--- /dev/null
+;
+; Timex VT primitives
+;
+; 512 pixel mode
+;
+
+ .module tmxvideo
+
+ ; exported symbols
+ .globl _plot_char
+ .globl _scroll_down
+ .globl _scroll_up
+ .globl _cursor_on
+ .globl _cursor_off
+ .globl _cursor_disable
+ .globl _clear_lines
+ .globl _clear_across
+ .globl _do_beep
+ .globl _fontdata_8x8
+ .globl _curattr
+ .globl _vtattr
+ .globl map_kernel
+ .globl map_video
+
+ ; Build the video library as the only driver
+ ; We will make this includable at some point
+
+TMXVID_ONLY .equ 1
+
+ .area _VIDEO
+
+;
+; zx128 vt primitives hacked a bit
+;
+; Will be replaced by Timex video shortly
+;
+ ; exported symbols
+ .globl tmx_plot_char
+ .globl tmx_scroll_down
+ .globl tmx_scroll_up
+ .globl tmx_cursor_on
+ .globl tmx_cursor_off
+ .globl tmx_cursor_disable
+ .globl tmx_clear_lines
+ .globl tmx_clear_across
+ .globl tmx_do_beep
+ .globl _fontdata_8x8
+ .globl _curattr
+ .globl _vtattr
+
+videopos:
+ srl d ; we alternate pixels between two screens
+ push af
+ ld a,e
+ and #7
+ rrca
+ rrca
+ rrca
+ add a,d
+ ld d,e
+ ld e,a
+ pop af
+ jr c, rightside
+ ld a,d
+ and #0x18
+ or #0x40 ; Left screen
+ ld d,a
+ jp map_video
+rightside:
+ ld a,d
+ and #0x18
+ or #0x60 ; Left screen
+ ld d,a
+ jp map_video
+
+ .if TMXVID_ONLY
+_plot_char:
+ .endif
+tmx_plot_char:
+ pop hl
+ pop de ; D = x E = y
+ pop bc
+ push bc
+ push de
+ push hl
+
+ ld hl,(_vtattr) ; l is vt attributes
+ push hl ; save attributes as inaccessible once vid mapped
+
+ call videopos
+
+ ld b, #0 ; calculating offset in font table
+ ld a, c
+
+ or a ; clear carry
+ rla
+ rl b
+ rla
+ rl b
+ rla
+ rl b
+ ld c, a
+
+ ld hl, #_fontdata_8x8-32*8 ; font
+ add hl, bc ; hl points to first byte of char data
+
+ pop bc
+ ; We do underline for now - not clear italic or bold are useful
+ ; with the font we have.
+
+ ; printing
+plot_char_loop:
+ ld a, (hl)
+ ld (de), a
+ inc hl ; next byte of char data
+ inc d ; next screen line
+
+ ld a, (hl)
+ ld (de), a
+ inc hl ; next byte of char data
+ inc d ; next screen line
+
+ ld a, (hl)
+ ld (de), a
+ inc hl ; next byte of char data
+ inc d ; next screen line
+
+ ld a, (hl)
+ ld (de), a
+ inc hl ; next byte of char data
+ inc d ; next screen line
+
+ ld a, (hl)
+ ld (de), a
+ inc hl ; next byte of char data
+ inc d ; next screen line
+
+ ld a, (hl)
+ ld (de), a
+ inc hl ; next byte of char data
+ inc d ; next screen line
+
+ ld a, (hl)
+ ld (de), a
+ inc hl ; next byte of char data
+ inc d ; next screen line
+
+ ld a, (hl)
+ bit 1,c ; underline ?
