1.1 --- a/hw.inc	Thu Jan 10 04:48:34 2019 +0200
     1.2 +++ b/hw.inc	Thu Jan 10 06:05:21 2019 +0200
     1.3 @@ -1,4 +1,5 @@
     1.4  ; vi:ft=rgbasm:
     1.5 +REG_P1		equ $ff00
     1.6  REG_LCDC        equ $ff40
     1.7  REG_STAT        equ $ff41
     1.8  REG_SCY         equ $ff42
     1.9 @@ -11,6 +12,17 @@
    1.10  REG_WY          equ $ff4a
    1.11  REG_WX          equ $ff4b
    1.12  
    1.13 +P1_RIGHT	equ $01
    1.14 +P1_A		equ $01
    1.15 +P1_LEFT		equ $02
    1.16 +P1_B		equ $02
    1.17 +P1_UP		equ $04
    1.18 +P1_SELECT	equ $04
    1.19 +P1_DOWN		equ $08
    1.20 +P1_START	equ $08
    1.21 +P1_DPAD		equ $20
    1.22 +P1_BUTTONS	equ $10
    1.23 +
    1.24  LCDC_BGON       equ $01
    1.25  LCDC_OBJON      equ $02
    1.26  LCDC_OBJ16      equ $04

     2.1 --- a/test.asm	Thu Jan 10 04:48:34 2019 +0200
     2.2 +++ b/test.asm	Thu Jan 10 06:05:21 2019 +0200
     2.3 @@ -4,7 +4,19 @@
     2.4  xoffs_center equ 4
     2.5  yoffs_center equ 12
     2.6  
     2.7 -frame_ptr equ $ff80
     2.8 +frame equ $ff80
     2.9 +bnstate equ $ff81
    2.10 +bnxor equ $ff82
    2.11 +pause equ $ff83
    2.12 +
    2.13 +BN_A		equ $01
    2.14 +BN_B		equ $02
    2.15 +BN_SELECT	equ $04
    2.16 +BN_START	equ $08
    2.17 +BN_RIGHT	equ $10
    2.18 +BN_LEFT		equ $20
    2.19 +BN_UP		equ $40
    2.20 +BN_DOWN		equ $80
    2.21  
    2.22  section "hdr", ROM0[$100]
    2.23          nop
    2.24 @@ -20,16 +32,53 @@
    2.25  	call init
    2.26  
    2.27  	xor a, a
    2.28 -	ldh [frame_ptr], a
    2.29 +	ldh [frame], a
    2.30 +	ldh [bnstate], a
    2.31 +	ldh [bnxor], a
    2.32 +	ldh [pause], a
    2.33 +
    2.34  .mainloop:
    2.35  	ldh a, [REG_LY]
    2.36  	cp a, 144
    2.37  	jr c, .wait_hsync
    2.38  
    2.39 -	; we're in vsync, increment frame counter and wait for the next frame
    2.40 -	ldh a, [frame_ptr]
    2.41 +	; we're in vsync, increment frame counter, handle input,
    2.42 +	; and wait for the next frame
    2.43 +	call read_input
    2.44 +
    2.45 +	; swap palette if A is pressed
    2.46 +	ldh a, [bnxor]
    2.47 +	and a, BN_A
    2.48 +	jr z, .skip_akey  ; skip if A haven't changed state since last frame
    2.49 +	ldh a, [bnstate]
    2.50 +	and a, BN_A
    2.51 +	jr z, .skip_akey  ; skip if A is not pressed
    2.52 +	ldh a, [REG_BGP]
    2.53 +	cpl
    2.54 +	ldh [REG_BGP], a
    2.55 +.skip_akey:
    2.56 +	; toggle pause if start is pressed
    2.57 +	ldh a, [bnxor]
    2.58 +	and a, BN_START
    2.59 +	jr z, .skip_startkey ; skip if start haven't changed state since last frame
    2.60 +	ldh a, [bnstate]
    2.61 +	and a, BN_START
    2.62 +	jr z, .skip_startkey ; skip if start is not pressed
    2.63 +	ldh a, [pause]
    2.64 +	cpl
    2.65 +	ldh [pause], a
    2.66 +.skip_startkey:
    2.67 +
    2.68 +	; increment frame if we're not paused
    2.69 +	ldh a, [pause]
    2.70 +	bit 0, a
    2.71 +	jr nz, .skip_frameinc
    2.72 +	ldh a, [frame]
    2.73  	inc a
    2.74 -	ldh [frame_ptr], a
    2.75 +	ldh [frame], a
    2.76 +.skip_frameinc:
    2.77 +
    2.78 +
    2.79  .wait_newframe:
    2.80  	ldh a, [REG_LY]
    2.81  	cp a, 0
    2.82 @@ -41,7 +90,7 @@
    2.83  	and a, STAT_MODE_MASK
    2.84  	jr nz, .wait_hsync
    2.85  
    2.86 -	ldh a, [frame_ptr]
    2.87 +	ldh a, [frame]
    2.88  	ld d, a
    2.89  
    2.90  	xor a, a
    2.91 @@ -98,7 +147,7 @@
    2.92  	and a, STAT_MODE_MASK
    2.93  	jr z, .wait_endhsync
    2.94  
    2.95 -	jr .mainloop 
    2.96 +	jp .mainloop 
    2.97  
    2.98  
    2.99  	di
   2.100 @@ -166,6 +215,40 @@
   2.101  	jr c, wait_vsync
   2.102  	ret
   2.103  
   2.104 +read_input:
   2.105 +	; read D-pad
   2.106 +	ld a, P1_DPAD
   2.107 +	ld [REG_P1], a
   2.108 +	ld a, [REG_P1]
   2.109 +	ld a, [REG_P1]
   2.110 +	cpl
   2.111 +	and a, $0f
   2.112 +	swap a
   2.113 +	ld b, a
   2.114 +	; read buttons
   2.115 +	ld a, P1_BUTTONS
   2.116 +	ld [REG_P1], a
   2.117 +	ld a, [REG_P1]
   2.118 +	ld a, [REG_P1]
   2.119 +	ld a, [REG_P1]
   2.120 +	ld a, [REG_P1]
   2.121 +	ld a, [REG_P1]
   2.122 +	ld a, [REG_P1]
   2.123 +	cpl
   2.124 +	and a, $0f
   2.125 +	or a, b
   2.126 +	ld b, a
   2.127 +	; reset port
   2.128 +	ld a, P1_DPAD | P1_BUTTONS
   2.129 +	ldh [REG_P1], a
   2.130 +	; calculate differences and save state variables
   2.131 +	ldh a, [bnstate]
   2.132 +	xor a, b
   2.133 +	ldh [bnxor], a
   2.134 +	ld a, b
   2.135 +	ldh [bnstate], a
   2.136 +	ret
   2.137 +
   2.138  section "data", ROM0, align[8]
   2.139  sintab:
   2.140  include "sin.inc"