738 lines
20 KiB
C++
738 lines
20 KiB
C++
// Copyright (C) 2002-2007 Nikolaus Gebhardt
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// This file is part of the "Irrlicht Engine".
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// For conditions of distribution and use, see copyright notice in irrlicht.h
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#include "CSceneCollisionManager.h"
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#include "ISceneNode.h"
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#include "ICameraSceneNode.h"
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#include "ITriangleSelector.h"
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#include "SViewFrustum.h"
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#include "os.h"
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#include "irrMath.h"
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namespace irr
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{
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namespace scene
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{
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//! constructor
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CSceneCollisionManager::CSceneCollisionManager(ISceneManager* smanager, video::IVideoDriver* driver)
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: SceneManager(smanager), Driver(driver)
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{
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#ifdef _DEBUG
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setDebugName("CSceneCollisionManager");
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#endif
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if (Driver)
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Driver->grab();
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}
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//! destructor
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CSceneCollisionManager::~CSceneCollisionManager()
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{
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if (Driver)
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Driver->drop();
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}
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//! Returns the scene node, which is currently visible under the overgiven
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//! screencoordinates, viewed from the currently active camera.
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ISceneNode* CSceneCollisionManager::getSceneNodeFromScreenCoordinatesBB(
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core::position2d<s32> pos, s32 idBitMask, bool bNoDebugObjects)
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{
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core::line3d<f32> ln = getRayFromScreenCoordinates(pos, 0);
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if ( ln.start == ln.end )
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return 0;
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return getSceneNodeFromRayBB(ln, idBitMask, bNoDebugObjects);
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}
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//! Returns the nearest scene node which collides with a 3d ray and
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//! which id matches a bitmask.
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ISceneNode* CSceneCollisionManager::getSceneNodeFromRayBB(core::line3d<f32> ray,
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s32 idBitMask,
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bool bNoDebugObjects)
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{
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ISceneNode* best = 0;
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f32 dist = 9999999999.0f;
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getPickedNodeBB(SceneManager->getRootSceneNode(), ray,
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idBitMask, bNoDebugObjects, dist, best);
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return best;
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}
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//! recursive method for going through all scene nodes
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void CSceneCollisionManager::getPickedNodeBB(ISceneNode* root,
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const core::line3df& ray,
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s32 bits,
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bool bNoDebugObjects,
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f32& outbestdistance,
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ISceneNode*& outbestnode)
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{
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core::vector3df edges[8];
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const core::list<ISceneNode*>& children = root->getChildren();
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core::list<ISceneNode*>::ConstIterator it = children.begin();
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for (; it != children.end(); ++it)
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{
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ISceneNode* current = *it;
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if (current->isVisible() &&
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(bNoDebugObjects ? !current->isDebugObject() : true) &&
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(bits==0 || (bits != 0 && (current->getID() & bits))))
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{
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// get world to object space transform
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core::matrix4 mat;
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if (!current->getAbsoluteTransformation().getInverse(mat))
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continue;
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// transform vector from world space to object space
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core::line3df line(ray);
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mat.transformVect(line.start);
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mat.transformVect(line.end);
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const core::aabbox3df& box = current->getBoundingBox();
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// do intersection test in object space
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if (box.intersectsWithLine(line))
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{
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box.getEdges(edges);
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f32 distance = 0.0f;
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for (s32 e=0; e<8; ++e)
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{
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f32 t = edges[e].getDistanceFromSQ(line.start);
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if (t > distance)
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distance = t;
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}
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if (distance < outbestdistance)
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{
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outbestnode = current;
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outbestdistance = distance;
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}
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}
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}
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getPickedNodeBB(current, ray, bits, bNoDebugObjects, outbestdistance, outbestnode);
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}
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}
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//! Returns the scene node, at which the overgiven camera is looking at and
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//! which id matches the bitmask.
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ISceneNode* CSceneCollisionManager::getSceneNodeFromCameraBB(
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ICameraSceneNode* camera, s32 idBitMask, bool bNoDebugObjects)
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{
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if (!camera)
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return 0;
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core::vector3df start = camera->getAbsolutePosition();
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core::vector3df end = camera->getTarget();
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end = start + ((end - start).normalize() * camera->getFarValue());
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core::line3d<f32> line(start, end);
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return getSceneNodeFromRayBB(line, idBitMask, bNoDebugObjects);
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}
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//! Finds the collision point of a line and lots of triangles, if there is one.
