opengl light position changes weirdly - c++

Question

When I use glRotatef to change the diretion of the objects(table and cups) which are created by my own using plenty of triangles(I know it seems a little bit stupid QAQ), the lighting effects change weirdly as if the light position has also changed. However the lighting effects on teapot which is directly invoked by using glutSolidTeapot acts normally. I think that invoking glRotatef will not change the light position, so I cannot figure out where comes the problems.
The code is shown below:
#include<GLFW\glfw3.h>
#include<GL/glut.h>
#include<math.h>
#include<stdio.h>
#define _CRT_SECURE_NO_WARNINGS
//系统屏幕大小初始化
GLint SCREEN_WIDTH = 0;
GLint SCREEN_HEIGHT = 0;
//窗口大小初始化
GLint window_width = 1000;
GLint window_height = 800;
//中心坐标计算
#define MIDWIDTH window_width/2
#define MIDHEIGHT window_height/2
//设置模型旋转角度
GLfloat xAngle = 0.0f;
GLfloat yAngle = 0.0f;
//设置模型初始距离
GLfloat distancex;
GLfloat distancey;
//受支持的点大小范围
GLfloat sizes[2];
//受支持的点大小增量
GLfloat step;
GLfloat mat_ambient_skew[] = { 0,0,0,0 };
GLfloat mat_diffuse_skew[] = { 0,0,0,0 };
GLfloat mat_specular_skew[] = { 0,0,0,0 };
GLfloat low_shininess[] = { 3.0 };
//线框0 or 实体1
GLint l_or_r = 1;
GLboolean mouseLeftDown = false; //鼠标左键按下状态，默认是未按下
//缩放倍数
GLfloat times = 0.8f;
//定义光源的颜色和位置
GLfloat ambient[] = { 0.0f, 0.0f, 0.0f, 1.0f }; //环境光
GLfloat position[] = { 10.0f,10.0f,10.0f,1.0f }; //光源位置
GLfloat matEmission[] = { 1.0f, 1.0f, 1.0f, 1.0 }; //反射光颜色
GLfloat diffuse[] = { 1.0, 1.0, 1.0, 1.0 }; //漫射光
GLfloat specular[] = { 1.0f, 1.0f, 1.0f, 1.0f }; //镜面反射
GLfloat mat_ambient[] = { 0.7f, 0.7f, 0.7f, 1.0f }; // 环境
GLfloat mat_diffuse[] = { 0.5f, 0.5f, 0.5f, 1.0f }; // 散射
GLfloat mat_specular[] = { 1.0f, 1.0f, 1.0f, 1.0f }; // 镜面反射
GLfloat high_shininess[] = { 18.0f }; // 镜面反射指数为
GLfloat no_mat[] = { 0.0f, 0.0f, 0.0f, 1.0f }; // 无材质颜色
void init() {
GLfloat local_view[] = { 0.0 };
glClearColor(0.0, 0.0, 0.0, 0.0);
glShadeModel(GL_SMOOTH);
glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse);
//glLightfv(GL_LIGHT0, GL_SPECULAR, mat_specular);
glLightfv(GL_LIGHT0, GL_POSITION, position);
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambient);
glLightModelfv(GL_LIGHT_MODEL_LOCAL_VIEWER, local_view);
glLightModelfv(GL_LIGHT_MODEL_TWO_SIDE, local_view);
glEnable(GL_COLOR_MATERIAL);
glColorMaterial(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE);
// 启用光照
glEnable(GL_DEPTH_TEST);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, matEmission);
glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, mat_ambient);
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, mat_diffuse);
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, mat_specular);
glMaterialfv(GL_FRONT_AND_BACK, GL_SHININESS, high_shininess);
glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, no_mat);
}
void translate()
{
//glColor3f(0.0f, 1.0f, 1.0f);
glScalef(times, times, times);
glTranslatef(distancex, distancey, 0);
glRotatef(xAngle, 1.0f, 0.0f, 0.0f);
glRotatef(yAngle, 0.0f, 1.0f, 0.0f);
}
void drawCube(double l, double w, double h, double x, double y, double z) {
glPushMatrix();
translate();
glTranslated(x, y, z);
glScaled(l, w, h);//沿x y z轴缩放 先缩放 再平移 一开始中心在原点
glColor3f(0.7, 0.35, 0.01);
if (l_or_r == 0) glutWireCube(1);
else if (l_or_r == 1) glutSolidCube(1);
glPopMatrix();
}
