glsl-shaders

GLSL Shaders

Three hosts: glslTOP/glslmultiTOP (pixels, or compute over an image), glslMAT (vertex + pixel over geometry), glslPOP (compute over points; the POP side lives in /pop-networks). Every function and parameter below compiled live on TD 2025.33230 (probed 2026-09-25). Anything you add beyond them: check the parameter with describe_op_type and the function with the docked info DAT before trusting it.

The docked-DAT contract

• Creating a glslTOP/glslmultiTOP docks <name>_pixel, <name>_compute, <name>_info, with pixeldat/computedat already pointing at them. A glslMAT docks <name>_vertex, <name>_pixel, <name>_info (vdat/pdat). A glslPOP docks <name>_compute and <name>_info.
• Name the operator at creation (glsl_<purpose>): dock names and the *dat references are snapshots taken then and do not follow a later rename.
• Write the shader INTO the docked DAT (set_dat_content / edit_dat_content). Delete the dock you do not use (_compute for a pixel shader) so it does not ship as dead weight. One exception: several GLSL ops running identical code point at ONE shared DAT and differ by uniforms (tdxn-economy.md).
• create_op hugs the docks under the host; an execute_python build must place them itself (/create-operator).
• Read compile results from <name>_info: op.errors() says only "Compile failed". get_op_errors returns them as shaderErrors, and every DAT write to a shader rides back _effects.new_shader_errors. Fix those before building further.

What TD gives you (never redeclare, never paste an alternative)

• No #version line: TD injects one, and writing your own fails with "'#version' : must occur first in shader". texture(), never texture2D() ("function not supported in this version; use texture() instead").
• Inputs: sTD2DInputs[i], sTD3DInputs[i], sTD2DArrayInputs[i], sTDCubeInputs[i], indexed per TYPE, not per connector. TD_NUM_2D_INPUTS (and the 3D/array/cube twins) bound a loop and guard a dynamic index. uTD2DInfos[i].res and uTDOutputInfo.res are (1/w, 1/h, w, h). vUV.st is the 0-1 texture coordinate when there is no custom vertex shader. uTDPass is the multi-pass index, uTDCurrentDepth the 3D slice.
• Lookups: sTDNoiseMap (256x256 random), sTDSineLookup.
• Functions: TDOutputSwizzle(vec4) on EVERY color you write out (channel order is wrong without it), TDDither, TDPerlinNoise(vec2|vec3|vec4) and TDSimplexNoise(vec2|vec3|vec4) (both in -1..1, available in TOP, MAT and glslPOP shaders on this build), TDHSVToRGB, TDRGBToHSV, TDRotateOnAxis(rad, axis), TDRotateX/Y/Z(rad).
• Compute in a glslTOP (mode=compute): declare layout(local_size_x = 8, local_size_y = 8) in;, write with TDImageStoreOutput(0, ivec3(gl_GlobalInvocationID.xy, 0), TDOutputSwizzle(color)), read the output back with TDImageLoadOutput(0, ivec3(...)).
• glslTOP has exactly 3 input connectors. glslmultiTOP takes more and adds POP buffer reads (buffer0pop, buffer0attr, buffer0name -> TDBuffer_<Name>(idx) in the shader). Reach for glslmultiTOP whenever you need a fourth input or a POP attribute.