progs/xdemos/wincopy.c

   1
   2 /*
   3  * Mesa 3-D graphics library
   4  * Version:  3.3
   5  *
   6  * Copyright (C) 1999  Brian Paul   All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included
  16  * in all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  22  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  23  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26
  27 /*
  28  * This program opens two GLX windows, renders into one and uses
  29  * glCopyPixels to copy the image from the first window into the
  30  * second by means of the GLX 1.3 function glxMakeContextCurrent().
  31  * This function works just like the glXMakeCurrentReadSGI() function
  32  * in the GLX_SGI_make_current_read extension.
  33  */
  34
  35
  36
  37 #include <GL/gl.h>
  38 #include <GL/glx.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <unistd.h>
  42
  43
  44 #ifdef GLX_VERSION_1_3
  45
  46
  47 static Display *Dpy;
  48 static int ScrNum;
  49 static GLXContext Context;
  50 static Window Win[2];  /* Win[0] = source,  Win[1] = dest */
  51 static GLint Width[2], Height[2];
  52
  53 static GLfloat Angle = 0.0;
  54
  55
  56
  57 static Window
  58 CreateWindow(Display *dpy, int scrnum, XVisualInfo *visinfo,
  59              int xpos, int ypos, int width, int height,
  60              const char *name)
  61 {
  62    Window win;
  63    XSetWindowAttributes attr;
  64    unsigned long mask;
  65    Window root;
  66
  67    root = RootWindow(dpy, scrnum);
  68
  69    /* window attributes */
  70    attr.background_pixel = 0;
  71    attr.border_pixel = 0;
  72    attr.colormap = XCreateColormap(dpy, root, visinfo->visual, AllocNone);
  73    attr.event_mask = StructureNotifyMask | ExposureMask | KeyPressMask;
  74    mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;
  75
  76    win = XCreateWindow(dpy, root, xpos, ypos, width, height,
  77                         0, visinfo->depth, InputOutput,
  78                         visinfo->visual, mask, &attr);
  79    if (win) {
  80       XSizeHints sizehints;
  81       sizehints.x = xpos;
  82       sizehints.y = ypos;
  83       sizehints.width  = width;
  84       sizehints.height = height;
  85       sizehints.flags = USSize | USPosition;
  86       XSetNormalHints(dpy, win, &sizehints);
  87       XSetStandardProperties(dpy, win, name, name,
  88                               None, (char **)NULL, 0, &sizehints);
  89
  90       XMapWindow(dpy, win);
  91    }
  92    return win;
  93 }
  94
  95
  96 static void
  97 Redraw(void)
  98 {
  99    /* make the first window the current one */
 100    if (!glXMakeContextCurrent(Dpy, Win[0], Win[0], Context)) {
 101       printf("glXMakeContextCurrent failed in Redraw()\n");
 102       return;
 103    }
 104
 105    Angle += 1.0;
 106
 107    glViewport(0, 0, Width[0], Height[0]);
 108    glMatrixMode(GL_PROJECTION);
 109    glLoadIdentity();
 110    glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
 111    glMatrixMode(GL_MODELVIEW);
 112
 113    glShadeModel(GL_FLAT);
 114    glClearColor(0.5, 0.5, 0.5, 1.0);
 115    glClear(GL_COLOR_BUFFER_BIT);
 116
 117    /* draw blue quad */
 118    glColor3f(0.3, 0.3, 1.0);
 119    glPushMatrix();
 120    glRotatef(Angle, 0, 0, 1);
 121    glBegin(GL_POLYGON);
 122    glVertex2f(-0.5, -0.25);
 123    glVertex2f( 0.5, -0.25);
 124    glVertex2f( 0.5, 0.25);
 125    glVertex2f(-0.5, 0.25);