GLvoid DrawCircleArea(float height, float top, float bot, int num_segments, int cup) {
if (l_or_r == 0) {
glPolygonMode(GL_BACK, GL_LINE);//线框
glPolygonMode(GL_FRONT, GL_LINE);//线框
}
else if (l_or_r == 1) {
glPolygonMode(GL_BACK, GL_FILL);//实体
glPolygonMode(GL_FRONT, GL_FILL);//实体
}
GLfloat vertex[4];
const GLfloat delta_angle = 2.0 * 3.1415926 / num_segments;
int h = height;
float cx = 0;
float cy = 0;
float cz = 0;
// 画底面
glBegin(GL_TRIANGLES);
for (int i = 0; i <= num_segments; i++) {
int j = i + 1;
vertex[0] = cx;
vertex[1] = cy;
vertex[2] = cz;
vertex[3] = 1.0;
glVertex4fv(vertex);
vertex[0] = cos(delta_angle * i) * bot + cx;
vertex[1] = cy;
vertex[2] = sin(delta_angle * i) * bot + cz;
vertex[3] = 1.0;
glVertex4fv(vertex);
vertex[0] = cos(delta_angle * j) * bot + cx;
vertex[1] = cy;
vertex[2] = sin(delta_angle * j) * bot + cz;
vertex[3] = 1.0;
glVertex4fv(vertex);
}
glEnd();
if (cup != 1) { // 画顶面
glBegin(GL_TRIANGLE_FAN);
for (int i = 0; i <= num_segments; i++) {
int j = i + 1;
vertex[0] = cx;
vertex[1] = cy + h;
vertex[2] = cz;
vertex[3] = 1.0;
glVertex4fv(vertex);
vertex[0] = cos(delta_angle * i) * top + cx;
vertex[1] = cy + h;
vertex[2] = sin(delta_angle * i) * top + cz;
vertex[3] = 1.0;
glVertex4fv(vertex);
vertex[0] = cos(delta_angle * j) * top + cx;
vertex[1] = cy + h;
vertex[2] = sin(delta_angle * j) * top + cz;
vertex[3] = 1.0;
glVertex4fv(vertex);
}
glEnd();
}
for (int i = 0; i <= num_segments; i++) { // 画侧面
int j = i + 1;
glBegin(GL_TRIANGLES);
vertex[0] = cos(delta_angle * i) * bot + cx;
vertex[1] = cy;
vertex[2] = sin(delta_angle * i) * bot + cz;
vertex[3] = 1.0;
glVertex4fv(vertex);
vertex[0] = cos(delta_angle * j) * bot + cx;
vertex[1] = cy;
vertex[2] = sin(delta_angle * j) * bot + cz;
vertex[3] = 1.0;
glVertex4fv(vertex);
vertex[0] = cos(delta_angle * j) * top + cx;
vertex[1] = cy + h;
vertex[2] = sin(delta_angle * j) * top + cz;
vertex[3] = 1.0;
glVertex4fv(vertex);
vertex[0] = cos(delta_angle * i) * top + cx;
vertex[1] = cy + h;
vertex[2] = sin(delta_angle * i) * top + cz;
vertex[3] = 1.0;
glVertex4fv(vertex);
vertex[0] = cos(delta_angle * j) * top + cx;
vertex[1] = cy + h;
vertex[2] = sin(delta_angle * j) * top + cz;
vertex[3] = 1.0;
glVertex4fv(vertex);
vertex[0] = cos(delta_angle * i) * bot + cx;
vertex[1] = cy;
vertex[2] = sin(delta_angle * i) * bot + cz;
vertex[3] = 1.0;
glVertex4fv(vertex);
glEnd();
}
}
void MydrawCylinder(GLdouble l, GLdouble w, GLdouble h,
GLdouble x, GLdouble y, GLdouble z,
GLdouble base, GLdouble top, GLdouble height,
GLint slices, GLint stacks, GLint cup,
GLfloat r, GLfloat g, GLfloat b) {
if (l_or_r == 0) {
glPolygonMode(GL_BACK, GL_LINE);//线框
glPolygonMode(GL_FRONT, GL_LINE);//线框
}
else if (l_or_r == 1) {
glPolygonMode(GL_BACK, GL_FILL);//实体
glPolygonMode(GL_FRONT, GL_FILL);//实体
}
glPushMatrix();
translate();
glTranslated(x, y, z);
glScaled(l, w, h);//沿x y z轴缩放 先缩放 再平移 一开始中心在原点
glColor3f(r, g, b); // 桌子颜色
DrawCircleArea(height, top, base, slices, cup);
glPopMatrix();
}
void drawTeapot() {
//FILE* filePtr = fopen("./1.bmp", "rb");
glPushMatrix();
// 平滑处理　
glEnable(GL_POINT_SMOOTH);
glHint(GL_POINT_SMOOTH, GL_NICEST);
glEnable(GL_LINE_SMOOTH);
glHint(GL_LINE_SMOOTH, GL_NICEST);
glEnable(GL_POLYGON_SMOOTH);
glHint(GL_POLYGON_SMOOTH, GL_NICEST);
translate();
glColor3f(0., 0.35, 0.01); // 茶壶颜色
// 线框 or 实体
if (l_or_r == 0) glutWireTeapot(3.0f);
else if (l_or_r == 1) glutSolidTeapot(3.0f);
