test/testdyngl.c
author Sam Lantinga <slouken@libsdl.org>
Tue, 21 Feb 2006 08:46:50 +0000
changeset 1402 d910939febfa
parent 1386 2b7e0180a72c
child 1436 b5d4f280c960
permissions -rw-r--r--
Use consistent identifiers for the various platforms we support.
Make sure every source file includes SDL_config.h, so the proper system
headers are chosen.
     1 /*
     2  * Small SDL example to demonstrate dynamically loading 
     3  * OpenGL lib and functions
     4  *
     5  * (FYI it was supposed to look like snow in the wind or something...)
     6  *
     7  * Compile with :
     8  * gcc testdyngl.c `sdl-config --libs --cflags` -o testdyngl -DHAVE_OPENGL
     9  *
    10  * You can specify a different OpenGL lib on the command line, i.e. :
    11  * ./testdyngl  /usr/X11R6/lib/libGL.so.1.2
    12  * or
    13  * ./testdyngl  /usr/lib/libGL.so.1.0.4496
    14  *
    15  */
    16 
    17 #include <stdio.h>
    18 #include <stdlib.h>
    19 
    20 #include "SDL.h"
    21 
    22 #ifdef HAVE_OPENGL
    23 
    24 #include "SDL_opengl.h"
    25 
    26 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
    27 static void quit(int rc)
    28 {
    29 	SDL_Quit();
    30 	exit(rc);
    31 }
    32 
    33 void* get_funcaddr(const char* p)
    34 {
    35 	void* f=SDL_GL_GetProcAddress(p);
    36 	if (f)
    37 	{
    38 		return f;
    39 	}
    40 	else
    41 	{
    42 		printf("Unable to get function pointer for %s\n",p);
    43 		quit(1);
    44 	}
    45 }
    46 
    47 typedef struct
    48 {
    49 	void(APIENTRY*glBegin)(GLenum);
    50 	void(APIENTRY*glEnd)();
    51 	void(APIENTRY*glVertex3f)(GLfloat, GLfloat, GLfloat);
    52 	void(APIENTRY*glClearColor)(GLfloat, GLfloat, GLfloat, GLfloat);
    53 	void(APIENTRY*glClear)(GLbitfield);
    54 	void(APIENTRY*glDisable)(GLenum);
    55 	void(APIENTRY*glEnable)(GLenum);
    56 	void(APIENTRY*glColor4ub)(GLubyte,GLubyte,GLubyte,GLubyte);
    57 	void(APIENTRY*glPointSize)(GLfloat);
    58 	void(APIENTRY*glHint)(GLenum,GLenum);
    59 	void(APIENTRY*glBlendFunc)(GLenum,GLenum);
    60 	void(APIENTRY*glMatrixMode)(GLenum);
    61 	void(APIENTRY*glLoadIdentity)();
    62 	void(APIENTRY*glOrtho)(GLdouble,GLdouble,GLdouble,GLdouble,GLdouble,GLdouble);
    63 	void(APIENTRY*glRotatef)(GLfloat,GLfloat,GLfloat,GLfloat);
    64 	void(APIENTRY*glViewport)(GLint,GLint,GLsizei,GLsizei);
    65 	void(APIENTRY*glFogf)(GLenum,GLfloat);
    66 }
    67 glfuncs;
    68 
    69 void init_glfuncs(glfuncs* f)
    70 {
    71 	f->glBegin=get_funcaddr("glBegin");
    72 	f->glEnd=get_funcaddr("glEnd");
    73 	f->glVertex3f=get_funcaddr("glVertex3f");
    74 	f->glClearColor=get_funcaddr("glClearColor");
    75 	f->glClear=get_funcaddr("glClear");
    76 	f->glDisable=get_funcaddr("glDisable");
    77 	f->glEnable=get_funcaddr("glEnable");
    78 	f->glColor4ub=get_funcaddr("glColor4ub");
    79 	f->glPointSize=get_funcaddr("glPointSize");
    80 	f->glHint=get_funcaddr("glHint");
    81 	f->glBlendFunc=get_funcaddr("glBlendFunc");
    82 	f->glMatrixMode=get_funcaddr("glMatrixMode");
    83 	f->glLoadIdentity=get_funcaddr("glLoadIdentity");
    84 	f->glOrtho=get_funcaddr("glOrtho");
    85 	f->glRotatef=get_funcaddr("glRotatef");
    86 	f->glViewport=get_funcaddr("glViewport");
    87 	f->glFogf=get_funcaddr("glFogf");
    88 }
    89 
    90 #define NB_PIXELS 1000
    91 
