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May 23, 2017 10:34
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/****************************************************************************** | |
* Spine Runtimes Software License v2.5 | |
* | |
* Copyright (c) 2013-2016, Esoteric Software | |
* All rights reserved. | |
* | |
* You are granted a perpetual, non-exclusive, non-sublicensable, and | |
* non-transferable license to use, install, execute, and perform the Spine | |
* Runtimes software and derivative works solely for personal or internal | |
* use. Without the written permission of Esoteric Software (see Section 2 of | |
* the Spine Software License Agreement), you may not (a) modify, translate, | |
* adapt, or develop new applications using the Spine Runtimes or otherwise | |
* create derivative works or improvements of the Spine Runtimes or (b) remove, | |
* delete, alter, or obscure any trademarks or any copyright, trademark, patent, | |
* or other intellectual property or proprietary rights notices on or in the | |
* Software, including any copy thereof. Redistributions in binary or source | |
* form must include this license and terms. | |
* | |
* THIS SOFTWARE IS PROVIDED BY ESOTERIC SOFTWARE "AS IS" AND ANY EXPRESS OR | |
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF | |
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO | |
* EVENT SHALL ESOTERIC SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, | |
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, BUSINESS INTERRUPTION, OR LOSS OF | |
* USE, DATA, OR PROFITS) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER | |
* IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
* POSSIBILITY OF SUCH DAMAGE. | |
*****************************************************************************/ | |
#include <spine/IkConstraint.h> | |
#include <spine/Skeleton.h> | |
#include <spine/extension.h> | |
#include <float.h> | |
/* Need to pass 0 as an argument, so VC++ doesn't error with C2124 */ | |
static int _isNan(float value, float zero) { | |
float _nan = (float)0.0 / zero; | |
return 0 == memcmp((void*)&value, (void*)&_nan, sizeof(value)); | |
} | |
spIkConstraint *spIkConstraint_create(spIkConstraintData *data, const spSkeleton *skeleton) { | |
int i; | |
spIkConstraint *self = NEW(spIkConstraint); | |
CONST_CAST(spIkConstraintData*, self->data) = data; | |
self->bendDirection = data->bendDirection; | |
self->mix = data->mix; | |
self->bonesCount = self->data->bonesCount; | |
self->bones = MALLOC(spBone*, self->bonesCount); | |
for (i = 0; i < self->bonesCount; ++i) | |
self->bones[i] = spSkeleton_findBone(skeleton, self->data->bones[i]->name); | |
self->target = spSkeleton_findBone(skeleton, self->data->target->name); | |
return self; | |
} | |
void spIkConstraint_dispose(spIkConstraint *self) { | |
FREE(self->bones); | |
FREE(self); | |
} | |
void spIkConstraint_apply(spIkConstraint *self) { | |
switch (self->bonesCount) { | |
case 1: | |
spIkConstraint_apply1(self->bones[0], self->target->worldX, self->target->worldY, self->mix); | |
break; | |
case 2: | |
spIkConstraint_apply2(self->bones[0], self->bones[1], self->target->worldX, self->target->worldY, self->bendDirection, self->mix); | |
break; | |
} | |
} | |
void spIkConstraint_apply1 (spBone* bone, float targetX, float targetY, float alpha) { | |
spBone* p = bone->parent; | |
float id, x, y, tx, ty, rotationIK; | |
if (!bone->appliedValid) spBone_updateAppliedTransform(bone); | |
id = 1 / (p->a * p->d - p->b * p->c); | |
x = targetX - p->worldX, y = targetY - p->worldY; | |
tx = (x * p->d - y * p->b) * id - bone->ax; ty = (y * p->a - x * p->c) * id - bone->ay; | |
rotationIK = ATAN2(ty, tx) * RAD_DEG - bone->ashearX - bone->arotation; | |
if (bone->ascaleX < 0) rotationIK += 180; | |
if (rotationIK > 180) rotationIK -= 360; | |
else if (rotationIK < -180) rotationIK += 360; | |
spBone_updateWorldTransformWith(bone, bone->ax, bone->ay, bone->arotation + rotationIK * alpha, bone->ascaleX, | |
bone->ascaleY, bone->ashearX, bone->ashearY); | |
} | |
