// computes a frustum with given far and near planes
Frustum BaseCamera::CalculateFrustum( float fNear, float fFar )
{
noVec3 vZ = Normalize(m_to - m_from);
noVec3 vX = Normalize(Cross(m_up, vZ));
noVec3 vY = Normalize(Cross(vZ, vX));
float fAspect = GetApp()->GetAspectRatio();
float fNearPlaneHalfHeight = tanf(m_fov * 0.5f) * fNear;
float fNearPlaneHalfWidth = fNearPlaneHalfHeight * fAspect;
float fFarPlaneHalfHeight = tanf(m_fov * 0.5f) * fFar;
float fFarPlaneHalfWidth = fFarPlaneHalfHeight * fAspect;
noVec3 vNearPlaneCenter = m_from + vZ * fNear;
noVec3 vFarPlaneCenter = m_from + vZ * fFar;
Frustum frustum;
frustum.m_pPoints[0] = noVec3(vNearPlaneCenter - vX*fNearPlaneHalfWidth - vY*fNearPlaneHalfHeight);
frustum.m_pPoints[1] = noVec3(vNearPlaneCenter - vX*fNearPlaneHalfWidth + vY*fNearPlaneHalfHeight);
frustum.m_pPoints[2] = noVec3(vNearPlaneCenter + vX*fNearPlaneHalfWidth + vY*fNearPlaneHalfHeight);
frustum.m_pPoints[3] = noVec3(vNearPlaneCenter + vX*fNearPlaneHalfWidth - vY*fNearPlaneHalfHeight);
frustum.m_pPoints[4] = noVec3(vFarPlaneCenter - vX*fFarPlaneHalfWidth - vY*fFarPlaneHalfHeight);
frustum.m_pPoints[5] = noVec3(vFarPlaneCenter - vX*fFarPlaneHalfWidth + vY*fFarPlaneHalfHeight);
frustum.m_pPoints[6] = noVec3(vFarPlaneCenter + vX*fFarPlaneHalfWidth + vY*fFarPlaneHalfHeight);
frustum.m_pPoints[7] = noVec3(vFarPlaneCenter + vX*fFarPlaneHalfWidth - vY*fFarPlaneHalfHeight);
// update frustum AABB
frustum.CalculateAABB();
return frustum;
}
// finds scene objects inside the camera frustum
std::vector<SceneObject *> ShadowCamera::FindReceivers(void)
{
Frustum cameraFrustum = CalculateFrustum(m_fNearMin, m_fFarMax);
cameraFrustum.CalculateAABB();
std::vector<SceneObject *> receivers;
receivers.reserve(g_SceneObjects.size());
for(unsigned int i=0; i<g_SceneObjects.size(); i++)
{
SceneObject *pObject = g_SceneObjects[i];
// intersection test
if(g_iVisibilityTest == VISTEST_ACCURATE) {
// test accurately
if(!IntersectionTest(pObject->m_AABB, cameraFrustum)) continue;
} else if(g_iVisibilityTest == VISTEST_CHEAP) {
// test only with AABB of frustum
if(!IntersectionTest(pObject->m_AABB, cameraFrustum.m_AABB)) continue;
}
receivers.push_back(pObject);
}
return receivers;
}
