Week15課堂作業

#include <stdio.h>
#include <GL/glut.h>
float a=0;
int angleID=0;
float angle[20]={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
float angleOld[20]={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
float angleNew[20]={90,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
void display()
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glRotatef(angle[0], 0, 0, 1);
glutSolidTeapot(0.2);
glPopMatrix();
glutSwapBuffers();
}
FILE* fout =NULL, *fin=NULL;
void readNext(){
if(fin==NULL) fin = fopen("saved_angles.txt", "r");
a+=0.1;
for(int i=0;i<20;i++) angle[i]=angleOld[i]*(1-a)+angleNew[i]*a;
if(a>1){
a=0;
for(int i=0;i<20;i++){
angleOld[i]=angleNew[i];
fscanf(fin, "%f ", &angleNew[i]);
}
}
}
void timer (int t)
{
glutTimerFunc(100, timer, 0); // 100 >> 0.1SEC 叫timer出來一次 
readNext();
glutPostRedisplay();
}
void keyboard(unsigned char key, int x, int y)
{
if (key=='0'){
angleID=1;
}
else if (key=='1'){
angleID=1;
}
else if (key=='2'){
angleID=2;
}
else if (key=='s'){
if(fout==NULL) fout=fopen("saved_angles.txt", "w+");
for(int i=0;i<20;i++) fprintf(fout, "%f ", angle[i]);
fprintf(fout, "\n");
}
else if (key=='r'){ //按下r 讀下一筆 readNext 
readNext(); // 將動作 整理到一個函式裡面 
glutPostRedisplay();
}
else if (key=='p'){ // 按下P啟動 timer 
glutTimerFunc(0, timer, 0); //0表示立即開始 
}
}
float OldX=0, OldY=0;
void mouse (int button, int state, int x, int y){ 
OldX=x, OldY=y;
}
void motion (int x, int y){
angle[angleID]+= (x-OldX) ; OldX=x;
glutPostRedisplay();
}
int main ()
{
glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);
glutCreateWindow("week15");
glutKeyboardFunc(keyboard);
glutMouseFunc(mouse);
glutMotionFunc(motion);
glutDisplayFunc(display);
glutMainLoop();
}