UPBGE: Simplify bullet occlusion.

The bullet occlusion and culling call was simplified by avoiding passing extra
arguments. The number of planes is statically set to 6, the modelview and projection
are replaced by the matrix from the camera frustum as this matrix is the result
of the same operation made in CullingTest.

In the same time the plane reordering is removed in favor of a reorder in SG_Frustum.

Author: panzergame

source/gameengine/Ketsji/KX_Scene.cpp

@@ -1321,6 +1321,8 @@ void KX_Scene::CalculateVisibleMeshes(KX_CullingNodeList& nodes, KX_Camera *cam,
 		return;
 	}
 
+	const SG_Frustum& frustum = cam->GetFrustum();
+
 	bool dbvt_culling = false;
 	if (m_dbvt_culling) {
 		/* Reset KX_GameObject m_bCulled to true before doing culling
@@ -1333,23 +1335,15 @@ void KX_Scene::CalculateVisibleMeshes(KX_CullingNodeList& nodes, KX_Camera *cam,
 
 		// test culling through Bullet
 		// get the clip planes
-		const std::array<MT_Vector4, 6>& cplanes = cam->GetFrustum().GetPlanes();
-		// and convert
-		MT_Vector4 planes[6] = {cplanes[4], cplanes[5], cplanes[0], cplanes[1], cplanes[2], cplanes[3]};
-
+		const std::array<MT_Vector4, 6>& planes = frustum.GetPlanes();
+		const MT_Matrix4x4& matrix = frustum.GetMatrix();
+		const int *viewport = KX_GetActiveEngine()->GetCanvas()->GetViewPort();
 		CullingInfo info(layer, nodes);
 
-		float mvmat[16] = {0.0f};
-		cam->GetModelviewMatrix().getValue(mvmat);
-		float pmat[16] = {0.0f};
-		cam->GetProjectionMatrix().getValue(pmat);
-
-		dbvt_culling = m_physicsEnvironment->CullingTest(PhysicsCullingCallback,&info,planes,6,m_dbvt_occlusion_res,
-		                                                 KX_GetActiveEngine()->GetCanvas()->GetViewPort(),
-		                                                 mvmat, pmat);
+		dbvt_culling = m_physicsEnvironment->CullingTest(PhysicsCullingCallback, &info, planes, m_dbvt_occlusion_res, viewport, matrix);
 	}
 	if (!dbvt_culling) {
-		KX_CullingHandler handler(nodes, cam->GetFrustum());
+		KX_CullingHandler handler(nodes, frustum);
 		for (KX_GameObject *gameobj : m_objectlist) {
 			if (gameobj->UseCulling() && gameobj->GetVisible() && (layer == 0 || gameobj->GetLayer() & layer)) {
 				handler.Process(gameobj->GetCullingNode());

source/gameengine/Physics/Bullet/CcdPhysicsEnvironment.cpp

@@ -1362,7 +1362,7 @@ struct OcclusionBuffer {
 		m[15] = btScalar(m1[3] * m2[12] + m1[7] * m2[13] + m1[11] * m2[14] + m1[15] * m2[15]);
 	}
 
-	void setup(int size, const int *view, float modelview[16], float projection[16])
+	void setup(int size, const int *view, float mat[16])
 	{
 		m_initialized = false;
 		m_occlusion = false;
@@ -1381,7 +1381,9 @@ struct OcclusionBuffer {
 		// at this time of the rendering, the modelview matrix is the
 		// world to camera transformation and the projection matrix is
 		// camera to clip transformation. combine both so that
-		CMmat4mul(m_wtc, projection, modelview);
+		for (unsigned short i = 0; i < 16; i++) {
+			m_wtc[i] = btScalar(mat[i]);
+		}
 	}
 
 	void initialize()
@@ -1897,30 +1899,31 @@ struct  DbvtCullingCallback : btDbvt::ICollide {
 };
 
