gluPerspective / gluLookat 소스코드

답답해서 뜯어보는중 ㅋㅋ

왜 이런 생각을 안했었지?

 

 

근데 본다고 이해할수 있는건 또 별개의 문제네 ㅋㅋㅋ

#define __glPi 3.14159265358979323846   void GLAPIENTRY gluPerspective(GLdouble fovy, GLdouble aspect, GLdouble zNear, GLdouble zFar) { GLdouble m[4][4]; double sine, cotangent, deltaZ; double radians = fovy / 2 * __glPi / 180;   deltaZ = zFar - zNear; sine = sin(radians); if ((deltaZ == 0) || (sine == 0) || (aspect == 0)) {     return; } cotangent = COS(radians) / sine;   __gluMakeIdentityd(&m[0][0]); m[0][0] = cotangent / aspect; m[1][1] = cotangent; m[2][2] = -(zFar + zNear) / deltaZ; m[2][3] = -1; m[3][2] = -2 * zNear * zFar / deltaZ; m[3][3] = 0; glMultMatrixd(&m[0][0]); }

 

void GLAPIENTRY gluLookAt(GLdouble eyex, GLdouble eyey, GLdouble eyez, GLdouble centerx,      GLdouble centery, GLdouble centerz, GLdouble upx, GLdouble upy,      GLdouble upz) { float forward[3], side[3], up[3]; GLfloat m[4][4];   forward[0] = centerx - eyex; forward[1] = centery - eyey; forward[2] = centerz - eyez;   up[0] = upx; up[1] = upy; up[2] = upz;   normalize(forward);   /* Side = forward x up */ cross(forward, up, side); normalize(side);   /* Recompute up as: up = side x forward */ cross(side, forward, up);   __gluMakeIdentityf(&m[0][0]); m[0][0] = side[0]; m[1][0] = side[1]; m[2][0] = side[2];   m[0][1] = up[0]; m[1][1] = up[1]; m[2][1] = up[2];   m[0][2] = -forward[0]; m[1][2] = -forward[1]; m[2][2] = -forward[2];   glMultMatrixf(&m[0][0]); glTranslated(-eyex, -eyey, -eyez); }