Question

I’m currently working on a simple 2D top-down shooter in which you maneuver your character around a map. The graphics are still very much in the “testing” phase (solid colors and rectangles). The drawing process is as follows:

• I have the map (this is basically just walls or free space) stored as an integer array which is then looped through and painted onto my JPanel.
• Once the map is drawn, I go through each “entity” on the map (powerups, other characters) and place them.
• Finally, I draw the user’s character

I experimented with different methods, and finally decided that the user’s character would stay in the center of the screen with the map moving around it.

Currently, it works but it seems slow. I only have 4 walls, 2 entities, and the user’s character being drawn and it’s at 90FPS, spiking around 60-70 quite often. This would be acceptable if the game were finished, however I still have fancier graphics, many more entities, walls, bullets, etc. to be rendered onto the map. I’ve tried increasing the speed of my gameLoop, which can get it as high as 230 FPS, but even then when I move into areas with entities or walls it spikes down to 50-70.

I’ve tried limiting what is drawn to only what is visible but the results were overall negligible and even negative.

The current paintComponent() method looks something like this:

public void painComponent(Graphics g) {

for(int x = 0; x < Map.size.getWidth() ; x++) {

        for(int y = 0; y < Map.size.getHeight(); y++) {

                if(mapArray[y][x] == WALL) {
                    g.setColor(Color.BLACK);
                    g.fillRect(x, y, wallSize, wallSize);
                }

        }
    }

    for(int i = 0; i < map.countEntities(); i++) {

        Entity obj = map.getEntity(i);

        g.setColor(Color.WHITE);
        g.fillRect(obj.getCoords().x, obj.getCoords().y, obj.getSize().width, obj.getSize().height);

    }

    Robot bot = map.getPlayerBot();

    g.setColor(Color.BLACK);
    g.fillRect(bot.getCoords().x, bot.getCoords().y, bot.getSize().width, bot.getSize().height);
}

Do any of you gurus out there have any tips to speed this up a bit?

Answer 1

Seph’s answer was taken into consideration and implemented, but it did not increase the speed. Apparently, the image being drawn was not the problem at all. The problem was the timer that I was using to call the update methods. I was using an instance of the Timer class which seems to be very unreliable, especially at small intervals such as these. Upon removing the timer and calling my update methods based on the system clock, I was able to reach and maintain incredibly high FPS.