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UnrealEngine/Engine/Source/ThirdParty/openexr/openexr-3.3.2/Contrib/DtexToExr/PxOneChanDeepOpacity.h
2025-05-18 13:04:45 +08:00

429 lines
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C++

//
// SPDX-License-Identifier: BSD-3-Clause
// Copyright (c) Contributors to the OpenEXR Project.
//
#ifndef _PxOneChanDeepOpacity_h_
#define _PxOneChanDeepOpacity_h_
#include "PxBaseDeepHelper.h"
#include "PxDeepUtils.h"
namespace PxDeep
{
//-*****************************************************************************
// ONE CHANNEL DEEP OPACITY CONTINUOUS
//-*****************************************************************************
template <typename RGBA_T>
class OneChanDeepOpacityContinuous : public BaseDeepHelper<
RGBA_T,
OneChanDeepOpacityContinuous<RGBA_T>,
SpanOpac>
{
public:
typedef BaseDeepHelper<
RGBA_T,
OneChanDeepOpacityContinuous<RGBA_T>,
SpanOpac>
super_type;
typedef OneChanDeepOpacityContinuous<RGBA_T> this_type;
typedef typename super_type::span_type span_type;
OneChanDeepOpacityContinuous (
DtexFile* i_dtexFile, int i_numDtexChans, const Parameters& i_params)
: BaseDeepHelper<
RGBA_T,
OneChanDeepOpacityContinuous<RGBA_T>,
SpanOpac> (i_dtexFile, i_numDtexChans, i_params)
{}
void processDeepPixel (int i_numPts);
};
//-*****************************************************************************
// ONE CHANNEL DEEP OPACITY DISCRETE
//-*****************************************************************************
template <typename RGBA_T>
class OneChanDeepOpacityDiscrete : public BaseDeepHelper<
RGBA_T,
OneChanDeepOpacityDiscrete<RGBA_T>,
SpanOpac>
{
public:
typedef BaseDeepHelper<RGBA_T, OneChanDeepOpacityDiscrete<RGBA_T>, SpanOpac>
super_type;
typedef OneChanDeepOpacityDiscrete<RGBA_T> this_type;
typedef typename super_type::span_type span_type;
OneChanDeepOpacityDiscrete (
DtexFile* i_dtexFile, int i_numDtexChans, const Parameters& i_params)
: BaseDeepHelper<RGBA_T, OneChanDeepOpacityDiscrete<RGBA_T>, SpanOpac> (
i_dtexFile, i_numDtexChans, i_params)
{}
void processDeepPixel (int i_numPts);
};
//-*****************************************************************************
template <typename RGBA_T>
void
OneChanDeepOpacityContinuous<RGBA_T>::processDeepPixel (int i_numPts)
{
assert (i_numPts > 0);
// Loop over all the dtex points and get their deepOpacities and
// depths.
(this->m_spans).resize ((size_t) i_numPts);
for (int j = 0; j < i_numPts; ++j)
{
float z;
float pts[4];
DtexPixelGetPoint ((this->m_pixel), j, &z, (float*) pts);
z = ClampDepth (z);
span_type& spanJ = (this->m_spans)[j];
spanJ.clear ();
spanJ.in = z;
spanJ.out = z;
// Data stored in dtex files for "deepopacity" is actually
// "deeptransmission", monotonically decreasing from an initial
// value of 1.0. We just convert it to viz directly.
// (viz == transmissivity)
spanJ.deepViz = ClampViz (pts[0]);
spanJ.index = j;
}
// Sort the spans by depth (and then index)
std::sort ((this->m_spans).begin (), (this->m_spans).end ());
// Combine identical depths, accumulating maximum density
// along the way. Because we have deep opacity,
// coincident samples use the maximum deepOpacity value.
double maxDensity = PXDU_MIN_NON_ZERO_DENSITY;
{
int prevSpanIndex = 0;
int activeBegin = 0;
int activeEnd = 0;
float interestingDepth = 0.0f;
int numRemoved = 0;
while (activeBegin < i_numPts)
{
span_type& spanActiveBegin = (this->m_spans)[activeBegin];
float nextInterestingDepth = spanActiveBegin.in;
assert (nextInterestingDepth > interestingDepth);
// This loop combines all the coincident samples
// into a single sample, invalidates the other coincident
// samples, and sets activeEnd to point to the next
// sample with a larger depth.
