week15

 到https://jsyeh.org/3dcg10/ 下載win32及data,將data資料夾放到windows資料夾,打開projection.exe,

glPerspective:調整投影機大小位置

eye:從哪裡看

center:看哪裡

up:順時針轉動

fovy(fov):視野範圍

aspect:長寬比

將glFrustum改成glOrtho

控制看茶壺的鏡頭

#include <GL/glut.h>

void display()

{

    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

    glutSolidTeapot(0.3);

    glutSwapBuffers();

}

void reshape(int w,int h){

    glViewport(0,0,w,h);///視窗裡,會看到2D範圍

    float ar =w/(float) h;///aspect ratio長寬比

    glMatrixMode(GL_PROJECTION);///先切換到Project矩陣

    glLoadIdentity();

    gluPerspective(60,ar,0.01,1000);///

    glMatrixMode(GL_MODELVIEW);///做好後馬上切回model view矩陣

    glLoadIdentity();///矩陣清空,成為單位矩陣

    gluLookAt(0,0,1, 0,0,0, 0,1,0);

    ///在0,0,1看著茶壺0,0,0,up是,0,1,0

    glutPostRedisplay();

}

float eyeX=0, eyeY=0;

void motion(int x, int y){

    eyeX=(x-150.0)/150.0;

    eyeY=(150.0-y)/150.0;

    glMatrixMode(GL_MODELVIEW);///做好後馬上切回modelview矩陣

    glLoadIdentity();///矩陣清空,成為單位矩陣

    gluLookAt(eyeX,eyeY,1, 0,0,0, 0,1,0);

    glutPostRedisplay();

}

int main(int argc,char** argv)

{

    glutInit(&argc,argv);

    glutInitDisplayMode(GLUT_DOUBLE|GLUT_DEPTH);

    glutCreateWindow("week15");

    glutMotionFunc(motion);

    glutDisplayFunc(display);

    glutReshapeFunc(reshape);

    glutMainLoop();

}