bool iTest (const AABB2D &ac, const Ray2D &bc)
{
assert(bc.direction[0] + bc.direction[1] != 0);
Ray2D ray = bc;
for (int i = 0; i < 2; ++i)
ray.direction[i] = (ray.direction[i] == 0) ? FLT_EPSILON : ray.direction[i];
Plane2D planes[4];
planes[0] = { Vector2{ ac.min.x , ac.pos().y },Vector2{ -1, 0 } };
planes[1] = { Vector2{ ac.pos().x, ac.min.y },Vector2{ 0,-1 } };
planes[2] = { Vector2{ ac.max.x , ac.pos().y },Vector2{ 1, 0 } };
planes[3] = { Vector2{ ac.pos().x, ac.max.y },Vector2{ 0, 1 } };
float dists[4];
float tmin = FLT_MAX;
float tmax = -FLT_MAX;
for (int i = 0; i < 4; ++i)
{
float deno = -(dot(planes[i].normal, ray.direction));
dists[i] = dot(planes[i].normal, (ray.position - planes[i].position)) / deno;
}
tmin = fmaxf(fminf(dists[0], dists[2]), fminf(dists[1], dists[3]));
tmax = fminf(fmaxf(dists[0], dists[2]), fmaxf(dists[1], dists[3]));
return tmin <= tmax && 0 <= tmin <= bc.length;
}
void Line2D::getAABB(AABB2D& bb, Real tmin, Real tmax) const
{
Point2D a,b;
eval(tmin,a);
eval(tmax,b);
bb.setPoint(a);
bb.expand(b);
}
void Player2D::render() {
glPushMatrix();
glColor3f(0x00, 0x11, 0xaa);
glTranslatef(this->getPosition().x + gCameraX, this->getPosition().y + gCameraY, 0.0f);
AABB2D temp = this->getBoundingBox(false);
temp.render();
glPopMatrix();
}
//------------------------------------------------------------------------------------------------------
//predicate function that checks if mouse cursor collides with passed box bound
//------------------------------------------------------------------------------------------------------
bool InputManager::IsMouseColliding(const AABB2D& bound)
{
//create a temporary bounding box to represent mouse cursor
AABB2D tempBound;
//set mouse cursor bounds of 1x1 based on mouse position
//flip Y axis as mouse coordinates run from top to bottom
tempBound.SetPosition(m_mousePosition.x,
TheScreen::Instance()->GetScreenSize().y - m_mousePosition.y);
tempBound.SetDimension(1, 1);
tempBound.Update();
//return flag based on if mouse collides with bound
return tempBound.IsColliding(bound);
}
Mouse Mouse::scaleMouse(const AABB2D& cam) const noexcept
{
Mouse temp = *this;
float camWidth = cam.width();
temp.position = cam.min + (temp.position * camWidth);
temp.motion = temp.motion * camWidth;
return temp;
}
Real Segment2D::distance(const AABB2D& bb, Real& tmin) const
{
Real tmax;
if(intersects(bb,tmin,tmax)) return 0;
//non-intersecting -- either bb vertex - seg is closest feature pair or
//bb edge - endpoint is closest feature pair
//first check segment endpoints
Real dmin;
dmin = bb.distance(a);
tmin = 0.0;
Real d=bb.distance(b);
if(d < dmin) {
dmin = d;
tmin = 1.0;
}
//now check vertices
Vector2 p;
Real t = closestPoint(bb.bmax,p);
d = p.distanceSquared(bb.bmax);
if(d < Sqr(dmin)) {
dmin = Sqrt(d);
tmin = t;
}
t = closestPoint(bb.bmin,p);
d = p.distanceSquared(bb.bmin);
if(d < Sqr(dmin)) {
dmin = Sqrt(d);
tmin = t;
}
t = closestPoint(Vector2(bb.bmin.x,bb.bmax.y),p);
d = p.distanceSquared(Vector2(bb.bmin.x,bb.bmax.y));
if(d < Sqr(dmin)) {
dmin = Sqrt(d);
tmin = t;
}
t = closestPoint(Vector2(bb.bmax.x,bb.bmin.y),p);
d = p.distanceSquared(Vector2(bb.bmax.x,bb.bmin.y));
if(d < Sqr(dmin)) {
dmin = Sqrt(d);
tmin = t;
}
return dmin;
}
CollisionData iTest_data(const AABB2D &ac, const Plane2D &bc)
{
if (iTest(ac, bc))
{
CollisionData r;
r.collisionNormal = bc.normal;
r.penDepth = dot(bc.normal, (ac.pos() - bc.position));
if (r.penDepth < 0) r.penDepth = 0;
return r;
}
else return CollisionData{ 0,0 };
}
void Segment2D::getAABB(AABB2D& bb) const
{
bb.setPoint(a);
bb.expand(b);
}
void FontRenderer::begin(const AABB2D& camera) noexcept
{
this->begin(camera.position(), camera.dimensions());
}
bool iTest (const AABB2D &ac, const Plane2D &bc)
{
return dot(bc.normal, (ac.pos() - bc.position)) <=
(ac.dim().x / 2) * dot(bc.normal, Vector2{ 1,0 })
+ (ac.dim().y / 2) * dot(bc.normal, Vector2{ 0,1 });
}
