wxBitmap LoadScaledBitmap(const wxString& name)
{
const wxString filename(name + ".png");
if (!wxFileExists(filename))
return wxNullBitmap;
#ifdef NEEDS_MANUAL_HIDPI
if (HiDPIScalingFactor() > 1.0)
{
wxImage img;
double imgScale = HiDPIScalingFactor();
const wxString filename_2x(name + "@2x.png");
if (wxFileExists(filename_2x))
{
LoadPNGImage(img, filename_2x);
if (HiDPIScalingFactor() == 2.0)
return wxBitmap(img);
else
imgScale /= 2.0;
}
else
{
LoadPNGImage(img, filename);
}
img.Rescale(img.GetWidth() * imgScale, img.GetHeight() * imgScale,
imgScale == 2.0 ? wxIMAGE_QUALITY_NEAREST : wxIMAGE_QUALITY_BICUBIC);
return wxBitmap(img);
}
// else: load normally
#endif
return wxBitmap(wxImage(filename, wxBITMAP_TYPE_PNG));
}
wxImage LoadScaledBitmap(const wxString& name)
{
const wxString filename(name + ".png");
if (!wxFileExists(filename))
return wxNullImage;
wxImage img;
#ifdef NEEDS_MANUAL_HIDPI
// On Windows, arbitrary scaling factors are possible and "ugly" values like 125%
// or 150% scaling are not only possible, but common. It is unrealistic to provide
// custom-drawn bitmaps for all of them, so we make do with a basic set of 100%/@1x,
// 200%/@2x (used on macOS too) and one more for 150%/@1.5x for Windows use.
// To eliminate smudged scaling artifacts, we use these fixed sizes even for zoom
// factors in-between (such as the very common 125% or less common 175%). This looks
// better and the size difference is negligible.
auto const screenScaling = HiDPIScalingFactor();
if (screenScaling > 1.25)
{
if (screenScaling <= 1.75) // @1.5x is reasonable
{
const wxString filename_15x(name + "@1.5x.png");
if (wxFileExists(filename_15x))
{
LoadPNGImage(img, filename_15x);
if (img.IsOk())
return img;
}
}
double imgScale = screenScaling;
const wxString filename_2x(name + "@2x.png");
if (wxFileExists(filename_2x))
{
LoadPNGImage(img, filename_2x);
if (screenScaling > 1.75 && screenScaling <= 2.50) // @2x is reasonable
return img;
else
imgScale /= 2.0;
}
else // fall back to upscaled @1x
{
LoadPNGImage(img, filename);
}
if (!img.IsOk())
return wxNullImage;
wxImageResizeQuality quality;
if (imgScale == 2.0)
quality = wxIMAGE_QUALITY_NEAREST;
else if (imgScale == 1.5)
quality = wxIMAGE_QUALITY_BILINEAR;
else
quality = wxIMAGE_QUALITY_BICUBIC;
img.Rescale(img.GetWidth() * imgScale, img.GetHeight() * imgScale, quality);
return img;
}
// else if screenScaling <= 1.25: @1x size is good enough, load normally
#endif
LoadPNGImage(img, filename);
return img;
}
