Oh I see what you're saying. For now basically you would need to call Resample to create a reduced image, and then display it, and then free it.
But it is slow and yes there is tricks for better result but it will be very good to have it in BGL.
Yes that's slow. The thing is that as far as I know OpenGL does not provide high quality resampling, apart from trilinear filtering, but in this case, you need to prepare the texture with different sizes.
That would be great. The problem is with LCL font rendering. So using the normal package, if you use TBGRABitmap.TextOut, it does not work.
Just font? I remember you talked about low speed with Lainz before.
OK I will check it.
Well basically it is the Canvas property that does not work. But this can be avoided most of the time, except when drawing text, because the default renderer depends on LCL rendering that is done on the Canvas. I am sometimes thinking about removing the Canvas property from TBGRABitmap, so that people would not be tempted to use it!
It is a bit slow indeed because the text is first drawn on a TBitmap.Canvas and then copied on the TBGRABitmap. And with fine resampling, this is much slower because a huge TBitmap is created to render with quality and is scaled down afterwards on a TBGRABitmap.
It would be faster to retrieve the shapes as Bezier curves instead. I know there a functions for that on Windows but that would not be cross-platform.