MRPalette.h

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#pragma once
#include "MRViewerFwd.h"
#include "MRMesh/MRMeshFwd.h"
#include "MRMesh/MRVector4.h"
#include "MRMesh/MRMeshTexture.h"
#include "MRMesh/MRColor.h"
#include "MRMesh/MRExpected.h"
#include "MRViewer/MRImGui.h"
#include "MRMesh/MRBox.h"
#include "MRMesh/MRVector.h"
#include <algorithm>
#include <filesystem>
 
namespace Json{ class Value; }
 
namespace MR
{
 
class Palette
{
public:
    MRVIEWER_API static const std::vector<Color> DefaultColors;
    [[nodiscard]] static const std::vector<Color> & BlueGreenRedColors() { return DefaultColors; }
 
    [[nodiscard]] MRVIEWER_API static const std::vector<Color> & GreenRedColors();
 
    MRVIEWER_API Palette( const std::vector<Color>& colors );
    MRVIEWER_API void setBaseColors( const std::vector<Color>& colors );
    MRVIEWER_API void setRangeMinMax( float min, float max );
    MRVIEWER_API void setRangeMinMaxNegPos( float minNeg, float maxNeg, float minPos, float maxPos );
 
    // set number of different colors for discrete palette
    MRVIEWER_API void setDiscretizationNumber( int discretization );
    // set palette type (linear / discrete)
    MRVIEWER_API void setFilterType( FilterType type );
 
    MRVIEWER_API void draw( const std::string& windowName, const ImVec2& pose, const ImVec2& size, bool onlyTopHalf = false );
 
    MRVIEWER_API void draw( ImDrawList* drawList, float scaling, const ImVec2& pos, const ImVec2& size, const Color& labelBgColor, bool onlyTopHalf = false ) const;
    MRVIEWER_API void draw( ImDrawList* drawList, float scaling, const ImVec2& pos, const ImVec2& size, bool onlyTopHalf = false ) const;
 
    // structure for label
    struct MRVIEWER_CLASS Label
    {
        float value = 0.f; // label position according normal scale (from Min to Max)
        std::string text; // label text
 
        // The special zero label.
        // The flag is there so we can hide it if we want.
        bool isZero = false;
 
        Label() = default;
        MRVIEWER_API Label( float val, std::string text );
    };
    // reset labels to standard view
    MRVIEWER_API void resetLabels();
    // set labels manually
    MRVIEWER_API void setCustomLabels( const std::vector<Label>& labels );
    // set labels visible
    MRVIEWER_API void setLabelsVisible( bool visible );
 
 
    // Setup palette data from JsonValue
    // @return return true if loading successful
    MRVIEWER_API bool loadFromJson( const Json::Value& root );
    // Serialize this palette data to JsonValue
    MRVIEWER_API void saveCurrentToJson( Json::Value& root ) const;
 
 
    MRVIEWER_API Color getColor( float relativeValue ) const;
    Color getInvalidColor() const { return Color::gray(); }
 
    MRVIEWER_API VertColors getVertColors( const VertScalars& values, const VertBitSet& region, const VertBitSet* valids, const VertBitSet* validsForStats );
 
    const MeshTexture& getTexture() const { return texture_; };
 
    // get relative position in [0,1], where 0 is for minimum and 1 is for maximum
    MRVIEWER_API float getRelativePos( float val ) const;
 
    UVCoord getUVcoord( float val, bool valid = true ) const
    {
        return {
            ( texEnd_ - texStart_ ) * getRelativePos( val ) + texStart_,
            valid ? 0.25f : 0.75f
        };
    }
 
    // If `bits` is non-zero, captures the pointer and returns a predicate that checks against this bitset.
    // Otherwise returns null.
    [[nodiscard]] MRVIEWER_API static VertPredicate predFromBitSet( const VertBitSet* bits );
 
    MRVIEWER_API VertUVCoords getUVcoords( const VertScalars & values, const VertBitSet & region, const VertPredicate & valids = {}, const VertPredicate & validsForStats = {} );
 
    VertUVCoords getUVcoords( const VertScalars & values, const VertBitSet & region, const VertBitSet * valids, const VertBitSet * validsForStats = nullptr )
    {
        return getUVcoords( values, region, predFromBitSet( valids ), predFromBitSet( validsForStats ) );
    }
 
    // base parameters of palette
    struct Parameters
    {
        std::vector<float> ranges = { 0.f, 1.f }; // range limits for palette
        std::vector<Color> baseColors; // palette base colors (need for calculate real colors according discretization)
        MinMaxf legendLimits; // if valid - limit legend range
        int discretization = 7; // number of different colors for discrete palette
    };
 
    [[nodiscard]] const Parameters& getParameters() const { return parameters_; }
 
    [[nodiscard]] float getRangeMin() const { return parameters_.ranges.front(); }
 
    [[nodiscard]] float getRangeMax() const { return parameters_.ranges.back(); }
 
    [[nodiscard]] float getRangeSq() const { return std::max( sqr( getRangeMin() ), sqr( getRangeMax() ) ); }
 
    MRVIEWER_API std::string getStringValue( float value ) const;
    MRVIEWER_API int getMaxLabelCount();
    MRVIEWER_API void setMaxLabelCount( int val );
 
    MRVIEWER_API void setLegendLimits( const MinMaxf& limits );
 
 
    // Histogram:
 
