After updating the copyright year in the Shadow Knights Editor (SKE), I was just drawing some random tiles on a map I had open and realized I wasn't satisfied with the rendering speed anymore. So I thought: "Screw it, I'm rewriting the map renderer in OpenGL."

Today, just one day later, the map renderer is running on OpenGL instead of GDI. I'm using OpenGL 3.3 with shaders as the default, with a fallback to OpenGL 2.1 for older hardware. I also fixed the clipping issue when copying map segments. There's still a small quirk where objects shift slightly when you rotate or flip them, but it's a minor issue that isn't worth fixing - rotating and flipping are more of a gimmick anyway.

If you compare the enlarged versions of the screenshots, they basically look the same, except the rectangles in the OpenGL version (screenshot #2) are "pixel-perfect", whereas the GDI ones (screenshot #1) aren't.

I'm really satisfied with the new rendering speed. Going forward, I'll be using OpenGL directly for map rendering in wxWidgets instead of trying to squeeze more performance out of GDI.