progs/xdemos/wincopy.c

   1 /* $Id: wincopy.c,v 1.1 1999/11/25 17:41:51 brianp Exp $ */
   2
   3 /*
   4  * Mesa 3-D graphics library
   5  * Version:  3.3
   6  *
   7  * Copyright (C) 1999  Brian Paul   All Rights Reserved.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included
  17  * in all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  23  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  24  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27
  28 /*
  29  * This program opens two GLX windows, renders into one and uses
  30  * glCopyPixels to copy the image from the first window into the
  31  * second by means of the GLX 1.3 function glxMakeContextCurrent().
  32  * This function works just like the glXMakeCurrentReadSGI() function
  33  * in the GLX_SGI_make_current_read extension.
  34  */
  35
  36
  37
  38 #include <GL/gl.h>
  39 #include <GL/glx.h>
  40 #include <stdio.h>
  41 #include <stdlib.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
  57
  58 static Window
  59 CreateWindow(Display *dpy, int scrnum, XVisualInfo *visinfo,
  60              int xpos, int ypos, int width, int height,
  61              const char *name)
  62 {
  63    Window win;
  64    XSetWindowAttributes attr;
  65    unsigned long mask;
  66    Window root;
  67
  68    root = RootWindow(dpy, scrnum);
  69
  70    /* window attributes */
  71    attr.background_pixel = 0;
  72    attr.border_pixel = 0;
  73    attr.colormap = XCreateColormap(dpy, root, visinfo->visual, AllocNone);
  74    attr.event_mask = StructureNotifyMask | ExposureMask | KeyPressMask;
  75    mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;
  76
  77    win = XCreateWindow(dpy, root, xpos, ypos, width, height,
  78                         0, visinfo->depth, InputOutput,
  79                         visinfo->visual, mask, &attr);
  80    if (win) {
  81       XSizeHints sizehints;
  82       sizehints.x = xpos;
  83       sizehints.y = ypos;
  84       sizehints.width  = width;
  85       sizehints.height = height;
  86       sizehints.flags = USSize | USPosition;
  87       XSetNormalHints(dpy, win, &sizehints);
  88       XSetStandardProperties(dpy, win, name, name,
  89                               None, (char **)NULL, 0, &sizehints);
  90
  91       XMapWindow(dpy, win);
  92    }
  93    return win;
  94 }
  95
  96
  97 static void
  98 Redraw(void)
  99 {
 100    /* make the first window the current one */
 101    if (!glXMakeContextCurrent(Dpy, Win[0], Win[0], Context)) {
 102       printf("glXMakeContextCurrent failed in Redraw()\n");
 103       return;
 104    }
 105
 106    Angle += 1.0;
 107
 108    glViewport(0, 0, Width[0], Height[0]);
 109    glMatrixMode(GL_PROJECTION);
 110    glLoadIdentity();
 111    glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
 112    glMatrixMode(GL_MODELVIEW);
 113
 114    glShadeModel(GL_FLAT);
 115    glClearColor(0.5, 0.5, 0.5, 1.0);
 116    glClear(GL_COLOR_BUFFER_BIT);
 117
 118    /* draw blue quad */
 119    glColor3f(0.3, 0.3, 1.0);
 120    glPushMatrix();
 121    glRotatef(Angle, 0, 0, 1);
 122    glBegin(GL_POLYGON);
 123    glVertex2f(-0.5, -0.25);
 124    glVertex2f( 0.5, -0.25);
 125    glVertex2f( 0.5, 0.25);
 126    glVertex2f(-0.5, 0.25);
 127    glEnd();
 128    glPopMatrix();
 129
 130    glXSwapBuffers(Dpy, Win[0]);
 131
 132
 133    /* copy image from window 0 to window 1 */
 134    if (!glXMakeContextCurrent(Dpy, Win[1], Win[0], Context)) {
 135       printf("glXMakeContextCurrent failed in Redraw()\n");
 136       return;
 137    }
 138
 139    /* raster pos setup */
 140    glViewport(0, 0, Width[1], Height[1]);
 141    glPushMatrix();
 142    glLoadIdentity();
 143    glMatrixMode(GL_PROJECTION);
 144    glPushMatrix();
 145    glLoadIdentity();
 146    glOrtho(-1, 1, -1, 1, -1, 1);
 147    glRasterPos2f(-1, -1);
 148
 149    /* copy the image between windows */
 150    glDrawBuffer(GL_FRONT);
 151    glCopyPixels(0, 0, Width[0], Height[0], GL_COLOR);
 152    glDrawBuffer(GL_BACK);
 153
 154    glPopMatrix();
 155    glMatrixMode(GL_MODELVIEW);
 156    glPopMatrix();
 157 }
 158
 159
 160
 161 static void
 162 Resize(Window win, unsigned int width, unsigned int height)
 163 {
 164    int i;
 165    if (win == Win[0]) {
 166       i = 0;
 167    }
 168    else {
 169       i = 1;
 170    }
 171    Width[i] = width;
 172    Height[i] = height;
 173    if (!glXMakeCurrent(Dpy, Win[i], Context)) {
 174       printf("glXMakeCurrent failed in Resize()\n");
 175       return;
 176    }
 177 }
 178
 179
 180
 181 static void
 182 EventLoop(void)
 183 {
 184    XEvent event;
 185    while (1) {
 186       if (XPending(Dpy) > 0) {
 187          XNextEvent( Dpy, &event );
 188          switch (event.type) {
 189             case Expose:
 190                Redraw();
 191                break;
 192             case ConfigureNotify:
 193                Resize(event.xany.window, event.xconfigure.width, event.xconfigure.height);
 194                break;
 195             case KeyPress:
 196                return;
 197             default:
 198                /*no-op*/ ;
 199          }
 200       }
 201       else {
 202          /* animate */
 203          Redraw();
 204       }
 205    }
 206 }
 207
 208
 209 static void
 210 Init(void)
 211 {
 212    XVisualInfo *visinfo;
 213    int attrib[] = { GLX_RGBA,
 214                     GLX_RED_SIZE, 1,
 215                     GLX_GREEN_SIZE, 1,
 216                     GLX_BLUE_SIZE, 1,
 217                     GLX_DOUBLEBUFFER,
 218                     None };
 219
 220    Dpy = XOpenDisplay(NULL);
 221    if (!Dpy) {
 222       printf("Couldn't open default display!\n");
 223       exit(1);
 224    }
 225
 226    ScrNum = DefaultScreen(Dpy);
 227
 228    visinfo = glXChooseVisual(Dpy, ScrNum, attrib);
 229    if (!visinfo) {
 230       printf("Unable to find RGB, double-buffered visual\n");
 231       exit(1);
 232    }
 233
 234    Context = glXCreateContext(Dpy, visinfo, NULL, True);
 235    if (!Context) {
 236       printf("Couldn't create GLX context\n");
 237       exit(1);
 238    }
 239
 240
 241    Win[0] = CreateWindow(Dpy, ScrNum, visinfo,
 242                          0, 0, 300, 300, "source window");
 243
 244    Win[1] = CreateWindow(Dpy, ScrNum, visinfo,
 245                          350, 0, 300, 300, "dest window");
 246
 247 }
 248
 249
 250 int
 251 main(int argc, char *argv[])
 252 {
 253    Init();
 254    EventLoop();
 255    return 0;
 256 }
 257
 258
 259 #else
 260
 261
 262 int
 263 main(int argc, char *argv[])
 264 {
 265    printf("This program requires GLX 1.3!\n");
 266    return 0;
 267 }
 268
 269
 270 #endif /* GLX_VERSION_1_3 */