/******************************************************************************
 * Spine Runtimes Software License
 * Version 2.3
 * 
 * Copyright (c) 2013-2015, 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 (the "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 otherwise create derivative works, improvements of the
 * Software or develop new applications using the Software 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; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) 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/TransformConstraint.h>
#include <spine/Skeleton.h>
#include <spine/extension.h>

spTransformConstraint* spTransformConstraint_create (spTransformConstraintData* data, const spSkeleton* skeleton) {
	int i;
	spTransformConstraint* self = NEW(spTransformConstraint);
	CONST_CAST(spTransformConstraintData*, self->data) = data;
	self->rotateMix = data->rotateMix;
	self->translateMix = data->translateMix;
	self->scaleMix = data->scaleMix;
	self->shearMix = data->shearMix;
	self->bonesCount = data->bonesCount;
	CONST_CAST(spBone**, 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 spTransformConstraint_dispose (spTransformConstraint* self) {
	FREE(self->bones);
	FREE(self);
}

void spTransformConstraint_apply (spTransformConstraint* self) {
	float rotateMix = self->rotateMix, translateMix = self->translateMix, scaleMix = self->scaleMix, shearMix = self->shearMix;
	spBone* target = self->target;
	float ta = target->a, tb = target->b, tc = target->c, td = target->d;
	int i;
	for (i = 0; i < self->bonesCount; ++i) {
		spBone* bone = self->bones[i];

		if (rotateMix > 0) {
			float a = bone->a, b = bone->b, c = bone->c, d = bone->d;
			float r = ATAN2(tc, ta) - ATAN2(c, a) + self->data->offsetRotation * DEG_RAD;
			float cosine, sine;
			if (r > PI) r -= PI2;
			else if (r < -PI) r += PI2;
			r *= rotateMix;
			cosine = COS(r);
			sine = SIN(r);
			CONST_CAST(float, bone->a) = cosine * a - sine * c;
			CONST_CAST(float, bone->b) = cosine * b - sine * d;
			CONST_CAST(float, bone->c) = sine * a + cosine * c;
			CONST_CAST(float, bone->d) = sine * b + cosine * d;
		}

		if (translateMix > 0) {
			float x, y;
			spBone_localToWorld(target, self->data->offsetX, self->data->offsetY, &x, &y);
			CONST_CAST(float, bone->worldX) += (x - bone->worldX) * translateMix;
			CONST_CAST(float, bone->worldY) += (y - bone->worldY) * translateMix;
		}

		if (scaleMix > 0) {
			float bs = SQRT(bone->a * bone->a + bone->c * bone->c);
			float ts = SQRT(ta * ta + tc * tc);
			float s = bs > 0.00001f ? (bs + (ts - bs + self->data->offsetScaleX) * scaleMix) / bs : 0;
			CONST_CAST(float, bone->a) *= s;
			CONST_CAST(float, bone->c) *= s;
			bs = SQRT(bone->b * bone->b + bone->d * bone->d);
			ts = SQRT(tb * tb + td * td);
			s = bs > 0.00001f ? (bs + (ts - bs + self->data->offsetScaleY) * scaleMix) / bs : 0;
			CONST_CAST(float, bone->b) *= s;
			CONST_CAST(float, bone->d) *= s;
		}

		if (shearMix > 0) {
			float b = bone->b, d = bone->d;
			float by = ATAN2(d, b);
			float r = ATAN2(td, tb) - ATAN2(tc, ta) - (by - ATAN2(bone->c, bone->a));
			float s = SQRT(b * b + d * d);
			if (r > PI) r -= PI2;
			else if (r < -PI) r += PI2;
			r = by + (r + self->data->offsetShearY * DEG_RAD) * shearMix;
			CONST_CAST(float, bone->b) = COS(r) * s;
			CONST_CAST(float, bone->d) = SIN(r) * s;
		}
	}
}