; Setting up a simple copperlist + 1 Bitplane and copy ; a single letter onto it! No (c)ode by aLpHa oNe! ; ==================================================== section flashtro,code_c move.l 4.w,a6 ; Get base of exec lib lea gfxlib(pc),a1 ; Adress of gfxlib string to a1 jsr -408(a6) ; Call OpenLibrary() move.l d0,gfxbase ; Save base of graphics.library move.l #bitplane,d0 ; Get adress of our bitplane... move.w d0,bplptr+6 ; ...and set up bitplaneregs in copperlist swap d0 ; move.w d0,bplptr+2 ; move.l #cop,$dff080 ; Set new copperlist lea bitplane(pc),a0 ; Adress of our bitplane to A0 add.l #40*40,a0 ; Move pointer to line 40 on it lea char(pc),a1 ; Adress of our char to A1 move.l #8,d0 ; Height of char = 8 copy: move.b (a1)+,(a0) ; Move a row from our char to bitplane and ; increase charptr by one ; *Remember 1 byte = 8 bit = 8 pixels ;) add.l #40,a0 ; Pointer to next line in bitplane ; *Remember 40 bytes = 320 bit = 320 pixels subq.l #1,d0 ; Decrease heightcounter bne.b copy ; If not zero, continue to copy char mouse: btst #6,$bfe001 ; Left mouse clicked ? bne.b mouse ; No, continue loop! move.l gfxbase(pc),a1 ; Base of graphics.library to a1 move.l 38(a1),$dff080 ; Restore old copperlist jsr -414(a6) ; Call CloseLibrary() moveq #0,d0 ; Over.. rts ; and out! ; Stuff ; ***** cop: dc.w $0106,$0000,$01fc,$0000 ; AGA compatible dc.w $008e,$1a64,$0090,$ffc4 ; Setting up display, dc.w $0092,$0038,$0094,$00d0 ; modulo and so on dc.w $0102,$0000,$0104,$0000 dc.w $0106,$0000,$0108,$0000 dc.w $0120,$0000,$0122,$0000 ; Clear spriteptrs dc.w $0124,$0000,$0126,$0000 dc.w $0128,$0000,$012a,$0000 dc.w $012c,$0000,$012e,$0000 dc.w $0130,$0000,$0132,$0000 dc.w $0134,$0000,$0136,$0000 dc.w $0138,$0000,$013a,$0000 dc.w $013c,$0000,$013e,$0000 dc.w $0100,$1200 ; 1 Bitplane bplptr: dc.w $00e0,$0000 ; Adress of bpl dc.w $00e2,$0000 dc.w $0180,$0000 ; Color00 = black dc.w $0182,$0fff ; Color01 = white dc.w $ffff,$fffe char: dc.b %01111110 ; our 8x8 letter dc.b %11100111 ; "A" dc.b %11100111 dc.b %11111111 dc.b %11100111 dc.b %11100111 dc.b %11100111 dc.b %11100111 bitplane: blk.b 10240,0 ; Space for one ; 320x256 bitplane ; 40 bytes each row ; (320 bits/pixels) gfxlib: dc.b "graphics.library",0,0 gfxbase: dc.l 0
Publication author
Comments: 1160Publics: 2780Registration: 06-03-2017
problem solved 😉
Just to say that in fact it works just fine on hardware 🙂
Sorry for the delay!
musashi9, using the "A500+" preset from this toolchain: http://pouet.net/prod.php?which=58703.
It’s using Full ECS, it seems…
Works on FULL-ESC for me, what are you winuae settings?
Hmmm, is there any reason why this would work perfectly on OCS and AGA but fail on ECS? Cos that’s what I’m seeing; ie no bitplane is displayed (although if I change COLOR0 I do see the BG color fine…) :/
interesting 🙂
This is my personal favourite way to store entire fonts (in a giant vertical ‘strip’) also…eg: 8×8 1bpl font:
;assume scrolltextptr in d0
lea scrolltext(pc),a0
lea (a0,d0),a0
lea fontgfx(pc),a1
move.b (a0),d1
sub.b #32,d1
lsl.w #3,d1
lea (a1,d1),a1
;now a1 points to the start of the gfx for this char
…amazingly optimised 8×8 drawing code here…
To me this is neater than the chartable-lookup stuff in some of Alpha-One’s other example source, but whatever works for you!
Here, you have the fonts in binary format. 1 bit = 1 pixel.
Alpha One copy each line of fonts in a screen. The font height is 8 pixel tall so, you have 8 iterations. The move.b (a0)+,(a1)+ is the most important because here you make the action of copying. you copy a line of 8 pixels of wide. move.b can be translated by copy a byte (so 8bits wide) to A0 towards A1 and after the operation, increment the address of A0 and A1 of a unit (1 position). This operation will repeat 8 times.
Voilà
This explains well how the bitmap characters are created.