I can’t seem to change image resampling quality on OSX.
First off, CoreGraphicsContext::setInterpolationQuality doesn’t even use all of the available enum values.
Second, toggling it has no effect on resized drawImage(). This can be seen in the Graphics::2D Rendering::Images demo (animate size to see resampling better). The resampling quality seems to be really low regardless of setting.
I would appreciate if someone from the Juce team could look into this.
In the latest JUCE release CoreGraphicsContext::setInterpolationQuality uses all the enum values of Graphics::ResamplingQuality, and these are correctly passed on to CoreGraphics to handle. For that particular example I couldn’t see any difference between the medium and high interpolation qualities, but exactly how they are rendered is determined by your operating system in this case.
If you change
in GraphicsDemoBase then the difference will be more obvious.
I wouldn’t say that the resampling quality is low - scale anything large enough and you’re going to see pixels!