week08

1. 打光

2. 試玩light_material.exe

3. 從 CodeBlocks GLUT專案的177行, 拿light打光相關的陣列、函式來用

#include <GL/glut.h>

#include <stdlib.h>

///光的值

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 };

///material的值

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);

    glutCreateWindow("light");

    glutInitDisplayMode(GLUT_DOUBLE|GLUT_DEPTH);

    glutDisplayFunc(display);///裡面要有打光的函式

    glEnable(GL_DEPTH_TEST);

    ///開第一個燈光

    glEnable(GL_LIGHT0);

    glEnable(GL_NORMALIZE);

    glEnable(GL_COLOR_MATERIAL);

    glEnable(GL_LIGHTING);

    ///光設定值

    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();

}

改變光源-用mouse移動來改變

#include <GL/glut.h>

#include <stdlib.h>

///光的值

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 };///刪掉const

///material的值

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();

}

void motion(int x,int y)

{

    light_position[0]=(x-150)/150.0;///光的x座標   

    light_position[1]=-(y-150)/150.0;///光的y座標

    glLightfv(GL_LIGHT0, GL_POSITION, light_position);

    glutPostRedisplay();

}

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

{

    glutInit(&argc, argv);

    glutCreateWindow("light");

    glutInitDisplayMode(GLUT_DOUBLE|GLUT_DEPTH);

    glutDisplayFunc(display);///裡面要有打光的函式

    glutMotionFunc(motion);

    glEnable(GL_DEPTH_TEST);

    ///開第一個燈光

    glEnable(GL_LIGHT0);

    glEnable(GL_NORMALIZE);

    glEnable(GL_COLOR_MATERIAL);

    glEnable(GL_LIGHTING);

    ///光設定值

    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();

}

5. 期中考題: OpenGL必背10函式

glTranslatef(x,y,z);

glRotatef(angle,x,y,z);

glPushMatrix();

glScalef(x,y,z);

glBegin(GL_POLYGON);

glColor3f(r,g,b);

glTexCoord2f(tx,ty);

glNormal3f(nx,ny,nz);

glEnd();

glVertex2f(x,y);

glPopMatrix();