Java - 为什么我的平台游戏的性能如此之低？

Question

I'm currently working on a platformer game in java, and I'm having trouble figuring out why this decreases performance so much. Only the textures in view of the camera are rendered, and I've even tried clearing all objects outside the camera's view, so that the array was almost empty, and I still was unable to get a good framerate. When I comment out the call to this method, the game runs at 300 FPS, but when I run it, even when I remove everything afterwords, I still only get 40 FPS. This is not an issue with rendering, as I have tested this thoroughly. Any feedback would be much appreciated. Here is the code:

public void buildTerrain(BufferedImage bi) {
    // this method will take an image and build a level based on it.
    int width = bi.getWidth();
    int height = bi.getHeight();
    for(int x = 0; x < width; x++){
        for(int y = 0; y < height; y++){
            int pixel = bi.getRGB(x, y);
            int r = (pixel >> 16) & 0xff;
            int g = (pixel >> 8) & 0xff;
            int b = (pixel) & 0xff;
            if(r == 255 &&
                g == 255 &&
                b == 255)
                h.addObject(new Block(x*32, y*32,
                ID.blockStone,GameState.level1, tex));
            if(r == 0 &&
                g == 0 &&
                b == 255){
                p.setX(x*32);
                p.setY(y*32);
                p.setHeight(64);
            }
        }
    }
}

references: h is a Handler object, witch contains a method addObject(GameObject) Block extends GameObject p is a Player, witch also extends GameObject.

EDIT: this code is not called in a loop, it is ran once at the beginning of each level to load the terrain. All the AddObject() method does is add the Blocks to an array where then are then iterated over in the tick() and render() methods. Only objects in the scope of the camera are rendered, and the tick() method of blocks is empty.

Answer 1

Could you try:

    if(0xffffff00 == (pixel & 0xffffff00))
        h.addObject(new Block(x*32, y*32,
        ID.blockStone,GameState.level1, tex));
    if(0x0000ff00 == (pixel & 0x0000ff00)){
        p.setX(x*32);
        p.setY(y*32);
        p.setHeight(64);
    }

Because I don't understand the need of decomposing (r, g, b) for each pixel while you can do that using a binary & (0xffffff00, it might be 0x00ffffff).

• in your code, you do width*height*(3 shift + 3 and + 3 equals + 3 equals) operations.
• in my code, you do width*height*2*(and + test) operations.