; 23.12.2002
;
; NOTES:
-; For any smart monkey that will try to optimize this: PLEASE do tests on real VDC,
-; not only VICE.
+; For any smart monkey that will try to optimize this: PLEASE do tests on
+; real VDC, not only VICE.
;
-; Only DONE routine contains C128-mode specific stuff, everything else will work in
-; C64-mode of C128 (C64 needs full VDC init then).
+; Only DONE routine contains C128-mode specific stuff, everything else will
+; work in C64-mode of C128 (C64 needs full VDC init then).
;
; With special initialization and CALC we can get 320x200 double-pixel mode.
;
-; Color translation values for BROWN and GRAY3 are obviously wrong, they could
-; be replaced by equiv. of ORANGE and GRAY2 but this would give only 14 of 16 colors available.
+; Color translation values for BROWN and GRAY3 are obviously wrong, they
+; could be replaced by equiv. of ORANGE and GRAY2 but this would give only
+; 14 of 16 colors available.
;
-; Register 25 ($19) is said to require different value for VDC v1, but I couldn't find what
-; it should be.
+; Register 25 ($19) is said to require different value for VDC v1, but I
+; couldn't find what it should be.
- .include "zeropage.inc"
+ .include "zeropage.inc"
- .include "tgi-kernel.inc"
+ .include "tgi-kernel.inc"
.include "tgi-mode.inc"
.include "tgi-error.inc"
; capabilities of the driver
.byte $74, $67, $69 ; "tgi"
- .byte $00 ; TGI version number
+ .byte TGI_API_VERSION ; TGI API version number
xres: .word 640 ; X resolution
yres: .word 200 ; Y resolution
.byte 2 ; Number of drawing colors
.res 4, $00 ; Reserved for future extensions
; Next comes the jump table. Currently all entries must be valid and may point
-; to an RTS for test versions (function not implemented). A future version may
-; allow for emulation: In this case the vector will be zero. Emulation means
-; that the graphics kernel will emulate the function by using lower level
-; primitives - for example ploting a line by using calls to SETPIXEL.
+; to an RTS for test versions (function not implemented).
.word INSTALL
.word UNINSTALL
; The graphics kernel will never call DONE when no graphics mode is active,
; so there is no need to protect against that.
;
-; Must set an error code: YES
+; Must set an error code: NO
;
DONE:
jsr VDCWriteReg ; restore color (background)
lda #$47
ldx #VDC_HSCROLL
- jsr VDCWriteReg ; switch to text screen
-; fall through to GETERROR in order to clear ERROR status
+ jmp VDCWriteReg ; switch to text screen
; ------------------------------------------------------------------------
; GETERROR: Return the error code in A and clear it.
ora COLTRANS,y
ldx #VDC_COLORS
- jmp VDCWriteReg
+ jsr VDCWriteReg ; Clear error code
+ lda #TGI_ERR_OK
+ sta ERROR
+ rts
; ------------------------------------------------------------------------
-; GETPALETTE: Return the current palette in A/X. Must return NULL and set an
-; error if palettes are not supported.
+; GETPALETTE: Return the current palette in A/X. Even drivers that cannot
+; set the palette should return the default palette here, so there's no
+; way for this function to fail.
;
-; Must set an error code: YES
+; Must set an error code: NO
;
GETPALETTE:
rts
; ------------------------------------------------------------------------
-; GETDEFPALETTE: Return the default palette for the driver in A/X. Must
-; return NULL and set an error of palettes are not supported.
+; GETDEFPALETTE: Return the default palette for the driver in A/X. All
+; drivers should return something reasonable here, even drivers that don't
+; support palettes, otherwise the caller has no way to determine the colors
+; of the (not changeable) palette.
;
-; Must set an error code: YES
+; Must set an error code: NO (all drivers must have a default palette)
;
GETDEFPALETTE:
; 23.12.2002
;
; NOTES:
-; For any smart monkey that will try to optimize this: PLEASE do tests on real VDC,
-; not only VICE.
+; For any smart monkey that will try to optimize this: PLEASE do tests on
+; real VDC, not only VICE.
;
-; Only DONE routine contains C128-mode specific stuff, everything else will work in
-; C64-mode of C128 (C64 needs full VDC init then).
+; Only DONE routine contains C128-mode specific stuff, everything else will
+; work in C64-mode of C128 (C64 needs full VDC init then).
;
; With special initialization and CALC we can get 320x200 double-pixel mode.
;
-; Color translation values for BROWN and GRAY3 are obviously wrong, they could
-; be replaced by equiv. of ORANGE and GRAY2 but this would give only 14 of 16 colors available.
+; Color translation values for BROWN and GRAY3 are obviously wrong, they
+; could be replaced by equiv. of ORANGE and GRAY2 but this would give only
+; 14 of 16 colors available.
;
-; Register 25 ($19) is said to require different value for VDC v1, but I couldn't find what
-; it should be.
+; Register 25 ($19) is said to require different value for VDC v1, but I
+; couldn't find what it should be.
- .include "zeropage.inc"
+ .include "zeropage.inc"
- .include "tgi-kernel.inc"
+ .include "tgi-kernel.inc"
.include "tgi-mode.inc"
.include "tgi-error.inc"
; capabilities of the driver
.byte $74, $67, $69 ; "tgi"
- .byte $00 ; TGI version number
+ .byte TGI_API_VERSION ; TGI version number
xres: .word 640 ; X resolution
yres: .word 480 ; Y resolution
.byte 2 ; Number of drawing colors
.res 4, $00 ; Reserved for future extensions
; Next comes the jump table. Currently all entries must be valid and may point
-; to an RTS for test versions (function not implemented). A future version may
-; allow for emulation: In this case the vector will be zero. Emulation means
-; that the graphics kernel will emulate the function by using lower level
-; primitives - for example ploting a line by using calls to SETPIXEL.
