Math::cVector CollisionDetection::CollideWithWorld(Math::cVector& position, Math::cVector& velocity,float length,bool isCamCollision)
{
if (velocity.GetLength() == 0)
return position;
CollisionData coll;
coll.foundCollision = false;
coll.nearestDistance = 0;
coll.sourcepoint = position;
coll.velocity = velocity.CreateNormalized();
coll.length = length;
for (int j = 0; j < mVertexPosition.size(); j += 3)
{
Math::cVector planeOrigin = mVertexPosition[mVertexIndices[j]];
Math::cVector B = mVertexPosition[mVertexIndices[j + 1]];
Math::cVector C =mVertexPosition[mVertexIndices[j + 2]];
RayTriangleIntersection(planeOrigin,B,C, length, &coll);
}
if (!isCamCollision)
return ResolvePlayerCollision(position,velocity, coll);
else
return ResolveCameraCollision(position,velocity, coll);
}
void eae6320::Graphics::traceRayHorizontal(float& timeCollided)
{
float shortestTime = FLT_MAX;
Math::cVector intersectionPoint;
Math::cVector normalAtIntersection;
Math::cVector parallelStart = gameObjects[0]->camObject->position;
/*Math::cVector parallelEnd = gameObjects[0]->camObject->position + gameObjects[0]->camObject->velocity +
gameObjects[0]->camObject->acceleration * timeLeftInFrame * timeLeftInFrame * 0.5f;*/
Math::cVector parallelEnd = gameObjects[0]->camObject->position +10.0f;
bool intersected = false;
float shortestTimeReal = FLT_MAX;
for (int i = 0; i < context.numberOfIndices; i += 3)
{
int index = context.indexData[i];
int index1 = context.indexData[i + 1];
int index2 = context.indexData[i + 2];
eae6320::Math::cVector vertexA = eae6320::Math::cVector(context.vertexData[index].x, context.vertexData[index].y, context.vertexData[index].z);
eae6320::Math::cVector vertexB = eae6320::Math::cVector(context.vertexData[index1].x, context.vertexData[index1].y, context.vertexData[index1].z);
eae6320::Math::cVector vertexC = eae6320::Math::cVector(context.vertexData[index2].x, context.vertexData[index2].y, context.vertexData[index2].z);
eae6320::Math::cVector normal = eae6320::Math::cVector(context.vertexData[i].nx, context.vertexData[i].ny, context.vertexData[i].nz);
float u = 0, v = 0, w = 0, t = 0;
int a = IntersectSegmentTriangle(parallelStart, parallelEnd,
vertexA, vertexC, vertexB, u, v, w, t,normal);
//normal = eae6320::Math::cVector(context.vertexData[i].nx, context.vertexData[i].ny, context.vertexData[i].nz);
if (a == 1)
{
if (t < shortestTime) {
shortestTime = t;
//intersectionPoint = vertexA*u + vertexB*v + vertexC*w;
intersectionPoint = parallelStart + (parallelEnd - parallelStart) * t;
//normalAtIntersection = normal * -1.0f;
shortestTimeReal = (intersectionPoint - parallelStart).GetLength() /
(parallelStart - parallelEnd).GetLength();
intersected = true;
}
}
}
if (intersected)
{
float oneByNormal = 1 /( normalAtIntersection.GetLength());
Math::cVector verticalProjectionAcceleration = normalAtIntersection * eae6320::Math::Dot(gameObjects[0]->camObject->acceleration, normalAtIntersection)*oneByNormal*oneByNormal;
gameObjects[0]->camObject->acceleration = gameObjects[0]->camObject->acceleration - verticalProjectionAcceleration;
Math::cVector verticalProjectionVelocity = normalAtIntersection * eae6320::Math::Dot(gameObjects[0]->camObject->velocity, normalAtIntersection)*oneByNormal*oneByNormal;
gameObjects[0]->camObject->velocity = gameObjects[0]->camObject->velocity - verticalProjectionVelocity;
