+
−/*
+
− * scene.cc: screen sample generation and image reconstruction
+
− *
+
− * This file is part of Pyrit Ray Tracer.
+
− *
+
− * Copyright 2008  Radek Brich
+
− *
+
− * Permission is hereby granted, free of charge, to any person obtaining a copy
+
− * of this software and associated documentation files (the "Software"), to deal
+
− * in the Software without restriction, including without limitation the rights
+
− * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+
− * copies of the Software, and to permit persons to whom the Software is
+
− * furnished to do so, subject to the following conditions:
+
− *
+
− * The above copyright notice and this permission notice shall be included in
+
− * all copies or substantial portions of the Software.
+
− *
+
− * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+
− * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+
− * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+
− * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+
− * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+
− * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+
− * THE SOFTWARE.
+
− */
+
−
+
−#include <math.h>
+
−
+
−#include "common.h"
+
−#include "scene.h"
+
−
+
−/* grid oversampling look up tables */
+
−static const int gridsamples[] = {1,4,9,16};
+
−static const Float osa4x[] = { -0.25f, +0.25f, +0.25f, -0.25f };
+
−static const Float osa4y[] = { -0.25f, -0.25f, +0.25f, +0.25f };
+
−static const Float osa9x[] =
+
−{
+
−	-0.34f,  0.00f, +0.34f,
+
−	-0.34f,  0.00f, +0.34f,
+
−	-0.34f,  0.00f, +0.34f
+
−};
+
−static const Float osa9y[] =
+
−{
+
−	-0.34f, -0.34f, -0.34f,
+
−	 0.00f,  0.00f,  0.00f,
+
−	+0.34f, +0.34f, +0.34f
+
−};
+
−static const Float osa16x[] =
+
−{
+
−	-0.375f, -0.125f, +0.125f, +0.375f,
+
−	-0.375f, -0.125f, +0.125f, +0.375f,
+
−	-0.375f, -0.125f, +0.125f, +0.375f,
+
−	-0.375f, -0.125f, +0.125f, +0.375f
+
−};
+
−static const Float osa16y[] =
+
−{
+
−	-0.375f, -0.375f, -0.375f, -0.375f,
+
−	-0.125f, -0.125f, -0.125f, -0.125f,
+
−	+0.125f, +0.125f, +0.125f, +0.125f,
+
−	+0.375f, +0.375f, +0.375f, +0.375f
+
−};
+
−static const Float *osaSx[] = {NULL, osa4x, osa9x, osa16x};
+
−static const Float *osaSy[] = {NULL, osa4y, osa9y, osa16y};
+
−
+
−
+
−void DefaultSampler::init()
+
−{
+
−	phase = 0;
+
−	packetable = (subsample <= 1);
+
−}
+
−
+
−int DefaultSampler::initSampleSet()
+
−{
+
−	const int samples = gridsamples[oversample];
+
−	const int &w = pixmap.getWidth(), &h = pixmap.getHeight();
+
−	Float *&buffer = pixmap.getFloatData();
+
−
+
−	if ( phase == 0 )
+
−	{
+
−		if (subsample > 1)
+
−		{
+
−			phase = 1;
+
−			sx = -1;
+
−			return (w/subsample+1)*(h/subsample+1);
+
−		}
+
−		else
+
−		{
+
−			phase = 2;
+
−			sx = -1;
+
−			return w*h*samples;
+
−		}
+
−	}
+
−	if ( phase == 1 )
