polyvox/tests/TestRaycast.cpp
2015-12-26 21:45:41 +00:00

129 lines
4.5 KiB
C++

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* The MIT License (MIT)
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* Copyright (c) 2015 Matthew Williams and David Williams
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#include "TestRaycast.h"
#include "PolyVox/Density.h"
#include "PolyVox/Raycast.h"
#include "PolyVox/RawVolume.h"
#include "PolyVox/Impl/RandomUnitVectors.h"
#include <QtTest>
using namespace PolyVox;
// This is the callback functor which is called by the raycast() function for every voxel it touches.
// It's primary purpose is to tell the raycast whether or not to continue (i.e. it tests whether the
// ray has hit a solid voxel). Because the instance of this class is passed to the raycast() function
// by reference we can also use it to encapsulate some state. We're testing this by counting the total
// number of voxels touched.
class RaycastTestFunctor
{
public:
RaycastTestFunctor()
:m_uVoxelsTouched(0)
,m_bRayLeftVolume(false)
{
}
bool operator()(const RawVolume<int8_t>::Sampler& sampler)
{
m_uVoxelsTouched++;
// For this particular test we know that we are always starting a ray inside the volume,
// so if it ever leaves the volume we know it can't go back in and so we can terminate early.
// This optimisation is worthwhile because samplers get slow once outside the volume.
if(!sampler.isCurrentPositionValid())
{
m_bRayLeftVolume = true;
return false;
}
// We are in the volume, so decide whether to continue based on the voxel value.
return sampler.getVoxel() <= 0;
}
uint32_t m_uVoxelsTouched;
bool m_bRayLeftVolume;
};
void TestRaycast::testExecute()
{
const int32_t uVolumeSideLength = 32;
//Create a hollow volume, with solid sides on x and y but with open ends in z.
RawVolume<int8_t> volData(Region(Vector3DInt32(0, 0, 0), Vector3DInt32(uVolumeSideLength - 1, uVolumeSideLength - 1, uVolumeSideLength - 1)));
for (int32_t z = 0; z < uVolumeSideLength; z++)
{
for (int32_t y = 0; y < uVolumeSideLength; y++)
{
for (int32_t x = 0; x < uVolumeSideLength; x++)
{
if((x == 0) || (x == uVolumeSideLength-1) || (y == 0) || (y == uVolumeSideLength-1))
{
volData.setVoxel(x, y, z, 100);
}
else
{
volData.setVoxel(x, y, z, -100);
}
}
}
}
//Cast rays from the centre. Roughly 2/3 should escape.
Vector3DFloat start (uVolumeSideLength / 2, uVolumeSideLength / 2, uVolumeSideLength / 2);
// We could have counted the total number of hits in the same way as the total number of voxels
// touched, but for demonstration and testing purposes we are making use of the raycast return value
// and counting them seperatly in this variable.
int hits = 0;
uint32_t uTotalVoxelsTouched = 0;
// Cast a large number of random rays
for(int ct = 0; ct < 1000000; ct++)
{
RaycastTestFunctor raycastTestFunctor;
RaycastResult result = raycastWithDirection(&volData, start, randomUnitVectors[ct % 1024] * 1000.0f, raycastTestFunctor);
uTotalVoxelsTouched += raycastTestFunctor.m_uVoxelsTouched;
// If the raycast completed then we know it did not hit anything.If it was interupted then it
// probably hit something, unless we noted that the reason it was interupted was that it left the volume.
if((result == RaycastResults::Interupted) && (raycastTestFunctor.m_bRayLeftVolume == false))
{
hits++;
}
}
// Check the number of hits.
QCOMPARE(hits, 687494);
// Check the total number of voxels touched
QCOMPARE(uTotalVoxelsTouched, static_cast<uint32_t>(29783248));
}
QTEST_MAIN(TestRaycast)