# HG changeset patch
# User John Tsiombikas <nuclear@member.fsf.org>
# Date 1547093121 -7200
# Node ID d7c6e1165028bf64afb2a0e4c3e4aeca99194496
# Parent  a8b7297e7e2cdaa7037495b37c1059677b3be50f
added input handling

diff -r a8b7297e7e2c -r d7c6e1165028 hw.inc
--- a/hw.inc	Thu Jan 10 04:48:34 2019 +0200
+++ b/hw.inc	Thu Jan 10 06:05:21 2019 +0200
@@ -1,4 +1,5 @@
 ; vi:ft=rgbasm:
+REG_P1		equ $ff00
 REG_LCDC        equ $ff40
 REG_STAT        equ $ff41
 REG_SCY         equ $ff42
@@ -11,6 +12,17 @@
 REG_WY          equ $ff4a
 REG_WX          equ $ff4b
 
+P1_RIGHT	equ $01
+P1_A		equ $01
+P1_LEFT		equ $02
+P1_B		equ $02
+P1_UP		equ $04
+P1_SELECT	equ $04
+P1_DOWN		equ $08
+P1_START	equ $08
+P1_DPAD		equ $20
+P1_BUTTONS	equ $10
+
 LCDC_BGON       equ $01
 LCDC_OBJON      equ $02
 LCDC_OBJ16      equ $04
diff -r a8b7297e7e2c -r d7c6e1165028 test.asm
--- a/test.asm	Thu Jan 10 04:48:34 2019 +0200
+++ b/test.asm	Thu Jan 10 06:05:21 2019 +0200
@@ -4,7 +4,19 @@
 xoffs_center equ 4
 yoffs_center equ 12
 
-frame_ptr equ $ff80
+frame equ $ff80
+bnstate equ $ff81
+bnxor equ $ff82
+pause equ $ff83
+
+BN_A		equ $01
+BN_B		equ $02
+BN_SELECT	equ $04
+BN_START	equ $08
+BN_RIGHT	equ $10
+BN_LEFT		equ $20
+BN_UP		equ $40
+BN_DOWN		equ $80
 
 section "hdr", ROM0[$100]
         nop
@@ -20,16 +32,53 @@
 	call init
 
 	xor a, a
-	ldh [frame_ptr], a
+	ldh [frame], a
+	ldh [bnstate], a
+	ldh [bnxor], a
+	ldh [pause], a
+
 .mainloop:
 	ldh a, [REG_LY]
 	cp a, 144
 	jr c, .wait_hsync
 
-	; we're in vsync, increment frame counter and wait for the next frame
-	ldh a, [frame_ptr]
+	; we're in vsync, increment frame counter, handle input,
+	; and wait for the next frame
+	call read_input
+
+	; swap palette if A is pressed
+	ldh a, [bnxor]
+	and a, BN_A
+	jr z, .skip_akey  ; skip if A haven't changed state since last frame
+	ldh a, [bnstate]
+	and a, BN_A
+	jr z, .skip_akey  ; skip if A is not pressed
+	ldh a, [REG_BGP]
+	cpl
+	ldh [REG_BGP], a
+.skip_akey:
+	; toggle pause if start is pressed
+	ldh a, [bnxor]
+	and a, BN_START
+	jr z, .skip_startkey ; skip if start haven't changed state since last frame
+	ldh a, [bnstate]
+	and a, BN_START
+	jr z, .skip_startkey ; skip if start is not pressed
+	ldh a, [pause]
+	cpl
+	ldh [pause], a
+.skip_startkey:
+
+	; increment frame if we're not paused
+	ldh a, [pause]
+	bit 0, a
+	jr nz, .skip_frameinc
+	ldh a, [frame]
 	inc a
-	ldh [frame_ptr], a
+	ldh [frame], a
+.skip_frameinc:
+
+
 .wait_newframe:
 	ldh a, [REG_LY]
 	cp a, 0
@@ -41,7 +90,7 @@
 	and a, STAT_MODE_MASK
 	jr nz, .wait_hsync
 
-	ldh a, [frame_ptr]
+	ldh a, [frame]
 	ld d, a
 
 	xor a, a
@@ -98,7 +147,7 @@
 	and a, STAT_MODE_MASK
 	jr z, .wait_endhsync
 
-	jr .mainloop 
+	jp .mainloop 
 
 
 	di
@@ -166,6 +215,40 @@
 	jr c, wait_vsync
 	ret
 
+read_input:
+	; read D-pad
+	ld a, P1_DPAD
+	ld [REG_P1], a
+	ld a, [REG_P1]
+	ld a, [REG_P1]
+	cpl
+	and a, $0f
+	swap a
+	ld b, a
+	; read buttons
+	ld a, P1_BUTTONS
+	ld [REG_P1], a
+	ld a, [REG_P1]
+	ld a, [REG_P1]
+	ld a, [REG_P1]
+	ld a, [REG_P1]
+	ld a, [REG_P1]
+	ld a, [REG_P1]
+	cpl
+	and a, $0f
+	or a, b
+	ld b, a
+	; reset port
+	ld a, P1_DPAD | P1_BUTTONS
+	ldh [REG_P1], a
+	; calculate differences and save state variables
+	ldh a, [bnstate]
+	xor a, b
+	ldh [bnxor], a
+	ld a, b
+	ldh [bnstate], a
+	ret
+
 section "data", ROM0, align[8]
 sintab:
 include "sin.inc"