//##################################################################################################
//
//   Custom Visualization Core library
//   Copyright (C) 2011-2013 Ceetron AS
//
//   This library may be used under the terms of either the GNU General Public License or
//   the GNU Lesser General Public License as follows:
//
//   GNU General Public License Usage
//   This library 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 library 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 at <<http://www.gnu.org/licenses/gpl.html>>
//   for more details.
//
//   GNU Lesser General Public License Usage
//   This library is free software; you can redistribute it and/or modify
//   it under the terms of the GNU Lesser General Public License as published by
//   the Free Software Foundation; either version 2.1 of the License, or
//   (at your option) any later version.
//
//   This library 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 at <<http://www.gnu.org/licenses/lgpl-2.1.html>>
//   for more details.
//
//##################################################################################################


#pragma once

#include "cvfOverlayItem.h"
#include "cvfArray.h"
#include "cvfCamera.h"
#include "cvfString.h"
#include "cvfRect.h"

namespace cvf {

class Font;
class ShaderProgram;
class MatrixState;
class TextDrawer;
struct OverlayColorLegendLayoutInfo;


//==================================================================================================
//
// Overlay color legend
//
//==================================================================================================
class OverlayColorLegend : public OverlayItem
{
public:
    OverlayColorLegend(Font* font);
    virtual ~OverlayColorLegend();

    virtual Vec2ui  sizeHint();

    virtual void    render(OpenGLContext* oglContext, const Vec2i& position, const Vec2ui& size);
    virtual void    renderSoftware(OpenGLContext* oglContext, const Vec2i& position, const Vec2ui& size);
    virtual bool    pick(int x, int y, const Vec2i& position, const Vec2ui& size);

    void            configureLevels(const Color3ubArray& levelColors, const DoubleArray& tickValues);

    void            setSizeHint(const Vec2ui& size);
    void            setWidthToFitText();
    
    void            setColor(const Color3f& color);
    const Color3f&  color() const;

    void            setLineColor(const Color3f& lineColor);
    const Color3f&  lineColor() const;
    void            setLineWidth(int lineWidth);
    int             lineWidth() const;
    
    void            setTitle(const String& title);
    String          title() const;

protected:
    void            render(OpenGLContext* oglContext, const Vec2i& position, const Vec2ui& size, bool software);
    virtual void    renderLegend(OpenGLContext* oglContext, OverlayColorLegendLayoutInfo* layout, const MatrixState& matrixState);
    virtual void    renderLegendImmediateMode(OpenGLContext* oglContext, OverlayColorLegendLayoutInfo* layout);
    virtual void    setupTextDrawer(TextDrawer* textDrawer, OverlayColorLegendLayoutInfo* layout);

    void            layoutInfo(OverlayColorLegendLayoutInfo* layout);

protected:
    Color3ubArray       m_levelColors;          // Colors for n levels
    DoubleArray         m_tickValues;           // Ticks between each level + top and bottom of legend (n+1 entries)
    std::vector<bool>   m_visibleTickLabels;    // Skip tick labels ending up on top of previous visible label

    Vec2ui              m_sizeHint;     // Pixel size of the color legend area
    
    Color3f             m_color;
    Color3f             m_lineColor;
    int                 m_lineWidth;
    std::vector<String> m_titleStrings;
    ref<Font>           m_font;

    const cvf::uint     m_margin;
};


//==================================================================================================
//
// Internal helper for storing layout info to allow for custom rendered legends
//
//==================================================================================================
struct OverlayColorLegendLayoutInfo
{
    float               charHeight;
    float               lineSpacing;
    Vec2f               margins;
    float               tickX;
    float               x0;
    float               x1;
    Rectf               legendRect;
    Vec2i               position;
    Vec2ui              size;
    ref<DoubleArray>    tickPixelPos;
};

}