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/*==LICENSE==*
CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011 Cyan Worlds, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
Additional permissions under GNU GPL version 3 section 7
If you modify this Program, or any covered work, by linking or
combining it with any of RAD Game Tools Bink SDK, Autodesk 3ds Max SDK,
NVIDIA PhysX SDK, Microsoft DirectX SDK, OpenSSL library, Independent
JPEG Group JPEG library, Microsoft Windows Media SDK, or Apple QuickTime SDK
(or a modified version of those libraries),
containing parts covered by the terms of the Bink SDK EULA, 3ds Max EULA,
PhysX SDK EULA, DirectX SDK EULA, OpenSSL and SSLeay licenses, IJG
JPEG Library README, Windows Media SDK EULA, or QuickTime SDK EULA, the
licensors of this Program grant you additional
permission to convey the resulting work. Corresponding Source for a
non-source form of such a combination shall include the source code for
the parts of OpenSSL and IJG JPEG Library used as well as that of the covered
work.
You can contact Cyan Worlds, Inc. by email legal@cyan.com
or by snail mail at:
Cyan Worlds, Inc.
14617 N Newport Hwy
Mead, WA 99021
*==LICENSE==*/
#include "plAnimEaseTypes.h"
#include "plAnimTimeConvert.h"
///////////////////////////////////////////////////////////////////////////////////////////////
plATCEaseCurve *plATCEaseCurve::CreateEaseCurve(UInt8 type, hsScalar minLength, hsScalar maxLength, hsScalar length,
hsScalar startSpeed, hsScalar goalSpeed)
{
if (type == plAnimEaseTypes::kConstAccel)
return TRACKED_NEW plConstAccelEaseCurve(minLength, maxLength, length, startSpeed, goalSpeed);
if (type == plAnimEaseTypes::kSpline)
return TRACKED_NEW plSplineEaseCurve(minLength, maxLength, length, startSpeed, goalSpeed);
return nil;
}
void plATCEaseCurve::RecalcToSpeed(hsScalar startSpeed, hsScalar goalSpeed, hsBool preserveRate /* = false */)
{
hsScalar rate = 1;
if (fSpeed == goalSpeed && fStartSpeed == startSpeed) // already there, no need to do anything
return;
if (preserveRate)
rate = (fSpeed - fStartSpeed) / fLength;
fStartSpeed = startSpeed;
fSpeed = goalSpeed;
if (preserveRate)
SetLengthOnRate(rate);
}
void plATCEaseCurve::SetLengthOnRate(hsScalar rate)
{
fLength = (fSpeed - fStartSpeed) / rate;
if (fLength < 0)
fLength = -fLength;
}
hsScalar plATCEaseCurve::GetMinDistance()
{
if (fMinLength == 0)
return 0;
hsScalar oldLength = fLength;
fLength = fMinLength;
hsScalar result = PositionGivenTime(fMinLength);
fLength = oldLength;
return result;
}
hsScalar plATCEaseCurve::GetMaxDistance()
{
if (fMaxLength == 0)
return 0;
hsScalar oldLength = fLength;
fLength = fMaxLength;
hsScalar result = PositionGivenTime(fMaxLength);
fLength = oldLength;
return result;
}
hsScalar plATCEaseCurve::GetNormDistance()
{
if (fNormLength == 0)
return 0;
hsScalar oldLength = fLength;
fLength = fNormLength;
hsScalar result = PositionGivenTime(fNormLength);
fLength = oldLength;
return result;
}
void plATCEaseCurve::Read(hsStream *s, hsResMgr *mgr)
{
plCreatable::Read(s, mgr);
fMinLength = s->ReadSwapScalar();
fMaxLength = s->ReadSwapScalar();
fNormLength = fLength = s->ReadSwapScalar();
fStartSpeed = s->ReadSwapScalar();
