glslr

glslr is a ultra-lightweight GLSL livecoding framework for x86 architecture.
glslr watches for changes in the input GLSL file and renders them to screen.
glslr is able to receive control data through a network socket which is then fed to the shader in the form of uniform variables.
glslr enables GLSL code-reuse across projects with its #include support.
glslr now has experimental Video4Linux support.

##Installation:

On Ubuntu its enough to install libgles2-mesa-dev and libglfw3-dev:

apt-get install git libgles2-mesa-dev libglfw3-dev
git clone https://github.com/k-o-l-e-k-t-i-v/glslr
cd glslr
make

##Usage:

usage: glslr [options] <layer0.glsl> [layer1.glsl] [layer2.glsl] ...
options:
  window properties:
    --primary-fs                            create a fullscreen window on primary monitor
    --primary-res [WidthxHeight]            create a width x height window on primary monitor (default: 800x600)
    --secondary-fs                          create a fullscreen window on secondary monitor
    --secondary-res [WidthxHeight]          create a width x height window on secondary monitor
  offscreen format:
    --RGB888
    --RGBA8888 (default)
    --RGB565
    --RGBA4444
  interpolation mode:
    --nearestneighbor (default)
    --bilinear
  wrap mode:
    --wrap-clamp_to_edge
    --wrap-repeat (default)
    --wrap-mirror_repeat
  backbuffer:
    --backbuffer                            enable backbuffer (default:OFF)
  network:
    --net                                   enable network (default:OFF)
    --tcp                                   enable TCP (default:UDP)
    --port [port]                           listen on port (default:6666)
    --params [n]                            number of net input params (default:0)
  video:
    --vdev [device number]                  v4l2 device number (default: 0 eg. /dev/video0)

##Usage with network:

glslr --net --port [port] --params N example.glsl

The parameters must be sent via UDP to the [port] in the form: "param0 param1 param2 ... paramN;".
A reference is to use PureData's object [netsend]. Currently only integer and float variables are supported.

##Usage with video:

glslr makes it possible to use experimental live video input from a V4L device. Currently only YUV422 devices are supported. The image is raw YUV422 - conversion into RGBA is up to you in the shader.

glslr --vdev [video device number] example.glsl

Provide the video device number to be able to use it in the shader. Default is 0 which expands to /dev/video0.
Eg. if you want to use /dev/video1 do:

glslr --vdev 1 example.glsl

In the shader you can access the video data by using uniform sampler2D variable called video:

uniform vec2 resolution;
uniform sampler2D video;

void main(void) {
	vec2 p = vec2( gl_FragCoord.x / resolution.x, 1.0 - gl_FragCoord.y / resolution.y);
	gl_FragColor = texture2D(video, p);
}

Using parameters:

glslr makes the parameters available in GLSL as uniform float type. The parameters can be accessed from the code, where N is the number of parameters specified on the command line (currently max 99), like this:

uniform float m0;
..
uniform float mN;

Using include:

glslr provides support to include GLSL files from within the shader. Lines containing the string //#include file will be replaced with the contents of the file:

function.glsl:

color = vec3(1.,0.,0.);

project.glsl:

void main(void) {
	vec3 c=vec3(0.,1.,0.);

	//#include function.glsl  
    // ^^^ this line will be replaced with contents of the function.glsl file
	
	gl_FragColor = vec4(c, 1.0);
}

glslr is a fork of pijockey-sound (https://github.com/k-o-l-e-k-t-i-v/pijockey-sound), a GLSL livecoding framework for RaspberryPi, an extension of the original sourcecode of PiJockey by sharrow.
glslr was ported to x86, using GLFW. The Video4Linux capability was scrambled from glutcam by George Koharchik.
glslr is being occasionally developed (when preparing for a new performance) by gnd ♥ itchybit.org.