc(this);
            wxFont font(24, wxFONTFAMILY_DEFAULT, wxFONTSTYLE_NORMAL, wxFONTWEIGHT_NORMAL);
            font.SetNoAntiAliasing(true);
            dc.SetFont(font);
            DrawString(dc, wxT("ABCDE"), -25);
            DrawString(dc, wxT("カタカナ ひらがな ローマ字"), 25);
        }
        
    private:
        DECLARE_EVENT_TABLE()
    };

BEGIN_EVENT_TABLE(TestFrame, wxFrame)
EVT_PAINT(TestFrame::OnPaint)
END_EVENT_TABLE()

class TestApp : public wxApp
    {
    public:
        bool OnInit()
        {
            TestFrame * frame = new TestFrame();
            frame->Show(true);
            return true;
        }
    };

DECLARE_APP(TestApp)
IMPLEMENT_APP(TestApp)



----------------------------------------------------------------------

Comment By: nusi (nusi)
Date: 2008-03-12 22:01

Message:
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Index: graphics.cpp
===================================================================
--- graphics.cpp	(revision 52458)
+++ graphics.cpp	(working copy)
@@ -1908,6 +1908,9 @@
 
     wxASSERT_MSG( status == noErr , wxT("couldn't create the layout of
the text") );
 
+    status = ::ATSUSetTransientFontMatching( atsuLayout , true );
+    wxASSERT_MSG( status == noErr , wxT("couldn't setup transient font
matching") );
+
     ATSUTextMeasurement textBefore, textAfter;
     ATSUTextMeasurement textAscent, textDescent;
 


----------------------------------------------------------------------

Comment By: nusi (nusi)
Date: 2008-03-12 21:59

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Stefan, the issue is in wxMacCoreGraphicsContext::GetTextExtent() in
graphics.cpp.
It happens because DrawText() uses a different calculation as
GetTextExtent().
Just look at the patch, it will explain everything.




----------------------------------------------------------------------

Comment By: David Whetstone (dwhetstone)
Date: 2008-03-10 22:00

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csomor: I'm getting different results from you.  This bug also exists for
me with the current trunk (2.9), built with the same configure options
(repeated here because of line breaks in my previous post).  

../configure --enable-universal_binary
--with-macosx-sdk=/Developer/SDKs/MacOSX10.4u.sdk
--with-macosx-version-min=10.4  --disable-shared --enable-unicode
--disable-debug --enable-catch_segvs  --enable-graphics_ctx
--enable-mediactrl --with-opengl --enable-monolithic --with-libjpeg=builtin
--with-libpng=builtin --with-libtiff=builtin --with-expat=builtin
--enable-gui --enable-xrc --enable-mdi --enable-gif  --enable-pcx
--enable-iff --enable-pnm --enable-xpm

----------------------------------------------------------------------

Comment By: David Whetstone (dwhetstone)
Date: 2008-03-09 16:16

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This is on OS X 10.5.2 using the WX_2_8_BRANCH from svn configured  with
the following options:

../configure --enable-universal_binary
--with-macosx-sdk=/Developer/SDKs/MacOSX10.4u.sdk -
-with-macosx-version-min=10.4  --disable-shared --enable-unicode
--enable-debug --enable-c
atch_segvs  --enable-graphics_ctx --enable-mediactrl --with-opengl
--enable-monolithic --w
ith-libjpeg=builtin --with-libpng=builtin --with-libtiff=builtin
--with-expat=builtin --en
able-gui --enable-xrc --enable-mdi --enable-gif  --enable-pcx --enable-iff
--enable-pnm --
enable-xpm 


----------------------------------------------------------------------

Comment By: Stefan Csomor (csomor)
Date: 2008-03-09 06:32

Message:
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could you please provide more details - are you using the unicode build -
on which OS X version are you running this, is this a 2.8.7 download or the
WX_2_8_BRANCH from svn (eg the current trunk runs the sample with no
problem on 10.5.2)

Thanks a lot,

Stefan

----------------------------------------------------------------------

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