[게임엔진활용] 10강 파티클 시스템

파티클 시스템 제작

 

브랜딩 방식 변경 Src : SrcAlpha Dst : One

 

using System;
using UnityEngine;
 
public class GamePS : RenderView
{
    Texture texPS;
    Vector2 position;
    float degree;
 
    class PS
    {
        public PS()
        {
            life = 0f;
        }
        public float life, _life;
        public Vector2 p, v;
        public Color cs, ce;
        public float ss, se;
    }
    PS[] _ps;// 활성화 + 비활성화 가리지 모든 입자
    PS[] ps;// 활성화 입자
    int psNum;
 
    float psDelta;
 
    public override void load()
    {
        materialIndex = 5;
 
        Texture2D tex = new Texture2D(32, 32);
        for (int i = 0; i < 32; i++)
        {
            for (int j = 0; j < 32; j++)
            {
                float d = (float)Math.Sqrt((16 - i) * (16 - i) + (16 - j) * (16 - j)) / 16;
                if (d > 1)
                    d = 1;
                float a = 1 - d;
                //a *= a;
                a = (float)Math.Sin(a * 90 * Math.PI / 180);
                tex.SetPixel(i, j, new Color(1, 1, 1, a));
            }
        }
        tex.Apply();
        texPS = tex;
 
        _ps = new PS[200];
        for (int i = 0; i < 200; i++)
            _ps[i] = new PS();
        ps = new PS[200];
        psNum = 0;
    }
 
    public override void free()
    {
    }
 
    public override void draw(float dt)
    {
        setRGBA(0, 0, 0, 0.7f);
        fillRect(0, 0, mc.devWidth, mc.devHeight);
        setRGBA(1, 1, 1, 1);
 
        materialIndex = 5;
        //drawImage(texPS, 300, 0, 0, 0, texPS.width, texPS.height, TOP | LEFT, 10, 10);
        for (int i = 0; i < psNum; i++)
        {
            PS p = ps[i];
            float r = p.life / p._life;
            p.p += p.v * dt;
            Color c = p.cs * (1 - r) + p.ce * r;
            float s = p.ss * (1 - r) + p.se * r;
            setRGBA(c.r, c.g, c.b, c.a);
            drawImage(texPS, p.p.x, p.p.y,
                0, 0, texPS.width, texPS.height, TOP | LEFT, s, s);
 
            p.life += dt;
            if (p.life > p._life)
            {
                p.life = 0;
                psNum--;
                ps[i] = ps[psNum];
                i--;
            }
        }
        setRGBA(1, 1, 1, 1);
 
        psDelta += dt;
        while (psDelta > 0.015f)
        {
            psDelta -= 0.015f;
 
            createPS((int)position.x, (int)position.y);
        }
 
        materialIndex = 0;
    }
 
    void createPS(int x, int y)
    {
        PS p = null;
        for (int i = 0; i < _ps.Length; i++)
        {
            p = _ps[i];
            if (p.life == 0)
                break;
        }
        if (p == null)
            return;
 
        p._life = 0.5f + 0.5f * (getRandom() % 100) / 99; //0.5 ~1.0f
        p.life = 0.000001f;
        p.p = new Vector2(
            (int)(x - 30 + 60f * (getRandom() % 100) / 99),
            (int)(y - 30 + 60f * (getRandom() % 100) / 99));
        p.v = new Vector2(-30 + 60 * (getRandom() % 100) / 99, -160);
        p.cs = new Color(1, 0, 0, 1);
        p.ce = new Color(1, 1, 0, 0.5f * (getRandom() % 100) / 99);
        p.ss = 2 + 1.0f * (getRandom() % 100) / 99;// 2~3
        p.se = 0.1f + 0.4f * (getRandom() % 100) / 99;// 0.1~0.5
 
        ps[psNum] = p;
        psNum++;
    }
 
    Vector2 prevPosition;
    public override void mouse(int state, float x, float y)
    {
        if (state == 0)
        {
            prevPosition = position;
            position = new Vector2(x, y);
            degree = (float)Math.Atan2(prevPosition.y - position.y, prevPosition.x - position.x);
        }
    }
}