The Agar sdl2gl driver provides an interface to the Simple DirectMedia Layer (SDL) library version 2, and renders GUI elements as OpenGL primitives and managed textures.

Using AG_InitVideoSDL(3) as opposed to AG_InitGraphics(3), it is possible to attach Agar to an existing SDL display surface. If the SDL surface has the SDL_OPENGL flag set then sdl2gl will be auto-selected by default.

AG_Driver(3)-> AG_DriverSw(3)-> AG_DriverSDL2GL.

ctrl	Enable game controller (gamepad) support.
haptic	Enable haptic (force feedback) subsystem.
joy	Enable joystick input device support.
width	Width (in pixels, in % of total desktop or "auto").
height	Height (in pixels, in % of total desktop or "auto").
bgColor	Solid background color (in 8-bit "R/G/B" format).
!bgPopup	Disable the right-click background popup menu (which includes, notably the list of active windows).
clampOnResize	Whenever the display is resized, clamp Agar window positions and sizes to fit the new display size.
debug	Capture GL_DEBUG_OUTPUT errors.
depth	Depth (in bits per pixel or "auto").
fpsMax	Limit refresh rate in frames/second (e.g., "60").
out	Export video frames to JPEG or PNG. Specify a format string for output file names. Example: %04d.jpg will output frames to 0001.jpg, 0002.jpg, and so on.
outFirst	Override first frame number (default = 0).
outLast	Terminate after # frames have been rendered.
jpegDCT	(JPEG Export) DCT method ("islow", "ifast" or "float").
jpegQual	(JPEG Export) Quality factor (100% = best).
stereo	Request a stereoscopic visual.

AG_DriverSDL2FB(3), AG_DriverSDL2MW(3), AG_DriverSDLFB(3), AG_DriverSDLGL(3), AG_Driver(3), AG_DriverSw(3), AG_GL(3), AG_InitGraphics(3), AG_Intro(3)

•  Simple DirectMedia Layer
  
•  OpenGL

The sdl2gl driver first appeared in Agar 1.7.0. The clampOnResize option appeared in Agar 1.7.0.