soft_shadow.h

/********************************************************************
 * Copyright (C) 2015 Liangliang Nan <liangliang.nan@gmail.com>
 * https://3d.bk.tudelft.nl/liangliang/
 *
 * This file is part of Easy3D. If it is useful in your research/work,
 * I would be grateful if you show your appreciation by citing it:
 * ------------------------------------------------------------------
 *      Liangliang Nan.
 *      Easy3D: a lightweight, easy-to-use, and efficient C++ library
 *      for processing and rendering 3D data.
 *      Journal of Open Source Software, 6(64), 3255, 2021.
 * ------------------------------------------------------------------
 *
 * Easy3D 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.
 *
 * Easy3D 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/>.
 ********************************************************************/
 
#ifndef EASY3D_RENDERER_SOFT_SHADOW_H
#define EASY3D_RENDERER_SOFT_SHADOW_H
 
#include <easy3d/renderer/shadow.h>
 
 
namespace easy3d {
 
    class SoftShadow : public Shadow
    {
    public:
        enum SamplePattern {
            SP_Poisson_25_25 = 0,   // 25 samples for the blocker search, 25 samples in the PCF filtering, all samples using a Poisson disk
            SP_Poisson_32_64 = 1,   // 32 samples for the blocker search, 64 samples for the PCF filtering, all samples using a Poisson disk
            SP_Poisson_64_128 = 2,  // 64 samples for the blocker search, 128 samples for the PCF filtering, all samples using a Poisson disk
            SP_Poisson_100_100 = 3, // 100 samples for the blocker search, 100 samples for the PCF filtering, all samples using a Poisson disk
            SP_Regular_49_225 = 4   // 49 samples for the blocker search, 225 samples for the PCF filtering, all samples using regular sampling (faster than Poisson disk)
        };
 
    public:
        explicit SoftShadow(Camera* cam);
        ~SoftShadow() override = default;
 
        // The softness of the shadow. Values must be in [0, 1]. Default: 0.5.
        float softness() const { return softness_; }
        void set_softness(float s) { softness_ = s; }
 
        // The sampler pattern used for blocker search and PCF filtering.
        SamplePattern sample_pattern() const { return sample_pattern_; }
        void set_sample_pattern(SamplePattern pattern) { sample_pattern_ = pattern; }
 
    protected:
        void ensure_fbo() override;
        void shadow_map_pass(const std::vector<TrianglesDrawable*>& surfaces) override;
        void render_pass(const std::vector<TrianglesDrawable*>& surfaces) override;
 
    protected:
        // The softness of the shadow, in [0, 1] (w.r.t. 10% of the light's size)
        float softness_;
 
        SamplePattern sample_pattern_;
 
    private:
        //copying disabled
        SoftShadow(const SoftShadow&);
        SoftShadow& operator=(const SoftShadow&);
    };
 
}
 
#endif // EASY3D_RENDERER_SOFT_SHADOW_H