mlt.h

/*
 * Fermat
 *
 * Copyright (c) 2016-2019, NVIDIA CORPORATION. All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *    * Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *    * Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *    * Neither the name of the NVIDIA CORPORATION nor the
 *      names of its contributors may be used to endorse or promote products
 *      derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL NVIDIA CORPORATION BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include <types.h>
#include <buffers.h>
#include <ray.h>
#include <lights.h>
#include <vertex_storage.h>
#include <bpt_options.h>
#include <bpt_queues.h>
#include <tiled_sequence.h>
#include <cugar/sampling/lfsr.h>
#include <cugar/color/rgbe.h>
#include <cugar/basic/memory_arena.h>
#include <renderer_interface.h>

struct RenderingContext;
struct RenderingContextView;

struct MLTContext;

struct MLTOptions : BPTOptionsBase
{
    uint32  n_chains;
    uint32  spp;
    uint32  reseeding_freq;
    uint32  mis                  : 1;
    float   st_perturbations;
    float   screen_perturbations;
    float   exp_perturbations;
    float   H_perturbations;
    float   perturbation_radius;
    uint32  flags;

    MLTOptions() :
        BPTOptionsBase(),
        n_chains(256 * 1024),
        spp(1),
        reseeding_freq(16),
        st_perturbations(1.0f),
        screen_perturbations(1.0f),
        exp_perturbations(0.45f),
        H_perturbations(0.45f),
        perturbation_radius(0.1f),
        mis(false),
        flags(0)
    {
        // temporarily kill light tracing
        BPTOptionsBase::light_tracing = 0.0f;
    }

    void parse(const int argc, char** argv)
    {
        BPTOptionsBase::parse(argc, argv);

        for (int i = 0; i < argc; ++i)
        {
            if (strcmp(argv[i], "-chains") == 0)
                n_chains = atoi(argv[++i]) * 1024;
            else if (strcmp(argv[i], "-spp") == 0)
                spp = atoi(argv[++i]);
            else if (strcmp(argv[i], "-st-mutations") == 0 ||
                     strcmp(argv[i], "-st-perturbations") == 0)
                st_perturbations = (float)atof(argv[++i]);
            else if (strcmp(argv[i], "-screen-perturbations") == 0 ||
                     strcmp(argv[i], "-lens-perturbations") == 0 ||
                     strcmp(argv[i], "-lp") == 0)
                screen_perturbations = (float)atof(argv[++i]);
            else if (strcmp(argv[i], "-H-perturbations") == 0 ||
                     strcmp(argv[i], "-h-perturbations") == 0 ||
                     strcmp(argv[i], "-hp") == 0 ||
                     strcmp(argv[i], "-H") == 0 ||
                     strcmp(argv[i], "-h") == 0)
                H_perturbations = (float)atof(argv[++i]);
            else if (strcmp(argv[i], "-exp-perturbations") == 0 ||
                     strcmp(argv[i], "-e-perturbations") == 0 ||
                     strcmp(argv[i], "-exp") == 0 ||
                     strcmp(argv[i], "-ep") == 0)
                exp_perturbations = (float)atof(argv[++i]);
            else if (strcmp(argv[i], "-rf") == 0 ||
                     strcmp(argv[i], "-reseed") == 0 ||
                     strcmp(argv[i], "-reseed-freq") == 0)
                reseeding_freq = atoi(argv[++i]);
            else if (strcmp(argv[i], "-mis") == 0)
                mis = atoi(argv[++i]) > 0;
            else if (strcmp(argv[i], "-pr") == 0 ||
                     strcmp(argv[i], "-perturbation-radius") == 0)
                perturbation_radius = (float)atof(argv[++i]);
            else if (strcmp(argv[i], "-flags") == 0)
                flags = strtol(argv[++i], NULL, 16u);
        }

        const float prob_perturbations = exp_perturbations + H_perturbations;
        if (prob_perturbations > 1.0f)
        {
            exp_perturbations /= prob_perturbations;
            H_perturbations   /= prob_perturbations;
        }
    }
};

struct MLT : RendererInterface
{
    MLT();

    void init(int argc, char** argv, RenderingContext& renderer);

    void render(const uint32 instance, RenderingContext& renderer);

    void sample_seeds(MLTContext& context);

    void recover_seed_paths(MLTContext& context, RenderingContextView& renderer_view);

    void destroy() { delete this; }

    static RendererInterface* factory();

    void alloc(MLTContext& context, cugar::memory_arena& arena, const uint32 n_pixels, const uint32 n_chains);

    MLTOptions                          m_options;
    TiledSequence                       m_sequence;
    BPTQueuesStorage                    m_queues;
    VertexStorage                       m_light_vertices;

    float                                       m_image_brightness;
    uint32                                      m_n_lights;
    uint32                                      m_n_init_paths;
    uint32                                      m_n_connections;

    DomainBuffer<CUDA_BUFFER, uint8>            m_memory_pool;
    DomainBuffer<CUDA_BUFFER, float>            m_connections_cdf;
    DomainBuffer<HOST_BUFFER, float>            m_path_pdf_backup;

    cugar::LFSRGeneratorMatrix  m_generator;
    cugar::LFSRRandomStream     m_random;
};