/* $Id: glxpixmap.c,v 1.1 1999/08/19 00:55:43 jtg Exp $ */ /* * A demonstration of using the GLXPixmap functions. This program is in * the public domain. * * Brian Paul */ /* * $Id: glxpixmap.c,v 1.1 1999/08/19 00:55:43 jtg Exp $ */ #include <GL/gl.h> #include <GL/glx.h> #include <stdio.h> #include <stdlib.h> static GLXContext ctx; static XVisualInfo *visinfo; static GC gc; static Window make_rgb_window( Display *dpy, unsigned int width, unsigned int height ) { int attrib[] = { GLX_RGBA, GLX_RED_SIZE, 1, GLX_GREEN_SIZE, 1, GLX_BLUE_SIZE, 1, None }; int scrnum; XSetWindowAttributes attr; unsigned long mask; Window root; Window win; scrnum = DefaultScreen( dpy ); root = RootWindow( dpy, scrnum ); visinfo = glXChooseVisual( dpy, scrnum, attrib ); if (!visinfo) { printf("Error: couldn't get an RGB, Double-buffered visual\n"); exit(1); } /* window attributes */ attr.background_pixel = 0; attr.border_pixel = 0; /* TODO: share root colormap if possible */ attr.colormap = XCreateColormap( dpy, root, visinfo->visual, AllocNone); attr.event_mask = StructureNotifyMask | ExposureMask; mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask; win = XCreateWindow( dpy, root, 0, 0, width, height, 0, visinfo->depth, InputOutput, visinfo->visual, mask, &attr ); /* make an X GC so we can do XCopyArea later */ gc = XCreateGC( dpy, win, 0, NULL ); ctx = glXCreateContext( dpy, visinfo, NULL, True ); return win; } static GLXPixmap make_pixmap( Display *dpy, Window win, unsigned int width, unsigned int height ) { Pixmap pm; GLXPixmap glxpm; XWindowAttributes attr; pm = XCreatePixmap( dpy, win, width, height, visinfo->depth ); XGetWindowAttributes( dpy, win, &attr ); /* * IMPORTANT: * Use the glXCreateGLXPixmapMESA funtion when using Mesa because * Mesa needs to know the colormap associated with a pixmap in order * to render correctly. This is because Mesa allows RGB rendering * into any kind of visual, not just TrueColor or DirectColor. */ #ifdef GLX_MESA_pixmap_colormap glxpm = glXCreateGLXPixmapMESA( dpy, visinfo, pm, attr.colormap ); #else /* This will work with Mesa too if the visual is TrueColor or DirectColor */ glxpm = glXCreateGLXPixmap( dpy, visinfo, pm ); #endif return glxpm; } static void event_loop( Display *dpy, GLXPixmap pm ) { XEvent event; while (1) { XNextEvent( dpy, &event ); switch (event.type) { case Expose: printf("Redraw\n"); /* copy the image from GLXPixmap to window */ XCopyArea( dpy, pm, event.xany.window, /* src, dest */ gc, 0, 0, 300, 300, /* gc, src pos, size */ 0, 0 ); /* dest pos */ break; case ConfigureNotify: /* nothing */ break; } } } int main( int argc, char *argv[] ) { Display *dpy; Window win; GLXPixmap pm; dpy = XOpenDisplay(NULL); win = make_rgb_window( dpy, 300, 300 ); pm = make_pixmap( dpy, win, 300, 300 ); #ifdef JUNK glXMakeCurrent( dpy, win, ctx ); /*to make sure ctx is properly initialized*/ #endif glXMakeCurrent( dpy, pm, ctx ); /* Render an image into the pixmap */ glShadeModel( GL_FLAT ); glClearColor( 0.5, 0.5, 0.5, 1.0 ); glClear( GL_COLOR_BUFFER_BIT ); glViewport( 0, 0, 300, 300 ); glOrtho( -1.0, 1.0, -1.0, 1.0, -1.0, 1.0 ); glColor3f( 0.0, 1.0, 1.0 ); glRectf( -0.75, -0.75, 0.75, 0.75 ); glFlush(); /* when a redraw is needed we'll just copy the pixmap image to the window */ XMapWindow( dpy, win ); event_loop( dpy, pm ); return 0; }