week06

1
期中考
glPushMatrix();               //push備份矩陣
     glTranslatef(x,y,z);                    //移動
     glRotatef(angle,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,tz);   //貼圖座標
          glColor3f(r,g,b);                   //色彩
          glVertex3f(x,y,z);                 //頂點
     glEnd();
glPopMatrix();                  //pop還原矩陣

2
下載jsyeh/3dcg10網頁裡的
windows、data和glut32.dll
開啟Light Material.exe,試著改變裡面的值

3
將茶壺的程式碼，加入light的程式碼
打光後讓茶壺看起來更立體
產生結果如下

程式碼:
#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 };

float rotX=0;
void display()
{
    glClearColor(1,1,1,1);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glPushMatrix();
        glRotatef(rotX, 0,1,0);
        glColor3f(1,0,0);
        glutSolidTeapot(0.3);
    glPopMatrix();
    glutSwapBuffers();
}
void motion(int x, int y)
{
    rotX=x;
    display();
}
int main(int argc, char**argv)
{
    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_DOUBLE |GLUT_DEPTH);
    glutCreateWindow("hello");

    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);


    glutDisplayFunc(display);
    glutMotionFunc(motion);

    glutMainLoop();


}
4

更改光的位置讓茶壺可以更亮 
(const GLfloat light_position[] = { 2.0f, 5.0f, 5.0f, 0.0f };)

5

程式碼:

再利用motion函式 讓滑鼠可以改變光源位置

#include <GL/glut.h>
#include <stdio.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, -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()
{
    glClearColor(1,1,1,1);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        glutSolidTeapot(0.3);
    glutSwapBuffers();
}
void motion(int x, int y)
{
   light_position[0]=(x-150)/150.0;
   light_position[1]=-(y-150)/150.0;
   glLightfv(GL_LIGHT0, GL_POSITION, light_position);
   glutPostRedisplay();
   printf("%f %f\n", light_position[0],light_position[1]);
}
int main(int argc, char**argv)
{
    glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_DOUBLE |GLUT_DEPTH);
    glutCreateWindow("hello");

    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);


    glutDisplayFunc(display);
    glutMotionFunc(motion);

    glutMainLoop();


}