 static OcclusionBuffer gOcb;
-bool CcdPhysicsEnvironment::CullingTest(PHY_CullingCallback callback, void *userData, MT_Vector4 *planes, int nplanes, int occlusionRes, const int *viewport, float modelview[16], float projection[16])
+bool CcdPhysicsEnvironment::CullingTest(PHY_CullingCallback callback, void *userData, const std::array<MT_Vector4, 6>& planes,
+										int occlusionRes, const int *viewport, const MT_Matrix4x4& matrix)
 {
 	if (!m_cullingTree)
 		return false;
 	DbvtCullingCallback dispatcher(callback, userData);
 	btVector3 planes_n[6];
 	btScalar planes_o[6];
-	if (nplanes > 6)
-		nplanes = 6;
-	for (int i = 0; i < nplanes; i++) {
+	for (int i = 0; i < 6; i++) {
 		planes_n[i] = ToBullet(planes[i]);
 		planes_o[i] = planes[i][3];
 	}
 	// if occlusionRes != 0 => occlusion culling
 	if (occlusionRes) {
-		gOcb.setup(occlusionRes, viewport, modelview, projection);
+		float mat[16];
+		matrix.getValue(mat);
+		gOcb.setup(occlusionRes, viewport, mat);
 		dispatcher.m_ocb = &gOcb;
 		// occlusion culling, the direction of the view is taken from the first plan which MUST be the near plane
-		btDbvt::collideOCL(m_cullingTree->m_sets[1].m_root, planes_n, planes_o, planes_n[0], nplanes, dispatcher);
-		btDbvt::collideOCL(m_cullingTree->m_sets[0].m_root, planes_n, planes_o, planes_n[0], nplanes, dispatcher);
+		btDbvt::collideOCL(m_cullingTree->m_sets[1].m_root, planes_n, planes_o, planes_n[0], 6, dispatcher);
+		btDbvt::collideOCL(m_cullingTree->m_sets[0].m_root, planes_n, planes_o, planes_n[0], 6, dispatcher);
 	}
 	else {
-		btDbvt::collideKDOP(m_cullingTree->m_sets[1].m_root, planes_n, planes_o, nplanes, dispatcher);
-		btDbvt::collideKDOP(m_cullingTree->m_sets[0].m_root, planes_n, planes_o, nplanes, dispatcher);
+		btDbvt::collideKDOP(m_cullingTree->m_sets[1].m_root, planes_n, planes_o, 6, dispatcher);
+		btDbvt::collideKDOP(m_cullingTree->m_sets[0].m_root, planes_n, planes_o, 6, dispatcher);
 	}
 	return true;
 }

source/gameengine/Physics/Bullet/CcdPhysicsEnvironment.h

@@ -187,7 +187,8 @@ class CcdPhysicsEnvironment : public PHY_IPhysicsEnvironment
 	btTypedConstraint *GetConstraintById(int constraintId);
 
 	virtual PHY_IPhysicsController *RayTest(PHY_IRayCastFilterCallback &filterCallback, float fromX, float fromY, float fromZ, float toX, float toY, float toZ);
-	virtual bool CullingTest(PHY_CullingCallback callback, void *userData, MT_Vector4 * planes, int nplanes, int occlusionRes, const int *viewport, float modelview[16], float projection[16]);
+	virtual bool CullingTest(PHY_CullingCallback callback, void *userData, const std::array<MT_Vector4, 6>& planes,
+							 int occlusionRes, const int *viewport, const MT_Matrix4x4& matrix);
 
 
 	//Methods for gamelogic collision/physics callbacks

source/gameengine/Physics/Common/PHY_IPhysicsEnvironment.h

@@ -33,10 +33,13 @@
 #define __PHY_IPHYSICSENVIRONMENT_H__
 
 #include "PHY_DynamicTypes.h"
+#include "MT_Matrix4x4.h"
 #include "MT_Vector2.h"
 #include "MT_Vector3.h"
 #include "MT_Vector4.h"
 
