glOrtho和glFrustumf相關參數計算

glOrtho和glFrustumf相關參數計算

 

最近在看Android的OpenGL ES，所以撰寫了這個程式，歡迎有興趣的同好，一起來C/P一下。

 

#include <iostream> #include <cmath> using namespace std; //////////////////////////////////// double ToRadians (double d);//度轉徑度 double ToDegrees (double r);//徑度轉度 float g_fltWidth=640;//螢幕寬度 float g_fltHight=480;//螢幕��度 float g_fltAspectRatio;//寬��比 float g_fltFieldOfView = 45.0; //視野角度 float g_fltNear = 0.1; //近端 float g_fltFar = 1000; //遠端 float g_fltSize;//glFrustumf函數參數 float g_fltOrthoRange = 420.0f;//空間大小 /////////////////////////////////// double ToRadians (double d)//度轉徑度 { return d * M_PI / 180; } double ToDegrees (double r)//徑度轉度 { return r * 180/ M_PI; } int main() { ////////////////////////////// if(g_fltWidth>g_fltHight) { g_fltAspectRatio=g_fltWidth/g_fltHight; } else { g_fltAspectRatio=g_fltHight/g_fltWidth; } /////////////////////////////// g_fltSize=g_fltNear * tanf(ToRadians(g_fltFieldOfView ) / 2.0); cout <<"Width="<<g_fltWidth<< endl; cout<<"Hight="<<g_fltHight<< endl; cout<<"Aspect Ratio="<<g_fltAspectRatio<< endl; cout<<"Field Of View="<<g_fltFieldOfView<<" Degrees"<<endl; cout<<"glFrustumf Near="<<g_fltNear<< endl; cout<<"glFrustumf Far="<<g_fltFar<< endl; cout<<"glFrustumf Left="<<-1*g_fltSize<< endl; cout<<"glFrustumf Right="<<g_fltSize<< endl; cout<<"glFrustumf Bottom="<<-1*g_fltSize/g_fltAspectRatio<< endl; cout<<"glFrustumf Top="<<g_fltSize/g_fltAspectRatio<< endl; //glFrustumf(-g_fltSize, g_fltSize, -g_fltSize/g_fltAspectRatio, g_fltSize/g_fltAspectRatio, g_fltNear, g_fltFar); cout<<"glOrtho Range"<<g_fltOrthoRange<< endl; cout<<"glOrtho Near="<<-1*g_fltOrthoRange*2<< endl; cout<<"glOrtho Far="<<g_fltOrthoRange*2<< endl; cout<<"glOrtho Left="<<-1*g_fltOrthoRange<< endl; cout<<"glOrtho Right="<<g_fltOrthoRange<< endl; cout<<"glOrtho Bottom="<<-1*g_fltOrthoRange*g_fltAspectRatio<< endl; cout<<"glOrtho Top="<<g_fltOrthoRange*g_fltAspectRatio<< endl; //void glOrtho(left,right,bottom,top,nearVal,farVal); /*     if (w <= h) glOrtho (-nRange, nRange, -nRange*h/w, nRange*h/w, -nRange*2, nRange*2);     else glOrtho (-nRange*w/h, nRange*w/h, -nRange, nRange, -nRange*2, nRange*2);     */ cout << "Hello world!" << endl; return 0; }