week 06 賀冠傑

1.期中考題

glPushMatrix();                        //備份矩陣
    glTranslatef(x,y,z);               //移動
    glRotatef(Angel,x,y,z);         //旋轉
    glScalef(x,y,z);                    //縮放
    glBegin(GL_POLYGON);     //開始畫
        glNormal3f(nx,ny,nz);     //法向量
        glTexCoord2f(tx,ty);       //貼圖座標
        glColor3f(r,g,b);              //色彩
        glVertex3f(x,y,z);            //頂點
    glEnd();                               //結束畫
glPopMatrix();                         //還原矩陣

2. 打光Light

Z軸打光 0.5f → -0.5f

#include<GL/glut.h>
const GLfloat light_ambient[]  = { 0.0f, 0.0f, 0.0f, 1.0f };
const GLfloat light_diffuse[]  = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat light_specular[] = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat light_position[] = { 2.0f, 5.0f, -5.0f, 0.0f };

const GLfloat mat_ambient[]    = { 0.7f, 0.7f, 0.7f, 1.0f };
const GLfloat mat_diffuse[]    = { 0.8f, 0.8f, 0.8f, 1.0f };
const GLfloat mat_specular[]   = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat high_shininess[] = { 100.0f };
void display()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glutSolidTeapot(0.3);
    glutSwapBuffers();
}

int main(int argc, char *argv[])
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);
    glutCreateWindow("hello 3D");
    glutDisplayFunc(display);

    glClearColor(1,1,1,1);
    glEnable(GL_CULL_FACE);
    glCullFace(GL_BACK);

    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);

    glEnable(GL_LIGHT0);
    glEnable(GL_NORMALIZE);
    glEnable(GL_COLOR_MATERIAL);
    glEnable(GL_LIGHTING);

    glLightfv(GL_LIGHT0, GL_AMBIENT,  light_ambient);
    glLightfv(GL_LIGHT0, GL_DIFFUSE,  light_diffuse);
    glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
    glLightfv(GL_LIGHT0, GL_POSITION, light_position);

    glMaterialfv(GL_FRONT, GL_AMBIENT,   mat_ambient);
    glMaterialfv(GL_FRONT, GL_DIFFUSE,   mat_diffuse);
    glMaterialfv(GL_FRONT, GL_SPECULAR,  mat_specular);
    glMaterialfv(GL_FRONT, GL_SHININESS, high_shininess);

    glutMainLoop();
}

3.打光(光源隨滑鼠移動)

#include<GL/glut.h>
const GLfloat light_ambient[]  = { 0.0f, 0.0f, 0.0f, 1.0f };
const GLfloat light_diffuse[]  = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat light_specular[] = { 1.0f, 1.0f, 1.0f, 1.0f };
GLfloat light_position[] = { 2.0f, 5.0f, -0.5f, 0.0f };//去掉const，使光緣位置可以改變

const GLfloat mat_ambient[]    = { 0.7f, 0.7f, 0.7f, 1.0f };
const GLfloat mat_diffuse[]    = { 0.8f, 0.8f, 0.8f, 1.0f };
const GLfloat mat_specular[]   = { 1.0f, 1.0f, 1.0f, 1.0f };
const GLfloat high_shininess[] = { 100.0f };
void motion(int x, int y)//滑鼠的motion函式
{
    light_position[0] = (x-150)/150.0*5;//換算出光源x的新位置(*5是因為z是-5.0)
    light_position[1] = -(y-150)/150.0*5;//換算出光源y的新位置(所以換算到-5~+5之間)
    glLightfv(GL_LIGHT0, GL_POSITION, light_position);
    glutPostRedisplay();//display();glut貼個Post文章, 請glut(re)顯示display

}