221 lines
6 KiB
C
221 lines
6 KiB
C
/*
|
|
Copyright (C) 1997-2011 Sam Lantinga <slouken@libsdl.org>
|
|
|
|
This software is provided 'as-is', without any express or implied
|
|
warranty. In no event will the authors be held liable for any damages
|
|
arising from the use of this software.
|
|
|
|
Permission is granted to anyone to use this software for any purpose,
|
|
including commercial applications, and to alter it and redistribute it
|
|
freely.
|
|
*/
|
|
/*
|
|
* 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 __MACOS__
|
|
#define HAVE_OPENGL
|
|
#endif
|
|
|
|
#ifdef HAVE_OPENGL
|
|
|
|
#include "SDL_opengl.h"
|
|
|
|
/* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
|
|
static void
|
|
quit(int rc)
|
|
{
|
|
SDL_Quit();
|
|
exit(rc);
|
|
}
|
|
|
|
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);
|
|
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);
|
|
const GLubyte* (APIENTRY * glGetString) (GLenum);
|
|
}
|
|
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");
|
|
f->glGetString = get_funcaddr("glGetString");
|
|
|
|
printf("Vendor : %s\n", f->glGetString(GL_VENDOR));
|
|
printf("Renderer : %s\n", f->glGetString(GL_RENDERER));
|
|
printf("Version : %s\n", f->glGetString(GL_VERSION));
|
|
printf("Extensions : %s\n", f->glGetString(GL_EXTENSIONS));
|
|
}
|
|
|
|
#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];
|
|
const char *gl_library = NULL; /* Use the default GL library */
|
|
|
|
if (argv[1]) {
|
|
gl_library = argv[1];
|
|
}
|
|
|
|
if (SDL_Init(SDL_INIT_VIDEO) < 0) {
|
|
printf("Unable to init SDL : %s\n", SDL_GetError());
|
|
return (1);
|
|
}
|
|
|
|
if (SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1) < 0) {
|
|
printf("Unable to set GL attribute : %s\n", SDL_GetError());
|
|
quit(1);
|
|
}
|
|
|
|
if (SDL_GL_LoadLibrary(gl_library) < 0) {
|
|
printf("Unable to dynamically open GL lib : %s\n", SDL_GetError());
|
|
quit(1);
|
|
}
|
|
|
|
if (SDL_SetVideoMode(640, 480, 0, SDL_OPENGL) == NULL) {
|
|
printf("Unable to open video mode : %s\n", SDL_GetError());
|
|
quit(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 */
|