activeEnd = i_numPts;
for (int a = activeBegin + 1; a < i_numPts; ++a)
{
span_type& spanNext = (this->m_spans)[a];
assert (spanNext.in > interestingDepth);
assert (spanNext.in >= nextInterestingDepth);
if (spanNext.in > nextInterestingDepth)
{
// This span is not active in this round,
// set activeEnd and get out.
activeEnd = a;
break;
}
else
{
// This span has an identical depth to
// the previous one, so we use whichever one has the
// largest deep opacity, which equates to the
// smallest deep viz.
spanActiveBegin.deepViz =
std::min (spanActiveBegin.deepViz, spanNext.deepViz);
spanNext.in = FLT_MAX;
spanNext.out = FLT_MAX;
++numRemoved;
}
}
// Okay, the deep vizibility at our in point
// is equal to the total vizibility before us,
// which is the deep vizibility at the previous point,
// times the vizibility of this point.
// deepViz = deepVizPrev * viz
// viz = deepViz / deepVizPrev;
if (activeBegin == 0)
{
spanActiveBegin.viz = spanActiveBegin.deepViz;
}
else
{
span_type& spanPrev = (this->m_spans)[prevSpanIndex];
// Make sure the deep visibilities are
// monotonically decreasing with depth.
spanActiveBegin.deepViz =
std::min (spanActiveBegin.deepViz, spanPrev.deepViz);
if (spanPrev.deepViz > 0.0)
{
// If we have non-zero accumulated visibility,
// we can compute the span visibility.
spanActiveBegin.viz =
spanActiveBegin.deepViz / spanPrev.deepViz;
}
else
{
// If we have zero accumulated visibility,
// then the span visibility is also zero.
spanActiveBegin.viz = 0.0;
}
// Use the viz of this span to update the
// max density.
spanActiveBegin.viz = ClampViz (spanActiveBegin.viz);
spanActiveBegin.in = spanPrev.out;
double dz = spanActiveBegin.out - spanActiveBegin.in;
assert (dz > 0.0);
assert (spanActiveBegin.out > spanActiveBegin.in);
double density = DensityFromVizDz (spanActiveBegin.viz, dz);
maxDensity = std::max (maxDensity, density);
}
prevSpanIndex = activeBegin;
activeBegin = activeEnd;
interestingDepth = nextInterestingDepth;
}
// If any removed, re-sort the list and remove the end
// points.
if (numRemoved > 0)
{
assert (numRemoved < i_numPts);
std::sort ((this->m_spans).begin (), (this->m_spans).end ());
i_numPts -= numRemoved;
(this->m_spans).resize (i_numPts);
}
}
// Handle the single point case.
if (i_numPts == 1)
{
span_type& span0 = (this->m_spans)[0];
if ((this->m_params).discardZeroAlphaSamples && span0.viz >= 1.0)
{
// Nothing!
return;
}
span0.in = ClampDepth (DecrementPositiveFloat (span0.out));
float alphaF = ClampAlpha (1.0 - span0.viz);
(this->m_deepOutPixel).push_back (span0.in, span0.out, alphaF);
return;
}
// Put the spans back out.
// If the first point has a non-zero alpha, extrapolate the
// maximum density to create a begin point.
for (int j = 0; j < i_numPts; ++j)
{
span_type& spanJ = (this->m_spans)[j];
if ((this->m_params.discardZeroAlphaSamples) && spanJ.viz >= 1.0)
{
// This span is transparent, ignore it.
continue;
}
if (j == 0)
{
// This is first point.
// If it has non-zero alpha, it needs depth,
// which we use the max density for.
if (spanJ.viz >= 1.0)
{
// Don't need to worry about this last span!
// It is at the end of the continuous span, and
// is completely transparent.
continue;
}
double dz = DzFromVizDensity (spanJ.viz, maxDensity);
spanJ.in = ClampDepth (spanJ.out - dz);
if (spanJ.out <= spanJ.in)
{
spanJ.in = ClampDepth (DecrementPositiveFloat (spanJ.out));
}
}
float alphaF = ClampAlpha (1.0 - spanJ.viz);
// Set the channels!
(this->m_deepOutPixel).push_back (spanJ.in, spanJ.out, alphaF);
}
}
//-*****************************************************************************
template <typename RGBA_T>
void
OneChanDeepOpacityDiscrete<RGBA_T>::processDeepPixel (int i_numPts)
{
assert (i_numPts > 0);
// Loop over all the dtex points and get their deepOpacities and
// depths.
