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|
;
; Ullrich von Bassewitz, 21.06.2002
;
; Common functions of the tgi graphics kernel.
;
.import tgi_libref
.importzp ptr1
.include "tgi-kernel.inc"
.include "tgi-error.inc"
;----------------------------------------------------------------------------
; Variables
.bss
_tgi_drv: .res 2 ; Pointer to driver
; From here on, variables get cleared when a new driver is loaded
cstart:
_tgi_error: .res 1 ; Last error code
_tgi_gmode: .res 1 ; Flag: Graphics mode active
_tgi_curx: .res 2 ; Current drawing cursor X
_tgi_cury: .res 2 ; Current drawing cursor Y
_tgi_color: .res 1 ; Current drawing color
_tgi_font: .res 1 ; Which font to use
_tgi_textdir: .res 1 ; Current text direction
_tgi_vectorfont: .res 2 ; Pointer to vector font
; The following are character scale/size variables in 8.8 fixed point
; format. They are required to be in this order and adjacent.
_tgi_textscalew: .res 2 ; Vector font width scale
.res 2 ; Bitmap font width scale
_tgi_charwidth: .res 2 ; Full width of one bitmap char
_tgi_textscaleh: .res 2 ; Vector font height scale
.res 2 ; Bitmap font height scale
_tgi_charheight: .res 2 ; Full height of one bitmap char
; End of section that gets cleared when a new driver is loaded
csize = * - cstart
; Maximum X and Y coordinate (that is, xres-1 and yres-1)
_tgi_xmax: .res 2
_tgi_ymax: .res 2
; The following variables are copied from the driver header for faster access.
; fontwidth and fontheight are expected to be in order and adjacent.
tgi_driver_vars:
_tgi_xres: .res 2 ; X resolution of the current mode
_tgi_yres: .res 2 ; Y resolution of the current mode
_tgi_colorcount: .res 1 ; Number of available colors
_tgi_pagecount: .res 1 ; Number of available screen pages
_tgi_fontwidth: .res 1 ; System font width in pixels
_tgi_fontheight: .res 1 ; System font height in pixels
_tgi_aspectratio: .res 2 ; Aspect ratio in 8.8 fixed point
_tgi_flags: .res 1 ; TGI driver flags
.data
; Jump table for the driver functions.
jumpvectors:
tgi_install: jmp $0000
tgi_uninstall: jmp $0000
tgi_init: jmp $0000
tgi_done: jmp $0000
tgi_geterror: jmp $0000
tgi_control: jmp $0000
tgi_clear: jmp $0000
tgi_setviewpage: jmp $0000
tgi_setdrawpage: jmp $0000
tgi_setcolor: jmp $0000
tgi_setpalette: jmp $0000
tgi_getpalette: jmp $0000
tgi_getdefpalette: jmp $0000
tgi_setpixel: jmp $0000
tgi_getpixel: jmp $0000
tgi_line: jmp $0000
tgi_bar: jmp $0000
tgi_textstyle: jmp $0000
tgi_outtext: jmp $0000
; Driver header signature
.rodata
tgi_sig: .byte $74, $67, $69, TGI_API_VERSION ; "tgi", version
.code
;----------------------------------------------------------------------------
; void __fastcall__ tgi_install (void* driver);
; /* Install an already loaded driver. */
_tgi_install:
sta _tgi_drv
sta ptr1
stx _tgi_drv+1
stx ptr1+1
; Check the driver signature
ldy #.sizeof(tgi_sig)-1
@L0: lda (ptr1),y
cmp tgi_sig,y
bne tgi_inv_drv
dey
bpl @L0
; Set the library reference
ldy #TGI_HDR::LIBREF
lda #<tgi_libref
sta (ptr1),y
iny
lda #>tgi_libref
sta (ptr1),y
; Copy the jump vectors
ldy #TGI_HDR::JUMPTAB
ldx #0
@L1: inx ; Skip JMP opcode
jsr copy ; Copy one byte
jsr copy ; Copy one byte
cpy #(TGI_HDR::JUMPTAB + .sizeof(TGI_HDR::JUMPTAB))
bne @L1
; Call the driver install routine. It may update header variables, so we copy
; them after this call.
jsr tgi_install
; Copy variables from the driver header for faster access.
jsr tgi_set_ptr ; Set ptr1 to tgi_drv
ldy #(TGI_HDR::VARS + .sizeof(TGI_HDR::VARS) - 1)
ldx #.sizeof(TGI_HDR::VARS)-1
@L3: lda (ptr1),y
sta tgi_driver_vars,x
dey
dex
bpl @L3
; Initialize some other variables
lda #$00
ldx #csize-1
@L4: sta cstart,x ; Clear error/mode/curx/cury/...
dex
bpl @L4
rts
; Copy one byte to the jump vectors
copy: lda (ptr1),y
sta jumpvectors,x
iny
inx
rts
;----------------------------------------------------------------------------
; Set an invalid argument error
tgi_inv_arg:
lda #TGI_ERR_INV_ARG
sta _tgi_error
rts
;----------------------------------------------------------------------------
; Set an invalid driver error
tgi_inv_drv:
lda #TGI_ERR_INV_DRIVER
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
;----------------------------------------------------------------------------
; void tgi_uninstall (void);
; /* Uninstall the currently loaded driver but do not unload it. Will call
; ** tgi_done if necessary.
; */
_tgi_uninstall:
jsr _tgi_done ; Switch off graphics
jsr tgi_uninstall ; Allow the driver to clean up
; Clear driver pointer and error code
tgi_clear_ptr:
lda #$00
sta _tgi_drv
sta _tgi_drv+1
sta _tgi_error
rts
|
