?? frustum.cpp
字號:
#include "Frustum.h"
#define FIRST_OBJECT_ID 3
enum FrustumSide
{
RIGHT = 0, // 右平面
LEFT = 1, // 左平面
BOTTOM = 2, // 底平面
TOP = 3, // 頂平面
BACK = 4, // 后平面
FRONT = 5 // 前平面
};
enum PlaneData
{
A = 0, //（A，B，C）分別為平面法向量
B = 1,
C = 2,
D = 3
};
void NormalizePlane(float frustum[6][4], int side)
{
float magnitude = (float)sqrt( frustum[side][A] * frustum[side][A] +
frustum[side][B] * frustum[side][B] +
frustum[side][C] * frustum[side][C] );
frustum[side][A] /= magnitude;
frustum[side][B] /= magnitude;
frustum[side][C] /= magnitude;
frustum[side][D] /= magnitude;
}
/** 從模型矩陣和投影矩陣計算平頭體 */
void CFrustum::CalculateFrustum()
{
float proj[16];
float modl[16];
float clip[16];
/** 獲得當前模型矩陣和投影矩陣 */
glGetFloatv( GL_PROJECTION_MATRIX, proj );
glGetFloatv( GL_MODELVIEW_MATRIX, modl );
clip[ 0] = modl[ 0] * proj[ 0] + modl[ 1] * proj[ 4] + modl[ 2] * proj[ 8] + modl[ 3] * proj[12];
clip[ 1] = modl[ 0] * proj[ 1] + modl[ 1] * proj[ 5] + modl[ 2] * proj[ 9] + modl[ 3] * proj[13];
clip[ 2] = modl[ 0] * proj[ 2] + modl[ 1] * proj[ 6] + modl[ 2] * proj[10] + modl[ 3] * proj[14];
clip[ 3] = modl[ 0] * proj[ 3] + modl[ 1] * proj[ 7] + modl[ 2] * proj[11] + modl[ 3] * proj[15];
clip[ 4] = modl[ 4] * proj[ 0] + modl[ 5] * proj[ 4] + modl[ 6] * proj[ 8] + modl[ 7] * proj[12];
clip[ 5] = modl[ 4] * proj[ 1] + modl[ 5] * proj[ 5] + modl[ 6] * proj[ 9] + modl[ 7] * proj[13];
clip[ 6] = modl[ 4] * proj[ 2] + modl[ 5] * proj[ 6] + modl[ 6] * proj[10] + modl[ 7] * proj[14];
clip[ 7] = modl[ 4] * proj[ 3] + modl[ 5] * proj[ 7] + modl[ 6] * proj[11] + modl[ 7] * proj[15];
clip[ 8] = modl[ 8] * proj[ 0] + modl[ 9] * proj[ 4] + modl[10] * proj[ 8] + modl[11] * proj[12];
clip[ 9] = modl[ 8] * proj[ 1] + modl[ 9] * proj[ 5] + modl[10] * proj[ 9] + modl[11] * proj[13];
clip[10] = modl[ 8] * proj[ 2] + modl[ 9] * proj[ 6] + modl[10] * proj[10] + modl[11] * proj[14];
clip[11] = modl[ 8] * proj[ 3] + modl[ 9] * proj[ 7] + modl[10] * proj[11] + modl[11] * proj[15];
clip[12] = modl[12] * proj[ 0] + modl[13] * proj[ 4] + modl[14] * proj[ 8] + modl[15] * proj[12];
clip[13] = modl[12] * proj[ 1] + modl[13] * proj[ 5] + modl[14] * proj[ 9] + modl[15] * proj[13];
clip[14] = modl[12] * proj[ 2] + modl[13] * proj[ 6] + modl[14] * proj[10] + modl[15] * proj[14];
clip[15] = modl[12] * proj[ 3] + modl[13] * proj[ 7] + modl[14] * proj[11] + modl[15] * proj[15];
m_Frustum[RIGHT][A] = clip[ 3] - clip[ 0];
m_Frustum[RIGHT][B] = clip[ 7] - clip[ 4];
m_Frustum[RIGHT][C] = clip[11] - clip[ 8];
m_Frustum[RIGHT][D] = clip[15] - clip[12];
NormalizePlane(m_Frustum, RIGHT);
/** 左平面 */
m_Frustum[LEFT][A] = clip[ 3] + clip[ 0];
m_Frustum[LEFT][B] = clip[ 7] + clip[ 4];
m_Frustum[LEFT][C] = clip[11] + clip[ 8];
m_Frustum[LEFT][D] = clip[15] + clip[12];
NormalizePlane(m_Frustum, LEFT);
