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/*
* Copyright (C) 1999-2001 Brian Paul All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
/*
* This is a port of the infamous "gears" demo to straight GLX (i.e. no GLUT)
* Port by Brian Paul 23 March 2001
*
* Command line options:
* -info print GL implementation information
*
*/
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <X11/Xlib.h>
#include <X11/keysym.h>
#include <GL/gl.h>
#include <GL/glx.h>
#define BENCHMARK
#ifdef BENCHMARK
/* XXX this probably isn't very portable */
#include <sys/time.h>
#include <unistd.h>
/* return current time (in seconds) */
static int
current_time(void)
{
struct timeval tv;
#ifdef __VMS
(void) gettimeofday(&tv, NULL );
#else
struct timezone tz;
(void) gettimeofday(&tv, &tz);
#endif
return (int) tv.tv_sec;
}
#else /*BENCHMARK*/
/* dummy */
static int
current_time(void)
{
return 0;
}
#endif /*BENCHMARK*/
#ifndef M_PI
#define M_PI 3.14159265
#endif
static GLfloat view_rotx = 20.0, view_roty = 30.0, view_rotz = 0.0;
static GLint gear1, gear2, gear3;
static GLfloat angle = 0.0;
static GLint WinWidth = 300, WinHeight = 300;
/*
*
* Draw a gear wheel. You'll probably want to call this function when
* building a display list since we do a lot of trig here.
*
* Input: inner_radius - radius of hole at center
* outer_radius - radius at center of teeth
* width - width of gear
* teeth - number of teeth
* tooth_depth - depth of tooth
*/
static void
gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width,
GLint teeth, GLfloat tooth_depth)
{
GLint i;
GLfloat r0, r1, r2;
GLfloat angle, da;
GLfloat u, v, len;
r0 = inner_radius;
r1 = outer_radius - tooth_depth / 2.0;
r2 = outer_radius + tooth_depth / 2.0;
da = 2.0 * M_PI / teeth / 4.0;
glShadeModel(GL_FLAT);
glNormal3f(0.0, 0.0, 1.0);
/* draw front face */
glBegin(GL_QUAD_STRIP);
for (i = 0; i <= teeth; i++) {
angle = i * 2.0 * M_PI / teeth;
glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
if (i < teeth) {
glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
width * 0.5);
}
}
glEnd();
/* draw front sides of teeth */
glBegin(GL_QUADS);
da = 2.0 * M_PI / teeth / 4.0;
for (i = 0; i < teeth; i++) {
angle = i * 2.0 * M_PI / teeth;
glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
width * 0.5);
glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
width * 0.5);
}
glEnd();
glNormal3f(0.0, 0.0, -1.0);
/* draw back face */
glBegin(GL_QUAD_STRIP);
for (i = 0; i <= teeth; i++) {
angle = i * 2.0 * M_PI / teeth;
glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
if (i < teeth) {
glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
-width * 0.5);
glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
}
}
glEnd();
/* draw back sides of teeth */
glBegin(GL_QUADS);
da = 2.0 * M_PI / teeth / 4.0;
for (i = 0; i < teeth; i++) {
angle = i * 2.0 * M_PI / teeth;
glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
-width * 0.5);
glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
-width * 0.5);
glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
}
glEnd();
/* draw outward faces of teeth */
glBegin(GL_QUAD_STRIP);