+ jr nz, last_ul
+plot_attr:
+ ld (de), a
+ jp map_kernel
+
+last_ul:
+ ld a,#0xff
+ jr plot_attr
+
+ .if TMXVID_ONLY
+_clear_lines:
+ .endif
+tmx_clear_lines:
+ pop hl
+ pop de ; E = line, D = count
+ push de
+ push hl
+ ; This way we handle 0 correctly
+ inc d
+ jr nextline
+
+clear_next_line:
+ push de
+ ld d, #0 ; from the column #0
+ ld b, d ; b = 0
+ ld c, #64 ; clear 64 cols
+ push bc
+ push de
+ call _clear_across
+ pop hl ; clear stack
+ pop hl
+
+ pop de
+ inc e
+nextline:
+ dec d
+ jr nz, clear_next_line
+
+ ret
+
+
+ .if TMXVID_ONLY
+_clear_across:
+ .endif
+tmx_clear_across:
+ pop hl
+ pop de ; DE = coords
+ pop bc ; C = count
+ push bc
+ push de
+ push hl
+ ld a,c
+ or a
+ ret z ; No work to do - bail out
+ call videopos ; first pixel line of first character in DE
+
+ ; Save it in HL
+ ld h,d
+ ld l,e
+
+ xor a
+
+ ; TODO Figure out if starting L or R
+ bit 5,d
+ jr nz, clear_start_r
+
+
+ ; no boundary checks. Assuming that D + C < SCREEN_WIDTH
+clear_line:
+
+ ; Do the left character
+ ld b, #8 ; 8 pixel lines to clear for this char
+clear_char_l:
+ ld (de), a
+ inc d
+ djnz clear_char_l
+
+ ; Left was final char
+ dec c
+ jr z, lines_done
+
+ ; Recover position from HL and move 8K up
+ ld d,h
+ ld e,l
+ set 5,d
+
+clear_start_r:
+ ld b, #8 ; 8 pixel lines to clear for this char
+clear_char_r:
+ ld (de), a
+ inc d
+ djnz clear_char_r
+
+ inc hl
+ ld d,h
+ ld e,l
+
+ ; Next character ?
+ dec c
+ jr nz, clear_line
+lines_done:
+ jp map_kernel
+
+copy_line:
+ ; HL - source, DE - destination
+
+ ; convert line coordinates to screen coordinates both for DE and HL
+ push de
+ ex de, hl
+ call videopos
+ ex de, hl
+ pop de
+ call videopos
+
+ ld c, #8
+
+copy_line_nextchar:
+ push hl
+ push de
+
+ ld b, #32
+
+copy_pixel_line:
+ ld a, (hl)
+ ld (de), a
+ inc e
+ inc l
+ djnz copy_pixel_line
+
+ pop de
+ pop hl
+ push hl
+ push de
+ set 5,d ; Even half
+ set 5,h
+ ld b,#32
+copy_pixel_line_r:
+ ld a,(hl)
+ ld (de),a
+ inc e
+ inc l
+ djnz copy_pixel_line_r
+ pop de
+ pop hl
+ inc d
+ inc h
+ dec c
+ jr nz, copy_line_nextchar
+ ret
+
+ ; TODO: the LDIR way should be much faster
+
+ .if TMXVID_ONLY
+_scroll_down:
+ .endif
+tmx_scroll_down:
+ ; set HL = (0,22), DE = (0, 23)
+ xor a
+ ld d, a
+ ld h, a
+ ld l, #22
+ ld e, #23
+ ld c, #23 ; 23 lines to move
+
+ call map_video
+
+loop_scroll_down:
+ push hl
+ push de
+ push bc
+
+ call copy_line
+
+ pop bc
+ pop de
+ pop hl
+
+ dec l
+ dec e
+ dec c
+ jr nz, loop_scroll_down
+ jp map_kernel
+
+
+ .if TMXVID_ONLY
+_scroll_up:
+ .endif
+tmx_scroll_up:
+ ; set HL = (0,1), DE = (0, 0)
+ xor a
+ ld d, a
+ ld e, a
+ ld h, a
+ ld l, #1
+ ld c, #23 ; 23 lines to move
+
+ call map_video
+
+loop_scroll_up:
+ push hl
+ push de
+ push bc
+
+ call copy_line
+
+ pop bc
+ pop de
+ pop hl
+
+ inc l
+ inc e
+ dec c
+ jr nz, loop_scroll_up
+ jp map_kernel
+
+ .if TMXVID_ONLY
+_cursor_on:
+ .endif
+tmx_cursor_on:
+ pop hl
+ pop de
+ push de
+ push hl
+ ld (cursorpos), de
+
+ call videopos
+ ld a, #7
+ add a, d
+ ld d, a
+ ld a, #0xFF
+ ld (de), a
+ jp map_kernel
+ .if TMXVID_ONLY
+_cursor_disable:
+_cursor_off:
+ .endif
+tmx_cursor_disable:
+tmx_cursor_off:
+ ld de, (cursorpos)
+ call videopos
+ ld a, #7
+ add a, d
+ ld d, a
+ xor a
+ ld (de), a
+ jp map_kernel
+
+ .if TMXVID_ONLY
+_do_beep:
+ .endif
+tmx_do_beep:
+ ret
+
+ .area _DATA
+
+cursorpos:
+ .dw 0
+
+ .area _COMMONDATA
+
+_curattr:
+ .db 7
+
public / FUZIX.git / commitdiff