fSpeed = s->ReadSwapScalar();
fBeginWorldTime = s->ReadSwapDouble();
}
void plATCEaseCurve::Write(hsStream *s, hsResMgr *mgr)
{
plCreatable::Write(s, mgr);
s->WriteSwapScalar(fMinLength);
s->WriteSwapScalar(fMaxLength);
s->WriteSwapScalar(fNormLength);
s->WriteSwapScalar(fStartSpeed);
s->WriteSwapScalar(fSpeed);
s->WriteSwapDouble(fBeginWorldTime);
}
///////////////////////////////////////////////////////////////////////////////////////////////
plConstAccelEaseCurve::plConstAccelEaseCurve()
{
fMinLength = fMaxLength = fNormLength = fLength = 1;
fBeginWorldTime = 0;
RecalcToSpeed(0, 1);
}
plConstAccelEaseCurve::plConstAccelEaseCurve(hsScalar minLength, hsScalar maxLength, hsScalar length,
hsScalar startSpeed, hsScalar goalSpeed)
{
fMinLength = minLength;
fMaxLength = maxLength;
fNormLength = fLength = length;
fBeginWorldTime = 0;
RecalcToSpeed(startSpeed, goalSpeed);
}
plATCEaseCurve *plConstAccelEaseCurve::Clone() const
{
plConstAccelEaseCurve *curve = TRACKED_NEW plConstAccelEaseCurve;
curve->fStartSpeed = fStartSpeed;
curve->fMinLength = fMinLength;
curve->fMaxLength = fMaxLength;
curve->fNormLength = fNormLength;
curve->fBeginWorldTime = fBeginWorldTime;
curve->fLength = fLength;
curve->fSpeed = fSpeed;
return curve;
}
void plConstAccelEaseCurve::SetLengthOnDistance(hsScalar dist)
{
fLength = 2 * dist / (fSpeed + fStartSpeed);
}
hsScalar plConstAccelEaseCurve::PositionGivenTime(hsScalar time) const
{
return (hsScalar)(fStartSpeed * time + (0.5 * (fSpeed - fStartSpeed) / fLength) * time * time);
}
hsScalar plConstAccelEaseCurve::VelocityGivenTime(hsScalar time) const
{
return fStartSpeed + ((fSpeed - fStartSpeed) / fLength) * time;
}
hsScalar plConstAccelEaseCurve::TimeGivenVelocity(hsScalar velocity) const
{
return (velocity - fStartSpeed) / ((fSpeed - fStartSpeed) / fLength);
}
///////////////////////////////////////////////////////////////////////////////////////////////
plSplineEaseCurve::plSplineEaseCurve()
{
fMinLength = fMaxLength = fNormLength = fLength = 1;
fBeginWorldTime = 0;
RecalcToSpeed(0, 1);
}
plSplineEaseCurve::plSplineEaseCurve(hsScalar minLength, hsScalar maxLength, hsScalar length,
hsScalar startSpeed, hsScalar goalSpeed)
{
fMinLength = minLength;
fMaxLength = maxLength;
fNormLength = fLength = length;
fBeginWorldTime = 0;
RecalcToSpeed(startSpeed, goalSpeed);
}
plATCEaseCurve *plSplineEaseCurve::Clone() const
{
plSplineEaseCurve *curve = TRACKED_NEW plSplineEaseCurve;
curve->fStartSpeed = fStartSpeed;
curve->fMinLength = fMinLength;
curve->fMaxLength = fMaxLength;
curve->fNormLength = fNormLength;
curve->fBeginWorldTime = fBeginWorldTime;
curve->fLength = fLength;
curve->fSpeed = fSpeed;
int i;
for (i = 0; i < 4; i++)
curve->fCoef[i] = fCoef[i];
return curve;
}
void plSplineEaseCurve::RecalcToSpeed(hsScalar startSpeed, hsScalar goalSpeed, hsBool preserveRate /* = false */)
{
plATCEaseCurve::RecalcToSpeed(startSpeed, goalSpeed, preserveRate);
// These are greatly simplified because the in/out tangents are always zero
// Note: "b" is always zero for the ease splines we're currently doing (and will remain that way
// so long as the initial acceleration is zero. Can optimize a bit of the eval math to take
// advantage of this.
