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Initial check in of RaycastWithCallback

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This commit is contained in:
David Williams 2011-04-17 11:53:13 +01:00
parent 55cbff1186
commit a5f37d7a3a
3 changed files with 216 additions and 0 deletions
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2
library/PolyVoxCore/CMakeLists.txt
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@ -40,6 +40,8 @@ SET(CORE_INC_FILES
include/PolyVoxForwardDeclarations.h
include/Raycast.h
include/Raycast.inl
include/RaycastWithCallback.h
include/RaycastWithCallback.inl
include/Region.h
include/SurfaceExtractor.h
include/SurfaceExtractor.inl

60
library/PolyVoxCore/include/RaycastWithCallback.h Normal file
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@ -0,0 +1,60 @@
/*******************************************************************************
Copyright (c) 2005-2009 David Williams
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source
distribution.
*******************************************************************************/
#ifndef __PolyVox_RaycastWithCallback_H__
#define __PolyVox_RaycastWithCallback_H__
namespace PolyVox
{
template <typename VoxelType>
class RaycastWithCallback
{
public:
///Constructor
RaycastWithCallback(Volume<VoxelType>* volData, const Vector3DFloat& v3dStart, const Vector3DFloat& v3dDirection, polyvox_function<bool(const Vector3DInt32& position)> funcCallback);
///Sets the start position for the ray.
void setStart(const Vector3DFloat& v3dStart);
///Set the direction for the ray.
void setDirection(const Vector3DFloat& v3dDirection);
///Performs the raycast.
void execute();
private:
polyvox_function<bool(const Vector3DInt32& position)> m_funcCallback;
void doRaycast(float x1, float y1, float z1, float x2, float y2, float z2);
Volume<VoxelType>* m_volData;
VolumeSampler<VoxelType> m_sampVolume;
Vector3DFloat m_v3dStart;
Vector3DFloat m_v3dDirection;
float m_fMaxDistance;
};
}
#include "RaycastWithCallback.inl"
#endif //__PolyVox_RaycastWithCallback_H__

