A commandline tool for running OpenGL fragment shaders or compute shaders to draw something or process some data using GPU.

When compiled, just run like this:

./offscreen_renderer [path/to/inifile]

It will load the ini file, read the [common] section to see how many tasks here, for example:

[common]
tasks=sometask1,sometask2

Then, it will see if [sometask1] and [sometask2] is there, and try to get some information about the task.

For example, [sometask1] will be like this:

[sometask1]
type=Draw
shader=xxxx.fsh
input=a1,a2
output=a3

See the type here should be Draw or Compute, which indicates the task type to be a fragment shader draw, or a compute shader task.

If type is Compute, you need also provide groups=x,y,z to indicate the work group size.

Then you need to define what is a1, a2, a3. To do this, you have to create sections for the input and output textures, for example:

[a1]
load=a1.png
format=RGBA8

Then a1 will be loaded from a1.png. You can use the same way to create a2.

The output a3 should also be defined like this:

[a3]
size=512,512
save=a3.png
format=RGBA8

Then your shader will run, process something, and draw some pixels to a3.png.

Your fragment shader can use uniform sampler2D a1, a2; to sample the textures from a1 and a2.

By default, your fragment shader has uniform vec2 Resolution; which is the size of output a3.

pano: a shader that turns 6 pictures into a pano.

test: a script that uses 2 shaders to do something to generate some picture. The 2 shaders contains a fragment shader and a compute shader.