/*
MultiSlice RTP Environment
(C) 1998,1999,2000,2001,2002 Yohann Sulaiman.
(C) 1998 Gloria Bueno
(C) 2002 Free Software Foundation, Inc.
This file is part of the source code of the MultiSlice RTP Environment.
MultiSlice RTP Environment is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
MultiSlice RTP Environment is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with MultiSlice RTP Environment; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/* $Revision: 1.1.1.1 $ */
/* compile: cc -o glxsimple glxsimple.c -lGL -lX11 */
#include <stdio.h>
#include <stdlib.h>
#include <GL/glx.h> /* this includes the necessary X headers */
#include <GL/gl.h>
static int snglBuf[] = {GLX_RGBA, GLX_DEPTH_SIZE, 16, None};
static int dblBuf[] = {GLX_RGBA, GLX_DEPTH_SIZE, 16, GLX_DOUBLEBUFFER, None};
Display *dpy;
Window win;
GLfloat xAngle = 42.0, yAngle = 82.0, zAngle = 112.0;
GLboolean doubleBuffer = GL_TRUE;
void
fatalError(char *message)
{
fprintf(stderr, "glxsimple: %s\n", message);
exit(1);
}
void
redraw(void)
{
static GLboolean displayListInited = GL_FALSE;
if (displayListInited) {
/* if display list already exists, just execute it */
glCallList(1);
} else {
/* otherwise compile and execute to create the display list */
glNewList(1, GL_COMPILE_AND_EXECUTE);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
/* front face */
glBegin(GL_QUADS);
glColor3f(0.0, 0.7, 0.1); /* green */
glVertex3f(-1.0, 1.0, 1.0);
glVertex3f(1.0, 1.0, 1.0);
glVertex3f(1.0, -1.0, 1.0);
glVertex3f(-1.0, -1.0, 1.0);
/* back face */
glColor3f(0.9, 1.0, 0.0); /* yellow */
glVertex3f(-1.0, 1.0, -1.0);
glVertex3f(1.0, 1.0, -1.0);
glVertex3f(1.0, -1.0, -1.0);
glVertex3f(-1.0, -1.0, -1.0);
/* top side face */
glColor3f(0.2, 0.2, 1.0); /* blue */
glVertex3f(-1.0, 1.0, 1.0);
glVertex3f(1.0, 1.0, 1.0);
glVertex3f(1.0, 1.0, -1.0);
glVertex3f(-1.0, 1.0, -1.0);
/* bottom side face */
glColor3f(0.7, 0.0, 0.1); /* red */
glVertex3f(-1.0, -1.0, 1.0);
glVertex3f(1.0, -1.0, 1.0);
glVertex3f(1.0, -1.0, -1.0);
glVertex3f(-1.0, -1.0, -1.0);
glEnd();
glEndList();
displayListInited = GL_TRUE;
}
if(doubleBuffer) glXSwapBuffers(dpy, win); /* buffer swap does implicit glFlush */
else glFlush(); /* explicit flush for single buffered case */
}
void
main(int argc, char **argv)
{
XVisualInfo *vi;
Colormap cmap;
XSetWindowAttributes swa;
GLXContext cx;
XEvent event;
GLboolean needRedraw = GL_FALSE, recalcModelView = GL_TRUE;
int dummy;
/*** (1) open a connection to the X server ***/
dpy = XOpenDisplay(NULL);
if (dpy == NULL) fatalError("could not open display");
/*** (2) make sure OpenGL's GLX extension supported ***/
if(!glXQueryExtension(dpy, &dummy, &dummy)) fatalError("X server has no OpenGL GLX extension");
/*** (3) find an appropriate visual ***/
/* find an OpenGL-capable RGB visual with depth buffer */
vi = glXChooseVisual(dpy, DefaultScreen(dpy), dblBuf);
if (vi == NULL) {
vi = glXChooseVisual(dpy, DefaultScreen(dpy), snglBuf);
if (vi == NULL) fatalError("no RGB visual with depth buffer");
doubleBuffer = GL_FALSE;
}
if(vi->class != TrueColor) fatalError("TrueColor visual required for this program");
/*** (4) create an OpenGL rendering context ***/
/* create an OpenGL rendering context */
cx = glXCreateContext(dpy, vi, /* no sharing of display lists */ None,
/* direct rendering if possible */ GL_TRUE);
if (cx == NULL) fatalError("could not create rendering context");
/*** (5) create an X window with the selected visual ***/
/* create an X colormap since probably not using default visual */
cmap = XCreateColormap(dpy, RootWindow(dpy, vi->screen), vi->visual, AllocNone);
swa.colormap = cmap;
swa.border_pixel = 0;
swa.event_mask = ExposureMask | ButtonPressMask | StructureNotifyMask;
win = XCreateWindow(dpy, RootWindow(dpy, vi->screen), 0, 0, 300, 300, 0, vi->depth,
InputOutput, vi->visual, CWBorderPixel | CWColormap | CWEventMask, &swa);
XSetStandardProperties(dpy, win, "glxsimple", "glxsimple", None, argv, argc, NULL);
/*** (6) bind the rendering context to the window ***/
glXMakeCurrent(dpy, win, cx);
/*** (7) request the X window to be displayed on the screen ***/
XMapWindow(dpy, win);
/*** (8) configure the OpenGL context for rendering ***/
glEnable(GL_DEPTH_TEST); /* enable depth buffering */
glDepthFunc(GL_LESS); /* pedantic, GL_LESS is the default */
glClearDepth(1.0); /* pedantic, 1.0 is the default */
/* frame buffer clears should be to black */
glClearColor(0.0, 0.0, 0.0, 0.0);
/* set up projection transform */
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustum(-1.0, 1.0, -1.0, 1.0, 1.0, 10.0);
/* establish initial viewport */
glViewport(0, 0, 300, 300); /* pedantic, full window size is default viewport */
/*** (9) dispatch X events ***/
while (1) {
do {
XNextEvent(dpy, &event);
switch (event.type) {
case ButtonPress:
recalcModelView = GL_TRUE;
switch (event.xbutton.button) {
case 1: xAngle += 10.0; break;
case 2: yAngle += 10.0; break;
case 3: zAngle += 10.0; break;
}
break;
case ConfigureNotify:
glViewport(0, 0, event.xconfigure.width, event.xconfigure.height);
/* fall through... */
case Expose:
needRedraw = GL_TRUE;
break;
}
} while(XPending(dpy)); /* loop to compress events */
if (recalcModelView) {
glMatrixMode(GL_MODELVIEW);
/* reset modelview matrix to the identity matrix */
glLoadIdentity();
/* move the camera back three units */
glTranslatef(0.0, 0.0, -3.0);
/* rotate by X, Y, and Z angles */
glRotatef(xAngle, 0.1, 0.0, 0.0);
glRotatef(yAngle, 0.0, 0.1, 0.0);
glRotatef(zAngle, 0.0, 0.0, 1.0);
recalcModelView = GL_FALSE;
needRedraw = GL_TRUE;
}
if (needRedraw) {
redraw();
needRedraw = GL_FALSE;
}
}
}