package greenfoot.gui;

import greenfoot.Actor;
import greenfoot.ActorVisitor;
import greenfoot.GreenfootImage;
import greenfoot.ImageVisitor;
import greenfoot.World;
import greenfoot.WorldVisitor;
import greenfoot.core.TextLabel;
import greenfoot.util.GreenfootUtil;
import threadchecker.OnThread;
import threadchecker.Tag;

import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.util.Iterator;
import java.util.List;
import java.util.Set;




| A class which handles the rendering of a World into a BufferedImage, including
| handling the currently-dragging actor (if any).
|
@OnThread(Tag.Simulation)
public class WorldRenderer
{       
private static final Color BACKGROUND = Color.WHITE;
    
   
   

| The actor being dragged. Null if no dragging.
|
private Actor dragActor;
   
   

| The current location where the object is dragged - in pixel coordinates relative to this canvas.
|
private Point dragLocation;
   
   

| Image used when dragging new actors on the world. Includes the drop shadow.
|
private BufferedImage dragImage;

   @OnThread(Tag.Any)
   
   public WorldRenderer()
   {     
   }
    
   



| Render the currently held world into the given image.  It is assumed
| that the image size matches the current world size.
|
| @param drawWorld The world to draw (may be null, in which case a blank image is drawn)
| @param worldImage The image to draw onto, which is assumed to be
|                   of the right size for the world (or desired blank size
|                   if drawWorld is null)
|
public void renderWorld(World drawWorld, BufferedImage worldImage)
   {
   Graphics2D g2 = (Graphics2D)worldImage.getGraphics();
        
   if (drawWorld == null)
       {
      g2.setColor(BACKGROUND);
      g2.fillRect(0, 0, worldImage.getWidth(), worldImage.getHeight());         
      }
       

   else
       {
      paintBackground(g2, drawWorld, worldImage.getWidth(), worldImage.getHeight());
      paintObjects(g2, drawWorld);
      paintDraggedObject(g2, drawWorld);
      WorldVisitor.paintDebug(drawWorld, g2);
      paintWorldText(g2, drawWorld);         
      }     
   }

   



| Paints all the objects.
|
| Must be synchronized on the World.lock.
|
private void paintObjects(Graphics2D g, World drawWorld)
   {        
   
   if (drawWorld == null)
           
   return;

   Set<Actor> objects = WorldVisitor.getObjectsListInPaintOrder(drawWorld);
       
   int paintSeq = 0;
       
   for (Iterator<Actor> iter = objects.iterator(); iter.hasNext();) {
      Actor thing = iter.next();
      int cellSize = WorldVisitor.getCellSize(drawWorld);

      GreenfootImage image = ActorVisitor.getDisplayImage(thing);
      if (image != null) {
         ActorVisitor.setLastPaintSeqNum(thing, paintSeq++);

         double halfWidth = image.getWidth() / 2.;
         double halfHeight = image.getHeight() / 2.;

               
         AffineTransform oldTx = null;
               
         try {
         int ax = ActorVisitor.getX(thing);
         int ay = ActorVisitor.getY(thing);
                   
         double xCenter = ax * cellSize + cellSize / 2.;
         int paintX = (int) Math.floor(xCenter - halfWidth);
                   
         double yCenter = ay * cellSize + cellSize / 2.;
         int paintY = (int) Math.floor(yCenter - halfHeight);

         int rotation = ActorVisitor.getRotation(thing);
         if (rotation != 0) {                        
            
            
            oldTx = g.getTransform();
            g.rotate(Math.toRadians(rotation), xCenter, yCenter);                     
            }

         ImageVisitor.drawImage(image, g, paintX, paintY, null, true);                 
         }
               
      catch (IllegalStateException e) {                    
         
         
         
                          
         }

               
      
      if (oldTx != null) {
         g.setTransform(oldTx);                 
         }             
      }         
   }     
}

   



| Paint the world background. This takes tiling into account: the
| world image is painted either once or tiled onto this component.
|
private void paintBackground(Graphics2D g, World drawWorld, int width, int height)
   {
   if (drawWorld != null) {
      GreenfootImage backgroundImage = WorldVisitor.getBackgroundImage(drawWorld);
      if (backgroundImage != null) {
         ImageVisitor.drawImage(backgroundImage, g, 0, 0, null, true);             
         }
           

      else {
      Color oldColor = g.getColor();
      g.setColor(BACKGROUND);
      g.fillRect(0, 0, width, height);
      g.setColor(oldColor);             
      }         
   }     
}

   



| Paint text labels that have been placed on the world using World.showText(...).
| @param g   The graphics context to draw on
| @param drawWorld   The world
|
private void paintWorldText(Graphics2D g, World drawWorld)
   {
   List<TextLabel> labels = WorldVisitor.getTextLabels(drawWorld);

   if (labels.isEmpty()) {            
      return;         
      }

       
   
   Font origFont = g.getFont();
   Color orig = g.getColor();
   Object origAntiAliasing = g.getRenderingHint(RenderingHints.KEY_ANTIALIASING);

   int cellsize = WorldVisitor.getCellSize(drawWorld);
       
   for (TextLabel label : labels) {
      label.draw(g, cellsize);         
      }

       
   
   g.setFont(origFont);
   g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, origAntiAliasing);
   g.setColor(orig);     
   }    
    
   



| If an object is being dragged, paint it.
|
private void paintDraggedObject(Graphics g, World drawWorld)
   {
   if (dragImage != null) {
      int x = (int) dragLocation.getX();
      int y = (int) dragLocation.getY();
      int xCell =  WorldVisitor.toCellFloor(drawWorld, x);
      int yCell =  WorldVisitor.toCellFloor(drawWorld, y);
      int cellSize = WorldVisitor.getCellSize(drawWorld);
      x = (int) ((xCell + 0.5) * cellSize - dragImage.getWidth()/2);
      y = (int) ((yCell + 0.5) * cellSize - dragImage.getHeight()/2);

      g.drawImage(dragImage, x, y, null);         
      }     
   } 
}