Functions for Canals/rivers

In m4nfo, canals and rivers are using only two types of functions:

• functions to define the layout of sprites from their graphics, coordinates and 3D-information, see functions for sprite layout definition
• functions to get information about the current tile's properties like terrain type, height, etc., as well as functions accessing game-intrinsic variables like current date, climate, etc. See functions for canals/rivers performance

Functions for sprite layout definition

The sprite layout for canals/rivers is very simple:

def(3) spriteset(0) // normal
def(4) spriteset(1) // snow

Functions for canal/river performance

These functions are used to evaluate game-intrinsic variables, and make them accessible to the canal/river's activation function. They are available for canal/river IDs CR_CLIFF (water cliffs), CR_LOCK (locks), CR_DIKE (canal banks), CR_SLOPE (river slopes), and CR_BANK (river banks).

Function	Description
tinfo_terrain(<block>)	Terrain type: "0" = normal, "1" = desert, "2" = rainforest, "4" = on or above snowline.
tinfo_height(<block>)	Height above ground
randomrel(0, <randombit> <list::ref()>)	Get random reference

def(6) tinfo_terrain(
	ref(4) if(SNOW)
	ref(3) else
)

randomrel(<trigger>, <randombit> <List::ref()>)

Unlike the performance functions above, whose results are always determined by a predictable decision, one can also use random functions to pick one of several graphics sets or callback results.

trigger

There are no triggers for canals/rivers, hence you must always define 0 (or CONSTRUCT).

randombit

Setting randombit determines the first bit to be re-randomized, as well as basing the random graphics on. The total number of bits used is the 2-logarithm of the number of references used, e.g., for 16 references, 4 bits are used.

Canals/rivers have 8 random bits.

List::ref()

The number of referenced sets to choose from must be a power of 2, i.e. 2, 4, 8, 16 etc.