+
−	{
+
−		// finalize subsampling
+
−		const Float subsample2 = 1.0f / (subsample*subsample);
+
−		int num_samples = 0;
+
−		Colour ic;
+
−		phase = 2;
+
−		sx = -1;
+
−		for (int y = 0; y < h/subsample; y++)
+
−			for (int x = 0; x < w/subsample; x++)
+
−			{
+
−				int x1 = x*subsample;
+
−				int y1 = y*subsample;
+
−				int x2 = (x+1)*subsample;
+
−				int y2 = (y+1)*subsample;
+
−				if (x2 > w-1)	x2 = w-1;
+
−				if (y2 > h-1)	y2 = h-1;
+
−				if (x1 == x2 || y1 == y2)
+
−					continue;
+
−				Float *p;
+
−				p = buffer + 3*(y1*w + x1);
+
−				Colour c1(*p, *(p+1), *(p+2));
+
−				p = buffer + 3*(y1*w + x2);
+
−				Colour c2(*p, *(p+1), *(p+2));
+
−				p = buffer + 3*(y2*w + x1);
+
−				Colour c3(*p, *(p+1), *(p+2));
+
−				p = buffer + 3*(y2*w + x2);
+
−				Colour c4(*p, *(p+1), *(p+2));
+
−				Float m = (c1-c2).mag2();
+
−				m = max(m, (c2-c3).mag2());
+
−				m = max(m, (c3-c4).mag2());
+
−				m = max(m, (c4-c1).mag2());
+
−				if (m < 0.002)
+
−				{
+
−					// interpolate
+
−					for (int i = 0; i < subsample; i++)
+
−						for (int j = 0; j < subsample; j++)
+
−						{
+
−							ic = c1*(Float)((subsample-i)*(subsample-j)*subsample2)
+
−								+ c2*(Float)((i)*(subsample-j)*subsample2)
+
−								+ c3*(Float)((subsample-i)*(j)*subsample2)
+
−								+ c4*(Float)((i)*(j)*subsample2);
+
−							p = buffer + 3*((y1+j)*w + x1+i);
+
−							*(p + 0) = ic.r;
+
−							*(p + 1) = oversample ? -ic.g : ic.g;
+
−							*(p + 2) = ic.b;
+
−						}
+
−				}
+
−				else
+
−				{
+
−					// mark as to be computed
+
−					num_samples += subsample * subsample;
+
−					for (int i = 0; i < subsample; i++)
+
−						for (int j = 0; j < subsample; j++)
+
−							if (oversample || i != 0 || j != 0)
+
−								*(buffer + 3*((y1+j)*w + x1+i)) = -1.;
+
−				}
+
−			}
+
−		return num_samples;
+
−	}
+
−	if ( phase == 2 && oversample )
+
−	{
+
−		// finalize oversampling
+
−		Float *buf;
+
−		if (subsample > 1)
+
−			for (buf = buffer; buf != buffer + w*h*3; buf += 3)
+
−				if (*(buf+1) < 0)
+
−				{
+
−					// interpolated
+
−					*(buf+1) = -*(buf+1);
+
−				}
+
−				else
+
−				{
+
−					*buf = *buf * (1.0f/samples);
+
−					*(buf+1) = *(buf+1) * (1.0f/samples);
+
−					*(buf+2) = *(buf+2) * (1.0f/samples);
+
−				}
+
−		else
+
−			for (buf = buffer; buf != buffer + w*h*3; buf++)
+
−				*buf = *buf * (1.0f/samples);
+
−	}
+
−	phase = -1;
+
−	return 0;
+
−}
+
−
+
−bool DefaultSampler::nextSample(Sample* s)
+
−{
+
−	const int &w = pixmap.getWidth(), &h = pixmap.getHeight();
+
−	Float *&buffer = pixmap.getFloatData();
+
−
+
−	if (phase == 1)
+
−	{
+
−		// subsampling
+
−		if (sx < 0)
+
−		{
+
−			// first sample
+
−			s->x = -(Float)w/h/2.0f;
+
−			s->y = -0.5f;
+
−			sx = 0;
+
−			sy = 0;
+
−			osa_samp = 0;
+
−		}
+
−		else
+
−		{
+
−			if (sx == w-1)