/** 底平面 */
m_Frustum[BOTTOM][A] = clip[ 3] + clip[ 1];
m_Frustum[BOTTOM][B] = clip[ 7] + clip[ 5];
m_Frustum[BOTTOM][C] = clip[11] + clip[ 9];
m_Frustum[BOTTOM][D] = clip[15] + clip[13];
NormalizePlane(m_Frustum, BOTTOM);
/** 頂平面 */
m_Frustum[TOP][A] = clip[ 3] - clip[ 1];
m_Frustum[TOP][B] = clip[ 7] - clip[ 5];
m_Frustum[TOP][C] = clip[11] - clip[ 9];
m_Frustum[TOP][D] = clip[15] - clip[13];
NormalizePlane(m_Frustum, TOP);
/** 后平面 */
m_Frustum[BACK][A] = clip[ 3] - clip[ 2];
m_Frustum[BACK][B] = clip[ 7] - clip[ 6];
m_Frustum[BACK][C] = clip[11] - clip[10];
m_Frustum[BACK][D] = clip[15] - clip[14];
NormalizePlane(m_Frustum, BACK);
/** 前平面 */
m_Frustum[FRONT][A] = clip[ 3] + clip[ 2];
m_Frustum[FRONT][B] = clip[ 7] + clip[ 6];
m_Frustum[FRONT][C] = clip[11] + clip[10];
m_Frustum[FRONT][D] = clip[15] + clip[14];
NormalizePlane(m_Frustum, FRONT);
}
bool CFrustum::PointInFrustum( float x, float y, float z )
{
for(int i = 0; i < 6; i++ )
{
if(m_Frustum[i][A] * x + m_Frustum[i][B] * y + m_Frustum[i][C] * z + m_Frustum[i][D] <= 0)
{
return false;
}
}
return true;
}
bool CFrustum::SphereInFrustum( float x, float y, float z, float radius )
{
for(int i = 0; i < 6; i++ )
{
if( m_Frustum[i][A] * x + m_Frustum[i][B] * y + m_Frustum[i][C] * z + m_Frustum[i][D] <= -radius )
{
return false;
}
}
return true;
}
bool CFrustum::CubeInFrustum( float x, float y, float z, float size )
{
for(int i = 0; i < 6; i++ )
{
if(m_Frustum[i][A] * (x - size) + m_Frustum[i][B] * (y - size) + m_Frustum[i][C] * (z - size) + m_Frustum[i][D] > 0)
continue;
if(m_Frustum[i][A] * (x + size) + m_Frustum[i][B] * (y - size) + m_Frustum[i][C] * (z - size) + m_Frustum[i][D] > 0)
continue;
if(m_Frustum[i][A] * (x - size) + m_Frustum[i][B] * (y + size) + m_Frustum[i][C] * (z - size) + m_Frustum[i][D] > 0)
continue;
if(m_Frustum[i][A] * (x + size) + m_Frustum[i][B] * (y + size) + m_Frustum[i][C] * (z - size) + m_Frustum[i][D] > 0)
continue;
if(m_Frustum[i][A] * (x - size) + m_Frustum[i][B] * (y - size) + m_Frustum[i][C] * (z + size) + m_Frustum[i][D] > 0)
continue;
if(m_Frustum[i][A] * (x + size) + m_Frustum[i][B] * (y - size) + m_Frustum[i][C] * (z + size) + m_Frustum[i][D] > 0)
continue;
if(m_Frustum[i][A] * (x - size) + m_Frustum[i][B] * (y + size) + m_Frustum[i][C] * (z + size) + m_Frustum[i][D] > 0)
continue;
if(m_Frustum[i][A] * (x + size) + m_Frustum[i][B] * (y + size) + m_Frustum[i][C] * (z + size) + m_Frustum[i][D] > 0)
continue;
return false;
}
return true;
}
bool CFrustum::BoxInFrustum( float x, float y, float z, float x2, float y2, float z2)
{
for(int i = 0; i < 6; i++ )
{
if(m_Frustum[i][A] * x + m_Frustum[i][B] * y + m_Frustum[i][C] * z + m_Frustum[i][D] > 0) continue;
if(m_Frustum[i][A] * x2 + m_Frustum[i][B] * y + m_Frustum[i][C] * z + m_Frustum[i][D] > 0) continue;
