week05(2020/3/31)紀錄

今天要學打光。
///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 };
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 };///照光方向數值

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 };

    ///打光也需要 3D的 depth test
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);

    ///打光1:要開啟光線, 原來範例就寫好了
    glEnable(GL_LIGHT0);
    glEnable(GL_NORMALIZE);
    glEnable(GL_COLOR_MATERIAL);
    glEnable(GL_LIGHTING);
    ///打光2:要設定光light的設定值 (前面有陣列,這裡拿來用
    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: 要把物體也設定好它的 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);
從範例檔找到打光程式

打過光的茶壺

光的方向想用滑鼠控制
void motion(int x,int y)
{
    GLfloat light_position[] = {2.0f, 5.0f, -5.0f, 0.0f};
    light_position[0] = (x-150)/150.0*10;
    light_position[1] = -(y-150)/150.0*10;
    glLightfv(GL_LIGHT0,GL_POSITION,light_position);
    glutPostRedisplay();
}
然後main函式中加上glutMotionFunc(motion);