progs/xdemos/wincopy.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.1
   4  *
   5  * Copyright (C) 1999-2004  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 GLX_GLXEXT_PROTOTYPES
  36 #include <GL/gl.h>
  37 #include <GL/glx.h>
  38 #include <X11/keysym.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42 #include <unistd.h>
  43
  44
  45 #ifdef GLX_VERSION_1_3
  46
  47
  48 static Display *Dpy;
  49 static int ScrNum;
  50 static GLXContext Context;
  51 static Window Win[2];  /* Win[0] = source,  Win[1] = dest */
  52 static GLint Width[2], Height[2];
  53
  54 static GLfloat Angle = 0.0;
  55
  56 static GLboolean DrawFront = GL_FALSE;
  57
  58 PFNGLXMAKECURRENTREADSGIPROC make_context_current = NULL;
  59
  60 static Window
  61 CreateWindow(Display *dpy, int scrnum, XVisualInfo *visinfo,
  62              int xpos, int ypos, int width, int height,
  63              const char *name)
  64 {
  65    Window win;
  66    XSetWindowAttributes attr;
  67    unsigned long mask;
  68    Window root;
  69
  70    root = RootWindow(dpy, scrnum);
  71
  72    /* window attributes */
  73    attr.background_pixel = 0;
  74    attr.border_pixel = 0;
  75    attr.colormap = XCreateColormap(dpy, root, visinfo->visual, AllocNone);
  76    attr.event_mask = StructureNotifyMask | ExposureMask | KeyPressMask;
  77    mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;
  78
  79    win = XCreateWindow(dpy, root, xpos, ypos, width, height,
  80                         0, visinfo->depth, InputOutput,
  81                         visinfo->visual, mask, &attr);
  82    if (win) {
  83       XSizeHints sizehints;
  84       sizehints.x = xpos;
  85       sizehints.y = ypos;
  86       sizehints.width  = width;
  87       sizehints.height = height;
  88       sizehints.flags = USSize | USPosition;
  89       XSetNormalHints(dpy, win, &sizehints);
  90       XSetStandardProperties(dpy, win, name, name,
  91                               None, (char **)NULL, 0, &sizehints);
  92
  93       XMapWindow(dpy, win);
  94    }
  95    return win;
  96 }
  97
  98
  99 static void
 100 Redraw(void)
 101 {
 102    /* make the first window the current one */
 103    if (! (*make_context_current)(Dpy, Win[0], Win[0], Context)) {
 104       printf("glXMakeContextCurrent failed in Redraw()\n");
 105       return;
 106    }
 107
 108    Angle += 1.0;
 109
 110    if (DrawFront) {
 111       glDrawBuffer(GL_FRONT);
 112       glReadBuffer(GL_FRONT);
 113    }
 114    else {
 115       glDrawBuffer(GL_BACK);
 116       glReadBuffer(GL_BACK);
 117    }
 118
 119    glViewport(0, 0, Width[0], Height[0]);
 120    glMatrixMode(GL_PROJECTION);
 121    glLoadIdentity();
 122    glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
 123    glMatrixMode(GL_MODELVIEW);
 124
 125    glShadeModel(GL_FLAT);
 126    glClearColor(0.5, 0.5, 0.5, 1.0);
 127    glClear(GL_COLOR_BUFFER_BIT);
 128
 129    /* draw blue quad */
 130    glColor3f(0.3, 0.3, 1.0);
 131    glPushMatrix();
 132    glRotatef(Angle, 0, 0, 1);
 133    glBegin(GL_POLYGON);
 134    glVertex2f(-0.5, -0.25);
 135    glVertex2f( 0.5, -0.25);
 136    glVertex2f( 0.5, 0.25);
 137    glVertex2f(-0.5, 0.25);
 138    glEnd();
 139    glPopMatrix();
 140
 141    if (DrawFront)
 142       glFinish();
 143    else
 144       glXSwapBuffers(Dpy, Win[0]);
 145
 146
 147    /* copy image from window 0 to window 1 */
 148    if (!(*make_context_current)(Dpy, Win[1], Win[0], Context)) {
 149       printf("glXMakeContextCurrent failed in Redraw()\n");
 150       return;
 151    }
 152
 153    /* raster pos setup */
 154    glViewport(0, 0, Width[1], Height[1]);
 155    glPushMatrix();
 156    glLoadIdentity();
 157    glMatrixMode(GL_PROJECTION);
 158    glPushMatrix();
 159    glLoadIdentity();
 160    glOrtho(-1, 1, -1, 1, -1, 1);
 161    glRasterPos2f(-1, -1);
 162
 163    /* copy the image between windows */
 164    glCopyPixels(0, 0, Width[0], Height[0], GL_COLOR);
 165
 166    glPopMatrix();
 167    glMatrixMode(GL_MODELVIEW);
 168    glPopMatrix();
 169
 170    if (DrawFront)
 171       glFinish();
 172    else
 173       glXSwapBuffers(Dpy, Win[1]);
 174 }
 175
 176
 177
 178 static void
 179 Resize(Window win, unsigned int width, unsigned int height)
