test/testdyngl.c
author Sam Lantinga <slouken@libsdl.org>
Sun, 28 May 2006 13:04:16 +0000
branchSDL-1.3
changeset 1662 782fd950bd46
parent 1659 14717b52abc0
child 1668 4da1ee79c9af
permissions -rw-r--r--
Revamp of the video system in progress - adding support for multiple displays, multiple windows, and a full video mode selection API.

WARNING: None of the video drivers have been updated for the new API yet! The API is still under design and very fluid.

The code is now run through a consistent indent format:
indent -i4 -nut -nsc -br -ce

The headers are being converted to automatically generate doxygen documentation.
     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 __MACOS__
    23 #define HAVE_OPENGL
    24 #endif
    25 
    26 #ifdef HAVE_OPENGL
    27 
    28 #include "SDL_opengl.h"
    29 
    30 /* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
    31 static void
    32 quit (int rc)
    33 {
    34     SDL_Quit ();
    35     exit (rc);
    36 }
    37 
    38 void *
    39 get_funcaddr (const char *p)
    40 {
    41     void *f = SDL_GL_GetProcAddress (p);
    42     if (f) {
    43         return f;
    44     } else {
    45         printf ("Unable to get function pointer for %s\n", p);
    46         quit (1);
    47     }
    48     return NULL;
    49 }
    50 
    51 typedef struct
    52 {
    53     void (APIENTRY * glBegin) (GLenum);
    54     void (APIENTRY * glEnd) ();
    55     void (APIENTRY * glVertex3f) (GLfloat, GLfloat, GLfloat);
    56     void (APIENTRY * glClearColor) (GLfloat, GLfloat, GLfloat, GLfloat);
    57     void (APIENTRY * glClear) (GLbitfield);
    58     void (APIENTRY * glDisable) (GLenum);
    59     void (APIENTRY * glEnable) (GLenum);
    60     void (APIENTRY * glColor4ub) (GLubyte, GLubyte, GLubyte, GLubyte);
    61     void (APIENTRY * glPointSize) (GLfloat);
    62     void (APIENTRY * glHint) (GLenum, GLenum);
    63     void (APIENTRY * glBlendFunc) (GLenum, GLenum);
    64     void (APIENTRY * glMatrixMode) (GLenum);
    65     void (APIENTRY * glLoadIdentity) ();
    66     void (APIENTRY * glOrtho) (GLdouble, GLdouble, GLdouble, GLdouble,
    67                                GLdouble, GLdouble);
    68     void (APIENTRY * glRotatef) (GLfloat, GLfloat, GLfloat, GLfloat);
    69     void (APIENTRY * glViewport) (GLint, GLint, GLsizei, GLsizei);
    70     void (APIENTRY * glFogf) (GLenum, GLfloat);
    71 }
    72 glfuncs;
    73 
    74 void
    75 init_glfuncs (glfuncs * f)
    76 {
    77     f->glBegin = get_funcaddr ("glBegin");
    78     f->glEnd = get_funcaddr ("glEnd");
    79     f->glVertex3f = get_funcaddr ("glVertex3f");
    80     f->glClearColor = get_funcaddr ("glClearColor");
    81     f->glClear = get_funcaddr ("glClear");
    82     f->glDisable = get_funcaddr ("glDisable");
    83     f->glEnable = get_funcaddr ("glEnable");
    84     f->glColor4ub = get_funcaddr ("glColor4ub");
    85     f->glPointSize = get_funcaddr ("glPointSize");
    86     f->glHint = get_funcaddr ("glHint");
    87     f->glBlendFunc = get_funcaddr ("glBlendFunc");
    88     f->glMatrixMode = get_funcaddr ("glMatrixMode");
    89     f->glLoadIdentity = get_funcaddr ("glLoadIdentity");
    90     f->glOrtho = get_funcaddr ("glOrtho");
    91     f->glRotatef = get_funcaddr ("glRotatef");
    92     f->glViewport = get_funcaddr ("glViewport");
    93     f->glFogf = get_funcaddr ("glFogf");
    94 }
    95 
    96 #define NB_PIXELS 1000
