This patch makes three separate changes to how thumbnails are shown in File Manager.
- Draws a checkboard pattern below thumbnails of images, videos, and blend files. This is to allow visualization of transparent areas.
- Removes of the outer border. This border always looked a bit awkward, but I had left it in because it served one purpose: framing the entire image in case only a portion is visible because of transparency. With the addition of the checkerboard there is no longer a need for it.
- Enables the filter options on immDrawPixelsTexScaled() that scales and draws the image. This removes much of the jaggedness.
The following illustrates all changes nicely. The current behavior is shown on the top row, while the bottom row shows after the patch is applied. It is best to compare them while viewing it full-screen.
The "Beans" should be much less blocky. The blender logo is less jagged and indicates which portions are transparent. The gun is less jagged.