6502/cc65
1
0
Fork 0
mirror of https://github.com/cc65/cc65.git synced 2025-01-03 01:31:55 +00:00
Code Issues Projects Releases Wiki Activity

setcolor, getcolor and setcolor_low functions

Browse Source 
git-svn-id: svn://svn.cc65.org/cc65/trunk@93 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
cpg 2000-06-22 00:42:26 +00:00
parent 564eed1a2d
commit 7198329ce3
1 changed files with 51 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

51
libsrc/atari/setcolor.s Normal file
View File

@ -0,0 +1,51 @@
;
; Christian Groessler, June 2000
;
; this file provides a setcolor() function similar to BASIC SETCOLOR
;
; void __fastcall__ setcolor (unsigned char color_reg, unsigned char hue, unsigned char luminace);
; void __fastcall__ setcolor_low (unsigned char color_reg, unsigned char color_value);
; unsigned char __fastcall__ getcolor (unsigned char color_reg);
;
.export _setcolor, _setcolor_low, _getcolor
.import popa
.include "atari.inc"
.proc _getcolor
tax
lda COLOR0,x ; get current value
ldx #0
rts
.endproc
.proc _setcolor
; asl a ; not -> BASIC compatible
sta lum ; remember luminance
jsr popa ; get hue
asl a
asl a
asl a
asl a
ora lum
; jmp _setcolor_low
.endproc
.proc _setcolor_low
pha
jsr popa
tax
pla
sta COLOR0,x
rts
.endproc
.bss
lum: .res 1