#ifndef Magnum_DebugTools_ForceRenderer_h
#define Magnum_DebugTools_ForceRenderer_h
/*
    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>

    This file is part of Magnum.

    Magnum is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License version 3
    only, as published by the Free Software Foundation.

    Magnum 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 Lesser General Public License version 3 for more details.
*/

/** @file
 * @brief Class Magnum::DebugTools::ForceRenderer, Magnum::DebugTools::ForceRendererOptions, typedef Magnum::DebugTools::ForceRenderer2D, Magnum::DebugTools::ForceRenderer3D
 */

#include "Color.h"
#include "Resource.h"
#include "SceneGraph/Drawable.h"
#include "Shaders/Shaders.h"

#include "magnumDebugToolsVisibility.h"

namespace Magnum { namespace DebugTools {

/**
@brief Force renderer options

See ForceRenderer documentation for more information.
*/
class ForceRendererOptions {
    public:
        inline constexpr ForceRendererOptions(): _size(1.0f) {}

        /** @brief Color of rendered arrow */
        inline constexpr Color3<> color() const { return _color; }

        /**
         * @brief Set color of rendered arrow
         * @return Pointer to self (for method chaining)
         *
         * Default is black.
         */
        inline ForceRendererOptions* setColor(const Color3<>& color) {
            _color = color;
            return this;
        }

        /** @brief Scale of rendered arrow */
        inline constexpr Float scale() const { return _size; }

        /**
         * @brief Set scale of rendered arrow
         * @return Pointer to self (for method chaining)
         *
         * Default is `1.0f`.
         */
        inline ForceRendererOptions* setSize(Float size) {
            _size = size;
            return this;
        }

    private:
        Color3<> _color;
        Float _size;
};

/**
@brief Force renderer

Visualizes force pushing on object by an arrow of the same direction and size.
See @ref debug-tools-renderers for more information.

@section ForceRenderer-usage Basic usage

Example code:
@code
// Create some options
DebugTools::ResourceManager::instance()->set("my", (new DebugTools::ForceRendererOptions()
    ->setScale(5.0f)
    ->setColor(Color3<>::fromHSV(120.0_degf, 1.0f, 0.7f)));

// Create debug renderer for given object, use "my" options for it
Object3D* object;
Vector3 force;
new DebugTools::ForceRenderer2D(object, {0.3f, 1.5f, -0.7f}, &force, "my", debugDrawables);
@endcode

@see ForceRenderer2D, ForceRenderer3D
*/
template<UnsignedInt dimensions> class MAGNUM_DEBUGTOOLS_EXPORT ForceRenderer: public SceneGraph::Drawable<dimensions> {
    public:
        /**
         * @brief Constructor
         * @param object        Object for which to create debug renderer
         * @param forcePosition Where to render the force, relative to object
         * @param force         Force vector
         * @param options       Options resource key. See
         *      @ref ForceRenderer-usage "class documentation" for more
         *      information.
         * @param drawables     Drawable group
         *
         * The renderer is automatically added to object's features, @p force is
         * saved as reference to original vector and thus it must be available
         * for the whole lifetime of the renderer.
         */
        explicit ForceRenderer(SceneGraph::AbstractObject<dimensions>* object, const typename DimensionTraits<dimensions, Float>::VectorType& forcePosition, const typename DimensionTraits<dimensions, Float>::VectorType* force, ResourceKey options = ResourceKey(), SceneGraph::DrawableGroup<dimensions>* drawables = nullptr);

    protected:
        /** @todoc Remove Float when Doxygen properly treats this as override */
        void draw(const typename DimensionTraits<dimensions, Float>::MatrixType& transformationMatrix, SceneGraph::AbstractCamera<dimensions, Float>* camera) override;

    private:
        const typename DimensionTraits<dimensions, Float>::VectorType forcePosition;
        const typename DimensionTraits<dimensions, Float>::VectorType* const force;

        Resource<ForceRendererOptions> options;
        Resource<AbstractShaderProgram, Shaders::FlatShader<dimensions>> shader;
        Resource<Mesh> mesh;
        Resource<Buffer> vertexBuffer, indexBuffer;
};

/** @brief Two-dimensional force renderer */
typedef ForceRenderer<2> ForceRenderer2D;

/** @brief Three-dimensional force renderer */
typedef ForceRenderer<3> ForceRenderer3D;

}}

#endif