progs/xdemos/wincopy.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5.2
   4  *
   5  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 /*
  27  * This program opens two GLX windows, renders into one and uses
  28  * glCopyPixels to copy the image from the first window into the
  29  * second by means of the GLX 1.3 function glxMakeContextCurrent().
  30  * This function works just like the glXMakeCurrentReadSGI() function
  31  * in the GLX_SGI_make_current_read extension.
  32  */
  33
  34
  35 #define GL_GLEXT_PROTOTYPES
  36 #define GLX_GLXEXT_PROTOTYPES
  37 #include <GL/gl.h>
  38 #include <GL/glx.h>
  39 #include <X11/keysym.h>
  40 #include <stdio.h>
  41 #include <stdlib.h>
  42 #include <string.h>
  43 #include <unistd.h>
  44
  45
  46 #ifdef GLX_VERSION_1_3
  47
  48
  49 static Display *Dpy;
  50 static int ScrNum;
  51 static GLXContext Context;
  52 static Window Win[2];  /* Win[0] = source,  Win[1] = dest */
  53 static GLint Width[2], Height[2];
  54 static GLboolean TestClipping = GL_FALSE;
  55 static GLfloat Angle = 0.0;
  56
  57 static GLboolean DrawFront = GL_FALSE;
  58
  59 PFNGLXMAKECURRENTREADSGIPROC make_context_current = NULL;
  60
  61 static Window
  62 CreateWindow(Display *dpy, int scrnum, XVisualInfo *visinfo,
  63              int xpos, int ypos, int width, int height,
  64              const char *name)
  65 {
  66    Window win;
  67    XSetWindowAttributes attr;
  68    unsigned long mask;
  69    Window root;
  70
  71    root = RootWindow(dpy, scrnum);
  72
  73    /* window attributes */
  74    attr.background_pixel = 0;
  75    attr.border_pixel = 0;
  76    attr.colormap = XCreateColormap(dpy, root, visinfo->visual, AllocNone);
  77    attr.event_mask = StructureNotifyMask | ExposureMask | KeyPressMask;
  78    mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;
  79
  80    win = XCreateWindow(dpy, root, xpos, ypos, width, height,
  81                         0, visinfo->depth, InputOutput,
  82                         visinfo->visual, mask, &attr);
  83    if (win) {
  84       XSizeHints sizehints;
  85       sizehints.x = xpos;
  86       sizehints.y = ypos;
  87       sizehints.width  = width;
  88       sizehints.height = height;
  89       sizehints.flags = USSize | USPosition;
  90       XSetNormalHints(dpy, win, &sizehints);
  91       XSetStandardProperties(dpy, win, name, name,
  92                               None, (char **)NULL, 0, &sizehints);
  93
  94       XMapWindow(dpy, win);
  95    }
  96    return win;
  97 }
  98
  99
 100 static void
 101 Redraw(void)
 102 {
 103    /* make the first window the current one */
 104    if (! (*make_context_current)(Dpy, Win[0], Win[0], Context)) {
 105       printf("glXMakeContextCurrent failed in Redraw()\n");
 106       return;
 107    }
 108
 109    Angle += 1.0;
 110
 111    if (DrawFront) {
 112       glDrawBuffer(GL_FRONT);
 113       glReadBuffer(GL_FRONT);
 114    }
 115    else {
 116       glDrawBuffer(GL_BACK);
 117       glReadBuffer(GL_BACK);
 118    }
 119
 120    glViewport(0, 0, Width[0], Height[0]);
 121    glMatrixMode(GL_PROJECTION);
 122    glLoadIdentity();
 123    glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
 124    glMatrixMode(GL_MODELVIEW);
 125
 126    glShadeModel(GL_FLAT);
 127    glClearColor(0.5, 0.5, 0.5, 0.0);
 128    glClear(GL_COLOR_BUFFER_BIT);
 129
 130    /* draw blue quad */
 131    glColor3f(0.3, 0.3, 1.0);
 132    glPushMatrix();
 133    glRotatef(Angle, 0, 0, 1);
 134    glBegin(GL_POLYGON);
 135    glVertex2f(-0.5, -0.25);
 136    glVertex2f( 0.5, -0.25);
 137    glVertex2f( 0.5, 0.25);
 138    glVertex2f(-0.5, 0.25);
 139    glEnd();
 140    glPopMatrix();
 141
 142    if (DrawFront)
 143       glFinish();
 144    else
 145       glXSwapBuffers(Dpy, Win[0]);
 146
 147
 148    /* copy image from window 0 to window 1 */
 149    if (!(*make_context_current)(Dpy, Win[1], Win[0], Context)) {
 150       printf("glXMakeContextCurrent failed in Redraw()\n");
 151       return;
 152    }
 153
 154    /* copy the image between windows */
 155    glClearColor(0.0, 0.0, 0.0, 0.0);
 156    glClear(GL_COLOR_BUFFER_BIT);
 157
 158    if (TestClipping) {
 159       glWindowPos2iARB(-2, -2);
 160       glCopyPixels(-2, -2, Width[0] + 4, Height[0] + 4, GL_COLOR);
 161    }
 162    else {
 163       glWindowPos2iARB(0, 0);
 164       glCopyPixels(0, 0, Width[0], Height[0], GL_COLOR);
 165    }
 166
 167    if (DrawFront)
 168       glFinish();
