week15

1.交叉相乘喔！內插用鍵盤讓茶壺轉動

#include <GL/glut.h>

float a=0;//a is the alpha weight內插的比重 

float angle=0;

float angleOld=0;

float angleNew=90;

void display()

{

glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

glPushMatrix();

glRotatef(angle, 0, 0, 1);//用現在的角度angle來轉動 

glutSolidTeapot(0.3);

glPopMatrix();

glutSwapBuffers();       

}

void keyboard(unsigned char key, int x, int y)

{

if(key=='z')

{

a+=0.1;

angle=angleOld*(1-a)+angleNew*a;//內插公式 

}

glutPostRedisplay();//重劃一次畫面

}

int main()

{

glutInitDisplayMode(GLUT_DOUBLE|GLUT_DEPTH);

glutCreateWindow("week15");

glutKeyboardFunc(keyboard);

glutDisplayFunc(display);

glutMainLoop();

}

2.把浮點數變成陣列。

#include <GL/glut.h>

float a=0;//a is the alpha weight內插的比重 

float angle[20]={0,90,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

float angleOld[20]={0,90,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

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);//用現在的角度angle來轉動 

glutSolidTeapot(0.3);

glPopMatrix();

glPushMatrix();

glTranslatef(0.5, 0, 0);

glRotatef(angle[1], 0, 0, 1);

glutSolidTeapot(0.3);

glPopMatrix();

glutSwapBuffers();       

}

void keyboard(unsigned char key, int x, int y)

{

if(key=='z')

{

a+=0.1;

angle[0]=angleOld[0]*(1-a)+angleNew[0]*a;//內插公式 

angle[1]=angleOld[1]*(1-a)+angleNew[1]*a;

angle[2]=angleOld[2]*(1-a)+angleNew[2]*a;

angle[3]=angleOld[3]*(1-a)+angleNew[3]*a;

angle[4]=angleOld[4]*(1-a)+angleNew[4]*a;

angle[5]=angleOld[5]*(1-a)+angleNew[5]*a;

angle[6]=angleOld[6]*(1-a)+angleNew[6]*a;

angle[7]=angleOld[7]*(1-a)+angleNew[7]*a;

angle[8]=angleOld[8]*(1-a)+angleNew[8]*a;

angle[9]=angleOld[9]*(1-a)+angleNew[9]*a;

}

glutPostRedisplay();//重劃一次畫面

}

int main()

{

glutInitDisplayMode(GLUT_DOUBLE|GLUT_DEPTH);

glutCreateWindow("week15");

glutKeyboardFunc(keyboard);

glutDisplayFunc(display);

glutMainLoop();

}

3.簡化程式&加上Timer讓程式自動播放！

#include <GL/glut.h>

float a=0;//a is the alpha weight內插的比重 

float angle[20]={0,90,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

float angleOld[20]={0,90,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

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();

glTranslatef(angle[3], angle[4], angle[5]);

glPushMatrix();

glRotatef(angle[0], 0, 0, 1);//用現在的角度angle來轉動 

glutSolidTeapot(0.3);

glPopMatrix();

glPushMatrix();

glTranslatef(0.5, 0, 0);

glRotatef(angle[1], 0, 0, 1);

glutSolidTeapot(0.3);

glPopMatrix();

glPopMatrix();

glutSwapBuffers();       

}

void readNext()

{

a+=0.1;

for (int i=0; i<20; i++)

{ angle[i]=angleOld[i]*(1-a)+angleNew[i]*a;//內插公式 

}

}

void timer(int t)

{

glutTimerFunc(10, timer, 0);//幾ms後開始, 0 ms後開始播放(一按按鍵就立即播放)

readNext();

glutPostRedisplay(); 

}

void keyboard(unsigned char key, int x, int y)

{

if(key=='x')

{

readNext(); //按x就一下一下轉

}

else if(key=='y')

{

glutTimerFunc(0, timer, 0);//按下y就一次自己轉

}

glutPostRedisplay();

}

int main()

{

glutInitDisplayMode(GLUT_DOUBLE|GLUT_DEPTH);

glutCreateWindow("week15");

glutKeyboardFunc(keyboard);

glutDisplayFunc(display);

glutMainLoop();

}