week04秦浩恩_畫圓

1.畫圓

#include <GL/glut.h>
#include <math.h>  //宣告數學函式頭檔
void display()
{

    glBegin(GL_POLYGON);

    for(float angle=0;angle<=3.1415926*2;angle+=0.01)   //3.1415626*2=2拍
    {
        glVertex2f(cos(angle),sin(angle));  //glVertex2f  頂點
    }
    glEnd();
    glutSwapBuffers();

}
int main(int argc,char *argv[])
{   
    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_RGB|GLUT_DOUBLE|GLUT_DEPTH);
    glutCreateWindow("04160711 Number 1");
    glutDisplayFunc(display);
    glutMainLoop();
}

2.圓變色+位置

#include <GL/glut.h>
#include <math.h>
#include <stdio.h>  //Now for printf()
void display()
{

    glBegin(GL_POLYGON);
    for(float angle=0;angle<=3.1415926*2;angle+=0.01)
    {
        glVertex2f(cos(angle),sin(angle));
    }
    glEnd();
    glutSwapBuffers();

}
void mouse(int button,int state,int x,int y)
{
    //Now mouse function
    printf("%d %d %d %d\n",button,state, x,y) ;//Now print the values
    glColor3f(1,x/300.0,y/300.0);//Now change color to any color

}
int main(int argc,char *argv[])
{    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_RGB|GLUT_DOUBLE|GLUT_DEPTH);
    glutCreateWindow("04160711 Number 1");
    glutDisplayFunc(display);
    glutMouseFunc(mouse);//Now we are using mouse function
    glutMainLoop();
}

3.滑鼠拖曳(DRAGGING) 嘴巴圓形(大魚吃小魚) 

#include <GL/glut.h>
#include <math.h>
#include <stdio.h>  //Now for printf()
float mouth=0;
void display()

{
    glClear(GL_COLOR_BUFFER_BIT |GL_DEPTH_BUFFER_BIT);
    glBegin(GL_TRIANGLE_FAN);
    glVertex2f(0,0);
    for(float angle=0+mouth;angle<=3.1415926*2-mouth;angle+=3.1415926/100)
    {
        glVertex2f(cos(angle),sin(angle));
    }
    glEnd();
    glutSwapBuffers();

}
void mouse(int button,int state,int x,int y)
{
    //Now mouse function
    //printf("%d %d %d %d\n",button,state, x,y) ;//Now print the values
    //glColor3f(1,x/300.0,y/300.0);//Now change color to any color

}
void motion(int x,int y)//+motion 函式
{
    //Now mouse dragging!
    mouth=x/300.0;
    glColor3f(1,x/300.0,y/300.0);
    glutPostRedisplay();//如果跑不動+這行
}
int main(int argc,char *argv[])
{    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_RGB|GLUT_DOUBLE|GLUT_DEPTH);

    glutCreateWindow("04160711 Number 1");
    glutDisplayFunc(display);
    glutMouseFunc(mouse);//Now we are using mouse function
    glutMotionFunc(motion);
    glutMainLoop();
}