// Trace a line through the world to simulate, eg, a bullet http://www.youtube.com/watch?v=USjbg5QXk3g
bool CGame::TraceLine(const Vector& v0, const Vector& v1, Vector& vecIntersection, CCharacter*& pHit)
{
float flLowestFraction = 1;
Vector vecTestIntersection;
float flTestFraction;
pHit = nullptr;
for (size_t i = 0; i < MAX_CHARACTERS; i++)
{
CCharacter* pCharacter = GetCharacterIndex(i);
if (!pCharacter)
continue;
// Only monsters and boxes get hit by traces. The player doesn't, he's immune to his own attacks.
if (!pCharacter->m_bHitByTraces)
continue;
Matrix4x4 mInverse = pCharacter->GetGlobalTransform().InvertedTR();
// The v0 and v1 are in the global coordinate system and we need to transform it to the target's
// local coordinate system to use axis-aligned intersection. We do so using the inverse transform matrix.
// http://youtu.be/-Fn4atv2NsQ
if (LineAABBIntersection(pCharacter->m_aabbSize, mInverse*v0, mInverse*v1, vecTestIntersection, flTestFraction) && flTestFraction < flLowestFraction)
{
// Once we have the result we can use the regular transform matrix to get it back in
// global coordinates. http://youtu.be/-Fn4atv2NsQ
vecIntersection = pCharacter->GetGlobalTransform()*vecTestIntersection;
flLowestFraction = flTestFraction;
pHit = pCharacter;
}
}
// Intersect with the floor.
// Line-Plane Intersection algorithm: http://youtu.be/fIu_8b2n8ZM
if (LinePlaneIntersection(Vector(0, 1, 0), Vector(0, 0, 0), v0, v1, vecTestIntersection, flTestFraction) && flTestFraction < flLowestFraction)
{
vecIntersection = vecTestIntersection;
flLowestFraction = flTestFraction;
pHit = nullptr;
}
if (flLowestFraction < 1)
return true;
return false;
}
TVector CCharacterCamera::GetThirdPersonCameraPosition()
{
CCharacter* pCharacter = m_hCharacter;
if (!pCharacter)
return TVector(10, 0, 0);
TVector vecEyeHeight = pCharacter->GetUpVector() * pCharacter->EyeHeight();
TMatrix mView = TMatrix(pCharacter->GetThirdPersonCameraAngles(), TVector());
TVector vecThird = pCharacter->GetGlobalTransform().GetTranslation() + vecEyeHeight;
vecThird -= Vector(mView.GetForwardVector()) * m_flBack;
vecThird += Vector(mView.GetUpVector()) * m_flUp;
vecThird += Vector(mView.GetLeftVector()) * m_flSide;
return vecThird;
}
void CGame::DrawCharacters(const std::vector<CCharacter*>& apRenderList, bool bTransparent)
{
CRenderer* pRenderer = GetRenderer();
// Loop through all characters, render them one at a time.
// Start at the back of the list so that transparent entities use the painter's algorithm.
for (size_t i = apRenderList.size()-1; i < apRenderList.size(); i--)
{
CCharacter* pCharacter = apRenderList[i];
CRenderingContext c(pRenderer, true);
c.SetBlend(BLEND_NONE);
c.SetAlpha(1);
// Set the color of the box to be rendered.
c.SetUniform("vecColor", pCharacter->m_clrRender);
if (pCharacter->m_iBillboardTexture)
{
c.SetBackCulling(false);
c.SetUniform("bDiffuse", true);
// Create a billboard by creating basis vectors. https://www.youtube.com/watch?v=puOTwCrEm7Q
Vector vecForward, vecRight, vecUp;
vecForward = pCharacter->GetGlobalOrigin() - pRenderer->GetCameraPosition();
vecRight = -Vector(0, 1, 0).Cross(vecForward).Normalized();
vecUp = vecForward.Cross(-vecRight).Normalized();
if (pCharacter->m_bDrawTransparent)
{
c.SetAlpha(0.6f);
c.SetBlend(BLEND_ALPHA);
}
c.LoadTransform(pCharacter->GetGlobalTransform());
c.Translate(Vector(0, pCharacter->m_aabbSize.GetHeight()/2, 0)); // Move the character up so his feet don't stick in the ground.
pCharacter->ShotEffect(&c);
c.RenderBillboard(pCharacter->m_iBillboardTexture, pCharacter->m_aabbSize.vecMax.x, vecUp, vecRight);
}
else
{
c.SetUniform("bDiffuse", false);
// The transform matrix holds all transformations for the player. Just pass it through to the renderer.
// http://youtu.be/7pe1xYzFCvA
c.Transform(pCharacter->GetGlobalTransform());
if (pCharacter->m_bDrawTransparent)
{
c.SetAlpha(0.6f);
c.SetBlend(BLEND_ALPHA);
}
if (pCharacter->m_iTexture)
{
c.SetUniform("bDiffuse", true);
c.BindTexture(pCharacter->m_iTexture);
}
// Render the player-box
c.RenderBox(pCharacter->m_aabbSize.vecMin, pCharacter->m_aabbSize.vecMax);
}
}
}