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bool CSceneCollisionManager::getCollisionPoint(const core::line3d<f32>& ray,
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ITriangleSelector* selector, core::vector3df& outIntersection,
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core::triangle3df& outTriangle)
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{
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if (!selector)
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{
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_IRR_IMPLEMENT_MANAGED_MARSHALLING_BUGFIX;
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return false;
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}
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s32 totalcnt = selector->getTriangleCount();
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Triangles.set_used(totalcnt);
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s32 cnt = 0;
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selector->getTriangles(Triangles.pointer(), totalcnt, cnt, ray);
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const core::vector3df linevect = ray.getVector().normalize();
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core::vector3df intersection;
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f32 nearest = 9999999999999.0f;
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bool found = false;
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const f32 raylength = ray.getLengthSQ();
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for (s32 i=0; i<cnt; ++i)
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{
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if (Triangles[i].getIntersectionWithLine(ray.start, linevect, intersection))
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{
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const f32 tmp = intersection.getDistanceFromSQ(ray.start);
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const f32 tmp2 = intersection.getDistanceFromSQ(ray.end);
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if (tmp < raylength && tmp2 < raylength && tmp < nearest)
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{
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nearest = tmp;
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outTriangle = Triangles[i];
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outIntersection = intersection;
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found = true;
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}
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}
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}
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_IRR_IMPLEMENT_MANAGED_MARSHALLING_BUGFIX;
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return found;
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}
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//! Collides a moving ellipsoid with a 3d world with gravity and returns
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//! the resulting new position of the ellipsoid.
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core::vector3df CSceneCollisionManager::getCollisionResultPosition(
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ITriangleSelector* selector,
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const core::vector3df &position, const core::vector3df& radius,
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const core::vector3df& direction,
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core::triangle3df& triout,
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bool& outFalling,
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f32 slidingSpeed,
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const core::vector3df& gravity)
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{
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if (!selector || radius.X == 0.0f || radius.Y == 0.0f || radius.Z == 0.0f)
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return position;
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return collideEllipsoidWithWorld(selector, position,
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radius, direction, slidingSpeed, gravity, triout, outFalling);
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}
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void CSceneCollisionManager::testTriangleIntersection(SCollisionData* colData,
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const core::triangle3df& triangle)
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{
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const core::plane3d<f32> trianglePlane = triangle.getPlane();
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// only check front facing polygons
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if ( !trianglePlane.isFrontFacing(colData->normalizedVelocity) )
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return;
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// get interval of plane intersection
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f32 t1, t0;
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bool embeddedInPlane = false;
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// calculate signed distance from sphere position to triangle plane
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f32 signedDistToTrianglePlane = trianglePlane.getDistanceTo(
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colData->basePoint);
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f32 normalDotVelocity =
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trianglePlane.Normal.dotProduct(colData->velocity);
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if ( core::iszero ( normalDotVelocity ) )
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{
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// sphere is traveling parallel to plane
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if (fabs(signedDistToTrianglePlane) >= 1.0f)
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return; // no collision possible
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else
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{
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// sphere is embedded in plane
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embeddedInPlane = true;
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t0 = 0.0;
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t1 = 1.0;
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}
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}
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else
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{
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normalDotVelocity = core::reciprocal ( normalDotVelocity );
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// N.D is not 0. Calculate intersection interval
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t0 = (-1.f - signedDistToTrianglePlane) * normalDotVelocity;
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t1 = (1.f - signedDistToTrianglePlane) * normalDotVelocity;
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// Swap so t0 < t1
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if (t0 > t1) { f32 tmp = t1; t1 = t0; t0 = tmp; }
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// check if at least one value is within the range
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if (t0 > 1.0f || t1 < 0.0f)
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return; // both t values are outside 1 and 0, no collision possible
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// clamp to 0 and 1
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t0 = core::clamp ( t0, 0.f, 1.f );
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t1 = core::clamp ( t1, 0.f, 1.f );
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}
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// at this point we have t0 and t1, if there is any intersection, it
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// is between this interval
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core::vector3df collisionPoint;
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bool foundCollision = false;
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f32 t = 1.0f;
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// first check the easy case: Collision within the triangle;
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// if this happens, it must be at t0 and this is when the sphere
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// rests on the front side of the triangle plane. This can only happen
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// if the sphere is not embedded in the triangle plane.
