Mercurial > sdl-ios-xcode
diff test/testdyngl.c @ 839:7b255f0290da
Added a test program for dynamically loading OpenGL
author | Sam Lantinga <slouken@libsdl.org> |
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date | Tue, 17 Feb 2004 18:16:49 +0000 |
parents | |
children | 0eec9985767d |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/test/testdyngl.c Tue Feb 17 18:16:49 2004 +0000 @@ -0,0 +1,196 @@ +/* + * 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 + * + * 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(*glBegin)(GLenum); + void(*glEnd)(); + void(*glVertex3f)(GLfloat, GLfloat, GLfloat); + void(*glClearColor)(GLfloat, GLfloat, GLfloat, GLfloat); + void(*glClear)(GLbitfield); + void(*glDisable)(GLenum); + void(*glEnable)(GLenum); + void(*glColor4ub)(GLubyte,GLubyte,GLubyte,GLubyte); + void(*glPointSize)(GLfloat); + void(*glHint)(GLenum,GLenum); + void(*glBlendFunc)(GLenum,GLenum); + void(*glMatrixMode)(GLenum); + void(*glLoadIdentity)(); + void(*glOrtho)(GLdouble,GLdouble,GLdouble,GLdouble,GLdouble,GLdouble); + void(*glRotatef)(GLfloat,GLfloat,GLfloat,GLfloat); + void(*glViewport)(GLint,GLint,GLsizei,GLsizei); + void(*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]; + char default_gl_lib[]="/usr/lib/libGL.so"; + char* current_gl_lib=default_gl_lib; + + if (argc==2) + { + current_gl_lib=argv[1]; + } + + if (SDL_Init(SDL_INIT_EVERYTHING)<0) + { + printf("Unable to init SDL : %s\n",SDL_GetError()); + exit(1); + } + + 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(current_gl_lib)<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); + } + + 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 */