    [[nodiscard]] bool isHistogramEnabled() const { return getNumHistogramBuckets() != 0; }
    [[nodiscard]] MRVIEWER_API int getNumHistogramBuckets() const;
    // Pass zero to disable the histogram. Pass `getDefaultNumHistogramBuckets()` or any other number to enable it.
    // This should probably be odd, to have a bucket for zero in the middle.
    MRVIEWER_API void setNumHistogramBuckets( int n );
    // Returns the recommended argument for `setNumHistogramBuckets()`.
    [[nodiscard]] MRVIEWER_API int getDefaultNumHistogramBuckets() const;
 
 
    // Should we maintain the percentages of distances in each discretization step?
    [[nodiscard]] bool isDiscretizationPercentagesEnabled() const { return enableHistogramDiscr_; }
    void enableDiscretizationPercentages( bool enable ) { histogramDiscr_.reset(); enableHistogramDiscr_ = enable; }
 
 
    // This is called automatically by `getValidVerts()` and `getUVcoords(), so usually you don't need to call this manually.
    // Call this after `setNumHistogramBuckets()`.
    MRVIEWER_API void updateStats( const VertScalars& values, const VertBitSet& region, const VertPredicate& vertPredicate );
 
    MRVIEWER_API std::vector<Label> createUniformLabels() const;
 
    struct Histogram
    {
        // If this is empty, the histogram is disabled.
        std::vector<int> buckets;
        // The buckets for out-of-range elements.
        int beforeBucket = 0;
        int afterBucket = 0;
        // The sum of all values in `buckets` and `{low,high}Bucket`.
        int numEntries = 0;
        // The max value in `buckets` (but ignoring `{low,high}Bucket`).
        int maxEntry = 0;
 
        // `reset()` sets this to true, and `finalize()` sets this to false.
        bool needsUpdate = true;
 
        MRVIEWER_API void reset();
        MRVIEWER_API void addValue( float value );
        // Call once after all `addValue()` calls.
        MRVIEWER_API void finalize();
    };
 
    // The normal histogram, if enabled (check with `isHistogramEnabled()`).
    [[nodiscard]] const Histogram &getHistogramValues() { return histogram_; }
    // This one has the size matching `getParameters().discretization`. Only has meaningful values if enabled, check with `isDiscretizationPercentagesEnabled()`.
    [[nodiscard]] const Histogram &getDiscrHistogramValues() const { return histogramDiscr_; }
 
private:
    void setRangeLimits_( const std::vector<float>& ranges );
 
    void updateDiscretizatedColors_();
    Color getBaseColor_( float val );
 
    // What color we assume the pallete is drawn on top of. Typically should be the viewport background color.
    const Color& getBackgroundColor_() const;
 
 
    // set labels with equal distance between
    void setUniformLabels_();
    // make labels with equal distance between
    void makeUniformLabels_( std::vector<Label>& labels ) const;
    // first label is equal to min value, last - to the max val
    // don't use with MinMaxNegPos mode
    void setZeroCentredLabels_();
 
    void updateCustomLabels_();
 
    void sortLabels_( std::vector<Label>& labels ) const;
 
    void updateLegendLimits_( const MinMaxf& limits );
    void updateLegendLimitIndexes_();
 
    std::vector<Label> customLabels_;
    std::vector<Label> labels_;
    bool showLabels_ = false;
 
    const char* getAdjustedLabelText_( std::size_t labelIndex, bool onlyTopHalf, std::string& storage ) const;
 
    float getMaxLabelWidth_( bool onlyTopHalf = false ) const;
 
    struct StyleVariables
    {
        // Top-left window padding.
        ImVec2 windowPaddingA;
        // Bottom-right window padding.
        ImVec2 windowPaddingB;
        // Spacing between the labels and the colored rect.
        float labelToColoredRectSpacing {};
        // The min width of the colored rect.
        float minColoredRectWidth {};
    };
    StyleVariables getStyleVariables_( float scaling ) const;
 
    // stores OpenGL textures. Change useDiscrete_ to switch between them
    MeshTexture texture_;
 
    // texture positions of min and max values
    float texStart_ = 0, texEnd_ = 1;
 
    Parameters parameters_;
 
    bool isWindowOpen_ = false;
 
    bool useCustomLabels_ = false;
 
    int maxLabelCount_ = 0;
 
    float prevMaxLabelWidth_ = 0.0f;
 
    MinMaxi legendLimitIndexes_ = { 0, 7 };
    MinMaxf relativeLimits_ = { 0.f, 1.f };
 
    // This one is of a user-defined size.
    Histogram histogram_;
 
    // This one has size matching `parameters_.discretization`.
    Histogram histogramDiscr_;
 
    // Whether we should actually update `histogramDiscr_`.
    bool enableHistogramDiscr_ = false;
 
    static void resizeCallback_( ImGuiSizeCallbackData* data );
};
 
class PalettePresets
{
public:
    MRVIEWER_API static const std::vector<std::string>& getPresetNames();
    MRVIEWER_API static bool loadPreset( const std::string& name, Palette& palette );
    MRVIEWER_API static Expected<void> savePreset( const std::string& name, const Palette& palette );
    MRVIEWER_API static std::filesystem::path getPalettePresetsFolder();
private:
    PalettePresets();
    ~PalettePresets() = default;
 
    std::vector<std::string> names_;
 
    void update_();
 
    static PalettePresets& instance_();
};
 
}