shade

shader-toy-like fragment shader development assistant tool. blockchain.

what

it's like shader-toy, but with basically no features of shader-toy. but you can run it off-line, and not in a browser. it has only one dependency - SDL2. this is not intended to be a standalone tool per se, but rather just something that you can easily modify (and extend, if required) to prototype a shader.

usage

modify fragment.glsl as you see fit, checkout your shader with make. the program takes no arguments - just edit the code :)

requirements

sdl2

install with your favorite package manager or installation method. most sane installation methods put the headers in your default include path. no need for any of this pkg-config nonsense.

fragment shader

format

the code is designed to handle fragment shaders of the form;

vec4
fragment
(vec2 p)
{
  vec4 result = /* some math */;

  return result;
}

input

a vec2 containing the fragment's co-ordinates in one of three spaces;

1. if built with FRAG_COORDS_NORMALISED, x and y will be in the range 0 to 1.
2. if built with FRAG_COORDS_SCREEN, x and y will be in the range -1 to 1.
3. if built with FRAG_COORDS_VIEWPORT, x and y will be in the range 0 to the size of the viewport - i.e, the resolution picked during initialisation.

output

a vec4 representing the colour in RGBA format.

globals

1. uTime - a float containing the number of seconds elapsed since the program began execution. sort of.
2. uSize - a vec2 containing the current dimensions of the viewport.

examples

there are some examples ~~stolen~~ borrowed from shadertoy included with this - they should be somewhat accurate renditions of the shaders found there.

to try these out for yourself, just copy over fragment.glsl with them, e.g

$ cp examples/light-ring.glsl fragment.glsl
$ make

displacement mapping

from shadertoy:

julia quaternion

from shadertoy:

light ring

from shadertoy:

todo

1. consider windows support
2. add some more features
3. ???
4. PROFIT
5. retire early 2000s memes from general usage.