IAPDemo/Libraries/redream/BezierEqualPointsAction.cpp

//
//  BezierEqualPointsAction.cpp
//  redream_runtime
//
//  Created by 潮伟钦 on 2022/7/18.
//

#include "BezierEqualPointsAction.hpp"

#define DEBUG_PATH false

BezierEqualPointsAction* BezierEqualPointsAction::create(float duration, std::vector<Vec2> equalPoints) {
    BezierEqualPointsAction *ret = new (std::nothrow) BezierEqualPointsAction();
    
    if (ret && ret->initWithDuration(duration, equalPoints))
    {
        ret->autorelease();
        return ret;
    }
    
    delete ret;
    return nullptr;
}

bool BezierEqualPointsAction::initWithDuration(float duration, std::vector<Vec2> equalPoints) {
    ActionInterval::initWithDuration(duration);
    
    _equalPoints = equalPoints;

#if DEBUG_PATH
    DrawNode* dn = DrawNode::create();
    for (Vec2 p : equalPoints) {
        dn->drawDot(p, 1, Color4F::RED);
    }

    dn->retain();
    Director::getInstance()->getScheduler()->schedule([=](float dt){
        Director::getInstance()->getRunningScene()->addChild(dn);
        dn->release();
    }, Director::getInstance(), 1, 0, 1, false, "!231231231");
#endif
    
    _length = 0;
    Vec2 last = _equalPoints[0];
    _count = (int)_equalPoints.size();
    for (int i = 1; i < _count; ++i) {
        Vec2 now = _equalPoints[i];
        float curLength = last.distance(now);
        _length = _length + curLength;
        last = now;
    }
    return true;
}

void BezierEqualPointsAction::update(float time) {
    float idx_f = (_count-1) * time;
    int idx_i = (int)idx_f;
    idx_i = min(idx_i, (int)(_equalPoints.size() - 1));
    idx_i = max(0, idx_i);
    Vec2 pos = _equalPoints.at(idx_i);
    float p = idx_f - idx_i;
    if (p > 0.0f) { // 有余数
        if (idx_i+1 < _equalPoints.size()) {
            Vec2 nextPos = _equalPoints.at(idx_i+1);
            pos = (nextPos-pos)*p + pos;
        }
    }
    _target->setPosition(pos);
    
#if DEBUG_PATH
    auto dn = static_cast<DrawNode*>(Director::getInstance()->getRunningScene()->getChildByTag(213));
    if (dn == nullptr) {
        dn = DrawNode::create();
        dn->setTag(213);
        Director::getInstance()->getRunningScene()->addChild(dn);
    }
    
    dn->drawDot(pos, 3, Color4F::BLUE);
#endif
}