Apple-2-SW/rnd
1
0
Fork 0
mirror of https://github.com/gungwald/rnd.git synced 2025-04-30 18:37:16 +00:00
Code Issues Projects Releases Wiki Activity

Expand subroutine names

Browse Source
This commit is contained in:
Bill Chatfield 2020-05-05 19:06:03 -04:00
parent 0597f9b2bb
commit 6b14fe6965
1 changed files with 41 additions and 41 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

82
src/rnd.s
View File

@ -9,67 +9,67 @@
.include "symbols.s"
.include "macros.s"
.org $8000
main jsr seedrnd
jsr rndcol ;Set the color
main jsr seedRandomNumGenerator
jsr setRandomColor ;Set the color
rts
; Add A to FAC leaving result in FAC
addafac
addAccumToFac
pha
jsr MOVAF ;Move FAC to ARG
jsr MOVAF ;Move FAC to ARG
pla
jsr FLOAT ;Convert A to floating point in FAC
lda FACEXP ;Required for FADDT
jsr FADDT ;Add ARG to FAC putting result in FAC
rts ;Return with result in FAC
jsr FLOAT ;Convert A to floating point in FAC
lda FACEXP ;Required for FADDT
jsr FADDT ;Add ARG to FAC putting result in FAC
rts ;Return with result in FAC
; Multiply FAC by A leaving result in FAC
mulafac
pha ;Save A on stack
jsr MOVAF ;Move FAC to ARG
pla ;Get original value back in A
jsr FLOAT ;Convert value in A to floating point in FAC
lda FACEXP ;Required for FMULTT
jsr FMULTT ;Multiply ARG by FAC putting result in FAC
rts ;Return with result in FAC
multFacByAccum
pha ;Save A on stack
jsr MOVAF ;Move FAC to ARG
pla ;Get original value back in A
jsr FLOAT ;Convert value in A to floating point in FAC
lda FACEXP ;Required for FMULTT
jsr FMULTT ;Multiply ARG by FAC putting result in FAC
rts ;Return with result in FAC
; Seed RND function by calling it with a variable negative number.
seedrnd lda RNDL ;RNDL is a good seed value, because it changes
ora #$80 ;Make it negative so RND will interpret it as a seed
jsr FLOAT ;Convert it to floating point
jsr RND ;Seed the random number generator
seedRandomNumGenerator
lda RNDL ;RNDL is a good seed value, because it changes
ora #$80 ;Make it negative so RND will interpret it as a seed
jsr FLOAT ;Convert it to floating point
jsr RND ;Seed the random number generator
rts
; Generate a floating point random number in the range [0,1) with result in FAC
genrnd lda #1 ;A 1 arg to RND says to give the next random num
jsr FLOAT ;Convert to floating point as required by RND
jsr RND ;Generate the random number
rts ;Return with result in FAC
generateRandomFloat0To1
lda #1 ;A 1 arg to RND says to give the next random num
jsr FLOAT ;Convert to floating point as required by RND
jsr RND ;Generate the random number
rts ;Return with result in FAC
; Generate an integer random number in the range [0,A-1] with result in A
rnda
pha ;Save parameter in A to stack
jsr genrnd ;Generate random number [0,1) in FAC
pla ;Load multiplier into accumulator
jsr mulafac ;Multiply FAC by A
jsr CONINT ;Convert FAC to 1-byte int in X
txa ;Put the result in A
rts ;Return with result A
generateRandomInt0ToA
pha ;Save parameter in A to stack
jsr generateRandomFloat0To1 ;Generate random number [0,1) in FAC
pla ;Load multiplier into accumulator
jsr multFacByAccum ;Multiply FAC by A
jsr CONINT ;Convert FAC to 1-byte int in X
txa ;Put the result in A
rts ;Return with result A
; Generate an integer random number in the range [1,A] inclusive
; with result in A
rnd1a
jsr rnda ;Get an integer between [0,A-1] in A
clc ;Change the range to [1,A]
generateRandomInt1ToA
jsr generateRandomInt0ToA ;Get an integer between [0,A-1] in A
clc ;Change the range to [1,A]
adc #1
rts
; Set the color to a random non-black value.
rndcol
lda #15 ;Max color number
jsr rnd1a ;Generate a random non-black color number
jsr SETCOL ;Set the color
setRandomColor
lda #15 ;Max color number
jsr generateRandomInt1ToA
jsr SETCOL ;Set the color
rts