SceneObstacle (Vect bl, Vect tr)
: _left(bl.x()), _bottom(bl.y()), _top(tr.y()), _right(tr.x()) {}
bool SceneObstacle::performCollide (
Vect pos, Vect::Component rad, Vect spd, float delta,
Vect& outPos, Vect& outSpd, float& outDelta, Vect& norm
) {
auto dest = pos + spd * delta;
auto left = _left + rad;
auto right = _right - rad;
auto bottom = _bottom + rad;
auto top = _top - rad;
bool outLeft = dest.x() < left;
bool outRight = dest.x() > right;
bool outBottom = dest.y() < bottom;
bool outTop = dest.y() > top;
if (!(outLeft | outRight | outTop | outBottom)) {
return false;
}
float dltLeft = delta * (pos.x() - left) / (pos.x() - dest.x());
float dltRight = delta * (pos.x() - right) / (pos.x() - dest.x());
float dltBottom = delta * (pos.y() - bottom) / (pos.y() - dest.y());
float dltTop = delta * (pos.y() - top) / (pos.y() - dest.y());
bool hor = outLeft | outRight;
bool ver = outTop | outBottom;
if (hor & ver) {
// Decide which bounces earlier
float dltHor = std::min(dltLeft, dltRight);
float dltVer = std::min(dltTop, dltBottom);
if (dltHor < dltVer) {
outTop = outBottom = false;
} else {
outLeft = outRight = false;
}
}
if (outLeft) {
outDelta = delta - dltLeft;
outPos = pos + spd * dltLeft;
outSpd = Vect(-spd.x(), spd.y(), 0.f);
return true;
} else if (outRight) {
outDelta = delta - dltRight;
outPos = pos + spd * dltRight;
outSpd = Vect(-spd.x(), spd.y(), 0.f);
return true;
} else if (outTop) {
outDelta = delta - dltTop;
outPos = pos + spd * dltTop;
outSpd = Vect(spd.x(), -spd.y(), 0.f);
return true;
} else/* if (outBottom) */{
outDelta = delta - dltBottom;
outPos = pos + spd * dltBottom;
outSpd = Vect(spd.x(), -spd.y(), 0.f);
return true;
}
}
