/* the errors I get are:

bash-3.2$ make
gcc -o testdyngl.exe testdyngl.cpp -g -O2 -I/usr/local/include/SDL -I/usr/include/mingw -mno-cygwin -Dmain=SDL_main -DHAVE_OPENGL -L/usr/local/lib -lmingw32 -lSDLmain -lSDL -mno-cygwin -mwindows
testdyngl.cpp: In function `void init_glfuncs(glfuncs*)':
testdyngl.cpp:76: error: invalid conversion from `void*' to `void (*)(GLenum)'
testdyngl.cpp:77: error: invalid conversion from `void*' to `void (*)()'
testdyngl.cpp:78: error: invalid conversion from `void*' to `void (*)(GLfloat, GLfloat, GLfloat)'
testdyngl.cpp:79: error: invalid conversion from `void*' to `void (*)(GLfloat, GLfloat, GLfloat, GLfloat)'
testdyngl.cpp:80: error: invalid conversion from `void*' to `void (*)(GLbitfield)'
testdyngl.cpp:81: error: invalid conversion from `void*' to `void (*)(GLenum)'
testdyngl.cpp:82: error: invalid conversion from `void*' to `void (*)(GLenum)'
testdyngl.cpp:83: error: invalid conversion from `void*' to `void (*)(GLubyte, GLubyte, GLubyte, GLubyte)'
testdyngl.cpp:84: error: invalid conversion from `void*' to `void (*)(GLfloat)'
testdyngl.cpp:85: error: invalid conversion from `void*' to `void (*)(GLenum, GLenum)'
testdyngl.cpp:86: error: invalid conversion from `void*' to `void (*)(GLenum, GLenum)'
testdyngl.cpp:87: error: invalid conversion from `void*' to `void (*)(GLenum)'
testdyngl.cpp:88: error: invalid conversion from `void*' to `void (*)()'
testdyngl.cpp:89: error: invalid conversion from `void*' to `void (*)(GLdouble, GLdouble, GLdouble, GLdouble, GLdouble, GLdouble)'
testdyngl.cpp:90: error: invalid conversion from `void*' to `void (*)(GLfloat, GLfloat, GLfloat, GLfloat)'
testdyngl.cpp:91: error: invalid conversion from `void*' to `void (*)(GLint, GLint, GLsizei, GLsizei)'
testdyngl.cpp:92: error: invalid conversion from `void*' to `void (*)(GLenum, GLfloat)'
make: *** [testdyngl.exe] Error 1












 --- next line is line #37 in reality too --- */
void* get_funcaddr(const char* p)
{
	void* f=SDL_GL_GetProcAddress(p);
	if (f)
	{
		return f;
	}
	else
	{
		fprintf(stderr,"Unable to get function pointer for %s\n",p);
		quit(1);
	}
	return NULL;
}

typedef struct
{
	void(APIENTRY*glBegin)(GLenum);
	void(APIENTRY*glEnd)();
	void(APIENTRY*glVertex3f)(GLfloat, GLfloat, GLfloat);
	void(APIENTRY*glClearColor)(GLfloat, GLfloat, GLfloat, GLfloat);
	void(APIENTRY*glClear)(GLbitfield);
	void(APIENTRY*glDisable)(GLenum);
	void(APIENTRY*glEnable)(GLenum);
	void(APIENTRY*glColor4ub)(GLubyte,GLubyte,GLubyte,GLubyte);
	void(APIENTRY*glPointSize)(GLfloat);
	void(APIENTRY*glHint)(GLenum,GLenum);
	void(APIENTRY*glBlendFunc)(GLenum,GLenum);
	void(APIENTRY*glMatrixMode)(GLenum);
	void(APIENTRY*glLoadIdentity)();
	void(APIENTRY*glOrtho)(GLdouble,GLdouble,GLdouble,GLdouble,GLdouble,GLdouble);
	void(APIENTRY*glRotatef)(GLfloat,GLfloat,GLfloat,GLfloat);
	void(APIENTRY*glViewport)(GLint,GLint,GLsizei,GLsizei);
	void(APIENTRY*glFogf)(GLenum,GLfloat);
}
glfuncs;

void init_glfuncs(glfuncs* f)
{
	f->glBegin=get_funcaddr("glBegin");
	f->glEnd=get_funcaddr("glEnd");
	f->glVertex3f=get_funcaddr("glVertex3f");
	f->glClearColor=get_funcaddr("glClearColor");
	f->glClear=get_funcaddr("glClear");
	f->glDisable=get_funcaddr("glDisable");
	f->glEnable=get_funcaddr("glEnable");
	f->glColor4ub=get_funcaddr("glColor4ub");
	f->glPointSize=get_funcaddr("glPointSize");
	f->glHint=get_funcaddr("glHint");
	f->glBlendFunc=get_funcaddr("glBlendFunc");
	f->glMatrixMode=get_funcaddr("glMatrixMode");
	f->glLoadIdentity=get_funcaddr("glLoadIdentity");
	f->glOrtho=get_funcaddr("glOrtho");
	f->glRotatef=get_funcaddr("glRotatef");
	f->glViewport=get_funcaddr("glViewport");
	f->glFogf=get_funcaddr("glFogf");
}