Upsilon/apps/shared/curve_view.h

#ifndef SHARED_CURVE_VIEW_H
#define SHARED_CURVE_VIEW_H

#include "banner_view.h"
#include "curve_view_range.h"
#include "curve_view_cursor.h"
#include <poincare/preferences.h>
#include <poincare/coordinate_2D.h>
#include <cmath>

namespace Shared {

class CurveView : public View {
public:
  /* We want a 3 characters margin before the first label tick, so that most
   * labels appear completely. This gives 3*charWidth/320 = 3*7/320= 0.066 */
  static constexpr float k_labelsHorizontalMarginRatio = 0.066f;
  typedef Poincare::Coordinate2D<float> (*EvaluateXYForParameter)(float t, void * model, void * context);
  typedef float (*EvaluateYForX)(float x, void * model, void * context);
  enum class Axis {
    Horizontal = 0,
    Vertical = 1
  };
  CurveView(CurveViewRange * curveViewRange = nullptr,
      CurveViewCursor * curveViewCursor = nullptr,
      BannerView * bannerView = nullptr,
      View * cursorView = nullptr,
      View * okView = nullptr,
      bool displayBanner = true);
  virtual void reload();
  // When the main view is selected, the banner view is visible
  bool isMainViewSelected() const;
  void selectMainView(bool mainViewSelected);
  View * cursorView() { return m_cursorView; }
  void setCursorView(View * cursorView);
  View * bannerView() { return m_bannerView; }
  void setBannerView(View * bannerView);
  void setOkView(View * okView);
  void setForceOkDisplay(bool force) { m_forceOkDisplay = force; }
  const float pixelWidth() const;
  const float pixelHeight() const;
protected:
  CurveViewRange * curveViewRange() const { return m_curveViewRange; }
  void setCurveViewRange(CurveViewRange * curveViewRange);
  // Drawing methods
  constexpr static KDCoordinate k_labelMargin = 4;
  constexpr static KDCoordinate k_okVerticalMargin = 23;
  constexpr static KDCoordinate k_okHorizontalMargin = 10;
  constexpr static KDCoordinate k_labelGraduationLength = 6;
  constexpr static int k_numberSignificantDigits = 6;
  constexpr static int k_bigNumberSignificantDigits = Poincare::Preferences::LargeNumberOfSignificantDigits;
  constexpr static int k_labelBufferMaxSize = 1 + k_bigNumberSignificantDigits + 3 + 3 + 1; // '-' + significant digits + '.' + "E-" + 3 digits + null-terminating char
  constexpr static int k_maxNumberOfXLabels = CurveViewRange::k_maxNumberOfXGridUnits;
  constexpr static int k_maxNumberOfYLabels = CurveViewRange::k_maxNumberOfYGridUnits;
  constexpr static int k_externRectMargin = 2;
  float pixelToFloat(Axis axis, KDCoordinate p) const;
  float floatToPixel(Axis axis, float f) const;
  void drawLine(KDContext * ctx, KDRect rect, Axis axis,
      float coordinate, KDColor color, KDCoordinate thickness = 1) const;
  void drawSegment(KDContext * ctx, KDRect rect, Axis axis,
      float coordinate, float lowerBound, float upperBound,
      KDColor color, KDCoordinate thickness = 1) const;
  void drawDot(KDContext * ctx, KDRect rect, float x, float y, KDColor color, bool oversize = false) const;
  void drawGrid(KDContext * ctx, KDRect rect) const;
  void drawAxes(KDContext * ctx, KDRect rect) const;
  void drawAxis(KDContext * ctx, KDRect rect, Axis axis) const;
  void drawCurve(KDContext * ctx, KDRect rect, float tStart, float tEnd, float tStep, EvaluateXYForParameter xyEvaluation, void * model, void * context, bool drawStraightLinesEarly, KDColor color, bool colorUnderCurve = false, float colorLowerBound = 0.0f, float colorUpperBound = 0.0f) const;
  void drawCartesianCurve(KDContext * ctx, KDRect rect, float xMin, float xMax, EvaluateXYForParameter xyEvaluation, void * model, void * context, KDColor color, bool colorUnderCurve = false, float colorLowerBound = 0.0f, float colorUpperBound = 0.0f) const;
  void drawHistogram(KDContext * ctx, KDRect rect, EvaluateYForX yEvaluation, void * model, void * context, float firstBarAbscissa, float barWidth,
    bool fillBar, KDColor defaultColor, KDColor highlightColor,  float highlightLowerBound = INFINITY, float highlightUpperBound = -INFINITY) const;
  void computeLabels(Axis axis);
  void simpleDrawBothAxesLabels(KDContext * ctx, KDRect rect) const;
  void drawLabels(KDContext * ctx, KDRect rect, Axis axis, bool shiftOrigin, bool graduationOnly = false, bool fixCoordinate = false, KDCoordinate fixedCoordinate = 0, KDColor backgroundColor = KDColorWhite) const;
  View * m_bannerView;
  CurveViewCursor * m_curveViewCursor;
private:
  static constexpr const KDFont * k_font = KDFont::SmallFont;
  void drawGridLines(KDContext * ctx, KDRect rect, Axis axis, float step, KDColor boldColor, KDColor lightColor) const;
  /* The window bounds are deduced from the model bounds but also take into
  account a margin (computed with k_marginFactor) */
  float min(Axis axis) const;
  float max(Axis axis) const;
  float gridUnit(Axis axis) const;
  virtual char * label(Axis axis, int index) const = 0;
  int numberOfLabels(Axis axis) const;
  /* Recursively join two dots (dichotomy). The method stops when the
   * maxNumberOfRecursion in reached. */
  void jointDots(KDContext * ctx, KDRect rect, EvaluateXYForParameter xyEvaluation, void * model, void * context, bool drawStraightLinesEarly, float t, float x, float y, float s, float u, float v, KDColor color, int maxNumberOfRecursion) const;
  /* Join two dots with a straight line. */
  void straightJoinDots(KDContext * ctx, KDRect rect, float pxf, float pyf, float puf, float pvf, KDColor color) const;
  /* Stamp centered around (pxf, pyf). If pxf and pyf are not round number, the
   * function shifts the stamp (by blending adjacent pixel colors) to draw with
   * anti alising. */
  void stampAtLocation(KDContext * ctx, KDRect rect, float pxf, float pyf, KDColor color) const;
  void layoutSubviews() override;
  KDRect cursorFrame();
  KDRect bannerFrame();
  KDRect okFrame();
  int numberOfSubviews() const override;
  View * subviewAtIndex(int index) override;
  /* m_curveViewRange has to be non null but the cursor model, the banner and
   * cursor views may be nullptr if not needed. */
  void computeHorizontalExtremaLabels(bool increaseNumberOfSignificantDigits = false);
  float labelValueAtIndex(Axis axis, int i) const;
  bool bannerIsVisible() const;
  CurveViewRange * m_curveViewRange;
  View * m_cursorView;
  View * m_okView;
  bool m_forceOkDisplay;
  bool m_mainViewSelected;
  uint32_t m_drawnRangeVersion;
};

}

#endif