SDL_gpu, a library for making hardware-accelerated 2D graphics easy.

 - High performance (it automatically collects and submits batches
   instead of separate draw commands for each sprite and redundant
   state changes)
 - Shader API
 - Arbitrary geometry rendering (triangles)
 - Can be integrated with explicit OpenGL calls (mixed 2D and 3D)
 - Full blend state control
 - Built-in primitive shapes (points, lines, tris, rects, ellipses,
   polygons, even arcs)
 - Uses a style familiar to SDL 1.2 users
 - Compatible with either SDL 1.2 or 2.0
 - Loads BMP, TGA, and PNG files via stb-image
 - Rotates and scales about the center of images, making reasoning
   about the resulting corner coordinates more obvious (adjustable 
   via anchor settings)