What am I doing Wrong (OpenGL & SDL)

[bearophile via Digitalmars-d-learn]

Sean Campbell:

> I cannot figure out what is wrong with this code and why i keep 
> getting object.error access violation. the code is simple 
> tutorial code for SDL and OpenGL what am i doing wrong (the 
> access violation seems to be with glGenBuffers)

I don't know where your problem is, but you can start helping 
yourself with more tidy code (because this makes it more easy to 
fix) and adding some asserts on the pointers.


> float vertices[] = [

Better to use the D syntax.


> int main(string args[]){
> 	DerelictSDL2.load();
> 	DerelictGL3.load();
> 	SDL_Init(SDL_INIT_EVERYTHING);

Better to add a space before the { and some blank lines to 
separate logically distinct pieces of your code.
Also, your main perhaps could be void (and use just empty returns 
inside it).


> 	SDL_Window* window = SDL_CreateWindow("OpenGL", 100, 100, 800, 
> 600, SDL_WINDOW_OPENGL);

Perhaps it's better to use auto here.


> 	glBufferData(GL_ARRAY_BUFFER, (vertices[0]).sizeof * 
> vertices.length, vertices.ptr, GL_STATIC_DRAW);

Better to define a little function that computes the bytes of an 
array, and call it here, it's less bug-prone.

As a first step you can assert that all the pointers that should 
not be null in your program are not null. And then run a debugger.

Bye,
bearophile