.include "tgi-kernel.inc"
.include "tgi-error.inc"
- .export tgi_clear_ptr
.importzp ptr1
+ .interruptor tgi_irq ; Export as IRQ handler
;----------------------------------------------------------------------------
.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_textmagx: .res 1 ; Text magnification in X dir
-_tgi_textmagy: .res 1 ; Text magnification in Y dir
+_tgi_vectorfont: .res 2 ; Pointer to vector font
+; The following two store an 8.8 fixed point value in the first two bytes,
+; and a rounded integer value in the third byte. The latter is passed to the
+; driver to scale the bitmap font. The variables are expected to be in
+; this order and adjacent.
+_tgi_textscalew: .res 3 ; Text scale for the width
+_tgi_textscaleh: .res 3 ; Text scale for the height
+
+; The following two must also be in exactly this order
+_tgi_charwidth: .res 1 ; Char width of system font
+_tgi_charheight: .res 1 ; Char height of system font
+
+; 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_fontsizex: .res 1 ; System font X size
-_tgi_fontsizey: .res 1 ; System font Y size
-tgi_driver_var_size = * - tgi_driver_vars
+_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
.data
; Jump table for the driver functions.
+jumpvectors:
tgi_install: jmp $0000
tgi_uninstall: jmp $0000
tgi_init: jmp $0000
tgi_getdefpalette: jmp $0000
tgi_setpixel: jmp $0000
tgi_getpixel: jmp $0000
-tgi_horline: jmp $0000
tgi_line: jmp $0000
tgi_bar: jmp $0000
-tgi_circle: jmp $0000
tgi_textstyle: jmp $0000
tgi_outtext: jmp $0000
+tgi_irq: .byte $60, $00, $00 ; RTS plus two dummy bytes
; Driver header signature
.rodata
tgi_sig: .byte $74, $67, $69, TGI_API_VERSION ; "tgi", version
-tgi_sig_len = * - tgi_sig
+.code
;----------------------------------------------------------------------------
; void __fastcall__ tgi_install (void* driver);
; /* Install an already loaded driver. */
; Check the driver signature
- ldy #tgi_sig_len-1
+ ldy #.sizeof(tgi_sig)-1
@L0: lda (ptr1),y
cmp tgi_sig,y
bne tgi_inv_drv
; Copy the jump vectors
- ldy #TGI_HDR_JUMPTAB
+ ldy #TGI_HDR::JUMPTAB
ldx #0
@L1: inx ; Skip JMP opcode
jsr copy ; Copy one byte
jsr copy ; Copy one byte
- cpx #(TGI_HDR_JUMPCOUNT*3)
+ cpy #(TGI_HDR::JUMPTAB + .sizeof(TGI_HDR::JUMPTAB))
bne @L1
-; Check for emulation vectors needed
-
- lda tgi_bar+1
- ora tgi_bar+2 ; Do we have a BAR vector?
- bne @L2 ; Jump if yes
- lda #<tgi_emu_bar ; Use emulation if no
- sta tgi_bar+1
- lda #>tgi_emu_bar
- sta tgi_bar+2
+; Call the driver install routine. It may update header variables, so we copy
+; them after this call.
-@L2: jsr tgi_install ; Call driver install routine, may...
- ; ...update variables
- jsr tgi_set_ptr ; Set ptr1 to tgi_drv
+ jsr tgi_install
-; Copy variables. Beware: We are using internal knowledge about variable
-; layout here!
+; Copy variables from the driver header for faster access.
- ldy #TGI_HDR_XRES
- ldx #0
+ 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
- iny
- inx
- cpx #tgi_driver_var_size
- bne @L3
+ dey
+ dex
+ bpl @L3
+
+; Install the IRQ vector if the driver needs it.
-; Initialize variables
+ lda tgi_irq+2 ; Check high byte of IRQ vector
+ beq @L4 ; Jump if vector invalid
+ lda #$4C ; Jump opcode
+ sta tgi_irq ; Activate IRQ routine
+
+; Initialize some other variables
lda #$00
- ldx #7-1
-@L4: sta _tgi_error,x ; Clear error/mode/curx/cury/textdir
+@L4: ldx #csize-1
+@L5: sta cstart,x ; Clear error/mode/curx/cury/...
dex
- bpl @L4
+ bpl @L5
rts
-; Copy one byte from the jump vectors
+; Copy one byte to the jump vectors
copy: lda (ptr1),y
- sta tgi_install,x
+ sta jumpvectors,x
iny
inx
rts
_tgi_uninstall:
jsr _tgi_done ; Switch off graphics
+
jsr tgi_uninstall ; Allow the driver to clean up
+ lda #$60 ; RTS opcode
+ sta tgi_irq ; Disable IRQ entry point
+
; Clear driver pointer and error code
-tgi_clear_ptr: ; External entry point
lda #$00
sta _tgi_drv
sta _tgi_drv+1
rts
+
projects / cc65 / blobdiff