week14 UC

 step1

開啟Git Bash

cd desktop 到桌面

git clone  http://github.com/mian9116/2022graphicsb 

cd 2022graphicsb 

start . 開啟檔案總管

step1-2

新的專案名為week14-1_timer

#include <GL/glut.h>

void display()

{

    glutSolidTeapot(0.3);

    glutSwapBuffers();

}

int main(int argc,char** argv)

{

    glutInit(&argc,argv);

    glutInitDisplayMode(GLUT_DOUBLE|GLUT_DEPTH);

    glutCreateWindow("week14");

    glutDisplayFunc(display);

    glutMainLoop();

}

step1-3

開啟新的專案

命名為week14-2_timer_play

修改程式碼，讓茶壺每隔幾秒旋轉90度

#include <GL/glut.h>

float angle=0;

void timer(int t)

{

    glutTimerFunc(500,timer,t+1);

    angle+=90;

    glutPostRedisplay();

}

void display()

{

    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

    glPushMatrix();

    glRotatef(angle,0,0,1);

    glutSolidTeapot(0.3);

    glPopMatrix();

    glutSwapBuffers();

}

int main(int argc,char** argv)

{

    glutInit(&argc,argv);

    glutInitDisplayMode(GLUT_DOUBLE|GLUT_DEPTH);

    glutCreateWindow("week14");

    glutTimerFunc(3000,timer,0);

    glutDisplayFunc(display);

    glutMainLoop();

}

step1-4

再修改程式碼，使茶壺在按下按鍵後持續旋轉

#include <GL/glut.h>

float angle=0;

void timer(int t)

{

    glutTimerFunc(500,timer,t+1);

    angle+=90;

    glutPostRedisplay();

}

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

{

    glutTimerFunc(0,timer,0);

}

void display()

{

    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

    glPushMatrix();

        glRotatef(angle,0,0,1);

        glutSolidTeapot(0.3);

    glPopMatrix();

    glutSwapBuffers();

}

int main(int argc,char** argv)

{

    glutInit(&argc,argv);

    glutInitDisplayMode(GLUT_DOUBLE|GLUT_DEPTH);

    glutCreateWindow("week14");

    glutKeyboardFunc(keyboard);

    //glutTimerFunc(3000,timer,0);

    glutDisplayFunc(display);

    glutMainLoop();

}

step02-1

使用excel，利用公式算出要的數值

開新專案

命名為week14-3_timer_alpha_interpolate

可以使茶壺用滑鼠控制到想要的位子，在按空白建使茶壺可以旋轉至指定位子

#include <GL/glut.h>

float angle = 0,newAngle = 0,oldAngle = 0;

float oldX = 0;

void timer(int t)

{

    if (t<100) glutTimerFunc(33, timer, t+1);

    float alpha = t/100.0;

    angle = alpha*newAngle + (1-alpha)*oldAngle;

    glutPostRedisplay();

}

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

{

     glutTimerFunc(0, timer, 0);

}

void mouse(int button, int state,int x,int y)

{

    if(state==GLUT_DOWN) oldAngle = angle;

    if(state==GLUT_UP) newAngle = angle;

    oldX = x;

    glutPostRedisplay();

}

void motion(int x,int y)

{

    angle += x-oldX;

    oldX = x;

    glutPostRedisplay();

}

void display()

{

    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

    glPushMatrix();

        glRotatef(angle, 0, 0, 1);

        glutSolidTeapot( 0.3 );

    glPopMatrix();

    glutSwapBuffers();

}

int main(int argc, char**argv)

{

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("week14");

    glutMouseFunc(mouse);

    glutMotionFunc(motion);

    glutKeyboardFunc(keyboard);

    ///glutTimerFunc(3000, timer, 0);

    glutDisplayFunc(display);

    glutMainLoop();

}