khanat-opennel-code/code/nel/include/nel/3d/ps_misc.h

79 lines
3 KiB
C++

// NeL - MMORPG Framework <http://dev.ryzom.com/projects/nel/>
// Copyright (C) 2010 Winch Gate Property Limited
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
#ifndef PS_MISC_H
#define PS_MISC_H
#include "nel/misc/types_nl.h"
#include "nel/misc/vector.h"
#include "nel/3d/particle_system_process.h"
namespace NL3D {
/** Find a quantity to add to a float f such as f + deltaT * numStep, be >= than a given float (endValue). numStep is an integer,.
* It gives the number of steps used. If the number of steps is equal or greater than numStep, it is clamped to numStep
* \param f the start value.
* \return The number of steps.
*/
inline uint ScaleFloatGE(float f, float deltaT, float clampValue, uint numStep)
{
NL_PS_FUNC(ScaleFloatGE)
if (f >= clampValue) return 0;
float endValue = f + numStep * deltaT;
if (endValue < clampValue) return numStep;
const uint numAfterInitialDate = (uint) ((endValue - clampValue) / deltaT);
return numStep - numAfterInitialDate;
}
/** Private function used to fill a buffer with the same value by using the given subdivision.
* NumStep and startValue are modified to give the steps that are above or equal to clampValue.
* \param value The value to fill the buffer with.
* \param clampValue A float such as startValue + n * deltaT < clampValue, where n is the number of value to fill.
* \param startValue The start value, used to get the number of steps, see clampValue.
* \param deltaT The step between values
* \param maxNumStep The max number of steps that can be filled. It is modified to
* \param destPos The destination, that will be filled with the given value
* \param stride Number of byte between each value to be copied
*/
inline NLMISC::CVector *FillBufUsingSubdiv(const NLMISC::CVector &value,
float clampValue,
float &startValue,
float deltaT,
uint &maxNumStep,
NLMISC::CVector *destPos,
uint32 stride
)
{
NL_PS_FUNC(FillBufUsingSubdiv)
uint numToFill = ScaleFloatGE(startValue, deltaT, clampValue, maxNumStep);
nlassert(numToFill <= maxNumStep);
startValue += numToFill * deltaT;
maxNumStep -= numToFill;
while (numToFill--)
{
*destPos = value;
destPos = (NLMISC::CVector *) ( (uint8 *) destPos + stride);
}
return destPos;
}
} // NL3D
#endif