Week 08 湘雯的筆記

1.複習函式+模擬考

glPushMatrix(); ///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

glColor3f(r,g,b); ///顏色

glNormal3f(nx,ny,nz); ///打光法向量

glTexCoord2f(tx,ty); ///貼圖座標

glVertex3f(x,y,z); ///頂點

glEnd(); ///結束

glPopMatrix(); ///還原矩陣

2.畫打光的茶壺

程式碼如下:

#include <GL/glut.h>

static void display(void)

{

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glPushMatrix();

        glutSolidTeapot(0.3);

    glPopMatrix();

    glutSwapBuffers();

}

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 };

/* Program entry point */

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

{

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("GLUT Shapes");

    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();

    return EXIT_SUCCESS;

}

補充:改第15行程式碼(light_position[])的參數，可以修改打光的角度，結果如下

3.修改程式碼，使程式執行結果為兩個茶壺，結果如下

程式碼如下:

#include <GL/glut.h>

static void display(void)

{

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glPushMatrix();

        glTranslatef(0,0.6,0); //將第一個茶壺的位置調高一點

        glutSolidTeapot(0.3);

    glPopMatrix();

    glPushMatrix();

        glRotatef(angle,0,1,0);

        glutSolidTeapot(0.3);

    glPopMatrix(); //畫第二個茶壺的過程

    glutSwapBuffers();

}

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, 4.0f, 0.0f, 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 };

/* Program entry point */

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

{

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("GLUT Shapes");

    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();

    return EXIT_SUCCESS;

}

4.加入Idle函式，使執行結果的第二個茶壺會旋轉，結果如下

程式碼如下:

#include <GL/glut.h>

float angle=0; //定義一個角度初始為0

static void display(void)

{

    angle++; //使其在電腦閒閒沒事時可以旋轉

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glPushMatrix();

        glTranslatef(0,0.6,0);

        glutSolidTeapot(0.3);

    glPopMatrix();

    glPushMatrix();

        glRotatef(angle,0,1,0);

        glutSolidTeapot(0.3);

    glPopMatrix();

    glutSwapBuffers();

}

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, 4.0f, 0.0f, 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 };

/* Program entry point */

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

{

    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("GLUT Shapes");

    glutIdleFunc(display); //Idle函式

    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();

    return EXIT_SUCCESS;

}

5.各種形狀的函式

glutSoildTeapot(大小); //茶壺

glutSoildCube(大小); //正方體

glutSoildCone(底r , 高h , slice(柳丁切) , stack(堆疊)); 

glutSoildSphere(r,slice,stack); //圓錐

glutDedocahedron();

glutIcosahedron();