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cc65/libsrc/tgi/tgi-kernel.s
cuz f82ac8a91c TGI Implementation
git-svn-id: svn://svn.cc65.org/cc65/trunk@1312 b7a2c559-68d2-44c3-8de9-860c34a00d81
2002-06-21 13:28:51 +00:00

93 lines
1.9 KiB
ArmAsm

;
; Ullrich von Bassewitz, 21.06.2002
;
; Common functions of the tgi graphics kernel.
;
.include "tgi-kernel.inc"
.importzp ptr1
;----------------------------------------------------------------------------
; Variables
.bss
_tgi_drv: .res 2 ; Pointer to driver
_tgi_error: .res 1 ; Last error code
_tgi_mode: .res 1 ; Graphics mode or zero
.data
; Jump table for the driver functions.
tgi_install: jmp $0000
tgi_deinstall: jmp $0000
tgi_init: jmp $0000
tgi_post: jmp $0000
tgi_control: jmp $0000
tgi_clear: jmp $0000
tgi_setcolor: jmp $0000
tgi_setpixel: jmp $0000
tgi_getpixel: jmp $0000
tgi_line: jmp $0000
tgi_bar: jmp $0000
tgi_circle: jmp $0000
;----------------------------------------------------------------------------
; Setup the TGI driver once it is loaded.
tgi_setup:
lda _tgi_drv
sta ptr1
lda _tgi_drv+1
sta ptr1+1
ldy #TGI_HDR_JUMPTAB
ldx #1
@L1: lda (ptr1),y
sta tgi_install,x
iny
inx
lda (ptr1),y
sta tgi_install,x
inx
cpx #(TGI_HDR_JUMPCOUNT*3)
bne @L1
; Initialize variables
lda #$00
sta _tgi_error
sta _tgi_mode
jsr tgi_install ; Call driver install routine
; jmp tgi_fetch_error
;----------------------------------------------------------------------------
; Fetch the error code from the driver and place it into the global error
; variable.
tgi_fetch_error:
jsr tgi_set_ptr
ldy #TGI_HDR_ERROR
lda (ptr1),y
sta _tgi_error
rts
;----------------------------------------------------------------------------
; Load the pointer to the tgi driver into ptr1.
tgi_set_ptr:
lda _tgi_drv
sta ptr1
lda _tgi_drv+1
sta ptr1+1
rts