wb_gl_loader

by William Bundy

A single-header OpenGL loader, using win32 or SDL as a backend out-of the box.

Also handles context creation on Win32 (because nobody wants to do that).

Sample usage:

#define WB_GL_USE_ALL_VERSIONS
#define WB_GL_WIN32
#define WB_GL_LOADER_IMPLEMENTATION
#include "wb_gl_loader.h"
...
// somewhere in main, maybe
{
	wbgl_win32_create_context(windowDC, 3, 3, 1);
	wbgl_load_all(NULL);
}

Versions

For simplicity, I handle OpenGL versions in groups:

• legacy (2.1 and previous)
• compat (3.1)
• core (3.2 and 3.3)
• modern (4.0 - 4.5)

These map on to several defines:

• WB_GL_USE_LEGACY
• WB_GL_USE_COMPAT
• WB_GL_USE_CORE
• WB_GL_USE_MODERN

Or, you can just use WB_GL_USE_ALL_VERSIONS

Defining your loader function

If you want to use a built-in loader, use either:

• WB_GL_WIN32
• WB_GL_SDL

If you don't define either of those, no loader function will be defined. You can define your own like so:

WB_GL_LOADER_API
void* wbgl__load_proc(const char* name, struct wbgl_ErrorContext* ctx, void* userdata)
{
	void* proc = MyGetProcAddress(name);
	if(!proc) {
		wbgl__load_proc_error(name, ctx);
	}
	return proc;
}

Error Handling

Supplied to the load proc is a struct that keeps track of the first WB_GL_MAX_ERRORS (default: 256) functions that fail to load. If you pass one of these struct wbgl_ErrorContext into wbgl_load, it'll tell you which functions failed to load.

However, it's largely safe to ignore unloaded functions; if you don't call them, everything will be fine.