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//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// * Neither the name of NVIDIA CORPORATION nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``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 THE COPYRIGHT OWNER OR
// CONTRIBUTORS 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.
//
// Copyright (c) 2018 NVIDIA Corporation. All rights reserved.
#include "Apex.h"
#include "PxAssert.h"
#include "nvparameterized/NvParameterized.h"
#include "Curve.h"
#include "CurveImpl.h"
namespace nvidia
{
namespace apex
{
/**
Linear interpolation. "in" and "out" stands here for X and Y coordinates of the control points
*/
inline float lerp(float inCurrent, float inMin, float inMax, float outMin, float outMax)
{
if (inMin == inMax)
{
return outMin;
}
return ((inCurrent - inMin) / (inMax - inMin)) * (outMax - outMin) + outMin;
}
/**
The CurveImpl is a class for storing control points on a curve and evaluating the results later.
*/
/**
Retrieve the output Y for the specified input x, based on the properties of the stored curve described
by mControlPoints.
*/
float CurveImpl::evaluate(float x) const
{
Vec2R xPoints, yPoints;
if (calculateControlPoints(x, xPoints, yPoints))
{
return lerp(x, xPoints[0], xPoints[1], yPoints[0], yPoints[1]);
}
else if (mControlPoints.size() == 1)
{
return mControlPoints[0].y;
}
else
{
// This is too noisy for editors...
//PX_ASSERT(!"Unable to find control points that contained the specified curve parameter");
return 0;
}
}
/**
Add a control point to the list of control points, returning the index of the new point.
*/
uint32_t CurveImpl::addControlPoint(const Vec2R& controlPoint)
{
uint32_t index = calculateFollowingControlPoint(controlPoint.x);
if (index == mControlPoints.size())
{
// add element to the end
Vec2R& v2 = mControlPoints.insert();
v2 = controlPoint;
}
else
{
// memmove all elements from index - end to index+1 - new_end
uint32_t oldSize = mControlPoints.size();
mControlPoints.insert();
memmove(&mControlPoints[index + 1], &mControlPoints[index], sizeof(Vec2R) * (oldSize - index));
mControlPoints[index] = controlPoint;
}
return index;
}
/**
Add a control points to the list of control points. Assuming the
hPoints points to a list of vec2s
*/
void CurveImpl::addControlPoints(::NvParameterized::Interface* param, ::NvParameterized::Handle& hPoints)
{
::NvParameterized::Handle ih(*param), hMember(*param);
int arraySize = 0;
PX_ASSERT(hPoints.getConstInterface() == param);
hPoints.getArraySize(arraySize);
for (int i = 0; i < arraySize; i++)
{
hPoints.getChildHandle(i, ih);
Vec2R tmpVec2;
ih.getChildHandle(0, hMember);
hMember.getParamF32(tmpVec2.x);
ih.getChildHandle(1, hMember);
hMember.getParamF32(tmpVec2.y);
addControlPoint(tmpVec2);
}
}
/**
Locates the control points that contain x, placing the resulting control points in the two
out parameters. Returns true if the points were found, false otherwise. If the points were not
found, the output variables are untouched
*/
bool CurveImpl::calculateControlPoints(float x, Vec2R& outXPoints, Vec2R& outYPoints) const
{
uint32_t controlPointSize = mControlPoints.size();
if (controlPointSize < 2)
{
return false;
}
uint32_t followControlPoint = calculateFollowingControlPoint(x);
if (followControlPoint == 0)
{
outXPoints[0] = outXPoints[1] = mControlPoints[0].x;
outYPoints[0] = outYPoints[1] = mControlPoints[0].y;
return true;
}
else if (followControlPoint == controlPointSize)
{
outXPoints[0] = outXPoints[1] = mControlPoints[followControlPoint - 1].x;
outYPoints[0] = outYPoints[1] = mControlPoints[followControlPoint - 1].y;
return true;
}
outXPoints[0] = mControlPoints[followControlPoint - 1].x;
outXPoints[1] = mControlPoints[followControlPoint].x;
outYPoints[0] = mControlPoints[followControlPoint - 1].y;
outYPoints[1] = mControlPoints[followControlPoint].y;
return true;
}
/**
Locates the first control point with x larger than xValue or the nimber of control points if such point doesn't exist
*/
uint32_t CurveImpl::calculateFollowingControlPoint(float xValue) const
{
// TODO: This could be made O(log(N)), but I think there should
// be so few entries that it's not worth the code complexity.
uint32_t cpSize = mControlPoints.size();
for (uint32_t u = 0; u < cpSize; ++u)
{
if (xValue <= mControlPoints[u].x)
{
return u;
}
}
return cpSize;
}
///get the array of control points
const Vec2R* CurveImpl::getControlPoints(uint32_t& outCount) const
{
outCount = mControlPoints.size();
if (outCount)
{
return &mControlPoints.front();
}
else
{
// LRR: there's more to this, chase this down later
return NULL;
}
}
}
} // namespace nvidia::apex
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