+#include <array>
+
 class PHY_IConstraint;
 class PHY_IVehicle;
 class PHY_ICharacter;
@@ -209,7 +212,8 @@ class PHY_IPhysicsEnvironment
 	// culling based on physical broad phase
 	// the plane number must be set as follow: near, far, left, right, top, botton
 	// the near plane must be the first one and must always be present, it is used to get the direction of the view
-	virtual bool CullingTest(PHY_CullingCallback callback, void *userData, MT_Vector4 * planeNormals, int planeNumber, int occlusionRes, const int *viewport, float modelview[16], float projection[16]) = 0;
+	virtual bool CullingTest(PHY_CullingCallback callback, void *userData, const std::array<MT_Vector4, 6>& planes,
+							 int occlusionRes, const int *viewport, const MT_Matrix4x4& matrix) = 0;
 
 	// Methods for gamelogic collision/physics callbacks
 	virtual void AddSensor(PHY_IPhysicsController *ctrl) = 0;

source/gameengine/Physics/Dummy/DummyPhysicsEnvironment.h

@@ -82,7 +82,8 @@ class DummyPhysicsEnvironment : public PHY_IPhysicsEnvironment
 	}
 
 	virtual PHY_IPhysicsController *RayTest(PHY_IRayCastFilterCallback &filterCallback, float fromX, float fromY, float fromZ, float toX, float toY, float toZ);
-	virtual bool CullingTest(PHY_CullingCallback callback, void *userData, class MT_Vector4 *planes, int nplanes, int occlusionRes, const int *viewport, float modelview[16], float projection[16])
+	virtual bool CullingTest(PHY_CullingCallback callback, void *userData, const std::array<MT_Vector4, 6>& planes,
+							 int occlusionRes, const int *viewport, const MT_Matrix4x4& matrix)
 	{
 		return false;
 	}

source/gameengine/SceneGraph/SG_Frustum.cpp

@@ -5,18 +5,18 @@
 SG_Frustum::SG_Frustum(const MT_Matrix4x4& matrix)
 	:m_matrix(matrix)
 {
+	// Near clip plane
+	m_planes[0] = m_matrix[3] + m_matrix[2];
+	// Far clip plane
+	m_planes[1] = m_matrix[3] - m_matrix[2];
 	// Left clip plane
-	m_planes[0] = m_matrix[3] + m_matrix[0];
+	m_planes[2] = m_matrix[3] + m_matrix[0];
 	// Right clip plane
-	m_planes[1] = m_matrix[3] - m_matrix[0];
+	m_planes[3] = m_matrix[3] - m_matrix[0];
 	// Top clip plane
-	m_planes[2] = m_matrix[3] - m_matrix[1];
+	m_planes[4] = m_matrix[3] - m_matrix[1];
 	// Bottom clip plane
-	m_planes[3] = m_matrix[3] + m_matrix[1];
-	// Near clip plane
-	m_planes[4] = m_matrix[3] + m_matrix[2];
-	// Far clip plane
-	m_planes[5] = m_matrix[3] - m_matrix[2];
+	m_planes[5] = m_matrix[3] + m_matrix[1];
 
 	// Normalize clip planes.
 	for (MT_Vector4& plane : m_planes) {
@@ -32,6 +32,11 @@ const std::array<MT_Vector4, 6>& SG_Frustum::GetPlanes() const
 	return m_planes;
 }
 
+const MT_Matrix4x4& SG_Frustum::GetMatrix() const
+{
+	return m_matrix;
+}
+
 SG_Frustum::TestType SG_Frustum::PointInsideFrustum(const MT_Vector3& point) const
 {
 	for (const MT_Vector4& plane : m_planes) {

source/gameengine/SceneGraph/SG_Frustum.h

@@ -27,6 +27,7 @@ class SG_Frustum
 	~SG_Frustum() = default;
 
 	const std::array<MT_Vector4, 6>& GetPlanes() const;
+	const MT_Matrix4x4& GetMatrix() const;
 
 	TestType PointInsideFrustum(const MT_Vector3& point) const;
 	TestType SphereInsideFrustum(const MT_Vector3& center, float radius) const;