for (i = 0; i < teeth; i++) {
angle = i * 2.0 * M_PI / teeth;
glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
u = r2 * cos(angle + da) - r1 * cos(angle);
v = r2 * sin(angle + da) - r1 * sin(angle);
len = sqrt(u * u + v * v);
u /= len;
v /= len;
glNormal3f(v, -u, 0.0);
glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
glNormal3f(cos(angle), sin(angle), 0.0);
glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
width * 0.5);
glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
-width * 0.5);
u = r1 * cos(angle + 3 * da) - r2 * cos(angle + 2 * da);
v = r1 * sin(angle + 3 * da) - r2 * sin(angle + 2 * da);
glNormal3f(v, -u, 0.0);
glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
width * 0.5);
glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
-width * 0.5);
glNormal3f(cos(angle), sin(angle), 0.0);
}
glVertex3f(r1 * cos(0), r1 * sin(0), width * 0.5);
glVertex3f(r1 * cos(0), r1 * sin(0), -width * 0.5);
glEnd();
glShadeModel(GL_SMOOTH);
/* draw inside radius cylinder */
glBegin(GL_QUAD_STRIP);
for (i = 0; i <= teeth; i++) {
angle = i * 2.0 * M_PI / teeth;
glNormal3f(-cos(angle), -sin(angle), 0.0);
glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
}
glEnd();
}
static void
draw(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glRotatef(view_rotx, 1.0, 0.0, 0.0);
glRotatef(view_roty, 0.0, 1.0, 0.0);
glRotatef(view_rotz, 0.0, 0.0, 1.0);
glPushMatrix();
glTranslatef(-3.0, -2.0, 0.0);
glRotatef(angle, 0.0, 0.0, 1.0);
glCallList(gear1);
glPopMatrix();
glPushMatrix();
glTranslatef(3.1, -2.0, 0.0);
glRotatef(-2.0 * angle - 9.0, 0.0, 0.0, 1.0);
glCallList(gear2);
glPopMatrix();
glPushMatrix();
glTranslatef(-3.1, 4.2, 0.0);
glRotatef(-2.0 * angle - 25.0, 0.0, 0.0, 1.0);
glCallList(gear3);
glPopMatrix();
glPopMatrix();
}
/* new window size or exposure */
static void
reshape(int width, int height)
{
GLfloat h = (GLfloat) height / (GLfloat) width;
glViewport(0, 0, (GLint) width, (GLint) height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustum(-1.0, 1.0, -h, h, 5.0, 60.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0, 0.0, -40.0);
WinWidth = width;
WinHeight = height;
}
static void
init(void)
{
static GLfloat pos[4] = { 5.0, 5.0, 10.0, 0.0 };
static GLfloat red[4] = { 0.8, 0.1, 0.0, 1.0 };
static GLfloat green[4] = { 0.0, 0.8, 0.2, 1.0 };
static GLfloat blue[4] = { 0.2, 0.2, 1.0, 1.0 };
glClearColor(1, 0, 0, 0);
glLightfv(GL_LIGHT0, GL_POSITION, pos);
glEnable(GL_CULL_FACE);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_DEPTH_TEST);
/* make the gears */
gear1 = glGenLists(1);
glNewList(gear1, GL_COMPILE);
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, red);
gear(1.0, 4.0, 1.0, 20, 0.7);
glEndList();
gear2 = glGenLists(1);
glNewList(gear2, GL_COMPILE);
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, green);
gear(0.5, 2.0, 2.0, 10, 0.7);
glEndList();
gear3 = glGenLists(1);
glNewList(gear3, GL_COMPILE);
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, blue);
gear(1.3, 2.0, 0.5, 10, 0.7);
glEndList();
glEnable(GL_NORMALIZE);
}
/*
* Create an RGB, double-buffered window.
* Return the window and context handles.
