project-kyoku/modes/classicmode/graphics/classicflyinganimationscenario.cpp

#include "classicflyinganimationscenario.h"
#include "classicsprite.h"

void ClassicFlyingAnimationScenario::launch(const std::shared_ptr<ClassicSprite> sprite, const microsec& time_begin, const microsec &time_end)
{
    _sprite = sprite;
    _time_begin = time_begin;
    _time_end = time_end;

    _percentage = ((_time_end - _time_begin) * 0.01);
}

float ClassicFlyingAnimationScenario::getPoint(float n1, float n2, float perc) const
{
    float diff = n2 - n1;

    return n1 + ( diff * perc );
}

void ClassicFlyingAnimationScenario::update(const microsec& music_offset)
{
    const auto crd = _sprite->coordinates();
    auto update_time = music_offset - _time_begin;
    float i = update_time / _percentage * 0.01;

    float xa = getPoint( crd.x + 20.  , crd.x + 90. , i );
    float ya = getPoint( crd.y - 600. , crd.y - 150. , i );
    float xb = getPoint( crd.x + 90.  , crd.x , i );
    float yb = getPoint( crd.y - 150. , crd.y , i );

    _sprite->setTrailCoordinates({getPoint( xa , xb , i ), getPoint( ya , yb , i )});

    bool pastPerfectScore = (i >= 1);

    if (pastPerfectScore)
        fadeTrailSprite();
}

bool ClassicFlyingAnimationScenario::isDone() const
{
    return false;
}

void ClassicFlyingAnimationScenario::fadeTrailSprite() const
{
    auto fill_color = _sprite->trailColor();

    if (fill_color.a == 0)
        return;

    auto new_alpha = fill_color.a - 35;
    fill_color.a = new_alpha < 0 ? 0 : new_alpha;

    _sprite->setTrailColor(fill_color);
}