gameObjects[0]->camObject->position = intersectionPoint - normalAtIntersection.CreateNormalized();
timeCollided = shortestTimeReal;
}
}
void eae6320::Graphics::DoCOllisions(GameObject* player)
{
// COllision Detection
player->m_velocity = player->m_position - s_playerPrevPos;
player->m_position = s_collisionDet->CollideWithWorld(player->m_position, player->m_velocity, 50, false);
player->m_velocity = Math::cVector(0, -9.8f, 0) * 5;
player->m_position = s_collisionDet->CollideWithWorld(player->m_position, player->m_velocity, 20, false);
s_playerPrevPos = player->m_position;
Math::cVector playerDir = player->m_position - s_camera->m_position;
Math::cMatrix_transformation mat = Math::cMatrix_transformation::cMatrix_transformation(player->m_orientation, player->m_position);
Math::cVector offset = Math::cMatrix_transformation::matrixMulVector(mat, Math::cVector(0, 120, 200));
Math::cVector rayOrigin = offset;
s_collisionDet->CollideWithWorld(rayOrigin, playerDir, playerDir.GetLength(), true);
}
bool CollisionDetection::CheckIfPointInTriangle(Math::cVector &polygonInterectionPoint, Math::cVector &vertex1, Math::cVector &vertex2, Math::cVector &vertex3)
{
float totalAngles=0;
Math::cVector A = polygonInterectionPoint - vertex1;
Math::cVector B = polygonInterectionPoint - vertex2;
Math::cVector C = polygonInterectionPoint - vertex3;
A = A.CreateNormalized();
B = B.CreateNormalized();
C= C.CreateNormalized();
float Dot1 = Math::Dot(A, B);
if (Dot1 < -1)
Dot1 = -1;
if (Dot1 > 1)
Dot1 = 1;
totalAngles += acos(Dot1);
float Dot2 = Math::Dot(B, C);
if (Dot2 < -1)
Dot2 = -1;
if (Dot2 > 1)
Dot2 = 1;
totalAngles += acos(Dot2);
float Dot3 = Math::Dot(A, C);
if (Dot3 < -1)
Dot3 = -1;
if (Dot3 > 1)
Dot3 = 1;
totalAngles += acos(Dot3);
if (fabs(totalAngles - 2 * 3.14159265f) <= 0.005f)
{
return true;
}
return false;
}
int CollisionDetection::RayTriangleIntersection(Math::cVector& v1, Math::cVector& v2, Math::cVector& v3,float length, CollisionData *collD)
{
Math::cVector e1, e2;
e1 = v2 - v1;
e2 = v3 - v1;
/*
Math::cVector n = Math::Cross(e1, e2);
n = n.CreateNormalized();
float det = Math::Dot(n, collD->velocity );
if (det <= 0.0f) return 0;
float inv_det = 1 / det;
Math::cVector sourceToVertex = v1 - collD->sourcepoint;
float e = Math::Dot(sourceToVertex,n);
if (e < 0.0f)
return 0;
//if (e > collD->length)
//return 0;
Math::cVector o = Math::Cross(collD->velocity ,sourceToVertex);
float v = Math::Dot(e2,o);
if (v<0.0f || v>collD->length) return 0;
float w = -Math::Dot(e1,o);
if (w<0.0f || v + w>collD->length) return 0;
e *= inv_det;
v *= inv_det;
w *= inv_det;
float u = 1.0f - v - w;
return 1;
*/
Math::cVector n = Math::Cross(e1, e2);
n = n.CreateNormalized();
Math::cVector ePoint = collD->sourcepoint;// -n;
float det = Math::Dot(n, collD->velocity );
if (det == 0.0f) return 0;
float inv_det = 1 / det;
float a = Math::Dot(v1,n);
float b = Math::Dot(n, ePoint);
float t = (a - b) * inv_det;
if (t < 0)
return 0;
if (t > 0 && t <= collD->length)
{
Math::cVector collPnt = ePoint + (collD->velocity * t);
if (CheckIfPointInTriangle(collPnt, v1, v2, v3))
{
{
collD->nearestPloygonIntersectionPoint = collPnt;
collD->collNormal = n;
collD->foundCollision = true;
collD->nearestDistance = t;
return 1;
}
}
}
return 0;
}
