/* * Example of using the X "shape" extension with OpenGL: render a spinning * cube inside of a non-rectangular window. * * Press ESC to exit. Press up/down to change window shape. * * To compile add "shape" to the PROGS list in Makefile. * * Brian Paul * June 16, 1997 * * This program is in the public domain. */ #include <math.h> #include <stdio.h> #include <stdlib.h> #include <sys/time.h> #include <time.h> #include <unistd.h> #include <X11/Xlib.h> #include <X11/Xutil.h> #include <X11/keysym.h> #include <X11/extensions/shape.h> #include <GL/glx.h> #ifndef PI #define PI 3.1415926 #endif static int Width=500, Height=500; static float Xangle = 0.0, Yangle = 0.0; static int Sides = 5; static int MinSides = 3; static int MaxSides = 20; /* return current time (in seconds) */ static double current_time(void) { struct timeval tv; #ifdef __VMS (void) gettimeofday(&tv, NULL ); #else struct timezone tz; (void) gettimeofday(&tv, &tz); #endif return (double) tv.tv_sec + tv.tv_usec / 1000000.0; } /* * Draw the OpenGL stuff and do a SwapBuffers. */ static void display(Display *dpy, Window win) { float scale = 1.7; glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glPushMatrix(); glScalef(scale, scale, scale); glRotatef(Xangle, 1.0, 0.0, 0.0); glRotatef(Yangle, 0.0, 1.0, 0.0); /* * wireframe box */ glColor3f(1.0, 1.0, 1.0); glBegin(GL_LINE_LOOP); glVertex3f(-1.0, -1.0, -1.0); glVertex3f( 1.0, -1.0, -1.0); glVertex3f( 1.0, 1.0, -1.0); glVertex3f(-1.0, 1.0, -1.0); glEnd(); glBegin(GL_LINE_LOOP); glVertex3f(-1.0, -1.0, 1.0); glVertex3f( 1.0, -1.0, 1.0); glVertex3f( 1.0, 1.0, 1.0); glVertex3f(-1.0, 1.0, 1.0); glEnd(); glBegin(GL_LINES); glVertex3f(-1.0, -1.0, -1.0); glVertex3f(-1.0, -1.0, 1.0); glVertex3f( 1.0, -1.0, -1.0); glVertex3f( 1.0, -1.0, 1.0); glVertex3f( 1.0, 1.0, -1.0); glVertex3f( 1.0, 1.0, 1.0); glVertex3f(-1.0, 1.0, -1.0); glVertex3f(-1.0, 1.0, 1.0); glEnd(); /* * Solid box */ glPushMatrix(); glScalef(0.75, 0.75, 0.75); glColor3f(1, 0, 0); glBegin(GL_POLYGON); glVertex3f(1, -1, -1); glVertex3f(1, 1, -1); glVertex3f(1, 1, 1); glVertex3f(1, -1, 1); glEnd(); glColor3f(0, 1, 1); glBegin(GL_POLYGON); glVertex3f(-1, -1, -1); glVertex3f(-1, 1, -1); glVertex3f(-1, 1, 1); glVertex3f(-1, -1, 1); glEnd(); glColor3f(0, 1, 0); glBegin(GL_POLYGON); glVertex3f(-1, 1, -1); glVertex3f( 1, 1, -1); glVertex3f( 1, 1, 1); glVertex3f(-1, 1, 1); glEnd(); glColor3f(1, 0, 1); glBegin(GL_POLYGON); glVertex3f(-1, -1, -1); glVertex3f( 1, -1, -1); glVertex3f( 1, -1, 1); glVertex3f(-1, -1, 1); glEnd(); glColor3f(0, 0, 1); glBegin(GL_POLYGON); glVertex3f(-1, -1, 1); glVertex3f( 1, -1, 1); glVertex3f( 1, 1, 1); glVertex3f(-1, 1, 1); glEnd(); glColor3f(1, 1, 0); glBegin(GL_POLYGON); glVertex3f(-1, -1, -1); glVertex3f( 1, -1, -1); glVertex3f( 1, 1, -1); glVertex3f(-1, 1, -1); glEnd(); glPopMatrix(); glPopMatrix(); glXSwapBuffers(dpy, win); } /* * This is called when we have to recompute the window shape bitmask. * We just generate an n-sided regular polygon here but any other shape * would be possible. */ static void make_shape_mask(Display *dpy, Window win, int width, int height, int sides) { Pixmap shapeMask; XGCValues xgcv; GC gc; /* allocate 1-bit deep pixmap and a GC */ shapeMask = XCreatePixmap(dpy, win, width, height, 1); gc = XCreateGC(dpy, shapeMask, 0, &xgcv); /* clear shapeMask to zeros */ XSetForeground(dpy, gc, 0); XFillRectangle(dpy, shapeMask, gc, 0, 0, width, height); /* draw mask */ XSetForeground(dpy, gc, 1); { int cx = width / 2; int cy = height / 2; float angle = 0.0; float step = 2.0 * PI / sides; float radius = width / 2; int i; XPoint points[100]; for (i=0;i<sides;i++) { int x = cx + radius * sin(angle); int y = cy - radius * cos(angle); points[i].x = x; points[i].y = y; angle += step; } XFillPolygon(dpy, shapeMask, gc, points, sides, Convex, CoordModeOrigin); } /* This is the only SHAPE extension call- simple! */ XShapeCombineMask(dpy, win, ShapeBounding, 0, 0, shapeMask, ShapeSet); XFreeGC(dpy, gc); XFreePixmap(dpy, shapeMask); } /* * Called when window is resized. Do OpenGL viewport and projection stuff. */ static void reshape(int width, int height) { glViewport(0, 0, width, height); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glFrustum(-1.0, 1.0, -1.0, 1.0, 3.0, 20.