.\" Copyright (c) 2022-2023 Julien Nadeau Carriere <vedge@csoft.net>
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.Dd December 23, 2022
.Dt AG_DRIVERSDL2GL 3
.Os Agar 1.7
.Sh NAME
.Nm AG_DriverSDL2GL
.Nd agar SDL2 OpenGL driver
.Sh DESCRIPTION
.\" IMAGE(/widgets/AG_DriverSDL2GL.png, "The sdl2gl driver")
The Agar
.Va sdl2gl
driver provides an interface to the Simple DirectMedia Layer (SDL) library
version 2, and renders GUI elements as OpenGL primitives and managed textures.
.Pp
Using
.Xr AG_InitVideoSDL 3
as opposed to
.Xr AG_InitGraphics 3 ,
it is possible to attach Agar to an existing SDL display surface.
If the SDL surface has the
.Dv SDL_OPENGL
flag set then
.Va sdl2gl
will be auto-selected by default.
.Sh INHERITANCE HIERARCHY
.Xr AG_Driver 3 ->
.Xr AG_DriverSw 3 ->
.Nm .
.Sh EXAMPLES
.Bd -literal -offset indent
.\" SYNTAX(c)
AG_InitGraphics("sdl2gl(width=640:height=480)");
AG_InitGraphics("sdl2gl(width=60%:height=80%)");
AG_InitGraphics("sdl2gl(bgColor=0/120/120)");
AG_InitGraphics("sdl2gl(out=%08d.jpg:jpegQual=100)");
AG_InitGraphics("sdl2gl(depth=64:stereo)");

AG_InitVideoSDL(an_existing_SDL_screen, 0);
.Ed
.Sh OPTIONS
.Bl -tag -compact -width "clampOnResize "
.It ctrl
Enable game controller (gamepad) support.
.It haptic
Enable haptic (force feedback) subsystem.
.It joy
Enable joystick input device support.
.It width
Width (in pixels, in % of total desktop or "auto").
.It height
Height (in pixels, in % of total desktop or "auto").
.It bgColor
Solid background color (in 8-bit "R/G/B" format).
.It !bgPopup
Disable the right-click background popup menu
(which includes, notably the list of active windows).
.It clampOnResize
Whenever the display is resized, clamp Agar window positions and sizes
to fit the new display size.
.It debug
Capture
.Dv GL_DEBUG_OUTPUT
errors.
.It depth
Depth (in bits per pixel or "auto").
.It fpsMax
Limit refresh rate in frames/second (e.g., "60").
.It out
Export video frames to JPEG or PNG.
Specify a format string for output file names.
Example:
.Sq %04d.jpg
will output frames to 0001.jpg, 0002.jpg, and so on.
.It outFirst
Override first frame number (default = 0).
.It outLast
Terminate after # frames have been rendered.
.It jpegDCT
(JPEG Export) DCT method ("islow", "ifast" or "float").
.It jpegQual
(JPEG Export) Quality factor (100% = best).
.It stereo
Request a stereoscopic visual.
.El
.Sh SEE ALSO
.Xr AG_DriverSDL2FB 3 ,
.Xr AG_DriverSDL2MW 3 ,
.Xr AG_DriverSDLFB 3 ,
.Xr AG_DriverSDLGL 3 ,
.Xr AG_Driver 3 ,
.Xr AG_DriverSw 3 ,
.Xr AG_GL 3 ,
.Xr AG_InitGraphics 3 ,
.Xr AG_Intro 3
.Pp
.Bl -tag -compact
.It Lk https://libsdl.org/ Simple DirectMedia Layer
.It Lk https://www.opengl.org/ OpenGL
.El
.Sh HISTORY
The
.Va sdl2gl
driver first appeared in Agar 1.7.0.
The
.Va clampOnResize
option appeared in Agar 1.7.0.