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if (!embeddedInPlane)
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{
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core::vector3df planeIntersectionPoint =
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(colData->basePoint - trianglePlane.Normal)
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+ (colData->velocity * t0);
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if (triangle.isPointInsideFast(planeIntersectionPoint))
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{
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foundCollision = true;
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t = t0;
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collisionPoint = planeIntersectionPoint;
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}
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}
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// if we havent found a collision already we will have to sweep
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// the sphere against points and edges of the triangle. Note: A
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// collision inside the triangle will always happen before a
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// vertex or edge collision.
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if (!foundCollision)
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{
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core::vector3df velocity = colData->velocity;
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core::vector3df base = colData->basePoint;
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f32 velocitySqaredLength = velocity.getLengthSQ();
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f32 a,b,c;
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f32 newT;
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// for each edge or vertex a quadratic equation has to be solved:
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// a*t^2 + b*t + c = 0. We calculate a,b, and c for each test.
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// check against points
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a = velocitySqaredLength;
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// p1
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b = 2.0f * (velocity.dotProduct(base - triangle.pointA));
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c = (triangle.pointA-base).getLengthSQ() - 1.f;
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if (getLowestRoot(a,b,c,t, &newT))
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{
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t = newT;
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foundCollision = true;
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collisionPoint = triangle.pointA;
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}
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// p2
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if (!foundCollision)
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{
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b = 2.0f * (velocity.dotProduct(base - triangle.pointB));
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c = (triangle.pointB-base).getLengthSQ() - 1.f;
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if (getLowestRoot(a,b,c,t, &newT))
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{
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t = newT;
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foundCollision = true;
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collisionPoint = triangle.pointB;
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}
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}
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// p3
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if (!foundCollision)
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{
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b = 2.0f * (velocity.dotProduct(base - triangle.pointC));
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c = (triangle.pointC-base).getLengthSQ() - 1.f;
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if (getLowestRoot(a,b,c,t, &newT))
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{
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t = newT;
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foundCollision = true;
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collisionPoint = triangle.pointC;
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}
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}
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// check against edges:
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// p1 --- p2
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core::vector3df edge = triangle.pointB - triangle.pointA;
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core::vector3df baseToVertex = triangle.pointA - base;
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f32 edgeSqaredLength = edge.getLengthSQ();
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f32 edgeDotVelocity = edge.dotProduct(velocity);
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f32 edgeDotBaseToVertex = edge.dotProduct(baseToVertex);
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// calculate parameters for equation
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a = edgeSqaredLength* -velocitySqaredLength +
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edgeDotVelocity*edgeDotVelocity;
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b = edgeSqaredLength* (2.f *velocity.dotProduct(baseToVertex)) -
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2.0f*edgeDotVelocity*edgeDotBaseToVertex;
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c = edgeSqaredLength* (1.f -baseToVertex.getLengthSQ()) +
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edgeDotBaseToVertex*edgeDotBaseToVertex;
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// does the swept sphere collide against infinite edge?
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if (getLowestRoot(a,b,c,t,&newT))
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{
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f32 f = (edgeDotVelocity*newT - edgeDotBaseToVertex) / edgeSqaredLength;
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if (f >=0.0f && f <= 1.0f)
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{
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// intersection took place within segment
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t = newT;
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foundCollision = true;
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collisionPoint = triangle.pointA + (edge*f);
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}
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}
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// p2 --- p3
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edge = triangle.pointC-triangle.pointB;
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baseToVertex = triangle.pointB - base;
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edgeSqaredLength = edge.getLengthSQ();
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edgeDotVelocity = edge.dotProduct(velocity);
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edgeDotBaseToVertex = edge.dotProduct(baseToVertex);
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// calculate parameters for equation
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a = edgeSqaredLength* -velocitySqaredLength +
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edgeDotVelocity*edgeDotVelocity;
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b = edgeSqaredLength* (2*velocity.dotProduct(baseToVertex)) -
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2.0f*edgeDotVelocity*edgeDotBaseToVertex;
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c = edgeSqaredLength* (1-baseToVertex.getLengthSQ()) +
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edgeDotBaseToVertex*edgeDotBaseToVertex;
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// does the swept sphere collide against infinite edge?
