spine-runtimes/spine-haxe/spine-haxe/spine/PhysicsConstraint.hx
2025-05-26 13:24:06 +02:00

341 lines
9.8 KiB
Haxe

/******************************************************************************
* Spine Runtimes License Agreement
* Last updated April 5, 2025. Replaces all prior versions.
*
* Copyright (c) 2013-2025, Esoteric Software LLC
*
* Integration of the Spine Runtimes into software or otherwise creating
* derivative works of the Spine Runtimes is permitted under the terms and
* conditions of Section 2 of the Spine Editor License Agreement:
* http://esotericsoftware.com/spine-editor-license
*
* Otherwise, it is permitted to integrate the Spine Runtimes into software
* or otherwise create derivative works of the Spine Runtimes (collectively,
* "Products"), provided that each user of the Products must obtain their own
* Spine Editor license and redistribution of the Products in any form must
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*
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*****************************************************************************/
package spine;
/** Stores the current pose for a physics constraint. A physics constraint applies physics to bones.
*
*
* @see https://esotericsoftware.com/spine-physics-constraints Physics constraints in the Spine User Guide
*/
class PhysicsConstraint implements Updatable {
private var _data:PhysicsConstraintData;
private var _bone:Bone = null;
public var inertia:Float = 0;
public var strength:Float = 0;
public var damping:Float = 0;
public var massInverse:Float = 0;
public var wind:Float = 0;
public var gravity:Float = 0;
/** A percentage (0-1) that controls the mix between the constrained and unconstrained poses. */
public var mix:Float = 0;
private var _reset:Bool = true;
public var ux:Float = 0;
public var uy:Float = 0;
public var cx:Float = 0;
public var cy:Float = 0;
public var tx:Float = 0;
public var ty:Float = 0;
public var xOffset:Float = 0;
public var xVelocity:Float = 0;
public var yOffset:Float = 0;
public var yVelocity:Float = 0;
public var rotateOffset:Float = 0;
public var rotateVelocity:Float = 0;
public var scaleOffset:Float = 0;
public var scaleVelocity:Float = 0;
public var active:Bool = false;
private var _skeleton:Skeleton;
public var remaining:Float = 0;
public var lastTime:Float = 0;
public function new(data: PhysicsConstraintData, skeleton: Skeleton) {
_data = data;
_skeleton = skeleton;
_bone = skeleton.bones[data.bone.index];
inertia = data.inertia;
strength = data.strength;
damping = data.damping;
massInverse = data.massInverse;
wind = data.wind;
gravity = data.gravity;
mix = data.mix;
}
public function reset () {
remaining = 0;
lastTime = skeleton.time;
_reset = true;
xOffset = 0;
xVelocity = 0;
yOffset = 0;
yVelocity = 0;
rotateOffset = 0;
rotateVelocity = 0;
scaleOffset = 0;
scaleVelocity = 0;
}
public function setToSetupPose () {
var data:PhysicsConstraintData = _data;
inertia = data.inertia;
strength = data.strength;
damping = data.damping;
massInverse = data.massInverse;
wind = data.wind;
gravity = data.gravity;
mix = data.mix;
}
public function isActive():Bool {
return active;
}
/** Applies the constraint to the constrained bones. */
public function update(physics:Physics):Void {
var mix:Float = this.mix;
if (mix == 0) return;
var x:Bool = _data.x > 0, y:Bool = _data.y > 0,
rotateOrShearX:Bool = _data.rotate > 0 || _data.shearX > 0,
scaleX:Bool = _data.scaleX > 0;
var bone:Bone = _bone;
var l:Float = bone.data.length;
switch (physics) {
case Physics.none:
return;
case Physics.reset, Physics.update:
if (physics == Physics.reset) reset();
var delta:Float = Math.max(skeleton.time - lastTime, 0);
remaining += delta;
lastTime = _skeleton.time;
var bx:Float = bone.worldX, by:Float = bone.worldY;
if (_reset) {
_reset = false;
ux = bx;
uy = by;
} else {
var a:Float = remaining,
i:Float = inertia,
t:Float = _data.step,
f:Float = skeleton.data.referenceScale,
d:Float = -1;
var qx:Float = _data.limit * delta,
qy:Float = qx * Math.abs(skeleton.scaleY);
qx *= Math.abs(skeleton.scaleX);
if (x || y) {
if (x) {
var u:Float = (ux - bx) * i;
