[ghillieLEAD]

I'm trying to get started using OpenGL rather than just SDL and am having a spot of trouble getting my first program to run. The following code compiles and links fine, but when I run the program I get an access violation error.

#include <Windows.h>
#include <gl\GL.h>
#include "SDL.h"

int main(int argc, char* argv[])
{
	SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 8);
	SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 8);
	SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8);
	SDL_GL_SetAttribute(SDL_GL_BUFFER_SIZE, 32);

	SDL_Init(SDL_INIT_VIDEO);
	SDL_SetVideoMode(900, 600, 0, SDL_OPENGL | SDL_HWSURFACE | SDL_NOFRAME);

	glViewport(0, 0, 900, 600);
	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
	glClearDepth(1.0);
	glDepthFunc(GL_LESS);
	glEnable(GL_DEPTH_TEST);
	glShadeModel(GL_SMOOTH);
	glMatrixMode(GL_PROJECTION);
	glMatrixMode(GL_MODELVIEW);

	SDL_Quit();
	return 0;
}

The exact error message I am getting when I run the program is this, "Unhandled exception at 0x6812a8b9 in OpenGL.exe: 0xC0000005: Access violation writing location 0x00000160."

What's the issue?

This post has been edited by ghillieLEAD: 24 February 2011 - 07:00 PM

[Aphex19]

You may need to call SDL_Init first.

#include <Windows.h>
#include <gl\GL.h>
#include "SDL.h"

int main(int argc, char* argv[])
{
	SDL_Init(SDL_INIT_VIDEO);

	SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 8);
	SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 8);
	SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8);
	SDL_GL_SetAttribute(SDL_GL_BUFFER_SIZE, 32);

	SDL_SetVideoMode(900, 600, 0, SDL_OPENGL | SDL_HWSURFACE | SDL_NOFRAME);

	glViewport(0, 0, 900, 600);
	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
	glClearDepth(1.0);
	glDepthFunc(GL_LESS);
	glEnable(GL_DEPTH_TEST);
	glShadeModel(GL_SMOOTH);
	glMatrixMode(GL_PROJECTION);
	glMatrixMode(GL_MODELVIEW);

	SDL_Quit();
	return 0;
}

[ghillieLEAD]

That did it. Thanks much.