/* * Copyright © 2007 Intel Corporation * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. * * Authors: * Jesse Barnes <jesse.barnes@intel.com> * */ /** @file glsync.c * The program is simple: it paints a window alternating colors (red & * white) either as fast as possible or synchronized to vblank events * * If run normally, the program should display a window that exhibits * significant tearing between red and white colors (e.g. you might get * a "waterfall" effect of red and white horizontal bars). * * If run with the '-s b' option, the program should synchronize the * window color changes with the vertical blank period, resulting in a * window that looks orangish with a high frequency flicker (which may * be invisible). If the window is moved to another screen, this * property should be preserved. If the window spans two screens, it * shouldn't tear on whichever screen most of the window is on; the * portion on the other screen may show some tearing (like the * waterfall effect above). * * Other options include '-w <width>' and '-h <height' to set the * window size. */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <GL/gl.h> #include <GL/glu.h> #include <GL/glx.h> #include <GL/glxext.h> #include <X11/X.h> #include <X11/Xlib.h> #include <X11/Xutil.h> void (*video_sync_get)(); void (*video_sync)(); void (*swap_interval)(); static int GLXExtensionSupported(Display *dpy, const char *extension) { const char *extensionsString, *client_extensions, *pos; extensionsString = glXQueryExtensionsString(dpy, DefaultScreen(dpy)); client_extensions = glXGetClientString(dpy, GLX_EXTENSIONS); pos = strstr(extensionsString, extension); if (pos != NULL && (pos == extensionsString || pos[-1] == ' ') && (pos[strlen(extension)] == ' ' || pos[strlen(extension)] == '\0')) return 1; pos = strstr(client_extensions, extension); if (pos != NULL && (pos == extensionsString || pos[-1] == ' ') && (pos[strlen(extension)] == ' ' || pos[strlen(extension)] == '\0')) return 1; return 0; } extern char *optarg; extern int optind, opterr, optopt; static char optstr[] = "w:h:s:vi:"; enum sync_type { none = 0, sgi_video_sync, buffer_swap }; static void usage(char *name) { printf("usage: %s [-w <width>] [-h <height>] [-s<sync method>] " "[-v]\n", name); printf("\t-s<sync method>:\n"); printf("\t\tn: none\n"); printf("\t\ts: SGI video sync extension\n"); printf("\t\tb: buffer swap\n"); printf("\t-i<swap interval>\n"); printf("\t-v: verbose (print count)\n"); exit(-1); } int main(int argc, char *argv[]) { Display *disp; XVisualInfo *pvi; XSetWindowAttributes swa; GLint last_val = -1, count = 0; Window winGL; GLXContext context; int dummy; Atom wmDelete; enum sync_type waitforsync = none; int width = 500, height = 500, verbose = 0, interval = 1; int c, i = 1; int ret; int attribs[] = { GLX_RGBA, GLX_RED_SIZE, 1, GLX_GREEN_SIZE, 1, GLX_BLUE_SIZE, 1, None }; int db_attribs[] = { GLX_RGBA, GLX_RED_SIZE, 1, GLX_GREEN_SIZE, 1, GLX_BLUE_SIZE, 1, GLX_DOUBLEBUFFER, GLX_DEPTH_SIZE, 1, None }; XSizeHints sizehints; opterr = 0; while ((c = getopt(argc, argv, optstr)) != -1) { switch (c) { case 'w': width = atoi(optarg); break; case 'h': height = atoi(optarg); break; case 's': switch (optarg[0]) { case 'n': waitforsync = none; break; case 's': waitforsync = sgi_video_sync; break; case 'b': waitforsync = buffer_swap; break; default: usage(argv[0]); break; } break; case 'v': verbose = 1; break; case 'i': interval = atoi(optarg); break; default: usage(argv[0]); break; } } disp = XOpenDisplay(NULL); if (!disp) { fprintf(stderr, "failed to open display\n"); return -1; } if (!glXQueryExtension(disp, &dummy, &dummy)) { fprintf(stderr, "glXQueryExtension failed\n"); return -1; } if (!GLXExtensionSupported(disp, "GLX_SGI_video_sync")) { fprintf(stderr, "GLX_SGI_video_sync not supported, exiting\n"); return -1; } if (waitforsync != buffer_swap) { pvi = glXChooseVisual(disp, DefaultScreen(disp), attribs); } else { pvi = glXChooseVisual(disp, DefaultScreen(disp), db_attribs); } if (!pvi) { fprintf(stderr, "failed to choose visual, exiting\n"); return -1; } pvi->screen = DefaultScreen(disp); swa.colormap = XCreateColormap(disp, RootWindow(disp, pvi->screen), pvi->visual, AllocNone); swa.border_pixel = 0; swa.event_mask = ExposureMask | KeyPressMask | ButtonPressMask | StructureNotifyMask; winGL = XCreateWindow(disp, RootWindow(disp, pvi->screen), 0, 0, width, height, 0, pvi->depth, InputOutput, pvi->visual, CWBorderPixel | CWColormap | CWEventMask, &swa); if (!winGL) { fprintf(stderr, "window creation failed\n"); return -1; } wmDelete = XInternAtom(disp, "WM_DELETE_WINDOW", True); XSetWMProtocols(disp, winGL, &wmDelete, 1); sizehints.x = 0; sizehints.y = 0; sizehints.width = width; sizehints.height = height; sizehints.flags = USSize | USPosition; XSetNormalHints(disp, winGL, &sizehints); XSetStandardProperties(disp, winGL, "glsync test", "glsync text", None, NULL, 0, &sizehints); context = glXCreateContext(disp, pvi, NULL, GL_TRUE); if (!context) { fprintf(stderr, "failed to create glx context\n"); return -1; } XMapWindow(disp, winGL); ret = glXMakeCurrent(disp, winGL, context); if (ret) { fprintf(stderr, "failed to make context current: %d\n", ret); } video_sync_get = glXGetProcAddress((unsigned char *)"glXGetVideoSyncSGI"); video_sync = glXGetProcAddress((unsigned char *)"glXWaitVideoSyncSGI"); swap_interval = glXGetProcAddress((unsigned char *)"glXSwapIntervalSGI"); if (!video_sync_get || !video_sync || !swap_interval) { fprintf(stderr, "failed to get sync functions\n"); return -1; } if (waitforsync == buffer_swap) { swap_interval(interval); fprintf(stderr, "set swap interval to %d\n", interval); } video_sync_get(&count); count++; glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); while (i++) { /* Alternate colors to make tearing obvious */ if (i & 1) { glClearColor(1.0f, 1.0f, 1.0f, 1.0f); glColor3f(1.0f, 1.0f, 1.0f); } else { glClearColor(1.0f, 0.0f, 0.0f, 0.0f); glColor3f(1.0f, 0.0f, 0.0f); } glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glRectf(0, 0, width, height); /* Wait for vsync */ if (waitforsync == sgi_video_sync) { if (verbose) fprintf(stderr, "waiting on count %d\n", count); video_sync(2, (count + 1) % 2, &count); if (count < last_val) fprintf(stderr, "error: vblank count went backwards: %d -> %d\n", last_val, count); if (count == last_val) fprintf(stderr, "error: count didn't change: %d\n", count); last_val = count; glFlush(); } else if (waitforsync == buffer_swap) { glXSwapBuffers(disp, winGL); } else { video_sync_get(&count); sleep(1); glFinish(); } if (verbose) { video_sync_get(&count); fprintf(stderr, "current count: %d\n", count); } } XDestroyWindow(disp, winGL); glXDestroyContext(disp, context); XCloseDisplay(disp); return 0; }