Why does mingw give an undefined reference to `glUseProgram'?

Question

The program is written in C using SDL2 and openGL. So long as I comment out

//glUseProgram(0);

the program compiles and runs and displays the glCleared color. Including the gl version checks:

const char* renderer = (const char*) glGetString(GL_RENDERER);
puts(renderer);
const char* version = (const char*) glGetString(GL_VERSION);
puts(version);
const char* glslVersion = (const char*) glGetString(GL_SHADING_LANGUAGE_VERSION);
puts(glslVersion);

Which print out:

ATI Radeon HD 5670
3.2.11927 Core Profile Context
4.20

And the gl error check:

GLenum error = glGetError();
switch(error){
  case GL_NO_ERROR: puts("no error"); break;
  case GL_INVALID_ENUM: puts("invalid enum"); break;
  case GL_INVALID_VALUE: puts("invalid value"); break;
  case GL_OUT_OF_MEMORY: puts("out of memory"); break;
  case GL_INVALID_FRAMEBUFFER_OPERATION: puts("invalid framebuffer operation"); break;
  default: break;   
}

which prints:

no error.

But when glUseProgram(0) is uncommented I get the following error:

D:\TEMP\ccSTF4cr.o:App.c:(.text+0x320): undefined reference to 'glUseProgram

I also get:

App.c:54.2: warning: implicit declaration of function 'glUseProgram'

The included files are:

#include "SDL2/SDL.h"
#include "SDL2/SDL_opengl.h"

The program is executed using a .bat file on Windows XP. The .bat is:

del /F /Q bin\app.exe

set files=main.c App.c EventHub.c Game.c MainShader.c
set libs=-LD:\environments\minGW\mingw32\lib -lmingw32 -lopengl32 -lSDL2main -mwindows -lSDL2  
set objs=bin\main.obj

gcc -Wall -o bin/app %files% %libs%

bin\app.exe

If you don't know .bats, the %file% and %libs% in the command are simply substituted for the strings in the variables.

The issue would seem to be that the context does not support the later glUseProgram function except for the fact that the context is version 3.2 which does support the function. In which case the issue seems to be around the SDL_opengl.h include is picking up a wrong -lopengl32. But frankly I don't really understand this linking stuff which why I am asking the question.

score 2 · Answer 1 · answered Nov 13 '13 at 23:51

2

The Microsoft Windows OpenGL API only has functions from version 1.X at best. (Because they'd prefer you use Direct3D.)

To use modern OpenGL - heck, anything newer than 1995 - on MS Windows, you need an extensions manager such as GLEW or GLEE. See the OpenGL SuperBible, any edition, for details.

answered Nov 13 '13 at 23:51

Hugh Fisher

2,321
13
8

Thankyou for pin pointing where the problem lies, but I understand that SDL2 is no longer compatible with GLEW. I don't suppose anyone knows any code for grabbing the required functionality from the graphic cards version of the gl dll. – ste3e Nov 14 '13 at 01:49

Why does mingw give an undefined reference to `glUseProgram'?

1 Answers1