*/
static void
make_window( Display *dpy, const char *name,
int x, int y, int width, int height,
Window *winRet, GLXContext *ctxRet)
{
int attrib[] = { GLX_RGBA,
GLX_RED_SIZE, 1,
GLX_GREEN_SIZE, 1,
GLX_BLUE_SIZE, 1,
GLX_DOUBLEBUFFER,
GLX_DEPTH_SIZE, 1,
None };
int scrnum;
XSetWindowAttributes attr;
unsigned long mask;
Window root;
Window win;
GLXContext ctx;
XVisualInfo *visinfo;
scrnum = DefaultScreen( dpy );
root = RootWindow( dpy, scrnum );
visinfo = glXChooseVisual( dpy, scrnum, attrib );
if (!visinfo) {
printf("Error: couldn't get an RGB, Double-buffered visual\n");
exit(1);
}
/* window attributes */
attr.background_pixel = 0;
attr.border_pixel = 0;
attr.colormap = XCreateColormap( dpy, root, visinfo->visual, AllocNone);
attr.event_mask = StructureNotifyMask | ExposureMask | KeyPressMask;
mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;
win = XCreateWindow( dpy, root, 0, 0, width, height,
0, visinfo->depth, InputOutput,
visinfo->visual, mask, &attr );
/* set hints and properties */
{
XSizeHints sizehints;
sizehints.x = x;
sizehints.y = y;
sizehints.width = width;
sizehints.height = height;
sizehints.flags = USSize | USPosition;
XSetNormalHints(dpy, win, &sizehints);
XSetStandardProperties(dpy, win, name, name,
None, (char **)NULL, 0, &sizehints);
}
ctx = glXCreateContext( dpy, visinfo, NULL, True );
if (!ctx) {
printf("Error: glXCreateContext failed\n");
exit(1);
}
XFree(visinfo);
*winRet = win;
*ctxRet = ctx;
}
static void
event_loop(Display *dpy, Window win)
{
while (1) {
while (XPending(dpy) > 0) {
XEvent event;
XNextEvent(dpy, &event);
switch (event.type) {
case Expose:
/* we'll redraw below */
break;
case ConfigureNotify:
reshape(event.xconfigure.width, event.xconfigure.height);
break;
case KeyPress:
{
char buffer[10];
int r, code;
code = XLookupKeysym(&event.xkey, 0);
if (code == XK_Left) {
view_roty += 5.0;
}
else if (code == XK_Right) {
view_roty -= 5.0;
}
else if (code == XK_Up) {
view_rotx += 5.0;
}
else if (code == XK_Down) {
view_rotx -= 5.0;
}
else {
r = XLookupString(&event.xkey, buffer, sizeof(buffer),
NULL, NULL);
if (buffer[0] == 27) {
/* escape */
return;
}
}
}
}
}
/* next frame */
angle += 2.0;
draw();
#if 0
glXSwapBuffers(dpy, win);
#else
{
GLfloat c[4];
glReadBuffer(GL_BACK);
glReadPixels(WinWidth-1, 0, 1, 1, GL_RGB, GL_FLOAT, c);
printf("Bottom right pixel color: %g, %g, %g\n", c[0], c[1], c[2]);
glDrawBuffer(GL_FRONT);
glWindowPos2iARB(0,0);
glCopyPixels(WinWidth/2, 0, WinWidth/2, WinHeight, GL_COLOR);
glDrawBuffer(GL_BACK);
}
#endif
/* calc framerate */
{
static int t0 = -1;
static int frames = 0;
int t = current_time();
if (t0 < 0)
t0 = t;
frames++;
if (t - t0 >= 5.0) {
GLfloat seconds = t - t0;
GLfloat fps = frames / seconds;
printf("%d frames in %3.1f seconds = %6.3f FPS\n", frames, seconds,
fps);
t0 = t;
frames = 0;
}
}
}
}
int
main(int argc, char *argv[])
{
Display *dpy;
Window win;
GLXContext ctx;
char *dpyName = ":0";
GLboolean printInfo = GL_FALSE;
int i;
for (i = 1; i < argc; i++) {
if (strcmp(argv[i], "-display") == 0) {
dpyName = argv[i+1];
i++;
}
else if (strcmp(argv[i], "-info") == 0) {
printInfo = GL_TRUE;
}
}
dpy = XOpenDisplay(dpyName);
if (!dpy) {
printf("Error: couldn't open display %s\n", dpyName);
return -1;
}
make_window(dpy, "glxgears", 0, 0, WinWidth, WinHeight, &win, &ctx);
XMapWindow(dpy, win);
glXMakeCurrent(dpy, win, ctx);
if (printInfo) {
printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
printf("GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
printf("GL_VENDOR = %s\n", (char *) glGetString(GL_VENDOR));
printf("GL_EXTENSIONS = %s\n", (char *) glGetString(GL_EXTENSIONS));
}
init();
event_loop(dpy, win);
glXDestroyContext(dpy, ctx);
XDestroyWindow(dpy, win);
XCloseDisplay(dpy);
return 0;
}
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