154
library/PolyVoxCore/include/RaycastWithCallback.inl Normal file
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@ -0,0 +1,154 @@
/*******************************************************************************
Copyright (c) 2005-2009 David Williams
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source
distribution.
*******************************************************************************/
namespace PolyVox
{
template <typename VoxelType>
RaycastWithCallback<VoxelType>::RaycastWithCallback(Volume<VoxelType>* volData, const Vector3DFloat& v3dStart, const Vector3DFloat& v3dDirection, polyvox_function<bool(const Vector3DInt32& position)> funcCallback)
:m_volData(volData)
,m_sampVolume(volData)
,m_v3dStart(v3dStart)
,m_v3dDirection(v3dDirection)
,m_funcCallback(funcCallback)
{
//Check the user provided a callback, because it
//is used to determine when to finish the raycast.
assert(m_funcCallback);
}
template <typename VoxelType>
void RaycastWithCallback<VoxelType>::setStart(const Vector3DFloat& v3dStart)
{
m_v3dStart = v3dStart;
}
template <typename VoxelType>
void RaycastWithCallback<VoxelType>::setDirection(const Vector3DFloat& v3dDirection)
{
m_v3dDirection = v3dDirection;
}
template <typename VoxelType>
void RaycastWithCallback<VoxelType>::execute(void)
{
//The doRaycast function is assuming that it is iterating over the areas defined between
//voxels. We actually want to define the areas as being centered on voxels (as this is
//what the CubicSurfaceExtractor generates). We add (0.5,0.5,0.5) here to adjust for this.
Vector3DFloat v3dStart = m_v3dStart + Vector3DFloat(0.5f, 0.5f, 0.5f);
//Compute the end point
Vector3DFloat v3dEnd = v3dStart + m_v3dDirection;
//Do the raycast
doRaycast(v3dStart.getX(), v3dStart.getY(), v3dStart.getZ(), v3dEnd.getX(), v3dEnd.getY(), v3dEnd.getZ());
}
// This function is based on Christer Ericson's code and description of the 'Uniform Grid Intersection Test' in
// 'Real Time Collision Detection'. The following information from the errata on the book website is also relevent:
//
// pages 326-327. In the function VisitCellsOverlapped() the two lines calculating tx and ty are incorrect.
// The less-than sign in each line should be a greater-than sign. That is, the two lines should read:
//
// float tx = ((x1 > x2) ? (x1 - minx) : (maxx - x1)) / Abs(x2 - x1);
// float ty = ((y1 > y2) ? (y1 - miny) : (maxy - y1)) / Abs(y2 - y1);
//
// Thanks to Jetro Lauha of Fathammer in Helsinki, Finland for reporting this error.
//
// Jetro also points out that the computations of i, j, iend, and jend are incorrectly rounded if the line
// coordinates are allowed to go negative. While that was not really the intent of the code — that is, I
// assumed grids to be numbered from (0, 0) to (m, n) — I'm at fault for not making my assumption clear.
// Where it is important to handle negative line coordinates the computation of these variables should be
// changed to something like this:
//
// // Determine start grid cell coordinates (i, j)
// int i = (int)floorf(x1 / CELL_SIDE);
// int j = (int)floorf(y1 / CELL_SIDE);
//
// // Determine end grid cell coordinates (iend, jend)
// int iend = (int)floorf(x2 / CELL_SIDE);
// int jend = (int)floorf(y2 / CELL_SIDE);
//
// page 328. The if-statement that reads "if (ty <= tx && ty <= tz)" has a superfluous condition.
// It should simply read "if (ty <= tz)".
//
// This error was reported by Joey Hammer (PixelActive).
template <typename VoxelType>
void RaycastWithCallback<VoxelType>::doRaycast(float x1, float y1, float z1, float x2, float y2, float z2)
{
int i = (int)floorf(x1);
int j = (int)floorf(y1);
int k = (int)floorf(z1);
int iend = (int)floorf(x2);
int jend = (int)floorf(y2);
int kend = (int)floorf(z2);
int di = ((x1 < x2) ? 1 : ((x1 > x2) ? -1 : 0));
int dj = ((y1 < y2) ? 1 : ((y1 > y2) ? -1 : 0));
int dk = ((z1 < z2) ? 1 : ((z1 > z2) ? -1 : 0));
float minx = floorf(x1), maxx = minx + 1.0f;
float tx = ((x1 > x2) ? (x1 - minx) : (maxx - x1)) / abs(x2 - x1);
float miny = floorf(y1), maxy = miny + 1.0f;
float ty = ((y1 > y2) ? (y1 - miny) : (maxy - y1)) / abs(y2 - y1);
float minz = floorf(z1), maxz = minz + 1.0f;
float tz = ((z1 > z2) ? (z1 - minz) : (maxz - z1)) / abs(z2 - z1);
float deltatx = 1.0f / abs(x2 - x1);
float deltaty = 1.0f / abs(y2 - y1);
float deltatz = 1.0f / abs(z2 - z1);
m_sampVolume.setPosition(i,j,k);
for(;;)
{
//Call the callback. If it returns false then finish the loop.
if(!m_funcCallback(Vector3DInt32(i,j,k)))
{
break;
}
if(tx <= ty && tx <= tz)
{
tx += deltatx;
i += di;
if(di == 1) m_sampVolume.movePositiveX();
if(di == -1) m_sampVolume.moveNegativeX();
} else if (ty <= tz)
{
ty += deltaty;
j += dj;
if(dj == 1) m_sampVolume.movePositiveY();
if(dj == -1) m_sampVolume.moveNegativeY();
} else
{
tz += deltatz;
k += dk;
if(dk == 1) m_sampVolume.movePositiveZ();
if(dk == -1) m_sampVolume.moveNegativeZ();
}
}
}
}