independent.cpp

/*
    This file is part of Nori, a simple educational ray tracer
 
    Copyright (c) 2015 by Wenzel Jakob
 
    Nori is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License Version 3
    as published by the Free Software Foundation.
 
    Nori 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 General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
 
#include <nori/sampler.h>
#include <nori/block.h>
#include <pcg32.h>
 
NORI_NAMESPACE_BEGIN
 
class Independent : public Sampler {
public:
    Independent(const PropertyList &propList) {
        m_sampleCount = (size_t) propList.getInteger("sampleCount", 1);
    }
 
    virtual ~Independent() { }
 
    std::unique_ptr<Sampler> clone() const {
        std::unique_ptr<Independent> cloned(new Independent());
        cloned->m_sampleCount = m_sampleCount;
        cloned->m_random = m_random;
        return std::move(cloned);
    }
 
    void prepare(const ImageBlock &block) {
        m_random.seed(
            block.getOffset().x(),
            block.getOffset().y()
        );
    }
 
    void generate() { /* No-op for this sampler */ }
    void advance()  { /* No-op for this sampler */ }
 
    float next1D() {
        return m_random.nextFloat();
    }
    
    Point2f next2D() {
        return Point2f(
            m_random.nextFloat(),
            m_random.nextFloat()
        );
    }
 
    virtual std::string toString() const override {
        return tfm::format("Independent[sampleCount=%i]", m_sampleCount);
    }
protected:
    Independent() { }
 
private:
    pcg32 m_random;
};
 
NORI_REGISTER_CLASS(Independent, "independent");
NORI_NAMESPACE_END