progs/miniglx/miniglxsample.c

   1
   2 #define USE_MINIGLX 1  /* 1 = use Mini GLX, 0 = use Xlib/GLX */
   3
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <unistd.h>
   7 #include <GL/gl.h>
   8
   9 #if USE_MINIGLX
  10 #include <GL/miniglx.h>
  11 #else
  12 #include <GL/glx.h>
  13 #include <X11/Xlib.h>
  14 #endif
  15
  16 static void _subset_Rectf( GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2 )
  17 {
  18    glBegin( GL_QUADS );
  19    glVertex2f( x1, y1 );
  20    glVertex2f( x2, y1 );
  21    glVertex2f( x2, y2 );
  22    glVertex2f( x1, y2 );
  23    glEnd();
  24 }
  25
  26
  27 /*
  28  * Create a simple double-buffered RGBA window.
  29  */
  30 static Window
  31 MakeWindow(Display * dpy, unsigned int width, unsigned int height)
  32 {
  33    int visAttributes[] = {
  34       GLX_RGBA,
  35       GLX_RED_SIZE, 1,
  36       GLX_GREEN_SIZE, 1,
  37       GLX_BLUE_SIZE, 1,
  38       GLX_DOUBLEBUFFER,
  39       None
  40    };
  41    XSetWindowAttributes attr;
  42    unsigned long attrMask;
  43    Window root;
  44    Window win;
  45    GLXContext ctx;
  46    XVisualInfo *visinfo;
  47
  48    root = RootWindow(dpy, 0);
  49
  50    /* Choose GLX visual / pixel format */
  51    visinfo = glXChooseVisual(dpy, 0, visAttributes);
  52    if (!visinfo) {
  53       printf("Error: couldn't get an RGB, Double-buffered visual\n");
  54       exit(1);
  55    }
  56
  57    /* Create the window */
  58    attr.background_pixel = 0;
  59    attr.border_pixel = 0;
  60    attr.colormap = XCreateColormap(dpy, root, visinfo->visual, AllocNone);
  61    attrMask = CWBackPixel | CWBorderPixel | CWColormap;
  62    win = XCreateWindow(dpy, root, 0, 0, width, height,
  63                        0, visinfo->depth, InputOutput,
  64                        visinfo->visual, attrMask, &attr);
  65    if (!win) {
  66       printf("Error: XCreateWindow failed\n");
  67       exit(1);
  68    }
  69
  70    /* Display the window */
  71    XMapWindow(dpy, win);
  72
  73    /* Create GLX rendering context */
  74    ctx = glXCreateContext(dpy, visinfo, NULL, True);
  75    if (!ctx) {
  76       printf("Error: glXCreateContext failed\n");
  77       exit(1);
  78    }
  79
  80    /* Bind the rendering context and window */
  81    glXMakeCurrent(dpy, win, ctx);
  82
  83    glViewport(0, 0, width, height);
  84
  85    return win;
  86 }
  87
  88
  89 /*
  90  * Draw a few frames of a rotating square.
  91  */
  92 static void
  93 DrawFrames(Display * dpy, Window win)
  94 {
  95    int angle;
  96    glShadeModel(GL_FLAT);
  97    glClearColor(0.5, 0.5, 0.5, 1.0);
  98    for (angle = 0; angle < 360; angle += 10) {
  99       glClear(GL_COLOR_BUFFER_BIT);
 100       glColor3f(1.0, 1.0, 0.0);
 101       glPushMatrix();
 102       glRotatef(angle, 0, 0, 1);
 103       _subset_Rectf(-0.8, -0.8, 0.8, 0.8);
 104       glPopMatrix();
 105       glXSwapBuffers(dpy, win);
 106       sleep(1);
 107    }
 108 }
 109
 110
 111 int
 112 main(int argc, char *argv[])
 113 {
 114    Display *dpy;
 115    Window win;
 116
 117    dpy = XOpenDisplay(NULL);
 118    if (!dpy) {
 119       printf("Error: XOpenDisplay failed\n");
 120       return 1;
 121    }
 122
 123    win = MakeWindow(dpy, 300, 300);
 124
 125    DrawFrames(dpy, win);
 126
 127    return 0;
 128 }