 180 {
 181    int i;
 182    if (win == Win[0]) {
 183       i = 0;
 184    }
 185    else {
 186       i = 1;
 187    }
 188    Width[i] = width;
 189    Height[i] = height;
 190    if (!glXMakeCurrent(Dpy, Win[i], Context)) {
 191       printf("glXMakeCurrent failed in Resize()\n");
 192       return;
 193    }
 194 }
 195
 196
 197
 198 static void
 199 EventLoop(void)
 200 {
 201    XEvent event;
 202    while (1) {
 203       if (XPending(Dpy) > 0) {
 204          XNextEvent( Dpy, &event );
 205          switch (event.type) {
 206             case Expose:
 207                Redraw();
 208                break;
 209             case ConfigureNotify:
 210                Resize(event.xany.window, event.xconfigure.width, event.xconfigure.height);
 211                break;
 212             case KeyPress:
 213                {
 214                   char buf[100];
 215                   KeySym keySym;
 216                   XComposeStatus stat;
 217                   XLookupString(&event.xkey, buf, sizeof(buf), &keySym, &stat);
 218                   if (keySym == XK_Escape) {
 219                         /* exit */
 220                         return;
 221                   }
 222                   else if (buf[0] == 'f') {
 223                      DrawFront = !DrawFront;
 224                      printf("Drawing to %s buffer\n",
 225                             DrawFront ? "GL_FRONT" : "GL_BACK");
 226                   }
 227                }
 228                break;
 229             default:
 230                /*no-op*/ ;
 231          }
 232       }
 233       else {
 234          /* animate */
 235          Redraw();
 236       }
 237    }
 238 }
 239
 240
 241 static void
 242 Init(void)
 243 {
 244    XVisualInfo *visinfo;
 245    int attrib[] = { GLX_RGBA,
 246                     GLX_RED_SIZE, 1,
 247                     GLX_GREEN_SIZE, 1,
 248                     GLX_BLUE_SIZE, 1,
 249                     GLX_DOUBLEBUFFER,
 250                     None };
 251    int major, minor;
 252
 253    Dpy = XOpenDisplay(NULL);
 254    if (!Dpy) {
 255       printf("Couldn't open default display!\n");
 256       exit(1);
 257    }
 258
 259    ScrNum = DefaultScreen(Dpy);
 260
 261    glXQueryVersion(Dpy, &major, &minor);
 262
 263    if (major * 100 + minor >= 103) {
 264       make_context_current = (PFNGLXMAKECURRENTREADSGIPROC)
 265           glXGetProcAddressARB( (GLubyte *) "glXMakeContextCurrent" );
 266    }
 267    else {
 268       const char * const glxExtensions = glXQueryExtensionsString(Dpy, ScrNum);
 269       const char * ext = strstr( glxExtensions, "GLX_SGI_make_current_read" );
 270       const size_t len = strlen( "GLX_SGI_make_current_read" );
 271
 272       if ( (ext != NULL)
 273            && ((ext[len] == ' ') || (ext[len] == '\0')) ) {
 274          make_context_current = (PFNGLXMAKECURRENTREADSGIPROC)
 275              glXGetProcAddressARB( (GLubyte *) "glXMakeCurrentReadSGI" );
 276       }
 277    }
 278
 279    if (make_context_current == NULL) {
 280       fprintf(stderr, "Sorry, this program requires either GLX 1.3 "
 281               "or GLX_SGI_make_current_read.\n");
 282       exit(1);
 283    }
 284
 285    visinfo = glXChooseVisual(Dpy, ScrNum, attrib);
 286    if (!visinfo) {
 287       printf("Unable to find RGB, double-buffered visual\n");
 288       exit(1);
 289    }
 290
 291    Context = glXCreateContext(Dpy, visinfo, NULL, True);
 292    if (!Context) {
 293       printf("Couldn't create GLX context\n");
 294       exit(1);
 295    }
 296
 297
 298    Win[0] = CreateWindow(Dpy, ScrNum, visinfo,
 299                          0, 0, 300, 300, "source window");
 300
 301    Win[1] = CreateWindow(Dpy, ScrNum, visinfo,
 302                          350, 0, 300, 300, "dest window");
 303
 304    printf("Press Esc to exit\n");
 305    printf("Press 'f' to toggle front/back buffer drawing\n");
 306 }
 307
 308
 309 int
 310 main(int argc, char *argv[])
 311 {
 312    Init();
 313    EventLoop();
 314    return 0;
 315 }
 316
 317
 318 #else
 319
 320
 321 int
 322 main(int argc, char *argv[])
 323 {
 324    printf("This program requires GLX 1.3!\n");
 325    return 0;
 326 }
 327
 328
 329 #endif /* GLX_VERSION_1_3 */