 126    glEnd();
 127    glPopMatrix();
 128
 129    glXSwapBuffers(Dpy, Win[0]);
 130
 131
 132    /* copy image from window 0 to window 1 */
 133    if (!glXMakeContextCurrent(Dpy, Win[1], Win[0], Context)) {
 134       printf("glXMakeContextCurrent failed in Redraw()\n");
 135       return;
 136    }
 137
 138    /* raster pos setup */
 139    glViewport(0, 0, Width[1], Height[1]);
 140    glPushMatrix();
 141    glLoadIdentity();
 142    glMatrixMode(GL_PROJECTION);
 143    glPushMatrix();
 144    glLoadIdentity();
 145    glOrtho(-1, 1, -1, 1, -1, 1);
 146    glRasterPos2f(-1, -1);
 147
 148    /* copy the image between windows */
 149    glDrawBuffer(GL_FRONT);
 150    glCopyPixels(0, 0, Width[0], Height[0], GL_COLOR);
 151    glDrawBuffer(GL_BACK);
 152
 153    glPopMatrix();
 154    glMatrixMode(GL_MODELVIEW);
 155    glPopMatrix();
 156 }
 157
 158
 159
 160 static void
 161 Resize(Window win, unsigned int width, unsigned int height)
 162 {
 163    int i;
 164    if (win == Win[0]) {
 165       i = 0;
 166    }
 167    else {
 168       i = 1;
 169    }
 170    Width[i] = width;
 171    Height[i] = height;
 172    if (!glXMakeCurrent(Dpy, Win[i], Context)) {
 173       printf("glXMakeCurrent failed in Resize()\n");
 174       return;
 175    }
 176 }
 177
 178
 179
 180 static void
 181 EventLoop(void)
 182 {
 183    XEvent event;
 184    while (1) {
 185       if (XPending(Dpy) > 0) {
 186          XNextEvent( Dpy, &event );
 187          switch (event.type) {
 188             case Expose:
 189                Redraw();
 190                break;
 191             case ConfigureNotify:
 192                Resize(event.xany.window, event.xconfigure.width, event.xconfigure.height);
 193                break;
 194             case KeyPress:
 195                return;
 196             default:
 197                /*no-op*/ ;
 198          }
 199       }
 200       else {
 201          /* animate */
 202          Redraw();
 203       }
 204    }
 205 }
 206
 207
 208 static void
 209 Init(void)
 210 {
 211    XVisualInfo *visinfo;
 212    int attrib[] = { GLX_RGBA,
 213                     GLX_RED_SIZE, 1,
 214                     GLX_GREEN_SIZE, 1,
 215                     GLX_BLUE_SIZE, 1,
 216                     GLX_DOUBLEBUFFER,
 217                     None };
 218
 219    Dpy = XOpenDisplay(NULL);
 220    if (!Dpy) {
 221       printf("Couldn't open default display!\n");
 222       exit(1);
 223    }
 224
 225    ScrNum = DefaultScreen(Dpy);
 226
 227    visinfo = glXChooseVisual(Dpy, ScrNum, attrib);
 228    if (!visinfo) {
 229       printf("Unable to find RGB, double-buffered visual\n");
 230       exit(1);
 231    }
 232
 233    Context = glXCreateContext(Dpy, visinfo, NULL, True);
 234    if (!Context) {
 235       printf("Couldn't create GLX context\n");
 236       exit(1);
 237    }
 238
 239
 240    Win[0] = CreateWindow(Dpy, ScrNum, visinfo,
 241                          0, 0, 300, 300, "source window");
 242
 243    Win[1] = CreateWindow(Dpy, ScrNum, visinfo,
 244                          350, 0, 300, 300, "dest window");
 245
 246 }
 247
 248
 249 int
 250 main(int argc, char *argv[])
 251 {
 252    Init();
 253    EventLoop();
 254    return 0;
 255 }
 256
 257
 258 #else
 259
 260
 261 int
 262 main(int argc, char *argv[])
 263 {
 264    printf("This program requires GLX 1.3!\n");
 265    return 0;
 266 }
 267
 268
 269 #endif /* GLX_VERSION_1_3 */