Re: [PATCH 0/1] MR3871: gdiplus: implement PixelOffsetMode Half and HighQuality for GdipDrawImagePointsRect

[Bartosz Kosiorek (＠gang65)]

Bartosz Kosiorek (@gang65) commented about dlls/gdiplus/graphics.c:
>  if (!srcwidth || !srcheight || (ptf[3].X == ptf[0].X && ptf[3].Y == ptf[0].Y))
>      return Ok;
>  gdip_transform_points(graphics, WineCoordinateSpaceGdiDevice, CoordinateSpaceWorld, ptf, 4);
>  round_points(pti, ptf, 4);

Here we are rounding points with `Rounding half up`. We need to do that with `Rounding half down`:

https://en.wikipedia.org/wiki/Rounding#Rounding_half_down

It could be implemented with:

```
ceil(x - 0.5)
```