    92 int main(int argc,char *argv[])
    93 {
    94 	glfuncs f;
    95 	int i;
    96 	SDL_Event event;
    97 	int done=0;
    98 	GLfloat pixels[NB_PIXELS*3];
    99 #if defined(__IRIX__)
   100 	const char *gl_library = "libGL.so";
   101 #elif defined(__MACOSX__)
   102 	const char *gl_library = "/usr/X11R6/lib/libGL.1.dylib";
   103 #elif defined(__QNXNTO__)
   104 	const char *gl_library = "libGL.so.3";
   105 #elif defined(__WIN32__)
   106 	const char *gl_library = "OpenGL32.DLL";
   107 #else
   108 	const char *gl_library = "libGL.so.1";
   109 #endif
   110 
   111 	if (argv[1]) {
   112 		gl_library = argv[1];
   113 	}
   114 	
   115 	if (SDL_Init(SDL_INIT_VIDEO)<0)
   116 	{
   117 		printf("Unable to init SDL : %s\n",SDL_GetError());
   118 		return(1);
   119 	}
   120 
   121 	if (SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER,1)<0)
   122 	{
   123 		printf("Unable to set GL attribute : %s\n",SDL_GetError());
   124 		quit(1);
   125 	}
   126 	
   127 	if (SDL_GL_LoadLibrary(gl_library)<0)
   128 	{
   129 		printf("Unable to dynamically open GL lib : %s\n",SDL_GetError());
   130 		quit(1);
   131 	}
   132 
   133 	if (SDL_SetVideoMode(640,480,0,SDL_OPENGL)==NULL)
   134 	{
   135 		printf("Unable to open video mode : %s\n",SDL_GetError());
   136 		quit(1);
   137 	}
   138 
   139 	/* Set the window manager title bar */
   140 	SDL_WM_SetCaption( "SDL Dynamic OpenGL Loading Test", "testdyngl" );
   141 
   142 	init_glfuncs(&f);
   143 
   144 	for(i=0;i<NB_PIXELS;i++)
   145 	{
   146 		pixels[3*i]=rand()%250-125;
   147 		pixels[3*i+1]=rand()%250-125;
   148 		pixels[3*i+2]=rand()%250-125;
   149 	}
   150 	
   151 	f.glViewport(0,0,640,480);
   152 	
   153 	f.glMatrixMode(GL_PROJECTION);
   154 	f.glLoadIdentity();
   155 	f.glOrtho(-100,100,-100,100,-500,500);
   156 	
   157 	f.glMatrixMode(GL_MODELVIEW);
   158 	f.glLoadIdentity();
   159 	
   160 	f.glEnable(GL_DEPTH_TEST);
   161 	f.glDisable(GL_TEXTURE_2D);
   162 	f.glEnable(GL_BLEND);
   163 	f.glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
   164 	
   165 	f.glClearColor(0.0f,0.0f,0.0f,0.0f);
   166 	f.glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
   167 	
   168 	f.glEnable(GL_POINT_SMOOTH);
   169 	f.glHint(GL_POINT_SMOOTH_HINT,GL_NICEST);
   170 	f.glPointSize(5.0f);
   171 	f.glEnable(GL_FOG);
   172 	f.glFogf(GL_FOG_START,-500);
   173 	f.glFogf(GL_FOG_END,500);
   174 	f.glFogf(GL_FOG_DENSITY,0.005);
   175 	
   176 	do
   177 	{
   178 		f.glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
   179 		
   180 		f.glRotatef(2.0,1.0,1.0,1.0);
   181 		f.glRotatef(1.0,0.0,1.0,1.0);
   182 		
   183 		f.glColor4ub(255,255,255,255);
   184 		f.glBegin(GL_POINTS);
   185 		for(i=0;i<NB_PIXELS;i++)
   186 		{
   187 			f.glVertex3f(pixels[3*i],pixels[3*i+1],pixels[3*i+2]);
   188 		}
   189 		f.glEnd();
   190 		SDL_GL_SwapBuffers();
   191 
   192 		while(SDL_PollEvent(&event))
   193 		{
   194 			if(event.type & SDL_KEYDOWN)
   195 				done=1;
   196 		}
   197 
   198 		SDL_Delay(20);
   199 	}
   200 	while(!done);
   201 	
   202 	SDL_Quit();
   203 	return 0;
   204 }
   205 
   206 #else /* HAVE_OPENGL */
   207 
   208 int main(int argc, char *argv[])
   209 {
   210 	printf("No OpenGL support on this system\n");
   211 	return 1;
   212 }
   213 
   214 #endif /* HAVE_OPENGL */