#pragma once
#include <windows.h>
#include "math_3d.h"
#define GLUT_DISABLE_ATEXIT_HACK
#include <gl/glew.h>/*GL_BGR*/
#include <gl/glut.h>
#include <atlimage.h>
// 全局变量光照参数
float ambientLight[] = { 0.3f, 0.3f, 0.3f, 1.0f };/*环境光参数*/
float diffuseLight[] = { 1.0f, 1.0f, 1.0f, 1.0f };/*漫反射光参数*/
float specular[] = { 1.0f, 1.0f, 1.0f, 1.0f };/*镜面反射光参数*/
float specref[] = { 1.0f, 1.0f, 1.0f, 1.0f };/*材质镜面反射颜色属性*/
float lightPos[] = { 8.0f, 10.0f, 4.0f, 1.0f };/*光源位置*/
//如果我们把lightPos数组的最后一个值设为0.0，
//可以使光源看上去像是来自无限远处，并沿着向量（X，Y，Z）所指定的方向射入。
//这种看似来自无限远处的光源称为方向性光源，它会均匀地照射在物体的表面，
//它的所有光线都是平行的, 是一种平行光。
//反之，对于位置性光源，光线会从光源处向不同方向发散开来。
float spotDir[] = { 0.0f, 0.0f, -1.0f };//聚光灯参数
//全局变量设置
// 旋转变量
static float g_xRot = 0.0f;
static float g_yRot = 0.0f;
float g_lightPos[] = { 4.0f, 4.0f, 2.0f, 1.0f };
float g_ambientLight[] = { 0.0f, 0.0f, 1.0f, 1.0f };
float g_cameraX = 0.0, g_cameraY = 0.0, g_cameraZ = 40.0;
unsigned int ATLLoadTexture(const char* fileName);
unsigned int g_groundtex;
unsigned int g_mirrorTex;
void InitTexture()
{
g_groundtex = ATLLoadTexture("data/ground.jpg");
g_mirrorTex = ATLLoadTexture("data/mirror.jpg");
}
//加载jpg/bmp等各种纹理返回纹理id
unsigned int ATLLoadTexture(const char* fileName)
{
BITMAP bm;
GLuint idTexture = 0;
CImage img; //需要头文件atlimage.h
HRESULT hr = img.Load(fileName);
if (!SUCCEEDED(hr)) //文件加载失败
{
MessageBox(NULL, "文件加载失败", "ERROR", 0);
return NULL;
}
HBITMAP hbmp = img;
if (!GetObject(hbmp, sizeof(bm), &bm))
return 0;
glGenTextures(1, &idTexture);
if (idTexture)
{
glBindTexture(GL_TEXTURE_2D, idTexture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glPixelStoref(GL_PACK_ALIGNMENT, 1);
glTexImage2D(GL_TEXTURE_2D, 0, 3, bm.bmWidth, bm.bmHeight, 0, GL_BGR, GL_UNSIGNED_BYTE, bm.bmBits); //这里不是GL_RGB
}
return idTexture;
}
// 声明一个阴影转换矩阵
M3DMatrix44f shadowMat;
//截图效果
<img src="https://img-blog.csdn.net/20151021183128451?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQv/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />
////////////////////////////////////////////////
// 绘制光照物以及影子
void DrawaScenes(int nShadow)
{
glPushAttrib(GL_CURRENT_BIT);
// 设置材质的颜色这里我们只需要设置为黑色表示阴影
if (nShadow == 0)
glColor3f(1.0, 1.0, 1.0);/*非阴影时颜色设置为白色等*/
else
{
glColor3f(0.1, 0.1, 0.1);/*阴影时颜色设置为黑色*/
/*绘制还要镜面反射的球体阴影*/
glPushMatrix();
glPushAttrib(GL_CURRENT_BIT);
glTranslatef(g_yRot, g_xRot, 4);//物体位置
glutSolidSphere(0.3, 20, 20);
glPopMatrix();
glPopAttrib();
}
/*绘制实体与阴影*/
glPushMatrix();
glTranslatef(-10.0, -5.0, 0.0);
glScalef(0.5, 0.5, 0.5);
glBegin(GL_QUADS); // 开始绘制四边形
// 前侧面
glNormal3f(0.0f, 0.0f, 1.0f); // 法线指向观察者