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if (getLowestRoot(a,b,c,t,&newT))
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{
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f32 f = (edgeDotVelocity*newT-edgeDotBaseToVertex) /
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edgeSqaredLength;
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if (f >=0.0f && f <= 1.0f)
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{
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// intersection took place within segment
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t = newT;
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foundCollision = true;
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collisionPoint = triangle.pointB + (edge*f);
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}
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}
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// p3 --- p1
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edge = triangle.pointA-triangle.pointC;
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baseToVertex = triangle.pointC - base;
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edgeSqaredLength = edge.getLengthSQ();
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edgeDotVelocity = edge.dotProduct(velocity);
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edgeDotBaseToVertex = edge.dotProduct(baseToVertex);
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// calculate parameters for equation
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a = edgeSqaredLength* -velocitySqaredLength +
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edgeDotVelocity*edgeDotVelocity;
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b = edgeSqaredLength* (2*velocity.dotProduct(baseToVertex)) -
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2.0f*edgeDotVelocity*edgeDotBaseToVertex;
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c = edgeSqaredLength* (1-baseToVertex.getLengthSQ()) +
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edgeDotBaseToVertex*edgeDotBaseToVertex;
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// does the swept sphere collide against infinite edge?
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if (getLowestRoot(a,b,c,t,&newT))
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{
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f32 f = (edgeDotVelocity*newT-edgeDotBaseToVertex) /
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edgeSqaredLength;
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if (f >=0.0f && f <= 1.0f)
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{
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// intersection took place within segment
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t = newT;
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foundCollision = true;
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collisionPoint = triangle.pointC + (edge*f);
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}
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}
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}// end no collision found
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// set result:
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if (foundCollision)
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{
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// distance to collision is t
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f32 distToCollision = t*colData->velocity.getLength();
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// does this triangle qualify for closest hit?
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if (!colData->foundCollision ||
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distToCollision < colData->nearestDistance)
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{
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colData->nearestDistance = distToCollision;
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colData->intersectionPoint = collisionPoint;
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colData->foundCollision = true;
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colData->intersectionTriangle = triangle;
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++colData->triangleHits;
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}
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}// end found collision
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}
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//! Collides a moving ellipsoid with a 3d world with gravity and returns
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//! the resulting new position of the ellipsoid.
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core::vector3df CSceneCollisionManager::collideEllipsoidWithWorld(
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ITriangleSelector* selector, const core::vector3df &position,
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const core::vector3df& radius, const core::vector3df& velocity,
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f32 slidingSpeed,
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const core::vector3df& gravity,
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core::triangle3df& triout, bool& outFalling)
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{
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if (!selector || radius.X == 0.0f || radius.Y == 0.0f || radius.Z == 0.0f)
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return position;
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// This code is based on the paper "Improved Collision detection and Response"
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// by Kasper Fauerby, but some parts are modified.
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SCollisionData colData;
