SaSpectrumView.h

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/* SaSpectrumView.h - declaration of SaSpectrumView class.
 *
 * Copyright (c) 2019 Martin Pavelek <he29/dot/HS/at/gmail/dot/com>
 *
 * Based partially on Eq plugin code,
 * Copyright (c) 2014 David French <dave/dot/french3/at/googlemail/dot/com>
 *
 * This file is part of LMMS - https://lmms.io
 *
 * 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 2 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 (see COPYING); if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301 USA.
 *
 */
 
#ifndef SASPECTRUMVIEW_H
#define SASPECTRUMVIEW_H
 
 
#include <string>
#include <utility>
#include <vector>
#include <QPainterPath>
#include <QWidget>
 
 
namespace lmms
{
 
 
class SaControls;
class SaProcessor;
 
namespace gui
{
 

class SaSpectrumView : public QWidget
{
        Q_OBJECT
public:
        explicit SaSpectrumView(SaControls *controls, SaProcessor *processor, QWidget *_parent = 0);
        ~SaSpectrumView() override = default;
 
        QSize sizeHint() const override {return QSize(400, 200);}
 
protected:
        void paintEvent(QPaintEvent *event) override;
        void mouseMoveEvent(QMouseEvent *event) override;
        void mousePressEvent(QMouseEvent *event) override;
        void resizeEvent(QResizeEvent *event) override;
 
private slots:
        void periodicUpdate();
 
private:
        const SaControls *m_controls;
        SaProcessor *m_processor;
 
        // grid labels (position, label) and methods to generate them
        std::vector<std::pair<int, std::string>> m_logFreqTics;         // 10-20-50... Hz
        std::vector<std::pair<int, std::string>> m_linearFreqTics;      // 2k-4k-6k... Hz
        std::vector<std::pair<float, std::string>> m_logAmpTics;        // dB
        std::vector<std::pair<float, std::string>> m_linearAmpTics;     // 0..1
 
        std::vector<std::pair<int, std::string>> makeLogFreqTics(int low, int high);
        std::vector<std::pair<int, std::string>> makeLinearFreqTics(int low, int high);
        std::vector<std::pair<float, std::string>> makeLogAmpTics(int low, int high);
        std::vector<std::pair<float, std::string>> makeLinearAmpTics(int low, int high);
 
        // currently selected ranges (see SaControls.h for enum definitions)
        int m_freqRangeIndex;
        int m_ampRangeIndex;
 
        // draw the grid and all labels based on selected ranges
        void drawGrid(QPainter &painter);
 
        // local buffers for frequency bin values and a method to update them
        // (mainly needed for averaging and to keep track of peak values)
        std::vector<float> m_displayBufferL;
        std::vector<float> m_displayBufferR;
        std::vector<float> m_peakBufferL;
        std::vector<float> m_peakBufferR;
        void updateBuffers(const float *spectrum, float *displayBuffer, float *peakBuffer);
 
        // final paths to be drawn by QPainter and methods to build them
        QPainterPath m_pathL;
        QPainterPath m_pathR;
        QPainterPath m_pathPeakL;
        QPainterPath m_pathPeakR;
        void refreshPaths();
        QPainterPath makePath(std::vector<float> &displayBuffer, float resolution);
 
        // helper variables for path drawing
        float m_decaySum;               // indicates if there is anything left to draw
        bool m_freezeRequest;   // new reference should be acquired
        bool m_frozen;                  // a reference is currently stored in the peakBuffer
 
        // top level: refresh buffers, make paths and draw the spectrum
        void drawSpectrum(QPainter &painter);
 
        // current cursor location and a method to draw it
        QPointF m_cursor;
        void drawCursor(QPainter &painter);
 
        // wrappers for most used SaProcessor conversion helpers
        // (to make local code more readable)
        float binToFreq(unsigned int bin_index);
        float freqToXPixel(float frequency, unsigned int width);
        float ampToYPixel(float amplitude, unsigned int height);
 
        // current boundaries for drawing
        unsigned int m_displayTop;
        unsigned int m_displayBottom;
        unsigned int m_displayLeft;
        unsigned int m_displayRight;
        unsigned int m_displayWidth;
 
        // cached frequency bin → x position conversion for better performance
        std::vector<float> m_cachedBinToX;
        float m_cachedRangeMin;
        float m_cachedRangeMax;
        bool m_cachedLogX;
        unsigned int m_cachedDisplayWidth;
        unsigned int m_cachedBinCount;
        unsigned int m_cachedSampleRate;
 
        #ifdef SA_DEBUG
                float m_execution_avg;
                float m_refresh_avg;
                float m_path_avg;
                float m_draw_avg;
        #endif
};
 
 
} // namespace gui
 
} // namespace lmms
 
#endif // SASPECTRUMVIEW_H