snuvi-engine/src/me/hammerle/snuviengine/game/Entity.java

package me.hammerle.snuviengine.game;

import java.util.List;
import me.hammerle.snuviengine.api.Shader;
import me.hammerle.snuviengine.game.BoxList.Node;
import me.hammerle.snuviengine.util.Face;

public class Entity implements IBoxListEntry
{
    private static final double STEP = 0.0625;
    
    public Game game;
    
    public double lastXPos;
    public double lastYPos;
    public double xPos;
    public double yPos;
    public double width;
    public double height;
    
    public double vx = 0.0f;
    public double vy = 0.0f;
    
    public Node node;
    
    public int counter = 0;
    
    public Entity(Game game, double width, double height)
    {
        this.game = game;
        xPos = 0.0f;
        yPos = 0.0f;
        this.width = width;
        this.height = height;
        
        vx = 1; //Math.random() * 8 + 5;
        vy = 1; //Math.random() * 8 + 5;
    }
    
    private boolean isColliding(Entity ent)
    {
        return xPos + width > ent.xPos && ent.xPos + ent.width > xPos &&
                yPos + height > ent.yPos && ent.yPos + ent.height > yPos;
    }
    
    @Override
    public boolean isColliding(double minX, double minY, double maxX, double maxY)
    {
        return xPos + width > minX && maxX > xPos &&
                yPos + height > minY && maxY > yPos;
    }
    
    public void tick()
    {
        if(!(this instanceof Hero))
        {
            if(xPos < STEP)
            {
                vx = Math.abs(vx);
            }
            if(xPos + width > 400 - STEP)
            {
                vx = -Math.abs(vx);
            }
            if(yPos < STEP)
            {
                vy = Math.abs(vx);
            }
            if(yPos + height > 300 - STEP)
            {
                vy = -Math.abs(vx);
            }
        }
        
        lastXPos = xPos;
        lastYPos = yPos;
        
        if(vx == 0.0 && vy == 0.0)
        {
            return;
        }
        
        double lvx = vx;
        double lvy = vy;
              
        List<Entity> list = game.entities.getAllEntitiesAt(this, 
                xPos - STEP + ((vx < 0) ? vx : 0), 
                yPos - STEP + ((vy < 0) ? vy : 0), 
                xPos + STEP + width + ((vx > 0) ? vx : 0), 
                yPos + STEP + height + ((vy > 0) ? vy : 0));
        if(list.isEmpty())
        {
            xPos += vx;
            yPos += vy;
            
            game.entities.update(this);
            return;
        }
        
        while(lvx != 0.0 || lvy != 0.0)
        {
            double oldXPos = xPos;
            double oldYPos = yPos;
            
            if(lvx < 0.0)
            {
                if(lvx > -STEP)
                {
                    xPos += lvx;
                    lvx = 0.0;
                }
                else
                {
                    xPos -= STEP;
                    lvx += STEP;
                }
            }
            else if(lvx > 0.0)
            {
                if(lvx < STEP)
                {
                    xPos += lvx;
                    lvx = 0.0;
                }
                else
                {
                    xPos += STEP;
                    lvx -= STEP;
                }
            }
            
            for(Entity ent : list)
            {
                if(this.isColliding(ent))
                {
                    lvx = 0.0f;
                    xPos = oldXPos;
                    break;
                }
            }
            
            if(lvy < 0.0)
            {
                if(lvy > -STEP)
                {
                    yPos += lvy;
                    lvy = 0.0;
                }
                else
                {
                    yPos -= STEP;
                    lvy += STEP;
                }
            }
            else if(lvy > 0.0)
            {
                if(lvy < STEP)
                {
                    yPos += lvy;
                    lvy = 0.0;
                }
                else
                {
                    yPos += STEP;
                    lvy -= STEP;
                }
            }
            
            for(Entity ent : list)
            {
                if(this.isColliding(ent))
                {
                    lvy = 0.0f;
                    yPos = oldYPos;
                    break;
                }
            }
        }
        
        game.entities.update(this);
        
        for(Face f : Face.values())
        {
            double minX = xPos + STEP * f.getOffsetX();
            double minY = yPos + STEP * f.getOffsetY();
            double maxX = minX + width;
            double maxY = minY + height;
            list.stream().filter(ent -> ent.isColliding(minX, minY, maxX, maxY))
                    .forEach(ent -> onCollide(f, ent));
        }
    }
    
    public void onCollide(Face f, Entity ent)
    {
        switch(f)
        {
            case UP: 
                vy = Math.abs(vy);
                break;
            case DOWN:
                vy = -Math.abs(vy);
                break;
            case LEFT:
                vx = Math.abs(vx);
                break;
            case RIGHT:
                vx = -Math.abs(vx);
                break;
        }
    }
    
    public void renderTick(float lag)
    {
        Shader.getColorRenderer().setDepth((float) yPos);
        float x = (float) (lastXPos + (xPos - lastXPos) * lag);
        float y = (float) (lastYPos + (yPos - lastYPos) * lag);
        Shader.getColorRenderer().drawRectangle(x, y, (float) (x + width), (float) (y + height), 0x770000FF);
    }
    
    public double getX()
    {
        return xPos;
    }
    
    public double getY()
    {
        return yPos;
    }
    
    public void setPosition(double x, double y)
    {
        xPos = x;
        yPos = y;
    }

    @Override
    public double getCenterX()
    {
        return xPos + width / 2;
    }

    @Override
    public double getCenterY()
    {
        return yPos + height / 2;
    }

    @Override
    public double getWidth()
    {
        return width;
    }

    @Override
    public double getHeight()
    {
        return height;
    }

    @Override
    public Node getNode()
    {
        return node;
    }
}