week06

期中考題
glPushMatrix(); //Push備份矩
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); //貼圖座標
  glColor3f(r,g,b); //色彩
  glVertex(3f)(x,y,z); //頂點
glEnd();
  glPopMatrix(); //pop還原矩陣

打光 -教材(理論/實作操作)

         -實作

打光茶壺->
從原程式中找到光度的程式碼複製到自己的程式碼
光線位置z值須改為負的才能看到亮的那面
自己打:#include <GL/glut.h>
複製: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 };
自己打: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);

複製: 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);
最後:
glutMainLoop();
}

可調整值去改顏色與光源

加入motion函式 用滑鼠移動光源
程式碼:#include <GL/glut.h>
#include <stdio.h>
const GLfloat light_ambient[]  = { 0.0f, 0.0f, 0.0f, 0.0f };
const GLfloat light_diffuse[]  = { 1.0f, 1.0f, 0.0f, 1.0f };
const GLfloat light_specular[] = { 0.0f, 1.0f, 0.0f, 1.0f };
 GLfloat light_position[] = { 2.0f, 5.0f, -5.0f, 0.0f };

const GLfloat mat_ambient[]    = { 1.0f, 0.6f, 1.0f, 1.0f };
const GLfloat mat_diffuse[]    = { 0.8f, 0.8f, 0.8f, 1.0f };
const GLfloat mat_specular[]   = { 1.0f, 0.5f, 0.3f, 1.0f };
const GLfloat high_shininess[] = { 100.0f };

void display()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glutSolidTeapot(0.3);
    glutSwapBuffers();
}

void motion(int x,int y)///滑鼠按下後的motion函式
{
    light_position[0]=(x-150)/150.0;
    light_position[1]=-(y-150)/150.0;
    glLightfv(GL_LIGHT0,GL_POSITION,light_position);///重設光位置
    glutPostRedisplay();///請glut送出re重新display顯示
    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 3D");
    glutDisplayFunc(display);
    glutMotionFunc(motion);///加入motion函式

    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();
}