(this->m_spans).resize ((size_t) i_numPts);
for (int j = 0; j < i_numPts; ++j)
{
float z;
float pts[4];
DtexPixelGetPoint ((this->m_pixel), j, &z, (float*) pts);
z = ClampDepth (z);
span_type& spanJ = (this->m_spans)[j];
spanJ.clear ();
spanJ.in = z;
spanJ.out = z;
// Data stored in dtex files for "deepopacity" is actually
// "deeptransmission", monotonically decreasing from an initial
// value of 1.0. We just convert it to viz directly.
// (viz == transmissivity)
spanJ.deepViz = ClampViz (pts[0]);
spanJ.index = j;
}
// Sort the spans.
std::sort ((this->m_spans).begin (), (this->m_spans).end ());
// Combine identical depths. Because we have deep opacity,
// coincident samples use the maximum deepOpacity value.
{
int prevSpanIndex = 0;
int activeBegin = 0;
int activeEnd = 0;
float interestingDepth = 0.0f;
int numRemoved = 0;
while (activeBegin < i_numPts)
{
span_type& spanActiveBegin = (this->m_spans)[activeBegin];
float nextInterestingDepth = spanActiveBegin.in;
assert (nextInterestingDepth > interestingDepth);
// This loop combines all the coincident samples
// into a single sample, invalidates the other coincident
// samples, and sets activeEnd to point to the next
// sample with a larger depth.
activeEnd = i_numPts;
for (int a = activeBegin + 1; a < i_numPts; ++a)
{
span_type& spanNext = (this->m_spans)[a];
assert (spanNext.in > interestingDepth);
assert (spanNext.in >= nextInterestingDepth);
if (spanNext.in > nextInterestingDepth)
{
// This span is not active in this round,
// set activeEnd and get out.
activeEnd = a;
break;
}
else
{
// This span has an identical depth to
// the previous one, so we use whichever one has the
// largest deep opacity, which equates to the
// smallest deep viz.
spanActiveBegin.deepViz =
std::min (spanActiveBegin.deepViz, spanNext.deepViz);
spanNext.in = FLT_MAX;
spanNext.out = FLT_MAX;
++numRemoved;
}
}
// Okay, the deep vizibility at our in point
// is equal to the total vizibility before us,
// which is the deep vizibility at the previous point,
// times the vizibility of this point.
// deepViz = deepVizPrev * viz
// viz = deepViz / deepVizPrev;
if (activeBegin == 0)
{
spanActiveBegin.viz = spanActiveBegin.deepViz;
}
else
{
span_type& spanPrev = (this->m_spans)[prevSpanIndex];
// Make sure the deep visibilities are
// monotonically decreasing with depth.
spanActiveBegin.deepViz =
std::min (spanActiveBegin.deepViz, spanPrev.deepViz);
if (spanPrev.deepViz > 0.0)
{
// If we have non-zero accumulated visibility,
// we can compute the span visibility.
spanActiveBegin.viz =
spanActiveBegin.deepViz / spanPrev.deepViz;
}
else
{
// If we have zero accumulated visibility,
// then the span visibility is also zero.
spanActiveBegin.viz = 0.0;
}
// Clean up the viz!
spanActiveBegin.viz = ClampViz (spanActiveBegin.viz);
}
prevSpanIndex = activeBegin;
activeBegin = activeEnd;
interestingDepth = nextInterestingDepth;
}
// If any removed, re-sort the list and remove the end
// points.
if (numRemoved > 0)
{
assert (numRemoved < i_numPts);
std::sort ((this->m_spans).begin (), (this->m_spans).end ());
i_numPts -= numRemoved;
(this->m_spans).resize (i_numPts);
}
}
// Put the spans back out.
for (int j = 0; j < i_numPts; ++j)
{
span_type& spanJ = (this->m_spans)[j];
if ((this->m_params).discardZeroAlphaSamples && spanJ.viz >= 1.0)
{
// This span is transparent, ignore it.
continue;
}
float alphaF = ClampAlpha (1.0 - spanJ.viz);
(this->m_deepOutPixel).push_back (spanJ.in, alphaF);
}
}
} // End namespace PxDeep
#endif