You can create, edit maps that contains one or more layers. All layers in a map asset can be rendered as a batch, or respectively rendered layer by layer.



The beginning index of map layer is 0, the number 0 layer of a map asset is for logic mark, it's up to you how to interpret the meaning of this layer; while all other number 1, 2, 3 layers are for rendering.



Map is loaded by LOAD_RESOURCE or LOAD_BLANK. The former function loads already edited map asset from disk, the latter loads blank for runtime accessing only, and all layers including number 0 loaded by LOAD_BLANK are for rendering.

A map is not filled by pixels directly, it's filled by tiles from the only "tiles asset" in each disk instead.

MAP m, x, y, r = 0: draws one or more map layers at a specific position.

The load functions return a LIST of layers. Pass either the whole list or a single layer to the m parameter of this MAP function for rendering, it doesn't renders logic marks.

Try the following code:


It's equivalent to:

These functions are used to get and set tiles of map. They apply to maps from both disk assets or blank. Read the manual for details:

• MGET m, i, x, y
  
• MSET m, i, x, y, v

SET_ORDERBY(drv, rule ...): sets ordering rules of graphics commands; defaults to "nil" without calling this function. rule ... can be one or more in "nil", "map", "spr", "all"; "all" is shortcut to "spr" and "map", I'll only explain "map" in this guide.

Sometimes we need to specify rendering orders of multiple objects, it is possible to simply make it without modifying few lines of code. After calling the above function with a "map" argument, BASIC8 will automatically sort all map layers, sprites and other primitives according to queue indices as follow top-down:

• 0. Layer 1 of map
  
• 1. Layer 2 of map
  
• 2. Sprites
  
• 3. Layer 3 of map
  
• 4. Other shape primitives such as CIRC, RECT, etc.

You can specify the queue index of quantized images under the "map" ordered mode, read the manual for details.

Try the following code and move it around: