#include?
#include?“Camera.h“
//-----------------------------------------------------------------------------
Camera::Camera（?void?）
{
????m_Pos.Set（?0.0f?0.0f?0.0f?）;??????//?我默認在原點
????m_Forward.Set（?0.0f?0.0f?-1.0f?）;?//?我向Z軸負半軸看
????m_Upward.Set（?0.0f?1.0f?0.0f?）;???//?Y軸正半軸是上
}
//-----------------------------------------------------------------------------
void?Camera::SetPos（?const?Point3F&?pos?）
{
????m_Pos?=?pos;
}
//-----------------------------------------------------------------------------
void?Camera::SetForward（const?Vector3F&?forward?）
{
????m_Forward?=?forward;
}
//-----------------------------------------------------------------------------
void?Camera::SetUpward（?const?Vector3F&?upward?）
{
????m_Upward?=?upward;
}
//-----------------------------------------------------------------------------
void?Camera::MoveForward（?const?float?step?）
{
????m_Pos?+=?m_Forward?*?step;
}
//-----------------------------------------------------------------------------
void?Camera::Apply（?void?）
{
????//?默認是自己建立一個矩陣并且設置的，但是glu提供的函數(shù)會更快。
????//?不過為了學習有關矩陣的知識，還是使用自己的變換吧
????float?matrix[16];

????//?首先獲取照相機觀察和向上向量生成的矩陣
????Vector3F?x?&y?=?m_Upward?z;
????z?=?-m_Forward;
????CrossProduct（?&x?y?z?）;
#define?MATRIX（?row?col?）?matrix[?row?*?4?+?col?]//?臨時定義的宏
????MATRIX（?0?0?）?=?x.m[0];
????MATRIX（?1?0?）?=?x.m[1];
????MATRIX（?2?0?）?=?x.m[2];
????MATRIX（?3?0?）?=?0.0f;
????MATRIX（?0?1?）?=?y.m[0];
????MATRIX（?1?1?）?=?y.m[1];
????MATRIX（?2?1?）?=?y.m[2];
????MATRIX（?3?1?）?=?0.0f;
????MATRIX（?0?2?）?=?z.m[0];
????MATRIX（?1?2?）?=?z.m[1];
????MATRIX（?2?2?）?=?z.m[2];
????MATRIX（?3?2?）?=?0.0f;
????MATRIX（?0?3?）?=?0.0f;
????MATRIX（?1?3?）?=?0.0f;
????MATRIX（?2?3?）?=?0.0f;
????MATRIX（?3?3?）?=?1.0f;
#undef?MATRIX

????//?設置矩陣
????glMultMatrixf（?matrix?）;

????//?移動模型視圖矩陣
????glTranslatef（?-m_Pos.x?-m_Pos.y?-m_Pos.z?）;
}
//-----------------------------------------------------------------------------
void?Camera::RotateX（?float?angleInRadius?）
{
????//?X軸（所謂的）是由向上向量（Y軸）和向前向量（Z軸）叉積得到的
????Vector3F?vecX;
????CrossProduct（?&vecX?m_Upward?m_Forward?）;

????float?rotMatrix[16];
????RotationMatrix（?rotMatrix?vecX?angleInRadius?）;//?計算旋轉矩陣

????//?更新向前的向量和向上的向量，將矩陣的3x3部分和向前和向上的向量相乘
????Vector3F?tmpVec;
????tmpVec.Set（?rotMatrix[0]?*?m_Forward.x?+?rotMatrix[4]?*?m_Forward.y?+?rotMatrix[8]?*?m_Forward.z
????????????rotMatrix[1]?*?m_Forward.x?+?rotMatrix[5]?*?m_Forward.y?+?rotMatrix[9]?*?m_Forward.z
????????????rotMatrix[2]?*?m_Forward.x?+?rotMatrix[6]?*?m_Forward.y?+?rotMatrix[10]?*?m_Forward.z?）;
????m_Forward?=?tmpVec;

????tmpVec.Set（?rotMatrix[0]?*?m_Upward.x?+?rotMatrix[4]?*?m_Upward.y?+?rotMatrix[8]?*?m_Upward.z
????????????rotMatrix[1]?*?m_Upward.x?+?rotMatrix[5]?*?m_Upward.y?+?rotMatrix[9]?*?m_Upward.z
????????????rotMatrix[2]?*?m_Upward.x?+?rotMatrix[6]?*?m_Upward.y?+?rotMatrix[10]?*?m_Upward.z?）;
????m_Upward?=?tmpVec;
}
//-----------------------------------------------------------------------------
void?Camera::RotateY（?floa