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f(1.0f, -1.0f, 1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f(1.0f, 1.0f, 1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f);
// 后侧面
glNormal3f(0.0f, 0.0f, -1.0f); // 法线背向观察者
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(1.0f, 1.0f, -1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(1.0f, -1.0f, -1.0f);
// 顶面
glNormal3f(0.0f, 1.0f, 0.0f); // 法线向上
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, 1.0f, 1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f(1.0f, 1.0f, 1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f(1.0f, 1.0f, -1.0f);
// 底面
glNormal3f(0.0f, -1.0f, 0.0f); // 法线朝下
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(1.0f, -1.0f, -1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(1.0f, -1.0f, 1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f);
// 右侧面
glNormal3f(1.0f, 0.0f, 0.0f); // 法线朝右
glTexCoord2f(1.0f, 0.0f); glVertex3f(1.0f, -1.0f, -1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f(1.0f, 1.0f, -1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(1.0f, 1.0f, 1.0f);
glTexCoord2f(0.0f, 0.0f); glVertex3f(1.0f, -1.0f, 1.0f);
// 左侧面
glNormal3f(-1.0f, 0.0f, 0.0f); // 法线朝左
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, 1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, 1.0f, 1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f, 1.0f, -1.0f);
glEnd(); // 四边形绘制结束
//glPopMatrix();
/*绘制一个三角形*/
glPushMatrix();
glTranslatef(-8, 0.0, -2.0);
glBegin(GL_TRIANGLES);
glVertex3f(0.0, 0.0, -1.0);
glVertex3f(-1.0, 0.0, 1.0);
glVertex3f(1.0, 0.0, 1.0);
glEnd();
glTranslatef(-5.0, 0.0, 0.0);
//glEnable(GL_TEXTURE_2D);
//glBindTexture(GL_TEXTURE_2D, g_groundtex);
glutSolidSphere(3.0, 20, 20);
//glDisable(GL_TEXTURE_2D);
glPopMatrix();
glPopAttrib();
}
//绘制球体的函数
void drawSphere()
{
glEnable(GL_LIGHTING);
glPushMatrix();
glPushAttrib(GL_CURRENT_BIT);
glColor3f(0.0, 0.5, 0.8);
glTranslatef(g_yRot, g_xRot, 4);//物体位置
glutSolidSphere(0.3, 20, 20);
glPopMatrix();
glPopAttrib();
glDisable(GL_LIGHTING);
}
// 绘制场景
void RenderScene(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glTranslatef(0.0, 0.0, 0.0);
//// 移动z轴坐标系看到前面的一切东西
glLightfv(GL_LIGHT0, GL_POSITION, lightPos);/*实时改变光源的位置*/
//glLightfv(GL_LIGHT0, GL_SPOT_DIRECTION, spotDir);/*聚光灯效果*/
//glLightf(GL_LIGHT0, GL_SPOT_CUTOFF, 60.0f);
gluLookAt(g_cameraX, g_cameraY, g_cameraZ, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
//地面任意三点
M3DVector3f points[3] = { { -3.0f, -10.0f, -2.0f },
{ -3.0f, -10.0f, 2.0f },
{ 4.0f, -10.0f, 2.0f } };
// 从三点得到的平面方程