+; to an RTS for test versions (function not implemented).
.word INSTALL
.word UNINSTALL
; ------------------------------------------------------------------------
; INIT: Changes an already installed device from text mode to graphics
-; mode.
+; mode.
; Note that INIT/DONE may be called multiple times while the driver
; is loaded, while INSTALL is only called once, so any code that is needed
; to initializes variables and so on must go here. Setting palette and
; The graphics kernel will never call DONE when no graphics mode is active,
; so there is no need to protect against that.
;
-; Must set an error code: YES
+; Must set an error code: NO
;
DONE:
jsr VDCWriteReg ; restore color (background)
lda #$47
ldx #VDC_HSCROLL
- jsr VDCWriteReg ; switch to text screen
-; fall through to GETERROR in order to clear ERROR status
+ jmp VDCWriteReg ; switch to text screen
; ------------------------------------------------------------------------
; GETERROR: Return the error code in A and clear it.
ora COLTRANS,y
ldx #VDC_COLORS
- jmp VDCWriteReg
+ jsr VDCWriteReg
+ lda #TGI_ERR_OK ; Clear error code
+ sta ERROR
+ rts
; ------------------------------------------------------------------------
-; GETPALETTE: Return the current palette in A/X. Must return NULL and set an
-; error if palettes are not supported.
+; GETPALETTE: Return the current palette in A/X. Even drivers that cannot
+; set the palette should return the default palette here, so there's no
+; way for this function to fail.
;
-; Must set an error code: YES
+; Must set an error code: NO
;
GETPALETTE:
rts
; ------------------------------------------------------------------------
-; GETDEFPALETTE: Return the default palette for the driver in A/X. Must
-; return NULL and set an error of palettes are not supported.
+; GETDEFPALETTE: Return the default palette for the driver in A/X. All
+; drivers should return something reasonable here, even drivers that don't
+; support palettes, otherwise the caller has no way to determine the colors
+; of the (not changeable) palette.
;
-; Must set an error code: YES
+; Must set an error code: NO (all drivers must have a default palette)
;
GETDEFPALETTE:
; capabilities of the driver
.byte $74, $67, $69 ; "tgi"
- .byte $00 ; TGI version number
+ .byte TGI_API_VERSION ; TGI API version number
.word 320 ; X resolution
.word 200 ; Y resolution
.byte 2 ; Number of drawing colors
; Variables mapped to the zero page segment variables. Some of these are
; used for passing parameters to the driver.
-X1 = ptr1
-Y1 = ptr2
-X2 = ptr3
-Y2 = ptr4
-RADIUS = tmp1
+X1 := ptr1
+Y1 := ptr2
+X2 := ptr3
+Y2 := ptr4
+RADIUS := tmp1
-ROW = tmp2 ; Bitmap row...
-COL = tmp3 ; ...and column, both set by PLOT
-TEMP = tmp4
-TEMP2 = sreg
-POINT = regsave
+ROW := tmp2 ; Bitmap row...
+COL := tmp3 ; ...and column, both set by PLOT
+TEMP := tmp4
+TEMP2 := sreg
+POINT := regsave
+INRANGE := regsave+2 ; PLOT variable, $00 = coordinates in range
-CHUNK = X2 ; Used in the line routine
-OLDCHUNK = X2+1 ; Dito
+CHUNK := X2 ; Used in the line routine
+OLDCHUNK := X2+1 ; Dito
; Absolute variables used in the code
; INIT/DONE
OLDD018: .res 1 ; Old register value
-; PLOT variables
-INRANGE: .res 1 ; $00 = coordinates in range
-
; Line routine stuff
DX: .res 2
DY: .res 2
; The graphics kernel will never call DONE when no graphics mode is active,
; so there is no need to protect against that.
;
-; Must set an error code: YES
+; Must set an error code: NO
;
DONE: lda $DD02 ; Set the data direction regs
lda $D011
and #<~$20
- jmp DONE1
+ sta $D011
+ rts
; ------------------------------------------------------------------------
; GETERROR: Return the error code in A and clear it.
sta $01
cli
-; Done
+; Done, reset the error code
+ lda #TGI_ERR_OK
+ sta ERROR
rts
; ------------------------------------------------------------------------
-; GETPALETTE: Return the current palette in A/X. Must return NULL and set an
-; error if palettes are not supported.
+; GETPALETTE: Return the current palette in A/X. Even drivers that cannot
+; set the palette should return the default palette here, so there's no
+; way for this function to fail.
;
-; Must set an error code: YES
+; Must set an error code: NO
;
GETPALETTE:
rts
; ------------------------------------------------------------------------
-; GETDEFPALETTE: Return the default palette for the driver in A/X. Must
-; return NULL and set an error of palettes are not supported.
+; GETDEFPALETTE: Return the default palette for the driver in A/X. All
+; drivers should return something reasonable here, even drivers that don't
+; support palettes, otherwise the caller has no way to determine the colors
+; of the (not changeable) palette.
;
-; Must set an error code: YES
+; Must set an error code: NO (all drivers must have a default palette)
;
GETDEFPALETTE:
@CONT1: inc ROW
bne @DONE
lda COL
- bmi @DONE
- lda #00
- sta INRANGE
+ bpl @CLEAR
@DONE: rts
@DECPTR: ;Okay, subtract 320 then
bne @DONE
lda COL
bmi @DONE
- lda #00
+@CLEAR: lda #00
sta INRANGE
rts
+
@TOAST: pla ;Remove old return address
pla
jmp EXIT ;Restore interrupts, etc.
projects / cc65 / commitdiff