www.pudn.com > SkyBox.zip > SkyBody.cpp

//----------------------------------------------------------------------------- 
// 
// @doc 
// 
// @module	SkyBody.cpp - Sky body | 
// 
// This module contains the support for the sky body. 
// 
// Copyright (c) 1999 - Descartes Systems Sciences, Inc. 
// 
// @end 
// 
// $History: DcComEngGenConfigurePage.h $ 
// 
//----------------------------------------------------------------------------- 
 
#include "stdafx.h" 
#include "SkyBody.h" 
#include "../_CoreLib/Matrix.h" 
#include "../_CoreLib/Utility.h" 
#include "RenderGlobals.h" 
 
#ifdef _DEBUG 
#define new DEBUG_NEW 
#undef THIS_FILE 
static char THIS_FILE[] = __FILE__; 
#endif 
 
// 
// Force all render code into own seg 
// 
 
#pragma code_seg ("renderer_segment") 
 
//----------------------------------------------------------------------------- 
// 
// @mfunc  constructor. 
// 
// @rdesc None. 
// 
//----------------------------------------------------------------------------- 
 
CSkyBody::CSkyBody ()  
{ 
	// 
	// Initialize 
	// 
} 
 
//----------------------------------------------------------------------------- 
// 
// @mfunc  destructor. 
// 
// @rdesc None. 
// 
//----------------------------------------------------------------------------- 
 
CSkyBody::~CSkyBody ()  
{ 
	// 
	// Rundown 
	// 
} 
 
//----------------------------------------------------------------------------- 
// 
// @mfunc Create the sky body 
// 
// @parm _Type | nType | Type of sky body 
// 
// @parm const char * | pszTexture | Name of the texture 
// 
// @parm float | fN | Longitude of the ascending node 
// 
// @parm float | fi | Incliation to the ecliptic 
// 
// @parm float | fw | Argument of perihelion 
// 
// @parm float | fa | Mean distance 
// 
// @parm float | fe | Eccentricity (0=circle, 0-1=ellipse, 1=parabole) 
// 
// @parm float | fM | Mean anomaly (0 at perihelion) 
// 
// @parm float | fdM | Mean anomaly adjust factor for days 
// 
// @parm float | fRadius | Radius of the object 
// 
// @parm const CVector3 & | vDayColor | Color of the clouds during the day 
// 
// @parm const CVector3 & | vNightColor | Color of the clouds during the night 
// 
// @rdesc None. 
// 
//----------------------------------------------------------------------------- 
 
void CSkyBody::Create (_Type nType, const char *pszTexture, float fN,  
	float fi, float fw, float fa, float fe, float fM, float fdM, 
	float fRadius, const CVector3 &vDayColor, const CVector3 &vNightColor)  
{ 
 
	// 
	// Initialize the variables 
	// 
 
	m_nType = nType; 
	m_fN = fN; 
	m_fi = fi; 
	m_fw = fw; 
	m_fa = fa; 
	m_fe = fe; 
	m_fM = fM; 
	m_fdM = fdM; 
	m_fRadius = fRadius; 
	m_strTexture = pszTexture; 
	m_vBaseDayColor = vDayColor; 
	m_vBaseNightColor = vNightColor; 
} 
 
//----------------------------------------------------------------------------- 
// 
// @mfunc Compute the position of the sky body 
// 
// @parm float | fTimeInDays | The current time in days 
// 
// @rdesc None. 
// 
//----------------------------------------------------------------------------- 
 
void CSkyBody::ComputePosition (float fTimeInDays) 
{ 
 
	// 
	// Compute the radian values of the settings 
	// 
 
	float M = (m_fM + m_fdM * fTimeInDays) * PI / 180.0f; 
	float e = m_fe * PI / 180.0f; 
	float N = m_fN * PI / 180.0f; 
	float w = m_fw * PI / 180.0f; 
	float i = m_fi * PI / 180.0f; 
	float a = m_fa; 
 
	// 
	// Compute the eccentric anomaly 
	// 
 
	float E = M + e * sin (M) * (1.0f + e * cos (M)); 
 
	// 
	// Compute the distance r and the true anomaly v 
	// 
 
	float xv = a * (cos (E) - e); 
	float yv = a * (sqrt (1.0 - e * e) * sin (E)); 
	float r = sqrt (xv * xv + yv * yv); 
	float v; 
	if (xv > 0.0) 
		v = atan (yv / xv); 
	else if (xv < 0.0) 
		v = atan (yv / xv) + PI; 
	else if (yv < 0.0) 
		v = -90; 
	else 
		v = 90; 
 
	// 
	// Compute the position in 3d space 
	// 
 
	CVector3 vDir; 
	vDir .m_x = r * (cos (N) * cos (v+w) - sin (N) * sin (v+w) * cos (i)); 
	vDir .m_y = r * (sin (N) * cos (v+w) + cos (N) * sin (v+w) * cos (i)); 
	vDir .m_z = r * (sin (v + w) * sin (i)); 
 
	// 
	// Rotate the position by the time of day 
	// 
 
	float fDays = floor (fTimeInDays); 
	float fRotation = (fTimeInDays - fDays) * 360.0f; 
	CMatrix m; 
	m .MakeRotation (fRotation, 0, 0, 1); 
	m .PreMultiply (vDir, vDir); 
 
	// 
	// Save the position 
	// 
 
	SetPosition (CVector3 (vDir .m_x, vDir .m_z, vDir .m_y)); 
} 
 
//----------------------------------------------------------------------------- 
// 
// @mfunc Compute the color of the sky body 
// 
// @parm float | fDayFactor | Factor of the day.  0 = night, 1 = day 
// 
// @rdesc None. 
// 
//----------------------------------------------------------------------------- 
 
void CSkyBody::ComputeColor (float fDayFactor) 
{ 
 
	// 
	// Set the day color 
	// 
 
	CVector3 vDelta = m_vBaseDayColor - m_vBaseNightColor; 
	m_vCurrentColor = m_vBaseNightColor + vDelta * fDayFactor; 
} 
 
//----------------------------------------------------------------------------- 
// 
// @mfunc Prepare a sky body 
// 
//		Prepare a sky body. 
// 
// @rdesc None. 
// 
//----------------------------------------------------------------------------- 
 
void CSkyBody::Prep () 
{ 
 
	// 
	// Load the texture 
	// 
 
	const char *pszTexture = GetTextureName (); 
	SetTextureIndex (g_sTextureManager .FindNormalN (pszTexture)); 
 
	// 
	// If a moon, create a mask texture 
	// 
 
	if (GetType () == Type_Moon) 
	{ 
		SetMaskTextureIndex (g_sTextureManager .FindMaskN (pszTexture)); 
	} 
}