glPopMatrix();
}
void display() {
init();
glClearColor(0.7f, 0.9f, 1.0f, 0.3f); // 背景颜色
glClearStencil(1);
glEnable(GL_STENCIL_TEST);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT); //清空颜色缓冲和深度缓冲
//设置观察点的位置，这里设置为从 - z轴观察
glLoadIdentity();
// GLdouble base, GLdouble top, GLdouble height, GLint slices, GLint stacks
// 桌子 table
MydrawCylinder(1, 1, 1, 0, -4.2, 0, 15, 15, 2, 100, 100, 0, 0.66, 0.47, 0.294);
MydrawCylinder(1, 1, 1, 0, -(4.2 + 15), 0, 0.75, 0.75, 15, 12, 100, 0, 0.66, 0.47, 0.294);
MydrawCylinder(1, 1, 1, 0, -(4.2 + 15 + 1), 0, 5, 5, 1, 100, 100, 0, 0.66, 0.47, 0.294);
// 四个杯子 four cups
int far = 5; // 杯子距离中心距离
MydrawCylinder(1, 1, 1, far, -2.2, -far, 0.5, 0.75, 2, 12, 100, 1, 0.478, 0.827, 0.475);
MydrawCylinder(1, 1, 1, -far, -2.2, far, 0.5, 0.75, 2, 12, 100, 1, 0.478, 0.827, 0.475);
MydrawCylinder(1, 1, 1, far, -2.2, far, 0.5, 0.75, 2, 12, 100, 1, 0.478, 0.827, 0.475);
MydrawCylinder(1, 1, 1, -far, -2.2, -far, 0.5, 0.75, 2, 12, 100, 1, 0.478, 0.827, 0.475);
// teapot
drawTeapot();
glutSwapBuffers();
}
void changeSize(GLint width, GLint height) { // 窗口改变尺寸
GLfloat ratio;
GLfloat coordinatesize = 16.0f;
if ((width == 0) || (height == 0))
return;
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
ratio = (GLfloat)width / (GLfloat)height;
if (width < height)
glOrtho(-coordinatesize, coordinatesize, -coordinatesize / ratio, coordinatesize / ratio, -coordinatesize, coordinatesize);
else
glOrtho(-coordinatesize * ratio, coordinatesize * ratio, -coordinatesize, coordinatesize, -coordinatesize, coordinatesize);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
void menuFunc(int key) {
switch (key) {
case 1:
l_or_r = 0;
break;
case 2:
l_or_r = 1;
break;
case 3:
position[0] -= 10.0;
break;
case 4:
position[0] += 10.0;
break;
case 5:
position[2] += 10.0;
break;
case 6:
position[2] -= 10.0;
break;
}
glutPostRedisplay();
}
void setMenu() { // 设置鼠标右键菜单
int mainMenu;
int slrMenu;
int lightPositionMenu;
slrMenu = glutCreateMenu(menuFunc);
glutAddMenuEntry("线框", 1);
glutAddMenuEntry("实体", 2);
lightPositionMenu = glutCreateMenu(menuFunc);
glutAddMenuEntry("向下", 3);
glutAddMenuEntry("向上", 4);
glutAddMenuEntry("向外", 5);
glutAddMenuEntry("向内", 6);
mainMenu = glutCreateMenu(menuFunc);
glutAddSubMenu("线框 or 实体", slrMenu);
glutAddSubMenu("光照位置", lightPositionMenu);
glutAttachMenu(GLUT_RIGHT_BUTTON);
glutPostRedisplay();
}
void keyFunc(int key, int x, int y) //键盘控制
{
//旋转
if (key == GLUT_KEY_UP) xAngle -= 5.0f; //绕x轴顺时针旋转
else if (key == GLUT_KEY_DOWN) xAngle += 5.0f; //绕x轴逆时针旋转
else if (key == GLUT_KEY_LEFT) yAngle -= 5.0f; //绕y轴顺时针旋转
else if (key == GLUT_KEY_RIGHT) yAngle += 5.0f; //绕y轴逆时针旋转
//缩放
if (key == GLUT_KEY_F1) times += 0.2f;
else if (key == GLUT_KEY_F2) times -= 0.2f;
glutPostRedisplay();
}
int main(int argc, char* argv[]) {
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH | GLUT_STENCIL);
SCREEN_WIDTH = glutGet(GLUT_SCREEN_WIDTH);
SCREEN_HEIGHT = glutGet(GLUT_SCREEN_HEIGHT);
glutCreateWindow(" ");
glutReshapeWindow(window_width, window_height);
setMenu();
glutReshapeFunc(changeSize);
glutDisplayFunc(display);
glutSpecialFunc(keyFunc);
glutMainLoop();
return 0;
}
The shadow of teapot does not match that of the table, and if rotate the table, the reflect light of teapot doesn't change it's postion while the reflect light of table changing weirdly.
image1
image2