view test/testdyngl.c @ 1077:f122afdfa025

The Darwin/MacOSX joystick code is largely copied from the HID Utilities package...make the symbols defined by HID Utilities static inside SDL so that an app can link against their own copy of this package without symbol clash.
author Ryan C. Gordon <icculus@icculus.org>
date Wed, 15 Jun 2005 23:41:57 +0000
parents 8e20c48a9c13
children be9c9c8f6d53
line wrap: on
line source

/*
 * Small SDL example to demonstrate dynamically loading 
 * OpenGL lib and functions
 *
 * (FYI it was supposed to look like snow in the wind or something...)
 *
 * Compile with :
 * gcc testdyngl.c `sdl-config --libs --cflags` -o testdyngl -DHAVE_OPENGL
 *
 * You can specify a different OpenGL lib on the command line, i.e. :
 * ./testdyngl  /usr/X11R6/lib/libGL.so.1.2
 * or
 * ./testdyngl  /usr/lib/libGL.so.1.0.4496
 *
 */

#include <stdio.h>
#include <stdlib.h>

#include "SDL.h"

#ifdef HAVE_OPENGL

#include "SDL_opengl.h"

void* get_funcaddr(const char* p)
{
	void* f=SDL_GL_GetProcAddress(p);
	if (f)
	{
		return f;
	}
	else
	{
		printf("Unable to get function pointer for %s\n",p);
		exit(1);
	}
}

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");
}

#define NB_PIXELS 1000

int main(int argc,char *argv[])
{
	glfuncs f;
	int i;
	SDL_Event event;
	int done=0;
	GLfloat pixels[NB_PIXELS*3];
#if defined(_WIN32)
	char *gl_library = "OpenGL32.DLL";
#elif defined(__QNXNTO__)
	char *gl_library = "libGL.so.3";
#else
	char *gl_library = "libGL.so.1";
#endif
	
	if (argv[1]) {
		gl_library = argv[1];
	}
	
	if (SDL_Init(SDL_INIT_VIDEO)<0)
	{
		printf("Unable to init SDL : %s\n",SDL_GetError());
		exit(1);
	}

	atexit(SDL_Quit);
	
	if (SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER,1)<0)
	{
		printf("Unable to set GL attribute : %s\n",SDL_GetError());
		exit(1);
	}
	
	if (SDL_GL_LoadLibrary(gl_library)<0)
	{
		printf("Unable to dynamically open GL lib : %s\n",SDL_GetError());
		exit(1);
	}

	if (SDL_SetVideoMode(640,480,0,SDL_OPENGL)==NULL)
	{
		printf("Unable to open video mode : %s\n",SDL_GetError());
		exit(1);
	}

	/* Set the window manager title bar */
	SDL_WM_SetCaption( "SDL Dynamic OpenGL Loading Test", "testdyngl" );

	init_glfuncs(&f);

	for(i=0;i<NB_PIXELS;i++)
	{
		pixels[3*i]=rand()%250-125;
		pixels[3*i+1]=rand()%250-125;
		pixels[3*i+2]=rand()%250-125;
	}
	
	f.glViewport(0,0,640,480);
	
	f.glMatrixMode(GL_PROJECTION);
	f.glLoadIdentity();
	f.glOrtho(-100,100,-100,100,-500,500);
	
	f.glMatrixMode(GL_MODELVIEW);
	f.glLoadIdentity();
	
	f.glEnable(GL_DEPTH_TEST);
	f.glDisable(GL_TEXTURE_2D);
	f.glEnable(GL_BLEND);
	f.glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	
	f.glClearColor(0.0f,0.0f,0.0f,0.0f);
	f.glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
	
	f.glEnable(GL_POINT_SMOOTH);
	f.glHint(GL_POINT_SMOOTH_HINT,GL_NICEST);
	f.glPointSize(5.0f);
	f.glEnable(GL_FOG);
	f.glFogf(GL_FOG_START,-500);
	f.glFogf(GL_FOG_END,500);
	f.glFogf(GL_FOG_DENSITY,0.005);
	
	do
	{
		f.glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
		
		f.glRotatef(2.0,1.0,1.0,1.0);
		f.glRotatef(1.0,0.0,1.0,1.0);
		
		f.glColor4ub(255,255,255,255);
		f.glBegin(GL_POINTS);
		for(i=0;i<NB_PIXELS;i++)
		{
			f.glVertex3f(pixels[3*i],pixels[3*i+1],pixels[3*i+2]);
		}
		f.glEnd();
		SDL_GL_SwapBuffers();

		while(SDL_PollEvent(&event))
		{
			if(event.type & SDL_KEYDOWN)
				done=1;
		}

		SDL_Delay(20);
	}
	while(!done);
	
	SDL_Quit();
	return 0;
}

#else /* HAVE_OPENGL */

int main(int argc, char *argv[])
{
	printf("No OpenGL support on this system\n");
	return 1;
}

#endif /* HAVE_OPENGL */