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colData.R3Position = position;
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colData.R3Velocity = velocity;
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colData.eRadius = radius;
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colData.nearestDistance = 9999999999999.0f;
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colData.selector = selector;
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colData.slidingSpeed = slidingSpeed;
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colData.triangleHits = 0;
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core::vector3df eSpacePosition = colData.R3Position / colData.eRadius;
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core::vector3df eSpaceVelocity = colData.R3Velocity / colData.eRadius;
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// iterate until we have our final position
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core::vector3df finalPos = collideWithWorld(
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0, colData, eSpacePosition, eSpaceVelocity);
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outFalling = false;
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// add gravity
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if (gravity != core::vector3df(0,0,0))
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{
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colData.R3Position = finalPos * colData.eRadius;
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colData.R3Velocity = gravity;
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colData.triangleHits = 0;
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eSpaceVelocity = gravity/colData.eRadius;
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finalPos = collideWithWorld(0, colData,
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finalPos, eSpaceVelocity);
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outFalling = (colData.triangleHits == 0);
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}
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if (colData.triangleHits)
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{
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triout = colData.intersectionTriangle;
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triout.pointA *= colData.eRadius;
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triout.pointB *= colData.eRadius;
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triout.pointC *= colData.eRadius;
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}
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finalPos *= colData.eRadius;
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return finalPos;
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}
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core::vector3df CSceneCollisionManager::collideWithWorld(s32 recursionDepth,
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SCollisionData &colData, core::vector3df pos, core::vector3df vel)
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{
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f32 veryCloseDistance = colData.slidingSpeed;
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if (recursionDepth > 5)
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return pos;
|
|
|
|
colData.velocity = vel;
|
|
colData.normalizedVelocity = vel;
|
|
colData.normalizedVelocity.normalize();
|
|
colData.basePoint = pos;
|
|
colData.foundCollision = false;
|
|
colData.nearestDistance = 9999999999999.0f;
|
|
|
|
//------------------ collide with world
|
|
|
|
// get all triangles with which we might collide
|
|
core::aabbox3d<f32> box(colData.R3Position);
|
|
box.addInternalPoint(colData.R3Position + colData.R3Velocity);
|
|
box.MinEdge -= colData.eRadius;
|
|
box.MaxEdge += colData.eRadius;
|
|
|
|
s32 totalTriangleCnt = colData.selector->getTriangleCount();
|
|
Triangles.set_used(totalTriangleCnt);
|
|
|
|
core::matrix4 scaleMatrix;
|
|
scaleMatrix.setScale(
|
|
core::vector3df(1.0f / colData.eRadius.X,
|
|
1.0f / colData.eRadius.Y,
|
|
1.0f / colData.eRadius.Z)
|
|
);
|
|
|
|
s32 triangleCnt = 0;
|
|
colData.selector->getTriangles(Triangles.pointer(), totalTriangleCnt, triangleCnt, box, &scaleMatrix);
|
|
//colData.selector->getTriangles(Triangles.pointer(), totalTriangleCnt, triangleCnt, &scaleMatrix);
|
|
|
|
for (s32 i=0; i<triangleCnt; ++i)
|
|
testTriangleIntersection(&colData, Triangles[i]);
|
|
|
|
//---------------- end collide with world
|
|
|
|
if (!colData.foundCollision)
|
|
return pos + vel;
|
|
|
|
// original destination point
|
|
core::vector3df destinationPoint = pos + vel;
|
|
core::vector3df newBasePoint = pos;
|
|
|
|
// only update if we are not already very close
|
|
// and if so only move very close to intersection, not to the
|
|
// exact point
|
|
if (colData.nearestDistance >= veryCloseDistance)
|
|
{
|
|
core::vector3df v = vel;
|
|
v.setLength( colData.nearestDistance - veryCloseDistance );
|
|
newBasePoint = colData.basePoint + v;
|
|
|
|
v.normalize();
|
|
colData.intersectionPoint -= (v * veryCloseDistance);
|
|
}
|
|
|
|
// calculate sliding plane
|
|
|
|
core::vector3df slidePlaneOrigin = colData.intersectionPoint;
|
|
core::vector3df slidePlaneNormal = newBasePoint - colData.intersectionPoint;
|
|
slidePlaneNormal.normalize();
|
|
core::plane3d<f32> slidingPlane(slidePlaneOrigin, slidePlaneNormal);
|
|
|
|
core::vector3df newDestinationPoint =
|
|
destinationPoint -
|
|
(slidePlaneNormal * slidingPlane.getDistanceTo(destinationPoint));
|
|
|
|
// generate slide vector
|
|
|
|
core::vector3df newVelocityVector = newDestinationPoint -
|
|
colData.intersectionPoint;
|
|
|
|
if (newVelocityVector.getLength() < veryCloseDistance)
|
|
return newBasePoint;
|
|
|
|
return collideWithWorld(recursionDepth+1, colData,
|
|
newBasePoint, newVelocityVector);
|
|
}
|
|
|
|
|
|
//! Returns a 3d ray which would go through the 2d screen coodinates.
