GDI+ pageoffset

[Stepa Nick]

Hello. I have following code:
> Bitmap * bmp = new Bitmap(500, 500, PixelFormat32bppARGB);
> {
>   Graphics gr(bmp);
>
> //FIRST LINE
>   PointF* local1PointF = new PointF(17.823631, 89.429169);
>   PointF* local2PointF = new PointF(17.823631, 87.577080);
>
> //SECOND LINE
>   PointF* local3PointF = new PointF(14.933444, 89.429169);
>   PointF* local4PointF = new PointF(14.933444, 87.577080);
>   Pen * pen = new Pen(Color(255, 0, 0), 0.1);
>   gr.SetPageUnit(UnitMillimeter);
>
> gr.SetPixelOffsetMode(PixelOffsetModeHalf); //PROBLEM!
>
> gr.DrawLine(pen,(*local1PointF),(*local2PointF));
>   gr.DrawLine(pen,(*local3PointF),(*local4PointF));
> }

When I run it without SetPixelOffsetMode i get equal line, but with it
line are not identical(first line is longer). I explore
"dlls/gdiplus/graphics.c" and i find this comment: "/* FIXME: Pixel
offset mode is not used anywhere except the getter/setter. */". So, I
what to understand why I have different images(how pixeloffset affect
on drawing lines)? I try to run windbg, run
`WINEDEBUG=gdiplus,gdi,ddraw,graphics wine ./my.exe`, but analyzing
output didn`t give my any results. Thanks!

[Austin English]

On Wed, Apr 11, 2012 at 10:23, Stepa Nick  wrote:
> Hello. I have following code:
> > Bitmap * bmp = new Bitmap(500, 500, PixelFormat32bppARGB);
> > {
> >   Graphics gr(bmp);
> >
> > //FIRST LINE
> >   PointF* local1PointF = new PointF(17.823631, 89.429169);
> >   PointF* local2PointF = new PointF(17.823631, 87.577080);
> >
> > //SECOND LINE
> >   PointF* local3PointF = new PointF(14.933444, 89.429169);
> >   PointF* local4PointF = new PointF(14.933444, 87.577080);
> >   Pen * pen = new Pen(Color(255, 0, 0), 0.1);
> >   gr.SetPageUnit(UnitMillimeter);
> >
> > gr.SetPixelOffsetMode(PixelOffsetModeHalf); //PROBLEM!
> >
> > gr.DrawLine(pen,(*local1PointF),(*local2PointF));
> >   gr.DrawLine(pen,(*local3PointF),(*local4PointF));
> > }
>
> When I run it without SetPixelOffsetMode i get equal line, but with it
> line are not identical(first line is longer). I explore
> "dlls/gdiplus/graphics.c" and i find this comment: "/* FIXME: Pixel
> offset mode is not used anywhere except the getter/setter. */". So, I
> what to understand why I have different images(how pixeloffset affect
> on drawing lines)? I try to run windbg, run
> `WINEDEBUG=gdiplus,gdi,ddraw,graphics wine ./my.exe`, but analyzing
> output didn`t give my any results. Thanks!

Run with `WINEDEBUG=loaddll wine my.exe` and ensure that builtin
gdiplus is being used.