PanScrolling Class Reference

#include <ImGuiWrapper.h>

Public Member Functions
void	enable ()
void	disable ()
void	moveTo (const float yPos)
void	start (const float yPos)
float	getScrollInMouseWheelCoords (const bool mouseDown, const float fontSize, const float t)
bool	enabled () const

Private Attributes
bool	_enabled = false
float	_lastPosY = 0.f
	mouse down start position More...
float	_diff = 0.f
	Summed up y difference between mouse move events. More...
float	_vMW = 0.f
	Mouse wheel velocity: used after pan scrolling for additional scrolling. More...
float	_tOld = 0.f
	Time at last call to getScrollInMouseWheelCoords. More...
const float	_aMW = 20.0f
	Mouse wheel acceleration (subtended velocity direction) More...

Detailed Description

Definition at line 129 of file ImGuiWrapper.h.

Member Function Documentation

disable()

void PanScrolling::disable ( )

inline

Definition at line 141 of file ImGuiWrapper.h.

    {
        _enabled = false;
    }

enable()

void PanScrolling::enable ( )

inline

Definition at line 132 of file ImGuiWrapper.h.

    {
        _enabled  = true;
        _lastPosY = 0.f;
        _diff     = 0.f;
        _vMW      = 0.f;
        _tOld     = 0.f;
    }

enabled()

bool PanScrolling::enabled ( ) const

inline

Definition at line 210 of file ImGuiWrapper.h.

{ return _enabled; }

getScrollInMouseWheelCoords()

float PanScrolling::getScrollInMouseWheelCoords ( const bool  mouseDown, const float  fontSize, const float  t  )

inline

Definition at line 165 of file ImGuiWrapper.h.

    {
        float dt = t - _tOld;
        _tOld    = t;
 
        if (mouseDown)
        {
            // Convertion to mouse wheel coords: One mouse wheel unit scrolls about 5 lines of text
            //(see io.MouseWheel comment)
            float diffMW = _diff / (fontSize * 5.f);
            _diff        = 0; // diff consumed, reset it
 
            // calculate v (of mouse wheel), we need it when left mouse button goes up
            if (dt > 0.000001f)
            {
                // v = s / t
                _vMW = diffMW / dt;
            }
 
            return diffMW;
        }
        else if (std::abs(_vMW) > 0.000001f)
        {
            // velocity damping
            // v = v - a * t
            if (_vMW > 0)
            {
                _vMW = _vMW - _aMW * dt;
                if (_vMW < 0.f)
                    _vMW = 0.f;
            }
            else
            {
                _vMW = _vMW + _aMW * dt;
                if (_vMW > 0.f)
                    _vMW = 0.f;
            }
 
            // s = v * t
            return _vMW * dt;
        }
        else
            return 0.f;
    }

moveTo()

void PanScrolling::moveTo ( const float  yPos )

inline

Definition at line 147 of file ImGuiWrapper.h.

    {
        _diff -= (_lastPosY - yPos);
        _lastPosY = yPos;
    }

start()

void PanScrolling::start ( const float  yPos )

inline

Definition at line 154 of file ImGuiWrapper.h.

    {
        _lastPosY = yPos;
        _diff     = 0.f;
        _vMW      = 0.f;
        _tOld     = 0.f;
    }

Member Data Documentation

_aMW

const float PanScrolling::_aMW = 20.0f

private

Mouse wheel acceleration (subtended velocity direction)

Definition at line 218 of file ImGuiWrapper.h.

_diff

float PanScrolling::_diff = 0.f

private

Summed up y difference between mouse move events.

Definition at line 215 of file ImGuiWrapper.h.

_enabled

bool PanScrolling::_enabled = false

private

Definition at line 213 of file ImGuiWrapper.h.

_lastPosY

float PanScrolling::_lastPosY = 0.f

private

mouse down start position

Definition at line 214 of file ImGuiWrapper.h.

_tOld

float PanScrolling::_tOld = 0.f

private

Time at last call to getScrollInMouseWheelCoords.

Definition at line 217 of file ImGuiWrapper.h.

_vMW

float PanScrolling::_vMW = 0.f

private

Mouse wheel velocity: used after pan scrolling for additional scrolling.

Definition at line 216 of file ImGuiWrapper.h.

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The documentation for this class was generated from the following file:

• ImGuiWrapper.h