#pragma once
/*
 *  Copyright (C) 2024  Brett Terpstra
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 <https://www.gnu.org/licenses/>.
 */

#ifndef BLT_GRAPHICS_RAYCAST_H
#define BLT_GRAPHICS_RAYCAST_H

#include <blt/math/vectors.h>
#include <blt/math/matrix.h>

namespace blt::gfx
{

    blt::vec3 calculateRay3D(float mx, float my, float width, float height, const blt::mat4x4& view, const blt::mat4x4& proj);
    blt::vec3 calculateRay3D(float width, float height, const blt::mat4x4& view, const blt::mat4x4& proj);
    blt::vec3 calculateRay2D(float mx, float my, float width, float height, const blt::vec3 scale, const blt::mat4x4& view, const blt::mat4x4& proj);
    blt::vec3 calculateRay2D(float width, float height, const blt::vec3 scale, const blt::mat4x4& view, const blt::mat4x4& proj);
    
    namespace detail
    {
        blt::vec3 toWorldCoords(const blt::vec4& eyeCoords, const blt::mat4x4& view);
        
        blt::vec4 toEyeCoords(const blt::vec4& clipCoords, const blt::mat4x4& proj);
        
        inline blt::vec2 getNormalisedDeviceCoordinates(float mx, float my, float width, float height)
        {
            float x = (2.0f * mx) / width - 1.0f;
            float y = (2.0f * my) / height - 1.0f;
            return blt::vec2(x, y);
        }
    }

}

#endif //BLT_GRAPHICS_RAYCAST_H