|
|
core::line3d<f32> CSceneCollisionManager::getRayFromScreenCoordinates(
|
|
core::position2d<s32> pos, ICameraSceneNode* camera)
|
|
{
|
|
core::line3d<f32> ln(0,0,0,0,0,0);
|
|
|
|
if (!SceneManager)
|
|
return ln;
|
|
|
|
if (!camera)
|
|
camera = SceneManager->getActiveCamera();
|
|
|
|
if (!camera)
|
|
return ln;
|
|
|
|
const scene::SViewFrustum* f = camera->getViewFrustum();
|
|
|
|
core::vector3df farLeftUp = f->getFarLeftUp();
|
|
core::vector3df lefttoright = f->getFarRightUp() - farLeftUp;
|
|
core::vector3df uptodown = f->getFarLeftDown() - farLeftUp;
|
|
|
|
core::rect<s32> viewPort = Driver->getViewPort();
|
|
core::dimension2d<s32> screenSize(viewPort.getWidth(), viewPort.getHeight());
|
|
|
|
f32 dx = pos.X / (f32)screenSize.Width;
|
|
f32 dy = pos.Y / (f32)screenSize.Height;
|
|
|
|
if (camera->isOrthogonal())
|
|
ln.start = f->cameraPosition + (lefttoright * (dx-0.5f)) + (uptodown * (dy-0.5f));
|
|
else
|
|
ln.start = f->cameraPosition;
|
|
|
|
ln.end = farLeftUp + (lefttoright * dx) + (uptodown * dy);
|
|
|
|
return ln;
|
|
}
|
|
|
|
|
|
|
|
//! Calculates 2d screen position from a 3d position.
|
|
core::position2d<s32> CSceneCollisionManager::getScreenCoordinatesFrom3DPosition(
|
|
core::vector3df pos3d, ICameraSceneNode* camera)
|
|
{
|
|
core::position2d<s32> pos2d(-1000,-1000);
|
|
|
|
if (!SceneManager || !Driver)
|
|
return pos2d;
|
|
|
|
if (!camera)
|
|
camera = SceneManager->getActiveCamera();
|
|
|
|
if (!camera)
|
|
return pos2d;
|
|
|
|
core::rect<s32> viewPort = Driver->getViewPort();
|
|
core::dimension2d<s32> dim(viewPort.getWidth(), viewPort.getHeight());
|
|
|
|
dim.Width /= 2;
|
|
dim.Height /= 2;
|
|
|
|
f32 transformedPos[4];
|
|
|
|
core::matrix4 trans = camera->getProjectionMatrix();
|
|
trans *= camera->getViewMatrix();
|
|
|
|
transformedPos[0] = pos3d.X;
|
|
transformedPos[1] = pos3d.Y;
|
|
transformedPos[2] = pos3d.Z;
|
|
transformedPos[3] = 1.0f;
|
|
|
|
trans.multiplyWith1x4Matrix(transformedPos);
|
|
|
|
if (transformedPos[3] < 0)
|
|
return core::position2d<s32>(-10000,-10000);
|
|
|
|
f32 zDiv = transformedPos[3] == 0.0f ? 1.0f :
|
|
(1.0f / transformedPos[3]);
|
|
|
|
pos2d.X = (s32)(dim.Width * transformedPos[0] * zDiv) + dim.Width;
|
|
pos2d.Y = ((s32)(dim.Height - (dim.Height * (transformedPos[1] * zDiv))));
|
|
|
|
return pos2d;
|
|
}
|
|
|
|
inline bool CSceneCollisionManager::getLowestRoot(f32 a, f32 b, f32 c, f32 maxR, f32* root)
|
|
{
|
|
// check if solution exists
|
|
f32 determinant = b*b - 4.0f*a*c;
|
|
|
|
// if determinant is negative, no solution
|
|
if (determinant < 0.0f) return false;
|
|
|
|
// calculate two roots: (if det==0 then x1==x2
|
|
// but lets disregard that slight optimization)
|
|
// burningwater: sqrt( 0) is an illegal operation.... smth should be done...
|
|
|
|
f32 sqrtD = (f32)sqrt(determinant);
|
|
|
|
f32 r1 = (-b - sqrtD) / (2*a);
|
|
f32 r2 = (-b + sqrtD) / (2*a);
|
|
|
|
// sort so x1 <= x2
|
|
if (r1 > r2) { f32 tmp=r2; r2=r1; r1=tmp; }
|
|
|
|
// get lowest root
|
|
if (r1 > 0 && r1 < maxR)
|
|
{
|
|
*root = r1;
|
|
return true;
|
|
}
|
|
|
|
// its possible that we want x2, this can happen if x1 < 0
|
|
if (r2 > 0 && r2 < maxR)
|
|
{
|
|
*root = r2;
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
|
|
} // end namespace scene
|
|
} // end namespace irr
|
|
|