Hydra organises all its operations into five types: source, geometry, color, blend, and modulate

Every function in Hydra belongs to one of five categories that map to distinct stages of video synthesis. Source functions (osc, noise, voronoi, shape, gradient, src, solid) generate texture data. Geometry functions (rotate, scale, pixelate, repeat, kaleid, scroll) transform the spatial coordinates of a texture. Color functions (brightness, contrast, saturate, hue, invert, luma, posterize, thresh, colorama) modify pixel colour values. Blend functions (add, diff, mult, blend, layer, mask, sub) combine two textures. Modulate functions (modulate, modulateScale, modulateRotate, modulateRepeat, …) use one texture to displace another rather than to colour it. A Hydra expression is a pipeline that begins with a source and chains these types in sequence, terminating with .out(). Knowing which category a function belongs to predicts where in the chain it can legally appear.

Examples

osc(20,0.1,0.8)      // source
  .rotate(0.5)         // geometry
  .brightness(0.2)     // color
  .modulate(noise(3))  // modulate
  .out()

diff(src(o0)) is a blend operation combining two textures.

Assessment

Given the function list: osc, kaleid, saturate, add, modulateScale — categorise each into its type and describe the role it plays in a signal chain. Then write a valid 4-step Hydra chain using one function from each of the five types.