# HG changeset patch
# User John Tsiombikas <nuclear@member.fsf.org>
# Date 1453266800 -7200
# Node ID f975431190f6963e7bbf2b7ff1ec03f6bc254eb5
# Parent  04fc17db12e6a2ed0411184c0ef51813c8cb272c
moving ship

diff -r 04fc17db12e6 -r f975431190f6 test.asm
--- a/test.asm	Tue Jan 19 03:29:23 2016 +0200
+++ b/test.asm	Wed Jan 20 07:13:20 2016 +0200
@@ -9,21 +9,194 @@
 	ld a, 2
 	out (254), a
 
+	call clear_scr
+
 drawloop:
-	call clear_scr
+	ld b, 0
+	ld a, (py)
+	ld c, a
+	push bc
+	ld a, (px)
+	ld c, a
+	push bc
+	call erase_blk
+	pop bc
+	pop bc
+
+	ld hl, sprite
+	push hl
+	ld b, 0
+	ld a, (ny)
+	ld (py), a
+	ld c, a
+	push bc
+	ld a, (nx)
+	ld (px), a
+	ld c, a
+	push bc
+	call draw_sprite
+	pop bc
+	pop bc
+	pop bc
+
+_endfrm:
+	ld a, 2
+	out (254), a
+
+	halt
 	jp drawloop
 
+px defb 16
+py defb 12
+nx defb 16
+ny defb 12
+
+inp_left:
+	ld a, (px)
+	cp 0
+	ret z
+	dec a
+	ld (nx), a
+	ret
+
+inp_right:
+	ld a, (px)
+	cp 31
+	ret z
+	inc a
+	ld (nx), a
+	ret
+
+inp_up:
+	ld a, (py)
+	cp 0
+	ret z
+	dec a
+	ld (ny), a
+	ret
+
+inp_down:
+	ld a, (py)
+	cp 23
+	ret z
+	inc a
+	ld (ny), a
+	ret
+
+inp_fire:	; TODO
+	ret
+
 clear_scr:
 	ld a, $ff
 	ld hl, fb_addr
 	ld b, 192
-_LY:	ld c, 32
-_LX:	ld (hl), a
+_ly:	ld c, 32
+_lx:	ld (hl), a
 	inc hl
 	dec c
-	jr nz, _LX
+	jr nz, _lx
 	dec b
-	jr nz, _LY
+	jr nz, _ly
+	ret
+
+erase_blk:
+	ld ix, 2
+	add ix, sp
+	ld c, (ix)
+	ld b, (ix + 2)
+
+	call calc_blk_addr
+
+	ld c, 8
+	ld a, $ff
+_loop:	ld (de), a
+	inc d
+	dec c
+	jr nz, _loop
+	ret
+	
+
+draw_sprite:
+	ld ix, 2
+	add ix, sp	; skip ret addr
+	ld c, (ix)	; c <- x
+	ld b, (ix + 2)	; b <- y
+	ld l, (ix + 4)	; hl <- sprite address
+	ld h, (ix + 5)
+
+	call calc_blk_addr
+
+	ld c, 8
+_loop:	ld a, (hl)
+	ld (de), a
+	inc hl
+	inc d
+	dec c
+	jr nz, _loop
+	ret
+
+; expects X -> c, Y -> b, returns in de
+calc_blk_addr:
+	push af
+	sla b
+	sla b		; change from blocks to pixels
+	sla b
+	; construct low address byte -> e
+	ld a, b		; start with Y
+	sla a
+	sla a
+	and $e0		; keep top 3 bits
+	ld e, a		; move into e
+	ld a, c		; a <- X
+	and $1f		; keep low 5 bits
+	or e		; combine with Y bits
+	ld e, a		; move the result back to e
+	; construct high address byte -> d
+	ld a, b		; start with Y again
+	sra a
+	sra a
+	sra a
+	and $18		; keep bits 3 and 4
+	ld d, a		; keep it in d
+	ld a, b		; grap Y one more time
+	and $7		; keep low 3 bits of Y in a
+	or d		; combine with Y6-Y7
+	ld bc, fb_addr
+	or b		; combine with high byte of fb address
+	ld d, a		; move result back to d
+	pop af
+	ret
+
+
+; port  | keys
+; ------+--------------------------
+; 32766 | B, N, M, SymbShift, Space
+; 64510 | T, R, E, W, Q
+; 65022 | G, F, D, S, A
+scan_keys:
+	ld bc, 65022	; check ASD
+	in a, (c)
+	rra
+	push af
+	call nc, inp_left
+	pop af
+	rra
+	push af
+	call nc, inp_down
+	pop af
+	rra
+	call nc, inp_right
+
+	ld bc, 64510	; check W
+	in a, (c)
+	rra	; skip Q
+	rra
+	call nc, inp_up
+
+	ld bc, 32766	; check space
+	in a, (c)
+	rra
+	call nc, inp_fire
 	ret
 
 ; ------ setup interrupt handler ------
@@ -33,12 +206,12 @@
 ;  - data bus has the vector index (low byte for the jump)
 ; (1) IVT must be 256-byte aligned (addr: xx00h)
 ; also the IVT should not be in ULA-contended memory
-; (2) IVT should be above 4000h
+; (2) IVT should be above 8000h
 ; also it would be a good idea to avoid putting the IVT somewhere which can be
 ; paged out on 128k models
 ; (3) IVT shouldn't extend beyond c000h (?)
-; finally, and this is the awesome bit, the data bus of the spectrum is
-; floating during the interrupt request... which leads us to
+; finally, and this is the awesome bit, the data bus of the spectrum contains
+; garbage during the interrupt request... which leads us to
 ; (4) we must populate the entire IVT with the same interrupt address
 ; (5) we must use an interrupt address with identical low and high bytes
 ; (6) we need 257 bytes for the IVT
@@ -63,10 +236,10 @@
 	ld hl, intr_tramp_addr
 	push hl
 	pop af	; a contains high byte of the trampoline address
-_Livt:	ld (ix), a
+_livt:	ld (ix), a
 	inc ix
 	dec c
-	jr nz, _Livt
+	jr nz, _livt
 	ld (ix), a	; final odd high byte of the address
 	; at $bdbd setup the jump to our interrupt routine
 	ld ix, $bdbd
@@ -80,16 +253,28 @@
 	ret
 
 intr:
-	push af
-	ld a, (border)
-	inc a
+	exx
+	ex af, af'
+
+	ld a, 1
 	out (254), a
-	ld (border), a
-	pop af
+
+	call scan_keys
+	ex af, af'
+	exx
 	ei
 	reti
 
 border defb 1
 nframe defw 0
 
+sprite	defb %11100111
+	defb %10000001
+	defb %11000011
+	defb %10000001
+	defb %00000000
+	defb %00011000
+	defb %00111100
+	defb %01111110
+
 end prog_test