WEEK06_燈光筆記

step01_講解光的性質:

Ambient

Diffuse 擴散

Specular 反射

step02_偷之前(六個紅紅)的程式碼，找到light函式

複製到自己的程式裡

程式碼:

#include <GL/glut.h> ///使用GLUT外掛,簡化程式

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 );

    glColor3f(1,1,0);

    glutSolidTeapot(0.3);

    glutSwapBuffers();///畫好後,交換出來

}

int main(int argc, char** argv) ///main()主函式 進階版

{

    glutInit( &argc, argv); ///把參數,送給 glutInit 初始化

    glutInitDisplayMode( GLUT_DOUBLE | GLUT_DEPTH ); ///雙緩衡區 + 3D深度功能

    glutCreateWindow("第06週的程式哦!");

    glutDisplayFunc(display); ///用來顯示的函式

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();

}

step02-2 把上週縮放的程式碼加進去，光線要跟著物體縮放改變

程式碼:

#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 };

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 x=150, y=150, z=0, scale=1.0;

int oldX=0, oldY=0;

void display()

{

    glClearColor( 0.5, 0.5, 0.5, 1 );

    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

    glPushMatrix();

        glTranslatef((x-150)/150.0 , -(y-150)/150.0 ,z );

        glScalef(scale, scale, scale);

        glColor3f(1,1,0);

        glutSolidTeapot(0.3);

    glPopMatrix();

    glutSwapBuffers();

}

void keyboard( unsigned char key, int x, int y)

{

}

void mouse (int button,int state,int mouseX,int mouseY)

{

    oldX = mouseX; oldY = mouseY;

}

void motion(int mouseX,int mouseY)

{

    if( mouseX-oldX > 0) scale *= 1.01;

    if( mouseX-oldX < 0) scale *= 0.99;

    oldX = mouseX;      oldY = mouseY;

    display();

}

int main(int argc, char**argv)

{

    glutInit( &argc, argv);

    glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("Week05 keyboard");

    glutDisplayFunc(display);

    glutKeyboardFunc(keyboard);

    glutMouseFunc(mouse);

    glutMotionFunc(motion);

    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();

}

step03 加入angle，讓茶壺有選轉的效果

#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 };

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 x=150, y=150, z=0, scale=1.0, angle=0.0;

int oldX=0, oldY=0;

void display()

{

    glClearColor( 0.5, 0.5, 0.5, 1 );

    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

    glPushMatrix();

        glTranslatef((x-150)/150.0 , -(y-150)/150.0 ,z );

        glRotatef(angle, 0,1,0);

        glScalef(scale, scale, scale);

        glColor3f(1,1,0);

        glutSolidTeapot(0.3);

    glPopMatrix();

    glutSwapBuffers();

}

void keyboard( unsigned char key, int x, int y)

{

}

void mouse (int button,int state,int mouseX,int mouseY)

{

    oldX = mouseX; oldY = mouseY;

}

void motion(int mouseX,int mouseY)

{

    angle += (mouseX-oldX);

    oldX = mouseX;      oldY = mouseY;

    display();

}

int main(int argc, char**argv)

{

    glutInit( &argc, argv);

    glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("Week05 keyboard");

    glutDisplayFunc(display);

    glutKeyboardFunc(keyboard);

    glutMouseFunc(mouse);

    glutMotionFunc(motion);

    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();

}