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glTranslatef(0.0, 0.0, -10.0); glEnable(GL_DEPTH_TEST); } /* * Process X events. */ static void event_loop(Display *dpy, Window win) { while (1) { XEvent event; if (XPending(dpy)) { XNextEvent(dpy, &event); switch (event.type) { case Expose: display(dpy, event.xexpose.window); break; case ConfigureNotify: Width = event.xconfigure.width; Height = event.xconfigure.height, make_shape_mask(dpy, win, Width, Height, Sides); reshape(Width, Height); break; case KeyPress: { char buf[100]; KeySym keySym; XComposeStatus stat; XLookupString(&event.xkey, buf, sizeof(buf), &keySym, &stat); switch (keySym) { case XK_Escape: exit(0); break; case XK_Up: Sides++; if (Sides>MaxSides) Sides = MaxSides; make_shape_mask(dpy, win, Width, Height, Sides); break; case XK_Down: Sides--; if (Sides<MinSides) Sides = MinSides; make_shape_mask(dpy, win, Width, Height, Sides); break; } } break; default: ;; } } else { static double t0 = -1.0; double dt, t = current_time(); if (t0 < 0.0) t0 = t; dt = t - t0; Xangle += 90.0 * dt; /* 90 degrees per second */ Yangle += 70.0 * dt; t0 = t; display(dpy, win); } } } /* * Allocate a "nice" colormap. This could be better (HP-CR support, etc). */ static Colormap alloc_colormap(Display *dpy, Window parent, Visual *vis) { Screen *scr = DefaultScreenOfDisplay(dpy); int scrnum = DefaultScreen(dpy); if (MaxCmapsOfScreen(scr)==1 && vis==DefaultVisual(dpy, scrnum)) { /* The window and root are of the same visual type so */ /* share the root colormap. */ return DefaultColormap(dpy, scrnum); } else { return XCreateColormap(dpy, parent, vis, AllocNone); } } int main(int argc, char *argv[]) { static int glAttribs[] = { GLX_DOUBLEBUFFER, GLX_RGBA, GLX_DEPTH_SIZE, 1, None }; Display *dpy; XVisualInfo *visInfo; int scrn; Window root; Colormap cmap; Window win; XSetWindowAttributes winAttribs; unsigned long winAttribsMask; GLXContext glCtx; int ignore; const char *name = "OpenGL in a Shaped Window"; dpy = XOpenDisplay(NULL); if (!dpy) { fprintf(stderr, "Couldn't open default display\n"); return 1; } /* check that we can use the shape extension */ if (!XQueryExtension(dpy, "SHAPE", &ignore, &ignore, &ignore )) { fprintf(stderr, "Display doesn't support shape extension\n"); return 1; } scrn = DefaultScreen(dpy); root = RootWindow(dpy, scrn); visInfo = glXChooseVisual(dpy, scrn, glAttribs); if (!visInfo) { fprintf(stderr, "Couldn't get RGB, DB, Z visual\n"); return 1; } glCtx = glXCreateContext(dpy, visInfo, 0, True); if (!glCtx) { fprintf(stderr, "Couldn't create GL context\n"); return 1; } cmap = alloc_colormap(dpy, root, visInfo->visual); if (!cmap) { fprintf(stderr, "Couln't create colormap\n"); return 1; } winAttribs.border_pixel = 0; winAttribs.colormap = cmap; winAttribs.event_mask = StructureNotifyMask | ExposureMask | KeyPressMask; winAttribsMask = CWBorderPixel | CWColormap | CWEventMask; win = XCreateWindow(dpy, root, 0, 0, Width, Height, 0, visInfo->depth, InputOutput, visInfo->visual, winAttribsMask, &winAttribs); { XSizeHints sizehints; /* sizehints.x = xpos; sizehints.y = ypos; sizehints.width = width; sizehints.height = height; */ sizehints.flags = 0; XSetNormalHints(dpy, win, &sizehints); XSetStandardProperties(dpy, win, name, name, None, (char **)NULL, 0, &sizehints); } XMapWindow(dpy, win); glXMakeCurrent(dpy, win, glCtx); printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER)); printf("Press ESC to exit.\n"); printf("Press up/down to change window shape.\n"); event_loop(dpy, win); return 0; }