Shader Library

Standalone fragment shaders. Each file is one main() against a resolution and time uniform pair, with no framework around it, so they drop into whatever you already have.

Every image above is the actual output, rendered headless at 512 by 512 with time fixed at 1.7. Full-size PNGs are in docs/.

The shaders

File	What it draws
HypnosisSpiral.h	sin(angle * 10 - radius * 20) in polar coordinates. Ten arms, tightening toward the centre.
AnimatedCircularGradient.h	Radial gradient with the colour driven by time.
CheckerBoard.h	Procedural checkerboard.
LoopingGradient.h	Colour gradient that returns to where it started.
NoiseAnimation.h	Hash-based noise field, reseeded each frame.
ScanLines.h	Horizontal bands over a gradient.
hearbeat.h	A waveform plotted as a line, in the shape of a heartbeat trace. The filename is misspelled and stays that way so existing links keep working.

Metal

DynamicColourGradient/DynamicColourGradient_metal.h is the same idea written for Metal, taking resolution and time through buffer bindings instead of uniforms.

fragment float4 fragmentShader (float2 fragCoord [[position]],
                                constant float2 &resolution [[buffer(0)]],
                                constant float &time [[buffer(1)]])

Known gap

DynamicColourGradient.h is empty. The Metal version above is the only implementation of it. Anything that includes the GLSL file will fail to link with No definition of main in fragment shader.

Use

uniform vec2  resolution;   // viewport size in pixels
uniform float time;         // seconds

Paste the body into any host that provides those two and writes gl_FragColor. hearbeat.h writes fragColor instead, so it needs an out vec4 fragColor on a core profile.

Rendering these yourself

The contact sheet came from a standalone OpenGL 3.3 context with no window. Each file is wrapped rather than edited: the wrapper supplies the #version, the uniforms and an out variable, and rewrites gl_FragColor to it, so the shader sources stay exactly as they are.