D008 - oops-gl grows to OpenGL 1 and 2, superseding D007's instrument-only scope

Status: decided Date: 2026-09-17

The choice

oops-gl is to support OpenGL 1.x and 2.x. The operator set that goal on 2026-09-17.

This supersedes D007, written the previous evening, which scoped oops-gl to "OpenGL 1.1-class fixed function plus whatever individual later calls an oracle program demands" and listed "growing oops-gl toward 1.3, 2.x or GLES" under what this rules out. That entry is superseded rather than deleted: its reasoning is still the reason the instrument role exists, and the oracle records it describes remain this repository's hardware tests.

What changes, and what does not

Changes. A missing entry point is now a gap to fill rather than a boundary to point at. D007 said a new entry point needs an oracle program that wants it and that "for completeness" was not a reason; under this decision completeness against GL 1.x and then 2.x is the reason.

Does not change. Three things from D007 survive intact, because the operator's goal does not touch them:

• The refusal discipline. A call whose behaviour is not known is still refused with an error rather than approximated. The whole of 2026-09-16's work was converting silent wrong answers into loud refusals, and a growth target is not a licence to guess - a wrong conversion still renders a plausible frame and fails nowhere.
• glIsHardwareAccelerated stays measured, not declared.
• oops-mesa still exists and still targets 3.3. Two implementations at different levels is not a contradiction: Mesa is upstream's GL for applications that want the modern core profile, and oops-gl is ours, small, and readable as a command stream. They still never link into one title.

What this makes hard, stated now rather than discovered later

OpenGL 2.0 means GLSL, and GLSL means a compiler: glCreateShader, glShaderSource, glCompileShader, glLinkProgram, glUseProgram, uniforms and vertex attributes, with a front-end that turns GLSL source into the RDNA2 bytecode this already emits by hand. That is the largest single piece of work in this repository by a wide margin, and it is the reason D007 pointed at Mesa in the first place.

The order that follows from it: finish 1.x first, where the pipeline is fixed-function and the work is ordinary, and reach 2.0's programmable pipeline last. Nothing about 1.x is wasted when GLSL arrives - a GL 2.0 context still has to answer every 1.x call.

Where 1.x stands as this is written

Of the 87 declared entry points, the surface is immediate mode, vertex arrays, one 2D texture unit, lighting, matrix stacks and blend/depth/cull. Absent, all of them ordinary GL 1.1: display lists, alpha test, fog, stencil, glReadPixels, glTexSubImage2D, glPixelStorei, glPolygonOffset, glDepthRange, glPolygonMode, and points and lines.

Points and lines are the one group with a hardware block in front of them: they are measured not to draw through the NGG passthrough path this uses, across four sweeps, and need a non-passthrough stage (obSCEne REQ-20260916T2223Z-b6d4). Everything else on that list is software and reachable now.