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handleBasicMovementCollision now moves the swept-sphere entity right up to the collision point

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Gered 2014-01-02 09:32:30 -05:00
parent 216ee98acc
commit fd60e74393
1 changed files with 24 additions and 17 deletions
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41
src/main/java/ca/blarg/gdx/math/SweptSphereHandler.java
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@ -119,12 +119,17 @@ public class SweptSphereHandler {
collisionChecker.checkForCollisions(sphere, possibleCollisionArea);
// if there was no collision, simply move along the velocity vector. if there was a collision
// then we just simple stop and don't even attempt to move at all
// then we just move right up to the collision but don't attempt any sliding or anything like that
if (!sphere.foundCollision) {
sphere.position.set(sphere.esPosition).add(sphere.esVelocity);
outVelocity.set(velocity); // keep the original input velocity as well
} else {
sphere.position.set(sphere.esPosition);
if (sphere.nearestCollisionDistance >= collisionVeryCloseDistance) {
// not quite at the collision point yet, so lets move up so we are at it
getMoveUpToCollisionVector(sphere, velocity, tmp1);
sphere.position.set(sphere.esPosition).add(tmp1);
}
// either way, the resulting velocity will be zero, as we are now right next to the collision point
outVelocity.set(Vector3.Zero);
}
@ -178,21 +183,7 @@ public class SweptSphereHandler {
if (sphere.nearestCollisionDistance >= collisionVeryCloseDistance) {
// we haven't yet moved up too close to the nearest collision, so
// let's inch forward a bit
// figure out the new position that we need to move up to
float moveUpLength = sphere.nearestCollisionDistance - collisionVeryCloseDistance;
// HACK: if the above length ends up being 0, "v" calculated below will
// end up with "NaN" x/y/z components which will eventually cause
// the resulting position from all this being "NaN" and the entity
// will seem to disappear entirely. If we catch this zero length
// condition and recalculate it so that the length is non-zero but
// still very small (below the VERY_CLOSE_DISTANCE threshold) then
// it appears to work fine.
if (moveUpLength == 0.0f)
moveUpLength = sphere.nearestCollisionDistance - (collisionVeryCloseDistance * 0.5f);
MathHelpers.setLengthOf(tmp1.set(velocity), moveUpLength);
getMoveUpToCollisionVector(sphere, velocity, tmp1);
tmpNewPosition.set(sphere.esPosition)
.add(tmp1);
@ -243,6 +234,22 @@ public class SweptSphereHandler {
return getNewPositionForMovement(recursionDepth, sphere, tmpNewPosition, tmpNewVelocity, responseVelocity, canSlide, onlySlideIfTooSteep, tooSteepAngleY);
}
private void getMoveUpToCollisionVector(SweptSphere sphere, Vector3 velocity, Vector3 outVector) {
float moveUpLength = sphere.nearestCollisionDistance - collisionVeryCloseDistance;
// HACK: if the above length ends up being 0, outVector will end up with
// NaN x/y/z components which will eventually cause any position
// update calculations using outVector being NaN and the entity
// will seem to disappear entirely. If we catch this zero length
// condition and recalculate it so that the length is non-zero but
// still very small (below the collisionVeryCloseDistance threshold)
// then it appears to work fine.
if (moveUpLength == 0.0f)
moveUpLength = sphere.nearestCollisionDistance - (collisionVeryCloseDistance * 0.5f);
MathHelpers.setLengthOf(outVector.set(velocity), moveUpLength);
}
private void calculatePossibleCollisionArea(SweptSphere sphere, Vector3 velocity) {
tmp1.set(sphere.position).add(velocity); // the "end" position
Vector3 radius = sphere.radius;