    97 
    98 int
    99 main (int argc, char *argv[])
   100 {
   101     glfuncs f;
   102     int i;
   103     SDL_Event event;
   104     int done = 0;
   105     GLfloat pixels[NB_PIXELS * 3];
   106     const char *gl_library = NULL;      /* Use the default GL library */
   107 
   108     if (argv[1]) {
   109         gl_library = argv[1];
   110     }
   111 
   112     if (SDL_Init (SDL_INIT_VIDEO) < 0) {
   113         printf ("Unable to init SDL : %s\n", SDL_GetError ());
   114         return (1);
   115     }
   116 
   117     if (SDL_GL_SetAttribute (SDL_GL_DOUBLEBUFFER, 1) < 0) {
   118         printf ("Unable to set GL attribute : %s\n", SDL_GetError ());
   119         quit (1);
   120     }
   121 
   122     if (SDL_GL_LoadLibrary (gl_library) < 0) {
   123         printf ("Unable to dynamically open GL lib : %s\n", SDL_GetError ());
   124         quit (1);
   125     }
   126 
   127     if (SDL_SetVideoMode (640, 480, 0, SDL_OPENGL) == NULL) {
   128         printf ("Unable to open video mode : %s\n", SDL_GetError ());
   129         quit (1);
   130     }
   131 
   132     /* Set the window manager title bar */
   133     SDL_WM_SetCaption ("SDL Dynamic OpenGL Loading Test", "testdyngl");
   134 
   135     init_glfuncs (&f);
   136 
   137     for (i = 0; i < NB_PIXELS; i++) {
   138         pixels[3 * i] = rand () % 250 - 125;
   139         pixels[3 * i + 1] = rand () % 250 - 125;
   140         pixels[3 * i + 2] = rand () % 250 - 125;
   141     }
   142 
   143     f.glViewport (0, 0, 640, 480);
   144 
   145     f.glMatrixMode (GL_PROJECTION);
   146     f.glLoadIdentity ();
   147     f.glOrtho (-100, 100, -100, 100, -500, 500);
   148 
   149     f.glMatrixMode (GL_MODELVIEW);
   150     f.glLoadIdentity ();
   151 
   152     f.glEnable (GL_DEPTH_TEST);
   153     f.glDisable (GL_TEXTURE_2D);
   154     f.glEnable (GL_BLEND);
   155     f.glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
   156 
   157     f.glClearColor (0.0f, 0.0f, 0.0f, 0.0f);
   158     f.glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   159 
   160     f.glEnable (GL_POINT_SMOOTH);
   161     f.glHint (GL_POINT_SMOOTH_HINT, GL_NICEST);
   162     f.glPointSize (5.0f);
   163     f.glEnable (GL_FOG);
   164     f.glFogf (GL_FOG_START, -500);
   165     f.glFogf (GL_FOG_END, 500);
   166     f.glFogf (GL_FOG_DENSITY, 0.005);
   167 
   168     do {
   169         f.glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   170 
   171         f.glRotatef (2.0, 1.0, 1.0, 1.0);
   172         f.glRotatef (1.0, 0.0, 1.0, 1.0);
   173 
   174         f.glColor4ub (255, 255, 255, 255);
   175         f.glBegin (GL_POINTS);
   176         for (i = 0; i < NB_PIXELS; i++) {
   177             f.glVertex3f (pixels[3 * i], pixels[3 * i + 1],
   178                           pixels[3 * i + 2]);
   179         }
   180         f.glEnd ();
   181         SDL_GL_SwapBuffers ();
   182 
   183         while (SDL_PollEvent (&event)) {
   184             if (event.type & SDL_KEYDOWN)
   185                 done = 1;
   186         }
   187 
   188         SDL_Delay (20);
   189     }
   190     while (!done);
   191 
   192     SDL_Quit ();
   193     return 0;
   194 }
   195 
   196 #else /* HAVE_OPENGL */
   197 
   198 int
   199 main (int argc, char *argv[])
   200 {
   201     printf ("No OpenGL support on this system\n");
   202     return 1;
   203 }
   204 
   205 #endif /* HAVE_OPENGL */