xOffset += u > qx ? qx : u < -qx ? -qx : u;
ux = bx;
}
if (y) {
var u:Float = (uy - by) * i;
yOffset += u > qy ? qy : u < -qy ? -qy : u;
uy = by;
}
if (a >= t) {
d = Math.pow(damping, 60 * t);
var m:Float = massInverse * t,
e:Float = strength,
w:Float = wind * f * skeleton.scaleX,
g:Float = gravity * f * skeleton.scaleY;
do {
if (x) {
xVelocity += (w - xOffset * e) * m;
xOffset += xVelocity * t;
xVelocity *= d;
}
if (y) {
yVelocity -= (g + yOffset * e) * m;
yOffset += yVelocity * t;
yVelocity *= d;
}
a -= t;
} while (a >= t);
}
if (x) bone.worldX += xOffset * mix * data.x;
if (y) bone.worldY += yOffset * mix * data.y;
}
if (rotateOrShearX || scaleX) {
var ca:Float = Math.atan2(bone.c, bone.a),
c:Float = 0,
s:Float = 0,
mr:Float = 0;
var dx:Float = cx - bone.worldX,
dy:Float = cy - bone.worldY;
if (dx > qx)
dx = qx;
else if (dx < -qx) //
dx = -qx;
if (dy > qy)
dy = qy;
else if (dy < -qy) //
dy = -qy;
if (rotateOrShearX) {
mr = (_data.rotate + _data.shearX) * mix;
var r:Float = Math.atan2(dy + ty, dx + tx) - ca - rotateOffset * mr;
rotateOffset += (r - Math.ceil(r * MathUtils.invPI2 - 0.5) * MathUtils.PI2) * i;
r = rotateOffset * mr + ca;
c = Math.cos(r);
s = Math.sin(r);
if (scaleX) {
r = l * bone.worldScaleX;
if (r > 0) scaleOffset += (dx * c + dy * s) * i / r;
}
} else {
c = Math.cos(ca);
s = Math.sin(ca);
var r:Float = l * bone.worldScaleX;
if (r > 0) scaleOffset += (dx * c + dy * s) * i / r;
}
a = remaining;
if (a >= t) {
if (d == -1) d = Math.pow(damping, 60 * t);
var m:Float = massInverse * t,
e:Float = strength,
w:Float = wind,
g:Float = (Bone.yDown ? -gravity : gravity),
h:Float = l / f;
while (true) {
a -= t;
if (scaleX) {
scaleVelocity += (w * c - g * s - scaleOffset * e) * m;
scaleOffset += scaleVelocity * t;
scaleVelocity *= d;
}
if (rotateOrShearX) {
rotateVelocity -= ((w * s + g * c) * h + rotateOffset * e) * m;
rotateOffset += rotateVelocity * t;
rotateVelocity *= d;
if (a < t) break;
var r:Float = rotateOffset * mr + ca;
c = Math.cos(r);
s = Math.sin(r);
} else if (a < t) //
break;
}
}
}
remaining = a;
}
cx = bone.worldX;
cy = bone.worldY;
case Physics.pose:
if (x) bone.worldX += xOffset * mix * data.x;
if (y) bone.worldY += yOffset * mix * data.y;
}
if (rotateOrShearX) {
var o:Float = rotateOffset * mix,
s:Float = 0,
c:Float = 0,
a:Float = 0;
if (_data.shearX > 0) {
var r:Float = 0;
if (_data.rotate > 0) {
r = o * _data.rotate;
s = Math.sin(r);
c = Math.cos(r);
a = bone.b;
bone.b = c * a - s * bone.d;
bone.d = s * a + c * bone.d;
}
r += o * _data.shearX;
s = Math.sin(r);
c = Math.cos(r);
a = bone.a;
bone.a = c * a - s * bone.c;
bone.c = s * a + c * bone.c;
} else {
o *= _data.rotate;
s = Math.sin(o);
c = Math.cos(o);
a = bone.a;
bone.a = c * a - s * bone.c;
bone.c = s * a + c * bone.c;
a = bone.b;
bone.b = c * a - s * bone.d;
bone.d = s * a + c * bone.d;
}
}
if (scaleX) {
var s:Float = 1 + scaleOffset * mix * data.scaleX;
bone.a *= s;
bone.c *= s;
}
if (physics != Physics.pose) {
tx = l * bone.a;
ty = l * bone.c;
}
bone.updateAppliedTransform();
}
/** Translates the physics constraint so next update(Physics) forces are applied as if the bone moved an additional
* amount in world space. */
public function translate (x:Float, y:Float):Void {
ux -= x;
uy -= y;
cx -= x;
cy -= y;
}
/** Rotates the physics constraint so next update(Physics) forces are applied as if the bone rotated around the
* specified point in world space. */
public function rotate (x:Float, y:Float, degrees:Float):Void {
var r:Float = degrees * MathUtils.degRad, cos:Float = Math.cos(r), sin:Float = Math.sin(r);
var dx:Float = cx - x, dy:Float = cy - y;
translate(dx * cos - dy * sin - dx, dx * sin + dy * cos - dy);
}
/** The bone constrained by this physics constraint. */
public var bone(get, never):Bone;
private function get_bone():Bone {
if (_bone == null)
throw new SpineException("Bone not set.")
else return _bone;
}
/** The physics constraint's setup pose data. */
public var data(get, never):PhysicsConstraintData;
private function get_data():PhysicsConstraintData {
return _data;
}
public var skeleton(get, never):Skeleton;
private function get_skeleton():Skeleton {
return _skeleton;
}
}