Flash bitmap engine Solution

Overview

Anyone familiar with flash game engines knows that flash game development mainly uses two rendering methods to implement game logic.

1. Display list
   The display unit is displayobject.
2. Bitmap
   All display units are bitmapdata

We will not discuss which of the two methods is good or bad. If you are interested, you can search for "flash game engine ". The most famous ones are Pushbutton engine, flixel, and flashpunk.

Bitmap engine concept

It is a bitmapdata-based image buffering technology. developers can determine what content should be painted in graphic rendering. It can be understood as painting. We open a piece of paper and fill the screen with what we want. Suitable for drawing a large number of units, such as particle systems, shooting games, and parkour games.

Bitmap engine implementation

• World cworld
  The world is a canvas, a bitmap buffer, where all the Genie of the game world exist.

• Genie cworldsprite
  A display object in the world, such as a bullet or an airplane.

• Camera cworldcamera
  If a world is large enough, it is impossible to display all the genie in one screen. Therefore, you need to scroll the screen to display the genie in different positions, that is, scroll.

Cworld is an inheritance class of Bitmap. It is mainly responsible for displaying the final rendering result to Sprite. In cworld, there is an array private VaR _ sprites: vector. <cworldsprite> = new vector. <cworldsprite> (); the array actually saves all the genie in the world, and the genie is finally drawn to the cworld buffer in the form of bitmapdata. For the bitmap engine, the camera is used to calculate the location where all the genie should draw to the world buffer zone. The cworld function is used to ultimately draw all the genie into the world buffer zone. Protected function rendersprites (G: igraphics, sprites: vector. <cworldsprite>): void {var X1: Int = getcamerax (); var Y1: Int = getcameray (); var X2: Int = getcamerax () + getcamerawidth (); vaR Y2: Int = getcameray () + getcameraheight (); For each (VAR spr: cworldsprite in sprites) {If (cmath. intersectrect (SPR. X + SPR. getanimates (). w_left, SPR. Y + SPR. getanimates (). w_top, SPR. X + SPR. getanimates (). w_rig HT, SPR. Y + SPR. getanimates (). w_bottom, X1, Y1, X2, Y2) {SPR. render (G, SPR. x-X1, SPR. y-Y1, SPR. getcurrentanimate (), SPR. getcurrentframe () ;}} cworldsprite. render, this method will eventually call the copypixels method or draw method of bitmapdata of cworld. Here, sourcebitmapdata is the image resource bitmapdata contained in the Genie. It copies or draws the sprite image to the buffer zone of the world. The above is the core idea and logic for implementing the bitmap engine.

Make the screen dynamic

The bitmap engine needs to repaint the buffer at each frame, so the enterframe event can meet this requirement. In the main Sprite, add the enterframe event listener. Create cworld and add it to the sprite container. Write Public Function update (E: Event) in your enterframe event: void {// logic of all genie in the New World (such as mobile, playing animated frames, etc .) Cworld. Update (); // redraw all the gems in the world cworld. Render ();} the game logic needs to be separated from the rendering logic to adapt to functions such as pause. Now, the main loop framework of a game comes out. You only need to manage the status of all the genie in cworld to control the game logic.