void spIkConstraint_apply2 (spBone* parent, spBone* child, float targetX, float targetY, int bendDir, float alpha) { | |
float px, py, psx, psy; | |
float cx, cy, csx, cwx, cwy; | |
int o1, o2, s2, u; | |
spBone* pp = parent->parent; | |
float tx, ty, dx, dy, l1, l2, a1, a2, r; | |
float id, x, y; | |
if (alpha == 0) { | |
spBone_updateWorldTransform(child); | |
return; | |
} | |
if (!parent->appliedValid) spBone_updateAppliedTransform(parent); | |
if (!child->appliedValid) spBone_updateAppliedTransform(child); | |
px = parent->ax; py = parent->ay; psx = parent->ascaleX; psy = parent->ascaleY; csx = child->ascaleX; | |
if (psx < 0) { | |
psx = -psx; | |
o1 = 180; | |
s2 = -1; | |
} else { | |
o1 = 0; | |
s2 = 1; | |
} | |
if (psy < 0) { | |
psy = -psy; | |
s2 = -s2; | |
} | |
if (csx < 0) { | |
csx = -csx; | |
o2 = 180; | |
} else | |
o2 = 0; | |
r = psx - psy; | |
cx = child->ax; | |
u = (r < 0 ? -r : r) <= 0.0001f; | |
if (!u) { | |
cy = 0; | |
cwx = parent->a * cx + parent->worldX; | |
cwy = parent->c * cx + parent->worldY; | |
} else { | |
cy = child->ay; | |
cwx = parent->a * cx + parent->b * cy + parent->worldX; | |
cwy = parent->c * cx + parent->d * cy + parent->worldY; | |
} | |
id = 1 / (pp->a * pp->d - pp->b * pp->c); | |
x = targetX - pp->worldX; | |
y = targetY - pp->worldY; | |
tx = (x * pp->d - y * pp->b) * id - px; | |
ty = (y * pp->a - x * pp->c) * id - py; | |
x = cwx - pp->worldX; | |
y = cwy - pp->worldY; | |
dx = (x * pp->d - y * pp->b) * id - px; | |
dy = (y * pp->a - x * pp->c) * id - py; | |
l1 = SQRT(dx * dx + dy * dy); | |
l2 = child->data->length * csx; | |
if (u) { | |
float cosine, a, b; | |
l2 *= psx; | |
cosine = (tx * tx + ty * ty - l1 * l1 - l2 * l2) / (2 * l1 * l2); | |
if (cosine < -1) cosine = -1; | |
else if (cosine > 1) cosine = 1; | |
a2 = ACOS(cosine) * bendDir; | |
a = l1 + l2 * cosine; | |
b = l2 * SIN(a2); | |
a1 = ATAN2(ty * a - tx * b, tx * a + ty * b); | |
} else { | |
float a = psx * l2, b = psy * l2; | |
float aa = a * a, bb = b * b, ll = l1 * l1, dd = tx * tx + ty * ty, ta = ATAN2(ty, tx); | |
float c0 = bb * ll + aa * dd - aa * bb, c1 = -2 * bb * l1, c2 = bb - aa; | |
float d = c1 * c1 - 4 * c2 * c0; | |
float minAngle = 0, minDist = FLT_MAX, minX = 0, minY = 0; | |
float maxAngle = 0, maxDist = 0, maxX = 0, maxY = 0; | |
float x = l1 + a, dist = x * x, angle, y; | |
if (d >= 0) { | |
float q = SQRT(d), r0, r1; | |
if (c1 < 0) q = -q; | |
q = -(c1 + q) / 2; | |
r0 = q / c2; r1 = c0 / q; | |
r = ABS(r0) < ABS(r1) ? r0 : r1; | |
if (r * r <= dd) { | |
y = SQRT(dd - r * r) * bendDir; | |
a1 = ta - ATAN2(y, r); | |
a2 = ATAN2(y / psy, (r - l1) / psx); | |
goto outer; | |
} | |
} | |
if (dist > maxDist) { | |
maxAngle = 0; | |
maxDist = dist; | |
maxX = x; | |
} | |
x = l1 - a; | |
dist = x * x; | |
if (dist < minDist) { | |
minAngle = PI; | |
minDist = dist; | |
minX = x; | |
} | |
angle = ACOS(-a * l1 / (aa - bb)); | |
x = a * COS(angle) + l1; | |
y = b * SIN(angle); | |
dist = x * x + y * y; | |
if (!_isNan(angle, 0)) { | |
if (dist < minDist) { | |
minAngle = angle; | |
minDist = dist; | |
minX = x; | |
minY = y; | |
} | |
if (dist > maxDist) { | |
maxAngle = angle; | |
maxDist = dist; | |
maxX = x; | |
maxY = y; | |
} | |
} | |
if (dd <= (minDist + maxDist) / 2) { | |
a1 = ta - ATAN2(minY * bendDir, minX); | |
a2 = minAngle * bendDir; | |
} else { | |
a1 = ta - ATAN2(maxY * bendDir, maxX); | |
a2 = maxAngle * bendDir; | |
} | |
} | |
outer: { | |
float os = ATAN2(cy, cx) * s2; | |
a1 = (a1 - os) * RAD_DEG + o1 - parent->arotation; | |
if (a1 > 180) a1 -= 360; | |
else if (a1 < -180) a1 += 360; | |
spBone_updateWorldTransformWith(parent, px, py, parent->rotation + a1 * alpha, parent->ascaleX, parent->ascaleY, 0, 0); | |
a2 = ((a2 + os) * RAD_DEG - child->ashearX) * s2 + o2 - child->arotation; | |
if (a2 > 180) a2 -= 360; | |
else if (a2 < -180) a2 += 360; | |
spBone_updateWorldTransformWith(child, cx, cy, child->arotation + a2 * alpha, child->ascaleX, child->ascaleY, child->ashearX, child->ashearY); | |
} | |
} |
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