Java-如何有效绘制图形

Question

What i´m trying to do here is rendering all graphics in my game as fast as possible. The game is tile-based and needs a lot of images to be rendered. The problem i´m having is that it takes to long to draw all the images. I don´t know if i´m supposed to draw the tiles in a special way but right now i´m rendering all tiles that are inside of the view port one by one.

Here is my drawing method:

public void draw(Graphics2D g){

    boolean drawn=false; // if player is drawn
    int px=vpPosX, py=vpPosY; // Viewport Position

    for(int y=Math.round(py/64); y<Math.round(py/64)+core.blcHeight; y++){
        for(int x=Math.round(px/64); x<Math.round(px/64)+core.blcWidth; x++){
            if(y<height && x<width && y>-1 && x>-1 && worldData[currentLayer][x][y] != 0){ // if tile is inside map
            BufferedImage img = tileset.tiles[worldData[currentLayer][x][y]]; //tile image
            if(-py+player.PosY+64-15 < (y*64)-py-(img.getHeight())+64 && drawn==false){player.draw(g);drawn=true;} // if player should be drawn
                if(worldBackground[currentLayer][x][y]!=0){ // if tile has background
                    BufferedImage imgBack = tileset.tiles[worldBackground[currentLayer][x][y]]; // background tile
                    g.drawImage(imgBack, (x*64)-px-(((imgBack.getWidth())-64)/2), (y*64)-py-(imgBack.getHeight())+64, null); //draw background
                }
                g.drawImage(img, (x*64)-px-(((img.getWidth())-64)/2), (y*64)-py-(img.getHeight())+64, null); // draw tile
            }
        }
    }

    if(!drawn){player.draw(g);} // if drawn equals false draw player

    }

All of the images are loaded in the tileset class.
The games fps/ups is locked at 60.
This method is called from the core class which has the gameloop.

The thing i want to know is what am i doing wrong?
Do i need to change the draw method?
Do i need to load the images in a special way?
Do i need to change the way i´m painting?

My goal is to make a lag free 2d tile game.

The things i noticed myself was that my bufferedimages that hold the tile images was in RGBA format. But when i made it RGB it took a lot less time to render. I know the extra info is taking more time to draw. But what i didn't know was how much it really was.

I managed to find one thing that made the performance better.
If i loaded all my images and copied them over to a image created in this way:

BufferedImage bi = ImageIO.read(ims[i]);
GraphicsConfiguration gc = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice().getDefaultConfiguration();
BufferedImage b = gc.createCompatibleImage(bi.getWidth()*4, bi.getHeight()*4, BufferedImage.TYPE_INT_ARGB);
Graphics2D g = b.createGraphics();
g.drawImage(bi, 0, 0, bi.getWidth()*4, bi.getHeight()*4, null);
tiles[id]=b;
g.dispose();

Then the it took a lot less time to draw all the tiles. But it could still be better. And when i´m going to make the light engine(for example underground). Then i would have to use transparent rectangles over the tiles. Or if someone could suggest a better way of making tiles darker without using transparent rectangles. But the thing is that the lag comes when trying to draw transparent rectangles too. I don´t know if i´m supposed to avoid using transparent images and rectangles or what.

Hope someone can point me in the right direction.

Answer 1

Some tricks you might find helpful:

• If you have lot of static background tiles , then don't redraw them all every frame - just draw them once into a BufferedImage and use this to draw the entire background in one go. You only need to update this background image if one of the tiles changes or if you scroll the screen etc.
• Make sure you are only drawing tiles that are visible . It looks like you might be doing this, but if core.blcHeight and core.blcWidth are too large then you could be drawing too many tiles.
• Don't worry about locking to 60FPs . For a tile based game, this probably isn't going to be necessary. I'd suggest decoupling your game logic from the frame rate, and letting the game render at whatever speed it can handle.
• For solid background tiles, you don't need to be drawing with alpha shading . This can significantly speed up drawing in some cases. ie you can use TYPE_INT_RGB rather than TYPE_INT_ARGB

If you really want high performance drawing/animation then you may want to consider switching to an OpenGL-based rendering engine - Slick2D or LWJGL for example.