#include "Spiral.h"

#include <raylib.h>
#include <cmath>


SpiralSystem::SpiralSystem()
{
    m_bullets.reserve(RESERVED);
}


void
SpiralSystem::update(const float dt)
{
    const int min_height = 0 - 3 * MARGIN;
    const int max_height = GetScreenHeight() + MARGIN;
    const int min_width = 0 - MARGIN;
    const int max_width = GetScreenWidth() + MARGIN;
    auto it = m_bullets.begin();
    while (it != m_bullets.end()) {
        auto& bullet = *it;
        bullet.timer += dt;
        if (bullet.timer > bullet.redirect_time) {
            bullet.timer -= bullet.redirect_time;
            bullet.angle = bullet.angle + bullet.redirect;
            if (bullet.angle > 2.0)
                bullet.angle -= 2.0;
            bullet.redirect *= bullet.redirect_decrease;
        }
        float velocity_x = bullet.velocity * std::cos(bullet.angle * M_PI);
        float velocity_y = bullet.velocity * std::sin(bullet.angle * M_PI);
        bullet.position.x += velocity_x * dt;
        bullet.position.y += velocity_y * dt;
        //bullet.position.x += 5*dt;
        const bool y_exceeded = bullet.position.y < min_height || bullet.position.y > max_height;
        const bool x_exceeded = bullet.position.x < min_width || bullet.position.x > max_width;
        if (y_exceeded || x_exceeded)
            it = m_bullets.erase(it);
        else
            ++it;
    }
}


void
SpiralSystem::draw()
{
    for (const auto& bullet : m_bullets)
        DrawCircle(bullet.position.x, bullet.position.y, bullet.radius, bullet.color);
}