301 lines
7.3 KiB
C
301 lines
7.3 KiB
C
/* gears.c */
|
|
|
|
/*
|
|
* 3-D gear wheels. This program is in the public domain.
|
|
*
|
|
* Brian Paul
|
|
*/
|
|
|
|
|
|
#include <math.h>
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
|
|
#include <GL/glx.h>
|
|
#include <GL/gl.h>
|
|
#include "ui.h"
|
|
|
|
#ifndef M_PI
|
|
# define M_PI 3.14159265
|
|
#endif
|
|
|
|
|
|
/*
|
|
* 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 );
|
|
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 );
|
|
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 GLfloat view_rotx=20.0, view_roty=30.0, view_rotz=0.0;
|
|
static GLint gear1, gear2, gear3;
|
|
static GLfloat angle = 0.0;
|
|
|
|
static GLuint limit;
|
|
static GLuint count = 1;
|
|
|
|
|
|
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();
|
|
|
|
tkSwapBuffers();
|
|
|
|
count++;
|
|
if (count==limit) {
|
|
exit(0);
|
|
}
|
|
}
|
|
|
|
|
|
|
|
void idle( void )
|
|
{
|
|
angle += 2.0;
|
|
draw();
|
|
}
|
|
|
|
|
|
|
|
/* change view angle, exit upon ESC */
|
|
GLenum key(int k, GLenum mask)
|
|
{
|
|
switch (k) {
|
|
case KEY_UP:
|
|
view_rotx += 5.0;
|
|
return GL_TRUE;
|
|
case KEY_DOWN:
|
|
view_rotx -= 5.0;
|
|
return GL_TRUE;
|
|
case KEY_LEFT:
|
|
view_roty += 5.0;
|
|
return GL_TRUE;
|
|
case KEY_RIGHT:
|
|
view_roty -= 5.0;
|
|
return GL_TRUE;
|
|
case 'z':
|
|
view_rotz += 5.0;
|
|
return GL_TRUE;
|
|
case 'Z':
|
|
view_rotz -= 5.0;
|
|
return GL_TRUE;
|
|
case KEY_ESCAPE:
|
|
exit(0);
|
|
}
|
|
return GL_FALSE;
|
|
}
|
|
|
|
|
|
|
|
/* new window size or exposure */
|
|
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 );
|
|
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
|
|
}
|
|
|
|
|
|
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 };
|
|
|
|
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 );
|
|
}
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
if (argc>1) {
|
|
/* do 'n' frames then exit */
|
|
limit = atoi( argv[1] ) + 1;
|
|
}
|
|
else {
|
|
limit = 0;
|
|
}
|
|
|
|
return ui_loop(argc, argv, "gears");
|
|
}
|
|
|
|
|