#week03- tp6vü[電腦圖學上課筆記]

[1]複習上周進度
    1.開啟main.cpp程式，然後進行刪減至:
       #include <GL/glut.h>
static void display(void)
{
    glutSolidTeapot(0.3);
    glutSwapBuffers();
}
int main(int argc, char *argv[])
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("04162495");
    glutDisplayFunc(display);
    glutMainLoop();
}
    就可以跑出茶壺

[2]將程式碼改為:
    #include <math.h>
#include <stdio.h>
#include <GL/glut.h>
void mouse(int button, int state, int x, int y)
{
    printf("%d %d %d %d\n", button, state, x, y);
}

void display()
{
    glutSolidTeapot(0.3);
    glutSwapBuffers();
}
int main(int argc, char *argv[])
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("04162495");
    glutDisplayFunc(display);
    glutMouseFunc(mouse);
    glutMainLoop();
}
可以使其顯示滑鼠點擊的座標，會有數字顯示

[3]在程式碼中增加:
    glColor3f( 1, x/300.0, y/300.0);
    glutPostRedisplay();

然後按執行，點擊不同座標，就可以使茶壺的顏色改變

[4]程式碼:

#include <math.h>

#include <stdio.h>

#include <GL/glut.h>

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

{///滑鼠函式

    printf("%d %d %d %d\n", button, state, x, y);

}

void motion(int x, int y)

{

    printf("%d %d\n", x, y);

    glColor3f( 1, x/500.0, y/500.0);

    glutPostRedisplay();

}

void display()

{

    glutSolidTeapot(0.3);

    glutSwapBuffers();

}

int main(int argc, char *argv[])

{

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

    glutInitWindowSize(500,500);

    glutCreateWindow("04162495");

    glutDisplayFunc(display);

    glutMouseFunc(mouse);

    glutMotionFunc(motion);

    glutMainLoop();

}

這樣就可以使滑鼠點擊滑行時，座標顯示會改變，茶壺的顏色也會隨之改變

[5]
#include <stdio.h>
#include <GL/glut.h>
void mouse(int button, int state, int x, int y)
{///滑鼠函式
    if(state==GLUT_DOWN) printf("glVertex2f( %.2f, %.2f);\n", (x-250)/250.0, -(y-250)/250.0);
}
float mouth=0;
void motion(int x, int y)
{

    glColor3f( 1, x/500.0, y/500.0);
    glutPostRedisplay();
    mouth = x/300.0;
}
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();
}
int main(int argc, char *argv[])
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
    glutInitWindowSize(500,500);
    glutCreateWindow("04162495");

    glutDisplayFunc(display);
    glutMouseFunc(mouse);
    glutMotionFunc(motion);

    glutMainLoop();
}
此程式碼可以做出會變色的小精靈