hsScalar a, b, c, d;
a = fStartSpeed;
b = 0;
c = -3 * fStartSpeed + 3 * fSpeed;
d = 2 * fStartSpeed - 2 * fSpeed;
fCoef[0] = a;
fCoef[1] = b;
fCoef[2] = c;
fCoef[3] = d;
}
void plSplineEaseCurve::SetLengthOnDistance(hsScalar dist)
{
hsScalar curDist = PositionGivenTime(fLength);
fLength = fLength * dist / curDist;
}
hsScalar plSplineEaseCurve::PositionGivenTime(hsScalar time) const
{
hsScalar t1, t2, t3, t4;
t1 = time / fLength;
t2 = t1 * t1;
t3 = t2 * t1;
t4 = t3 * t1;
return fLength * (fCoef[0] * t1 + fCoef[1] * t2 / 2 + fCoef[2] * t3 / 3 + fCoef[3] * t4 / 4);
}
hsScalar plSplineEaseCurve::VelocityGivenTime(hsScalar time) const
{
hsScalar t1, t2, t3;
t1 = time / fLength;
t2 = t1 * t1;
t3 = t2 * t1;
return fCoef[0] + fCoef[1] * t1 + fCoef[2] * t2 + fCoef[3] * t3;
}
hsScalar plSplineEaseCurve::TimeGivenVelocity(hsScalar velocity) const
{
// Code based off of Graphics Gems V, pp 11-12 and
// http://www.worldserver.com/turk/opensource/FindCubicRoots.c.txt
// Solving the equation: fCoef[0] + fCoef[1] * t + fCoef[2] * t^2 + fCoef[3] * t^3 - velocity = 0
hsScalar root;
hsScalar a = (fCoef[0] - velocity) / fCoef[3];
hsScalar b = fCoef[1] / fCoef[3];
hsScalar c = fCoef[2] / fCoef[3];
hsScalar Q = (c * c - 3 * b) / 9;
hsScalar R = (2 * c * c * c - 9 * c * b + 27 * a) / 54;
hsScalar Q3 = Q * Q * Q;
hsScalar D = Q3 - R * R;
if (D >= 0)
{
// 3 roots, find the one in the range [0, 1]
const hsScalar pi = 3.14159;
double theta = acos(R / sqrt(Q3));
double sqrtQ = sqrt(Q);
root = (hsScalar)(-2 * sqrtQ * cos((theta + 4 * pi) / 3) - c / 3); // Middle root, most likely to match
if (root < 0.f || root > 1.f)
{
root = (hsScalar)(-2 * sqrtQ * cos((theta + 2 * pi) / 3) - c / 3); // Lower root
if (root < 0.f || root > 1.f)
{
root = (hsScalar)(-2 * sqrtQ * cos(theta / 3) - c / 3); // Upper root
}
}
}
else // One root to the equation (I don't expect this to happen for ease splines, but JIC)
{
double E = sqrt(-D) + pow(fabs(R), 1.f / 3.f);
root = (hsScalar)((E + Q / E) - c / 3);
if (R > 0)
root = -root;
}
if (root < 0.f || root > 1.f)
{
hsAssert(false, "No valid root found while solving animation spline");
// Either a bug, or a rare case of floating-point inaccuracy. Either way, guess
// the proper root as either the start or end of the curve based on the velocity.
hsScalar dStart = velocity - fStartSpeed;
if (dStart < 0)
dStart = -dStart;
hsScalar dEnd = velocity - fSpeed;
if (dEnd < 0)
dEnd = -dEnd;
root = (dStart < dEnd ? 0.f : 1.f);
}
return root * fLength;
}
void plSplineEaseCurve::Read(hsStream *s, hsResMgr *mgr)
{
plATCEaseCurve::Read(s, mgr);
fCoef[0] = s->ReadSwapScalar();
fCoef[1] = s->ReadSwapScalar();
fCoef[2] = s->ReadSwapScalar();
fCoef[3] = s->ReadSwapScalar();
}
void plSplineEaseCurve::Write(hsStream *s, hsResMgr *mgr)
{
plATCEaseCurve::Write(s, mgr);
s->WriteSwapScalar(fCoef[0]);
s->WriteSwapScalar(fCoef[1]);
s->WriteSwapScalar(fCoef[2]);
s->WriteSwapScalar(fCoef[3]);
}