M3DVector4f vPlaneEquation;
m3dGetPlaneEquation(vPlaneEquation, points[0], points[1], points[2]);
// 计算投影在一个平面上的阴影矩阵
m3dMakePlanarShadowMatrix(shadowMat, vPlaneEquation, lightPos);
//glEnable(GL_NORMALIZE);
glPushMatrix();
//绘制平面即阴影体的依附平面
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, g_groundtex);
float lenghtGround = 80.0;//地面长宽度
float heightGround = -11.0;
glBegin(GL_QUADS);
glTexCoord2f(0.0f, 0.0f); glVertex3f(-lenghtGround, heightGround, -lenghtGround); // 纹理和四边形的左下
glTexCoord2f(1.0f, 0.0f); glVertex3f(-lenghtGround, heightGround, lenghtGround); // 纹理和四边形的右下
glTexCoord2f(1.0f, 1.0f); glVertex3f(lenghtGround, heightGround, lenghtGround); // 纹理和四边形的右上
glTexCoord2f(0.0f, 1.0f); glVertex3f(lenghtGround,heightGround, -lenghtGround); // 纹理和四边形的左上
glEnd();
glDisable(GL_TEXTURE_2D);
glPopMatrix();
// 保存矩阵状态并进行旋转
glPushMatrix();
// 在绘制物体前将光源放在合适位置
glEnable(GL_LIGHTING);
glRotatef(g_xRot, 1.0f, 0.0f, 0.0f);
glRotatef(g_yRot, 0.0f, 1.0f, 0.0f);
DrawaScenes(0);/*绘制物体*/
// 恢复原矩阵状态
glPopMatrix();
//// 绘制阴影与地面
//// 首先关闭光照和深度测试
glDisable(GL_DEPTH_TEST);
glDisable(GL_LIGHTING);
glPushMatrix();
// 绘制光源体
glPushMatrix();
glTranslatef(lightPos[0], lightPos[1], lightPos[2]);
glColor3f(1.0, 0.0, 0.0);
glutSolidSphere(0.5f, 20, 20);
glPopMatrix();
glEnable(GL_DEPTH_TEST);
glDisable(GL_STENCIL_TEST);
drawSphere();
glClearStencil(0x0);
glClear(GL_STENCIL_BUFFER_BIT);
glStencilFunc(GL_ALWAYS, 1, 0xFF);
glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
glEnable(GL_STENCIL_TEST);
glDisable(GL_LIGHTING);
/*绘制平面镜子*/
glPushMatrix();
glPushAttrib(GL_CURRENT_BIT);
glColor3f(1.0f, 1.0f, 1.0f);
glDepthMask(GL_FALSE);//设置深度缓冲区为只读
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, g_mirrorTex);
float lengthMirror = 10.0;//镜子长宽
glBegin(GL_QUADS);
//前面
glTexCoord2f(0.0f, 0.0f); glVertex3f(-lengthMirror, -lengthMirror, -2.0f); // 纹理和四边形的左下
glTexCoord2f(1.0f, 0.0f); glVertex3f(lengthMirror, -lengthMirror, -2.0f); // 纹理和四边形的右下
glTexCoord2f(1.0f, 1.0f); glVertex3f(lengthMirror, lengthMirror, -2.0f); // 纹理和四边形的右上
glTexCoord2f(0.0f, 1.0f); glVertex3f(-lengthMirror, lengthMirror, -2.0f); // 纹理和四边形的左上
glEnd();
glDisable(GL_TEXTURE_2D);
glPopMatrix();
glPopAttrib();
/*绘制光源体*/
glPushMatrix();
glTranslatef(lightPos[0], lightPos[1], lightPos[2]);
glColor3f(1.0, 1.0, 1.0);
glutSolidSphere(0.1f, 20, 20);
glPopMatrix();
//// 乘以阴影矩阵
glMultMatrixf((float *)shadowMat);
//// 旋转物体
glRotatef(g_xRot, 1.0f, 0.0f, 0.0f);
glRotatef(g_yRot, 0.0f, 1.0f, 0.0f);
// 给予true来绘制阴影
DrawaScenes(1);
// 恢复矩阵
glPopMatrix();
glDepthMask(GL_TRUE);//重新启用深度缓冲区
///明确说明函数的测试功能GL_NEVER,，GL_LESS， GL_LEQUAL，
