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Data update

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Ingy döt Net 2026-02-01 16:33:20 -08:00
parent 5150844a7d
commit 4bb20c9b71
7735 changed files with 38060 additions and 199180 deletions
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104
Task/Animate-a-pendulum/C/animate-a-pendulum.c
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@ -1,7 +1,7 @@
#include <stdlib.h>
#include <math.h>
#include <GL/glut.h>
#include <GL/gl.h>
#include <GL/glut.h>
#include <math.h>
#include <stdlib.h>
#include <sys/time.h>
#define length 5
@ -10,68 +10,66 @@ double alpha, accl, omega = 0, E;
struct timeval tv;
double elappsed() {
struct timeval now;
gettimeofday(&now, 0);
int ret = (now.tv_sec - tv.tv_sec) * 1000000
+ now.tv_usec - tv.tv_usec;
tv = now;
return ret / 1.e6;
struct timeval now;
gettimeofday(&now, 0);
int ret = (now.tv_sec - tv.tv_sec) * 1000000 + now.tv_usec - tv.tv_usec;
tv = now;
return ret / 1.e6;
}
void resize(int w, int h)
{
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
void resize(int w, int h) {
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glOrtho(0, w, h, 0, -1, 1);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glOrtho(0, w, h, 0, -1, 1);
}
void render()
{
double x = 320 + 300 * sin(alpha), y = 300 * cos(alpha);
resize(640, 320);
glClear(GL_COLOR_BUFFER_BIT);
void render() {
double x = 320 + 300 * sin(alpha), y = 300 * cos(alpha);
resize(640, 320);
glClear(GL_COLOR_BUFFER_BIT);
glBegin(GL_LINES);
glVertex2d(320, 0);
glVertex2d(x, y);
glEnd();
glFlush();
glBegin(GL_LINES);
glVertex2d(320, 0);
glVertex2d(x, y);
glEnd();
glFlush();
double us = elappsed();
alpha += (omega + us * accl / 2) * us;
omega += accl * us;
double us = elappsed();
alpha += (omega + us * accl / 2) * us;
omega += accl * us;
/* don't let precision error go out of hand */
if (length * g * (1 - cos(alpha)) >= E) {
alpha = (alpha < 0 ? -1 : 1) * acos(1 - E / length / g);
omega = 0;
}
accl = -g / length * sin(alpha);
/* don't let precision error go out of hand */
if (length * g * (1 - cos(alpha)) >= E) {
alpha = (alpha < 0 ? -1 : 1) * acos(1 - E / length / g);
omega = 0;
}
accl = -g / length * sin(alpha);
}
void init_gfx(int *c, char **v)
{
glutInit(c, v);
glutInitDisplayMode(GLUT_RGB);
glutInitWindowSize(640, 320);
glutIdleFunc(render);
glutCreateWindow("Pendulum");
void init_gfx(int *c, char **v) {
glutInit(c, v);
glutInitDisplayMode(GLUT_RGB);
glutInitWindowSize(640, 320);
int winid = glutCreateWindow("Pendulum");
glutSetWindow(winid);
glutDisplayFunc(render);
glutIdleFunc(render);
glutReshapeFunc(resize);
}
int main(int c, char **v)
{
alpha = 4 * atan2(1, 1) / 2.1;
E = length * g * (1 - cos(alpha));
int main(int c, char **v) {
alpha = 4 * atan2(1, 1) / 2.1;
E = length * g * (1 - cos(alpha));
accl = -g / length * sin(alpha);
omega = 0;
accl = -g / length * sin(alpha);
omega = 0;
gettimeofday(&tv, 0);
init_gfx(&c, v);
glutMainLoop();
return 0;
gettimeofday(&tv, 0);
init_gfx(&c, v);
glutMainLoop();
return 0;
}