2 ; Ullrich von Bassewitz, 21.06.2002
4 ; Common functions of the tgi graphics kernel.
7 .include "tgi-kernel.inc"
8 .include "tgi-error.inc"
11 .interruptor tgi_irq ; Export as IRQ handler
14 ;----------------------------------------------------------------------------
19 _tgi_drv: .res 2 ; Pointer to driver
20 _tgi_error: .res 1 ; Last error code
21 _tgi_gmode: .res 1 ; Flag: Graphics mode active
22 _tgi_curx: .res 2 ; Current drawing cursor X
23 _tgi_cury: .res 2 ; Current drawing cursor Y
24 _tgi_color: .res 1 ; Current drawing color
25 _tgi_textdir: .res 1 ; Current text direction
26 _tgi_textmagx: .res 1 ; Text magnification in X dir
27 _tgi_textmagy: .res 1 ; Text magnification in Y dir
29 ; The following variables are copied from the driver header for faster access
31 _tgi_xres: .res 2 ; X resolution of the current mode
32 _tgi_yres: .res 2 ; Y resolution of the current mode
33 _tgi_colorcount: .res 1 ; Number of available colors
34 _tgi_pagecount: .res 1 ; Number of available screen pages
35 _tgi_fontsizex: .res 1 ; System font X size
36 _tgi_fontsizey: .res 1 ; System font Y size
41 ; Jump table for the driver functions.
43 tgi_install: jmp $0000
44 tgi_uninstall: jmp $0000
47 tgi_geterror: jmp $0000
48 tgi_control: jmp $0000
50 tgi_setviewpage: jmp $0000
51 tgi_setdrawpage: jmp $0000
52 tgi_setcolor: jmp $0000
53 tgi_setpalette: jmp $0000
54 tgi_getpalette: jmp $0000
55 tgi_getdefpalette: jmp $0000
56 tgi_setpixel: jmp $0000
57 tgi_getpixel: jmp $0000
61 tgi_textstyle: jmp $0000
62 tgi_outtext: jmp $0000
63 tgi_irq: .byte $60, $00, $00 ; RTS plus two dummy bytes
65 ; Driver header signature
67 tgi_sig: .byte $74, $67, $69, TGI_API_VERSION ; "tgi", version
70 ;----------------------------------------------------------------------------
71 ; void __fastcall__ tgi_install (void* driver);
72 ; /* Install an already loaded driver. */
81 ; Check the driver signature
83 ldy #.sizeof(tgi_sig)-1
90 ; Copy the jump vectors
94 @L1: inx ; Skip JMP opcode
95 jsr copy ; Copy one byte
96 jsr copy ; Copy one byte
97 cpy #(TGI_HDR::JUMPTAB + .sizeof(TGI_HDR::JUMPTAB))
100 ; Call the driver install routine. It may update header variables, so we copy
101 ; them after this call.
105 ; Copy variables from the driver header for faster access.
107 jsr tgi_set_ptr ; Set ptr1 to tgi_drv
108 ldy #(TGI_HDR::VARS + .sizeof(TGI_HDR::VARS) - 1)
109 ldx #.sizeof(TGI_HDR::VARS)-1
111 sta tgi_driver_vars,x
116 ; Install the IRQ vector if the driver needs it.
118 lda tgi_irq+2 ; Check high byte of IRQ vector
119 beq @L4 ; Jump if vector invalid
120 lda #$4C ; Jump opcode
121 sta tgi_irq ; Activate IRQ routine
123 ; Initialize some other variables
127 @L5: sta _tgi_error,x ; Clear error/mode/curx/cury/textdir
133 ; Copy one byte from the jump vectors
141 ;----------------------------------------------------------------------------
142 ; Set an invalid argument error
149 ;----------------------------------------------------------------------------
150 ; Set an invalid driver error
153 lda #TGI_ERR_INV_DRIVER
157 ;----------------------------------------------------------------------------
158 ; Load the pointer to the tgi driver into ptr1.
167 ;----------------------------------------------------------------------------
168 ; void __fastcall__ tgi_uninstall (void);
169 ; /* Uninstall the currently loaded driver but do not unload it. Will call
170 ; * tgi_done if necessary.
174 jsr _tgi_done ; Switch off graphics
176 jsr tgi_uninstall ; Allow the driver to clean up
178 lda #$60 ; RTS opcode
179 sta tgi_irq ; Disable IRQ entry point
181 ; Clear driver pointer and error code