if(m_Frustum[i][A] * x + m_Frustum[i][B] * y2 + m_Frustum[i][C] * z + m_Frustum[i][D] > 0) continue;
if(m_Frustum[i][A] * x2 + m_Frustum[i][B] * y2 + m_Frustum[i][C] * z + m_Frustum[i][D] > 0) continue;
if(m_Frustum[i][A] * x + m_Frustum[i][B] * y + m_Frustum[i][C] * z2 + m_Frustum[i][D] > 0) continue;
if(m_Frustum[i][A] * x2 + m_Frustum[i][B] * y + m_Frustum[i][C] * z2 + m_Frustum[i][D] > 0) continue;
if(m_Frustum[i][A] * x + m_Frustum[i][B] * y2 + m_Frustum[i][C] * z2 + m_Frustum[i][D] > 0) continue;
if(m_Frustum[i][A] * x2 + m_Frustum[i][B] * y2 + m_Frustum[i][C] * z2 + m_Frustum[i][D] > 0) continue;
return false;
}
return true;
}
void CDebug::RenderDebugLines()
{
glDisable(GL_TEXTURE_2D);
glBegin(GL_LINES);
glColor3ub(255, 255, 0);
for(unsigned int i = 0; i < m_vLines.size(); i++)
{
glVertex3f(m_vLines[i].x, m_vLines[i].y, m_vLines[i].z);
}
glEnd();
}
void CDebug::AddDebugLine(CVector3 vPoint1, CVector3 vPoint2)
{
m_vLines.push_back(vPoint1);
m_vLines.push_back(vPoint2);
}
void CDebug::AddDebugBox(CVector3 vCenter, float width, float height, float depth)
{
width /= 2.0f; height /= 2.0f; depth /= 2.0f;
CVector3 vTopLeftFront( vCenter.x - width, vCenter.y + height, vCenter.z + depth);
CVector3 vTopLeftBack( vCenter.x - width, vCenter.y + height, vCenter.z - depth);
CVector3 vTopRightBack( vCenter.x + width, vCenter.y + height, vCenter.z - depth);
CVector3 vTopRightFront(vCenter.x + width, vCenter.y + height, vCenter.z + depth);
CVector3 vBottom_LeftFront( vCenter.x - width, vCenter.y - height, vCenter.z + depth);
CVector3 vBottom_LeftBack( vCenter.x - width, vCenter.y - height, vCenter.z - depth);
CVector3 vBottomRightBack( vCenter.x + width, vCenter.y - height, vCenter.z - depth);
CVector3 vBottomRightFront(vCenter.x + width, vCenter.y - height, vCenter.z + depth);
m_vLines.push_back(vTopLeftFront); m_vLines.push_back(vTopRightFront);
m_vLines.push_back(vTopLeftBack); m_vLines.push_back(vTopRightBack);
m_vLines.push_back(vTopLeftFront); m_vLines.push_back(vTopLeftBack);
m_vLines.push_back(vTopRightFront); m_vLines.push_back(vTopRightBack);
m_vLines.push_back(vBottom_LeftFront); m_vLines.push_back(vBottomRightFront);
m_vLines.push_back(vBottom_LeftBack); m_vLines.push_back(vBottomRightBack);
m_vLines.push_back(vBottom_LeftFront); m_vLines.push_back(vBottom_LeftBack);
m_vLines.push_back(vBottomRightFront); m_vLines.push_back(vBottomRightBack);
m_vLines.push_back(vTopLeftFront); m_vLines.push_back(vBottom_LeftFront);
m_vLines.push_back(vTopLeftBack); m_vLines.push_back(vBottom_LeftBack);
m_vLines.push_back(vTopRightBack); m_vLines.push_back(vBottomRightBack);
m_vLines.push_back(vTopRightFront); m_vLines.push_back(vBottomRightFront);
}
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