DerelictGL3调用glCreateShader触发访问违规问题求助

Hey there! Let's dig into that weird glCreateShader error you're hitting after restructuring your D/Derelict OpenGL code. I've run into similar gotchas before, so here are the most likely culprits to check:

This is the most common pitfall. Derelict loads OpenGL functions dynamically, so you must initialize DerelictGL3 (or your target OpenGL version binding) after creating and making your OpenGL context current. If you flip this order, functions like glCreateShader won't resolve properly, leading to null pointer crashes or unexpected behavior.

A correct flow should look like this:

// First set up your window and OpenGL context (e.g., via DerelictGLFW)
DerelictGLFW3.load();
glfwInit();
// ... create window, configure context attributes, make context current ...

// THEN initialize Derelict OpenGL bindings
DerelictGL3.load();

Since you moved shader code into spacegame.game.game, double-check that this module can access the loaded Derelict functions:

• Make sure you have import derelict.opengl3; at the top of the module.
• Verify your build script (dub.json/dub.sdl) explicitly includes DerelictGL3 as a dependency—sometimes restructuring can break implicit dependency links.

Ensure the OpenGL context is still current when you call glCreateShader. If you're switching contexts, or if the window/context was accidentally made non-current before this call, OpenGL functions will fail silently or throw weird errors.

Add quick error checks to narrow this down:

GLenum preErr = glGetError();
if (preErr != GL_NO_ERROR) writeln("Pre-shader error code: ", preErr);

GLuint shader = glCreateShader(GL_VERTEX_SHADER);

GLenum postErr = glGetError();
if (postErr != GL_NO_ERROR) writeln("Post-shader error code: ", postErr);

GL_INVALID_OPERATION here would strongly suggest a missing or inactive context.

Since the error started after optimizing your code, check if your build flags changed. Aggressive optimizations (like -O3) or linker flags that strip unused symbols can sometimes break Derelict's dynamic function loading.

Try temporarily disabling optimizations in your dub config to see if the error disappears. If it does, you'll need to adjust your flags to preserve Derelict's function pointer logic.

If you refactored to use classes/structs for context management, make sure the context object isn't going out of scope before glCreateShader runs. A destroyed context means all OpenGL function calls will behave unpredictably.

If none of these fix the issue, sharing a minimal snippet of your spacegame.game.game shader creation code and your initialization sequence would help zero in on the problem.

内容的提问来源于stack exchange，提问作者D. Ataro