9. Functions¶
WLA supports functions in addition to .MACRO s. Functions are different from
.MACRO s as functions always return a value.
9.1. User defined functions¶
Use .FUNCTION to create your own functions.
9.2. Built-in functions¶
The following built-in functions can be used where ever a number is expected:
abs() |
Returns the positive version of the argument |
acos() |
The same as ANSI C90 acos() |
asc() |
Uses |
asin() |
The same as ANSI C90 asin() |
atan() |
The same as ANSI C90 atan() |
atan2() |
The same as ANSI C90 atan2() |
bank() |
Returns the bank (the same as preceding |
bankbyte() |
Returns the bank byte, bits 16-23 |
ceil() |
The same as ANSI C90 ceil() |
clamp() |
Takes three arguments, value, min and max, clamps the value between min and max |
cos() |
The same as ANSI C90 cos() |
cosh() |
The same as ANSI C90 cosh() |
defined() |
Returns 1 (true) if the supplied definition exists, 0 (false) otherwise |
exists() |
Returns 1 (true) if the supplied file exists, 0 (false) otherwise |
floor() |
The same as ANSI C90 floor() |
hibyte() |
Returns the high byte, bits 8-15 (the same as preceding |
hiword() |
Returns the high word, bits 16-31 |
lobyte() |
Returns the low byte, bits 0-7 (the same as preceding |
log() |
The same as ANSI C90 log() |
log10() |
The same as ANSI C90 log10() |
loword() |
Returns the low word, bits 0-15 |
max() |
Takes two arguments, a and b, returns the bigger value |
min() |
Takes two arguments, a and b, returns the smaller value |
pow() |
The same as ANSI C90 pow() |
random() |
Takes two arguments, min and max, returns a pseudo random integer like |
round() |
The same as ANSI C99 round() |
sign() |
Return 0 if the supplied value is 0, -1 if negative and 1 if positive |
sin() |
The same as ANSI C90 sin() |
sinh() |
The same as ANSI C90 sinh() |
sqrt() |
Returns the square root of the supplied value |
tan() |
The same as ANSI C90 tan() |
tanh() |
The same as ANSI C90 tanh() |
Note! Use bankbyte() with WLA-65816 as on that platform the bank (+ base) bits are 16-23. On other platforms bank() works better.
9.3. Examples of functions¶
Here’s an example about how these functions can be used
.IF defined(USE_DEBUG) && defined(DEBUG_SHOW) && min(VALUE_A, VALUE_B) > 10
LDX #loword(CPU_ADDR) ; instead of (CPU_ADDR & $00FFFF)
LDA #bankbyte(CPU_ADDR) ; instead of :CPU_ADDR
.DB random(0, 10) ; defines a byte with value 0-10
.ENDIF
NOTE: random() needs immediate min and max values.