A wrapper DLL draws nothing under Wine on macOS, and its log says "version '130' is not supported"

Symptoms

A wrapper that draws with OpenGL opens its window, but every pixel stays black. Its log shows OpenGL 2.1 Metal - 90.5, then a shader error: version '130' is not supported. Calls that do not draw still work.

Cause

Wine's macOS driver gives wglCreateContext an OpenGL 2.1 context, which has GLSL up to 1.20 (observed). macOS gives OpenGL 3.2 and later only as a forward-compatible core profile (observed). A request for a core profile without the forward-compatible flag returns no context (observed).

Evidence

glidetest.exe under Wine on an Apple M3 Max. With GLIDE_LOG set, the log showed OpenGL 2.1 Metal. Then wglCreateContextAttribsARB with version 3.2 and the core profile returned null. With WGL_CONTEXT_FLAGS_ARB set to WGL_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB it returned a context that reports OpenGL 4.1 Metal, and all 27 checks of the test passed.

What to do

Create the plain context. If GL_VERSION is below 3, create a core context with wglCreateContextAttribsARB, with the forward-compatible flag (0x2094 = 2) and the core profile (0x9126 = 1), and make it current. Compile the shaders as GLSL 1.50 there. Bind a vertex array object before drawing, as a core context draws nothing without one. Keep line widths at 1, as a forward-compatible context refuses wider lines. wrappers/glide/src/window.rs (core_context) does this. The other choice is shaders in GLSL 1.20, as wrappers/sgl has.

Tried

• A 3.2 core profile without the forward-compatible flag: no context.
• Loading glGenVertexArrays in the function table of a 2.1 context: missing, so the table fails to load. Load it apart, only in a core context.