week05-茶壺移動打光

移動茶壺打光

先了解光線

1.如何有光

2.滑鼠移動茶壺程式

程式碼

#include <GL/glut.h>

///打光的第0步,宣告陣列,裡面有光的屬性值
const GLfloat light_ambient[]  = { 0.0f, 0.0f, 0.0f, 1.0f };///ambient無所不在的光
const GLfloat light_diffuse[]  = { 1.0f, 1.0f, 1.0f, 1.0f };///diffuse當角度不同時光的能量就會有所不同,因此可能某些角度比較亮
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);
    glutSolidTeapot(0.3);
    glutSwapBuffers();
}
///要讓光源動,用motion函式做
void motion(int x,int y)
{
    GLfloat light_position[]={2.0f,5.0f,-5.0f,0.0f};///1.陣列放位置
    light_position[0]=(x-150)/150.0*10;///2.用motion的x座標,算光的位置
    light_position[1]=(y-150)/150.0*10;
    glLightfv(GL_LIGHT0,GL_POSITION,light_position);///3.用函式把光設好
    glutPostRedisplay();///4.請GLUT重畫畫面
}
int main(int argc, char *argv[])
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
    glutCreateWindow("GLUT Shapes");
    glutDisplayFunc(display);
    glutMotionFunc(motion);
    ///打光3D深淺
    glEnable(GL_DEPTH_TEST);

    ///打光1:開啟光線
    glEnable(GL_LIGHT0);
    glEnable(GL_NORMALIZE);
    glEnable(GL_COLOR_MATERIAL);
    glEnable(GL_LIGHTING);
///打光2:要設定light的設定值(前面是陣列)
    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);
///打光2.2:物體也設定material
    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;
}