3D+OpenGL里的光照平面镜面反射以及漫游移动物体位置等的具体实现

3D+OpenGL里的光照平面镜面反射以及漫游移动物体位置等的具体实现在实现过程中涉及到1.opengl里的蒙版缓冲等相关知识2.观察坐标系的转换摄像漫游等3.此外图中的mirror图片为导入的mirror.jpg文件4.在纹理贴图中

unsigned int ATLLoadTexture(const char* fileName)函数实现了jpg/bmp等图片的加载<pre name="code" class="cpp">//加载jpg/bmp等各种纹理返回纹理id

#define GLUT_DISABLE_ATEXIT_HACK 
#include <gl/glew.h>/*GL_BGR*/
#include <atlimage.h>
#include <GL/glut.h>//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 = 10.0;unsigned int g_mirrorTex;//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;
}void init()
{
	glClearColor(0.0, 0.0, 0.0, 0.0);
	glShadeModel(GL_SMOOTH);
	g_mirrorTex = ATLLoadTexture("data/mirror.jpg");
}//绘制球体的函数
void drawSphere()
{
	//光源设置
	glEnable(GL_LIGHT0);
	glEnable(GL_LIGHTING);
	glEnable(GL_COLOR_MATERIAL);
	glLightfv(GL_LIGHT0, GL_POSITION, g_lightPos);
	glLightfv(GL_LIGHT0, GL_AMBIENT, g_ambientLight);	
	glPushMatrix();
	glPushAttrib(GL_CURRENT_BIT);
	glColor3f(0.0, 0.5,0.8);
	glTranslatef(g_xRot, g_yRot, 4);//物体位置
	glutSolidSphere(0.3, 20, 20);
	glPopMatrix();
	glPopAttrib();
}void display()
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);	//设置观察点
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(60, 1, 0.1, 500);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	gluLookAt(g_cameraX,g_cameraY,g_cameraZ, 0, 0, 0, 0, 1, 0);
	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);
	glBegin(GL_QUADS);
	//前面
	glTexCoord2f(0.0f, 0.0f); glVertex3f(-2.0f, -2.0f, 1.0f);	// 纹理和四边形的左下
	glTexCoord2f(1.0f, 0.0f); glVertex3f(2.0f, -2.0f, 1.0f);	// 纹理和四边形的右下
	glTexCoord2f(1.0f, 1.0f); glVertex3f(2.0f, 2.0f, 1.0f);	    // 纹理和四边形的右上
	glTexCoord2f(0.0f, 1.0f); glVertex3f(-2.0f, 2.0f, 1.0f);	// 纹理和四边形的左上
	glEnd();
	glDisable(GL_TEXTURE_2D);
	glPopMatrix();
	glPopAttrib();	/*绘制光源体*/	glPushMatrix();
	glTranslatef(g_lightPos[0], g_lightPos[1], g_lightPos[2]);
	glColor3f(1.0, 1.0, 1.0);
	glutSolidSphere(0.1f, 20, 20);
	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();	glutSwapBuffers();
}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': g_cameraX += 1.0; glutPostRedisplay(); break;
	case 'd': g_cameraX -= 1.0; glutPostRedisplay(); break; 
	default:break;	}
}void SpecialKeys(int key, int x, int y)
{
	if (key == GLUT_KEY_UP)
		g_yRot += 0.1f;
	if (key == GLUT_KEY_DOWN)
		g_yRot -= 0.1f;
	if (key == GLUT_KEY_LEFT)
		g_xRot -= 0.1f;
	if (key == GLUT_KEY_RIGHT)
		g_xRot += 0.1f;
		// Refresh the Window
	glutPostRedisplay();
}int main(int argc, char** argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_STENCIL | GLUT_DEPTH);
	glutInitWindowSize(1376, 768);
	glutInitWindowPosition(0, 0);
	glutCreateWindow("镜面反射");
	init();
	glutDisplayFunc(display);
	//glutReshapeFunc(reshape);
	glutKeyboardFunc(NormalKeys);
	glutSpecialFunc(SpecialKeys);
	glutMainLoop();
	return 0;
}

镜面反射实现的结果截图：