+
−			{
+
−				if (sy == h-1)
+
−					return false;
+
−				sy += subsample;
+
−				if (sy > h-1)
+
−					sy = h-1;
+
−				sx = 0;
+
−			}
+
−			else
+
−			{
+
−				sx += subsample;
+
−				if (sx > w-1)
+
−					sx = w-1;
+
−			}
+
−
+
−			s->x = (Float)sx/h - (Float)w/h/2.0f;
+
−			s->y = (Float)sy/h - 0.5f;
+
−		}
+
−	}
+
−	else if (phase == 2)
+
−	{
+
−		/* grid oversampling */
+
−		const int samples = gridsamples[oversample];
+
−		const Float *osax = osaSx[oversample];
+
−		const Float *osay = osaSy[oversample];
+
−
+
−		if (sx < 0)
+
−		{
+
−			// first sample
+
−			s->x = -(Float)w/h/2.0f;
+
−			s->y = -0.5f;
+
−			sx = 0;
+
−			sy = 0;
+
−			osa_samp = 0;
+
−		}
+
−		else
+
−		{
+
−			osa_samp++;
+
−
+
−			if (oversample && oversample <= 3 && osa_samp < samples)
+
−			{
+
−				s->x = osax[osa_samp]/h + (Float)sx/h - (Float)w/h/2.0f;
+
−				s->y = osay[osa_samp]/h + (Float)sy/h - 0.5f;
+
−			}
+
−			else
+
−			{
+
−				if (subsample > 1)
+
−				{
+
−					// find next not interpolated pixel
+
−					do
+
−					{
+
−						sx++;
+
−						if (sx >= w)
+
−						{
+
−							sx = 0;
+
−							sy++;
+
−						}
+
−						if (sy >= h)
+
−							return false;
+
−					}
+
−					while ( *(buffer + 3*(sy*w + sx)) >= 0. );
+
−				}
+
−				else if (!oversample && !(w&1) && !(h&1))
+
−				{
+
−					// generate good raster for packet tracing
+
−					const int j = ((sy&1)<<1) + (sx&1);
+
−					switch (j)
+
−					{
+
−						case 0:
+
−						case 2:
+
−							sx++;
+
−							break;
+
−						case 1:
+
−							sx--;
+
−							sy++;
+
−							break;
+
−						case 3:
+
−							sx++;
+
−							if (sx >= w)
+
−							{
+
−								sx = 0;
+
−								sy++;
+
−							}
+
−							else
+
−								sy--;
+
−							if (sy >= h)
+
−								return false;
+
−							break;
+
−					}
+
−				}
+
−				else
+
−				{
+
−					sx++;
+
−					if (sx >= w)
+
−					{
+
−						sx = 0;
+
−						sy++;
+
−					}
+
−					if (sy >= h)
+
−						return false;
+
−				}
+
−
+
−				s->x = (Float)sx/h - (Float)w/h/2.0f;
+
−				s->y = (Float)sy/h - 0.5f;
+
−				osa_samp = 0;
+
−			}
+
−		}
+
−
+
−		if (osa_samp == 0 && oversample && oversample <= 3)
+
−		{
+
−			s->x += osax[0]/h;
+
−			s->y += osay[0]/h;
+
−			Float *buf = buffer + 3*(sy*w + sx);
+
−			*(buf++) = 0;
+
−			*(buf++) = 0;
+
−			*(buf++) = 0;
+
−		}
+
−	}
+
−
+
−	s->sx = sx;
+
−	s->sy = sy;
+
−	s->osa_samp = osa_samp;
+
−
+
−	return true;
+
−}
+
−
+
−void DefaultSampler::saveSample(const Sample &samp, const Colour &col)
+
−{
+
−	Float *buf = pixmap.getFloatData()
+
−		+ 3*(samp.sy * pixmap.getWidth() + samp.sx);
+
−	if (phase == 2 && oversample)
+
−	{
+
−		*(buf+0) += col.r;
+
−		*(buf+1) += col.g;
+
−		*(buf+2) += col.b;
+
−	}
+
−	else
+
−	{
+
−		*(buf++) = col.r;
+
−		*(buf++) = col.g;
+
−		*(buf++) = col.b;
+
−	}
+
−}
+
−