Having trouble getting GLEW to work - c

Question

note: glGetString(GL_VERSION) returned: 2.1.0 - Build 8.15.10.2361
I have installed GLEW to System32, and VCDir/lib and VCDir/include directories. So the linker should not have any issues finding the necessary bits of GLEW. The trouble I am having though is that the following code:
void foo()
{
Uint32 vboId;
glGenBuffers(1, &vboId);
}
Gives me the following error:
unresolved external symbol __imp____glewGenBuffers
This error was the entire reason I decided to install GLEW. See: unresolved external symbol _glGenBuffers error
In addition to this error, there are a few warnings that are a bit concerning:
Warning 1 warning C4028: formal parameter 3 different from declaration c:\sdl-1.2.14\include\sdl_opengl.h 4855 1 Prototek
Warning 2 warning C4028: formal parameter 3 different from declaration c:\sdl-1.2.14\include\sdl_opengl.h 4857 1 Prototek
Warning 3 warning C4028: formal parameter 2 different from declaration c:\sdl-1.2.14\include\sdl_opengl.h 4859 1 Prototek
Warning 4 warning C4028: formal parameter 2 different from declaration c:\sdl-1.2.14\include\sdl_opengl.h 4861 1 Prototek
Warning 5 warning C4028: formal parameter 3 different from declaration c:\sdl-1.2.14\include\sdl_opengl.h 4868 1 Prototek
Warning 6 warning C4028: formal parameter 3 different from declaration c:\sdl-1.2.14\include\sdl_opengl.h 4869 1 Prototek
Also, is it a good idea to simply install SDL to my VC inc and lib and System32 directories as I have done for GLEW?
My #include's at the top of my file look like this:
#include <stdio.h>
#include <glew.h>
#include "sdl.h"
#include "sdl_opengl.h"
#include <gl/GLU.h>
#include <gl/GL.h>
But in case it is needed, here is the entire body of code:
#include <stdio.h>
#include <glew.h>
#include "sdl.h"
#include "sdl_opengl.h"
#include <gl/GLU.h>
#include <gl/GL.h>
Uint32 loadTexture(char* fileName)
{
Uint32 id;
SDL_Surface *img = NULL;
//load into memory using SDL
img = SDL_LoadBMP(fileName);
//generate an id for this texture
glGenTextures(1, &id);
//use this texture
glBindTexture(GL_TEXTURE_2D, id);
//load the texture into video memory via OpenGL
glTexImage2D(
GL_TEXTURE_2D,
0,
GL_RGB,
img->w,
img->h,
0,
GL_BGR,
GL_UNSIGNED_BYTE,
img->pixels
);
//set mip map settings
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
SDL_FreeSurface(img);
return id;
}
Uint32 tex;
void init()
{
glClearColor(0.0, 0.0, 0.0, 1.0);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0.0, 1.0, 1.0, 0.0, -1.0, 1.0);
glMatrixMode(GL_MODELVIEW);
glEnable(GL_TEXTURE_2D);
tex = loadTexture("fireball.bmp");
}
void foo()
{
Uint32 vboId;
glGenBuffers(1, &vboId);
}
void display()
{
glClear(GL_COLOR_BUFFER_BIT);
glLoadIdentity();
glBindTexture(GL_TEXTURE_2D, tex);
glBegin(GL_QUADS);
glTexCoord2f(0.5, 0.5);
glVertex3f(0.25, 0.25, 0.0);
glTexCoord2f(1.0, 0.5);
glVertex3f(0.5, 0.25, 0.0);
glTexCoord2f(1.0, 1.0);
glVertex3f(0.5, 0.5, 0.0);
glTexCoord2f(0.5, 1.0);
glVertex3f(0.25, 0.5, 0.0);
glEnd();
}
int main()
{
Uint32 isRunning = 1;
SDL_Surface *screen = NULL;
SDL_Event event;
Uint32 start;
Uint32 FPS = 30;
SDL_Init(SDL_INIT_EVERYTHING);
screen = SDL_SetVideoMode(640, 480, 32, SDL_OPENGL);
init();
while(isRunning)
{
start = SDL_GetTicks();
while(SDL_PollEvent(&event))
{
switch(event.type)
{
case SDL_QUIT: isRunning = 0; break;
}
}
display();
SDL_GL_SwapBuffers();
if(1000 / FPS > SDL_GetTicks() - start)
{
SDL_Delay(1000 / FPS - (SDL_GetTicks() - start));
}
}
SDL_Quit();
return(0);
}

Answer 1

I noticed you didn't include a call to glewInit(), if you are planning to use glew make sure you call it before using any of the openGL function pointers it provides.

Answer 2

Did you actually link to the GLEW library? Simply telling VS where the directory is isn't enough; you have to tell it what library to link to.
A quick way to test if you're linking to the library is to delete it and recompile. If VC doesn't complain about not being able to find a particular library, then you didn't link to it.
Also, is it a good idea to simply install SDL to my VC inc and lib and System32 directories as I have done for GLEW?
It wasn't a good idea to install GLEW there, let alone anything else. Visual Studio is not like a Linux install; there isn't a global repository of libraries and headers. It is up to you to point your VS project to the particular libraries and header files (you can even set these globally if you want). Leave the VS directories alone.

Answer 3

glGenBuffers second parameter is a pointer to a GLuint (GLuint ), not a Pointer to a Pointer to a GLuint (GLuint *, which is what you're passing). Instead, do this:
Uint32 vboId;
glGenBuffers(1, &vboId);