fasthexavaluegridportrayal2d.java

MASON代表多主体邻里或网络仿真(Multi-Agent Simulator of Neighborhoods or Networks)。它是乔治梅森大学用Java开发的离散事件多主体仿真核心库

                
                // Some history here.  We initially started by using setRGB in BufferedImage.
                // But based on some hints, we dug down.  First we grabbed the Raster and
                // used setDataElements, which gave us a big speed boost.
                // Now we're digging even further down and grabbing the data buffer, which
                // we know is a DataBufferInt, using a scanlineStride as shown.  The DataBufferInt
                // docs show how to compute which value in the (one-dimensional) data buffer to
                // poke in order to set the equivalent pixel value.  This gives us a slight
                // improvement.  We've since deleted the setRGB code, but we've kept the more
                // readable setDataElements code in comments because the scanlineStride code 
                // is so illegible.  :-)
                //
                // FastValueGridPortrayal2D has a significantly faster method still: directly setting elements
                // in the data array.  But while this works great for rectangular regions, it's
                // quite complex to do with hexagonal stuff so instead we're just setting the
                // various pixels via setElem as we go.
                //
                // Apparently for opaque BufferedImages in Sun implementations (Windows, etc.),
                // there's a new "Managed Buffer" notion -- if you don't extract the buffer, they
                // do what they can to make things as fast for you as possible -- but it doesn't
                // help in the case of transparent images.  If we add a transparency constructor,
                // we should undo the dbuffer code and go back to the raster code and see if that's
                // faster in Windows in 1.4.2 and on.  See
                // http://weblogs.java.net/blog/chet/archive/2003/08/bufferedimage_a_1.html
                
                int load;
                
                int scanlineStride = 
                    ((SinglePixelPackedSampleModel)(raster.getSampleModel())).getScanlineStride();
                if (isDoubleGrid2D)                  
                    for(int x=sx;x<ex;x++)
                        for(int y=sy;y<ey;y++)
                            {
                            if((x&1)==0)
                                {
                                // btw, setting each pixel separately is faster 
                                // than setting a 1x2 pixel grid with setDataElements!
                                load = map.getRGB(doubleField[x][y]);
                                _dbuffer.setElem((2*y)*scanlineStride + x, load);
                                _dbuffer.setElem((2*y+1)*scanlineStride + x, load);
//                              load[0] = map.getRGB(doubleField[x][y]);
//                              _raster.setDataElements(x,2*y,load);
//                              _raster.setDataElements(x,2*y+1,load);
                                }
                            else
                                {
                                load = map.getRGB(doubleField[x][y]);
                                _dbuffer.setElem((2*y+1)*scanlineStride + x, load);
                                _dbuffer.setElem((2*y+2)*scanlineStride + x, load);
//                              load[0] = map.getRGB(doubleField[x][y]);
//                              _raster.setDataElements(x,2*y+1,load);
//                              _raster.setDataElements(x,2*y+2,load);
                                }
                            }
                else
                    for(int x=sx;x<ex;x++)
                        for(int y=sy;y<ey;y++)
                            {
                            if((x&1)==0)
                                {
                                load = map.getRGB(intField[x][y]);
                                _dbuffer.setElem((2*y)*scanlineStride + x, load);
                                _dbuffer.setElem((2*y+1)*scanlineStride + x, load);
//                              load[0] = map.getRGB(intField[x][y]);
//                              _raster.setDataElements(x,2*y,load);
//                              _raster.setDataElements(x,2*y+1,load);
                                }
                            else
                                {
                                load = map.getRGB(intField[x][y]);
                                _dbuffer.setElem((2*y+1)*scanlineStride + x, load);
                                _dbuffer.setElem((2*y+2)*scanlineStride + x, load);
//                              load[0] = map.getRGB(intField[x][y]);
//                              _raster.setDataElements(x,2*y+1,load);
//                              _raster.setDataElements(x,2*y+2,load);
                                }
                            }
                }            
            
            // MacOS X 10.3 Panther has a bug which resets the clip, YUCK
            //                    graphics.setClip(clip);
            graphics.drawImage(buffer, (int)(info.draw.x+translateWidth), (int)info.draw.y, (int)(maxX*scaleWidth), (int)info.draw.height,null);
            }
        else
            {
            buffer = null;  // GC the buffer in case the user had changed his mind

            if (endx > maxX) endx = maxX;
            if (endy > maxY) endy = maxY;
            if( startx < 0 ) startx = 0;
            if( starty < 0 ) starty = 0;

            final int ex = endx;
            final int ey = endy;
            final int sx = startx;
            final int sy = starty;

            int _x = 0;
            int _y = 0;
            int _width = 0;
            int _height = 0;

            // locals are faster...
            final ColorMap map = this.map;
            final double infodrawx = info.draw.x;
            final double infodrawy = info.draw.y;
 
            // 1.3.1 doesn't hoist -- does 1.4.1?
            if (isDoubleGrid2D)
                for(int x=sx;x<ex;x++)
                    for(int y=sy;y<ey;y++)
                        {
                        final Color c = map.getColor(doubleField[x][y]);
                        if (c.getAlpha() == 0) continue;

                        _x = (int)(translateWidth + infodrawx + scaleWidth * x);
                        _y = (int)(infodrawy + (yScale) * ((x&1)==0?2*y:2*y+1));
                        _width = (int)(translateWidth + infodrawx + scaleWidth * (x+1)) - _x;
                        _height = (int)(infodrawy + (yScale) * ((x&1)==0?2*y+2:2*y+3)) - _y;
                    
                        // draw
                        // MacOS X 10.3 Panther has a bug which resets the clip, YUCK
                        //                    graphics.setClip(clip);
                        if( graphics!=null )
                            {
                            graphics.setColor(c);
                            graphics.fillRect(_x,_y,_width,_height);
                            }
                        else
                            {
                            if( info.clip.intersects(_x,_y,_width,_height) )
                                putInHere.add(getWrapper((doubleField[x][y]), x, y));
                            }
                        }
            else
                for(int x=sx;x<ex;x++)
                    for(int y=sy;y<ey;y++)
                        {
                        final Color c = map.getColor(intField[x][y]);
                        if (c.getAlpha() == 0) continue;

                        _x = (int)(translateWidth + infodrawx + scaleWidth * x);
                        _y = (int)(infodrawy + (yScale) * ((x&1)==0?2*y:2*y+1));
                        _width = (int)(translateWidth + infodrawx + scaleWidth * (x+1)) - _x;
                        _height = (int)(infodrawy + (yScale) * ((x&1)==0?2*y+2:2*y+3)) - _y;
                    
                        // draw
                        // MacOS X 10.3 Panther has a bug which resets the clip, YUCK
                        //                    graphics.setClip(clip);
                        if( graphics!=null )
                            {
                            graphics.setColor(c);
                            graphics.fillRect(_x,_y,_width,_height);
                            }
                        else
                            {
                            if( info.clip.intersects(_x,_y,_width,_height) )
                                putInHere.add(getWrapper((intField[x][y]), x, y));
                            }
                        }
            }
        // finally, clear dirty flag if we've just drawn (don't clear if we're doing hit testing)
        if (graphics!=null) dirtyField = false;
        }
    }