//GL_GREATER， GL_GEQUAL,，GL_EQUAL， GL_NOTEQUAL和 GL_ALWAYS。
//初始化的值是GL_ALWAYS
//ref
//明确说明该模板测试的引用值。 ref 值被限制在0~2 ^ (n - 1)间，
//其中n是模板缓存中位平面数。初始化值是0
//mask
// 该参数表示一个模板，用来和ref值以及存储的模板值做与运算。初始化值是全1
//要允许或禁止该测试的话，使用glEnable(GL_STENCIL_TEST)或glDisable(GL_STENCIL_TEST)
glStencilFunc(GL_EQUAL, 1, 0xFF);//0xff==255
//glStencilOp函数，它用来根据比较结果修改蒙板缓存区中的值
//sfail当蒙板测试失败时所执行的操作
//zfail当蒙板测试通过，深度测试失败时所执行的操作
//zpass当蒙板测试通过，深度测试通过时所执行的操作
glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
glScalef(1.0f, 1.0f, -1.0f);//镜子里的影子方向取反
glPushAttrib(GL_CURRENT_BIT);
drawSphere();
glPopAttrib();
glDisable(GL_STENCIL_TEST);
glDepthMask(true);//重新启用深度缓冲区
glutSwapBuffers();
}
void SetupRC()
{
InitTexture();/*初始化图片纹理*/
glShadeModel(GL_SMOOTH);
glEnable(GL_DEPTH_TEST); // 隐藏面消除;
glFrontFace(GL_CCW); // 逆时针多边形面
glEnable(GL_CULL_FACE); // 剔除内部表面影响
// 启动光源0
glLightfv(GL_LIGHT0, GL_AMBIENT, ambientLight);
glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuseLight);
glLightfv(GL_LIGHT0, GL_SPECULAR, specular);
glLightfv(GL_LIGHT0, GL_POSITION, lightPos);
glEnable(GL_LIGHT0);
// 启用颜色跟踪
glEnable(GL_COLOR_MATERIAL);
// 实时设置材料属性遵循glColor值
glColorMaterial(GL_FRONT, GL_AMBIENT_AND_DIFFUSE);
// 所有材料有全反射
glMaterialfv(GL_FRONT, GL_SPECULAR, specref);/*指定用于光照计算的当前材质属性*/
glMateriali(GL_FRONT, GL_SHININESS, 128);/*高亮显示*/
// 黑色背景
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
}
void SpecialKeys(int key, int x, int y)
{
if (key == GLUT_KEY_UP)
g_xRot -= 1.0f;
if (key == GLUT_KEY_DOWN)
g_xRot += 1.0f;
if (key == GLUT_KEY_LEFT)
g_yRot -= 1.0f;
if (key == GLUT_KEY_RIGHT)
g_yRot += 1.0f;
// Refresh the Window
glutPostRedisplay();
}
void NormalKeys(unsigned char key, int x, int y)
{
switch (key) {
case VK_ESCAPE:exit(0); break;
/*摄像机移动命令*/
case 'w': g_cameraZ -= 1.0; glutPostRedisplay(); break;
case 's': g_cameraZ += 1.0; glutPostRedisplay(); break;
case 'a':lightPos[0] += 2.0; glutPostRedisplay(); break;
case 'd':lightPos[0] -= 2.0; glutPostRedisplay(); break;
default:break;
}
}
void ChangeSize(int w, int h)
{
float fAspect;
// 防止被0除
if (h == 0)
h = 1;
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
fAspect = (float)w / (float)h;
gluPerspective(60.0f, fAspect, 0.1, 2000.0);
glMatrixMode(GL_MODELVIEW);
}
int main(int argc, char* argv[])
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH | GLUT_STENCIL);
glutInitWindowSize(1366, 768);
glutCreateWindow("LightShadowMirrorReflect");
glutReshapeFunc(ChangeSize);
glutSpecialFunc(SpecialKeys);
glutKeyboardFunc(NormalKeys);
glutDisplayFunc(RenderScene);
SetupRC();
glutMainLoop();
return 0;
}
光照阴影镜面反射综合算法：