Note by Jack Week06

光線

示範光線如何照射

利用示範程式打光

打光的茶壺

重新調整視窗

#include <GL/glut.h>

const GLfloat light_ambient[]  = { 1.5f, 0.5f, 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 };

static void resize(int width, int height)

{

    const float ar = (float) width / (float) height;

    glViewport(0, 0, width, height);

    glMatrixMode(GL_PROJECTION);

    glLoadIdentity();

    glOrtho(-ar,ar,-1,+1,-1,+1);

    //glFrustum(-ar, ar, -1.0, 1.0, 0.2, 100.0);

    glMatrixMode(GL_MODELVIEW);

    glLoadIdentity() ;

}

void display()

{

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glutSolidTeapot(0.3);

    glutSwapBuffers();

}

void motion(int x,int y)

{

    GLfloat light_position[]={2.0f,5.0f,-5.0f,0.0f};

    light_position[0]=(x-640)/640.0*10;

    light_position[1]=-(y-360)/360.0*10;

    glLightfv(GL_LIGHT0,GL_POSITION,light_position);

    glutPostRedisplay();

}

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

{

    glutInit(&argc, argv);

    glutInitWindowSize(1280,720);

    //glutInitWindowPosition(1920,1080);

    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);

    glutCreateWindow("GLUT Shapes");

    glutReshapeFunc(resize);

    glutDisplayFunc(display);

    glutMotionFunc(motion);

    glEnable(GL_DEPTH_TEST);

    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;

}