 169    else
 170       glXSwapBuffers(Dpy, Win[1]);
 171 }
 172
 173
 174
 175 static void
 176 Resize(Window win, unsigned int width, unsigned int height)
 177 {
 178    int i;
 179    if (win == Win[0]) {
 180       i = 0;
 181    }
 182    else {
 183       i = 1;
 184    }
 185    Width[i] = width;
 186    Height[i] = height;
 187    if (!glXMakeCurrent(Dpy, Win[i], Context)) {
 188       printf("glXMakeCurrent failed in Resize()\n");
 189       return;
 190    }
 191 }
 192
 193
 194
 195 static void
 196 EventLoop(void)
 197 {
 198    XEvent event;
 199    while (1) {
 200       if (XPending(Dpy) > 0) {
 201          XNextEvent( Dpy, &event );
 202          switch (event.type) {
 203             case Expose:
 204                Redraw();
 205                break;
 206             case ConfigureNotify:
 207                Resize(event.xany.window, event.xconfigure.width, event.xconfigure.height);
 208                break;
 209             case KeyPress:
 210                {
 211                   char buf[100];
 212                   KeySym keySym;
 213                   XComposeStatus stat;
 214                   XLookupString(&event.xkey, buf, sizeof(buf), &keySym, &stat);
 215                   if (keySym == XK_Escape) {
 216                         /* exit */
 217                         return;
 218                   }
 219                   else if (buf[0] == 'f') {
 220                      DrawFront = !DrawFront;
 221                      printf("Drawing to %s buffer\n",
 222                             DrawFront ? "GL_FRONT" : "GL_BACK");
 223                   }
 224                }
 225                break;
 226             default:
 227                /*no-op*/ ;
 228          }
 229       }
 230       else {
 231          /* animate */
 232          Redraw();
 233       }
 234    }
 235 }
 236
 237
 238 static void
 239 Init(void)
 240 {
 241    XVisualInfo *visinfo;
 242    int attrib[] = { GLX_RGBA,
 243                     GLX_RED_SIZE, 1,
 244                     GLX_GREEN_SIZE, 1,
 245                     GLX_BLUE_SIZE, 1,
 246                     GLX_DOUBLEBUFFER,
 247                     None };
 248    int major, minor;
 249
 250    Dpy = XOpenDisplay(NULL);
 251    if (!Dpy) {
 252       printf("Couldn't open default display!\n");
 253       exit(1);
 254    }
 255
 256    ScrNum = DefaultScreen(Dpy);
 257
 258    glXQueryVersion(Dpy, &major, &minor);
 259
 260    if (major * 100 + minor >= 103) {
 261       make_context_current = (PFNGLXMAKECURRENTREADSGIPROC)
 262           glXGetProcAddressARB( (GLubyte *) "glXMakeContextCurrent" );
 263    }
 264    else {
 265       const char * const glxExtensions = glXQueryExtensionsString(Dpy, ScrNum);
 266       const char * ext = strstr( glxExtensions, "GLX_SGI_make_current_read" );
 267       const size_t len = strlen( "GLX_SGI_make_current_read" );
 268
 269       if ( (ext != NULL)
 270            && ((ext[len] == ' ') || (ext[len] == '\0')) ) {
 271          make_context_current = (PFNGLXMAKECURRENTREADSGIPROC)
 272              glXGetProcAddressARB( (GLubyte *) "glXMakeCurrentReadSGI" );
 273       }
 274    }
 275
 276    if (make_context_current == NULL) {
 277       fprintf(stderr, "Sorry, this program requires either GLX 1.3 "
 278               "or GLX_SGI_make_current_read.\n");
 279       exit(1);
 280    }
 281
 282    visinfo = glXChooseVisual(Dpy, ScrNum, attrib);
 283    if (!visinfo) {
 284       printf("Unable to find RGB, double-buffered visual\n");
 285       exit(1);
 286    }
 287
 288    Context = glXCreateContext(Dpy, visinfo, NULL, True);
 289    if (!Context) {
 290       printf("Couldn't create GLX context\n");
 291       exit(1);
 292    }
 293
 294
 295    Win[0] = CreateWindow(Dpy, ScrNum, visinfo,
 296                          0, 0, 300, 300, "source window");
 297
 298    Win[1] = CreateWindow(Dpy, ScrNum, visinfo,
 299                          350, 0, 300, 300, "dest window");
 300
 301    printf("Press Esc to exit\n");
 302    printf("Press 'f' to toggle front/back buffer drawing\n");
 303 }
 304
 305
 306 int
 307 main(int argc, char *argv[])
 308 {
 309    if (argc > 1 && strcmp(argv[1], "-clip") == 0)
 310       TestClipping = GL_TRUE;
 311    Init();
 312    EventLoop();
 313    return 0;
 314 }
 315
 316
 317 #else
 318
 319
 320 int
 321 main(int argc, char *argv[])
 322 {
 323    printf("This program requires GLX 1.3!\n");
 324    return 0;
 325 }
 326
 327
 328 #endif /* GLX_VERSION_1_3 */