From 6a650e3e08da161fcebeb9181da60e110893fa8b Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@member.fsf.org>
Date: Sun, 18 Apr 2021 09:15:38 +0300
Subject: [PATCH] added input handling

---
 src/debug.h   |    6 +++++-
 src/gamescr.c |   22 ++++++++++++++++++----
 src/input.c   |   39 +++++++++++++++++++++++++++++++++++++++
 src/input.h   |   24 ++++++++++++++++++++++++
 4 files changed, 86 insertions(+), 5 deletions(-)
 create mode 100644 src/input.c
 create mode 100644 src/input.h

diff --git a/src/debug.h b/src/debug.h
index 45cc067..921fd12 100644
--- a/src/debug.h
+++ b/src/debug.h
@@ -12,6 +12,7 @@ volatile int vblperf_count;
 
 void vblperf_setcolor(int palidx);
 
+#ifdef VBLBAR
 #define vblperf_begin()	\
 	do { \
 		*vblperf_palptr = 0; \
@@ -22,7 +23,10 @@ void vblperf_setcolor(int palidx);
 	do { \
 		*vblperf_palptr = vblperf_color[vblperf_count]; \
 	} while(0)
-
+#else
+#define vblperf_begin()
+#define vblperf_end()
+#endif
 
 void panic(void *pc, const char *fmt, ...) __attribute__((noreturn));
 
diff --git a/src/gamescr.c b/src/gamescr.c
index 30ae380..f927cee 100644
--- a/src/gamescr.c
+++ b/src/gamescr.c
@@ -5,6 +5,7 @@
 #include "data.h"
 #include "util.h"
 #include "intr.h"
+#include "input.h"
 #include "debug.h"
 
 static void draw_tunnel(void);
@@ -12,6 +13,7 @@ static void draw_tunnel(void);
 static int nframes, backbuf;
 static uint16_t *vram[] = { (uint16_t*)VRAM_LFB_FB0_ADDR, (uint16_t*)VRAM_LFB_FB1_ADDR };
 static unsigned char *tex;
+static uint16_t bnstate;
 
 void gamescr(void)
 {
@@ -36,10 +38,14 @@ void gamescr(void)
 	tex = iwram_sbrk(32 * 32);
 	memcpy(tex, tuncross_pixels, 32 * 32);
 
+	select_input(BN_DPAD);
+
 	nframes = 0;
 	for(;;) {
 		backbuf = ++nframes & 1;
 
+		bnstate = get_input();
+
 		draw_tunnel();
 
 		vblperf_end();
@@ -52,22 +58,30 @@ void gamescr(void)
 __attribute__((noinline, target("arm"), section(".iwram")))
 static void draw_tunnel(void)
 {
-	int i, j, tx, ty, angle, depth, zoffs, uoffs;
+	static int uoffs;
+	int i, j, tx, ty, angle, depth, zoffs;
 	uint16_t pptop, ppbot;
 	uint16_t *top, *bot;
 	uint32_t tun, *tunptr;
 
 	zoffs = nframes;
-	uoffs = 0;
+
+	if(bnstate & BN_LEFT) uoffs++;
+	if(bnstate & BN_RIGHT) uoffs--;
 
 	top = vram[backbuf];
 	bot = vram[backbuf] + 159 * 240 / 2;
 	tunptr = tunmap;
 	for(i=0; i<80; i++) {
+#ifdef VBLBAR
 		top++;
 		bot++;
 		tunptr++;
+
 		for(j=1; j<240/2; j++) {
+#else
+		for(j=0; j<240/2; j++) {
+#endif
 			tun = *tunptr++;
 
 			angle = tun & 0xff;
@@ -75,7 +89,7 @@ static void draw_tunnel(void)
 			tx = ((angle >> 1) + uoffs) & 0x1f;
 			ty = ((depth >> 1) + zoffs) & 0x1f;
 			pptop = tex[(ty << 5) + tx];
-			tx = ((angle >> 1) - uoffs) & 0x1f;
+			tx = ~((angle >> 1) - uoffs) & 0x1f;
 			ppbot = tex[(ty << 5) + tx];
 
 			angle = (tun >> 16) & 0xff;
@@ -83,7 +97,7 @@ static void draw_tunnel(void)
 			tx = ((angle >> 1) + uoffs) & 0x1f;
 			ty = ((depth >> 1) + zoffs) & 0x1f;
 			pptop |= (uint16_t)tex[(ty << 5) + tx] << 8;
-			tx = ((angle >> 1) - uoffs) & 0x1f;
+			tx = ~((angle >> 1) - uoffs) & 0x1f;
 			ppbot |= (uint16_t)tex[(ty << 5) + tx] << 8;
 
 			*top++ = pptop;
diff --git a/src/input.c b/src/input.c
new file mode 100644
index 0000000..6a66dd1
--- /dev/null
+++ b/src/input.c
@@ -0,0 +1,39 @@
+#include "input.h"
+#include "gbaregs.h"
+#include "intr.h"
+
+static void keyintr(void);
+
+static uint16_t bnstate;
+
+void select_input(uint16_t bmask)
+{
+	bnstate = 0;
+
+	mask(INTR_KEY);
+	if(bmask) {
+		REG_KEYCNT = bmask | KEYCNT_IE;
+		interrupt(INTR_KEY, keyintr);
+		unmask(INTR_KEY);
+	} else {
+		REG_KEYCNT = 0;
+		interrupt(INTR_KEY, 0);
+	}
+}
+
+uint16_t get_input(void)
+{
+	uint16_t s;
+
+	mask(INTR_KEY);
+	s = bnstate;
+	bnstate = 0;
+	unmask(INTR_KEY);
+
+	return s;
+}
+
+static void keyintr(void)
+{
+	bnstate |= ~REG_KEYINPUT;
+}
diff --git a/src/input.h b/src/input.h
new file mode 100644
index 0000000..3ed22a0
--- /dev/null
+++ b/src/input.h
@@ -0,0 +1,24 @@
+#ifndef INPUT_H_
+#define INPUT_H_
+
+#include <stdint.h>
+
+enum {
+	BN_A		= 0x0001,
+	BN_B		= 0x0002,
+	BN_SELECT	= 0x0004,
+	BN_START	= 0x0008,
+	BN_RIGHT	= 0x0010,
+	BN_LEFT		= 0x0020,
+	BN_UP		= 0x0040,
+	BN_DOWN		= 0x0080,
+	BN_RT		= 0x0100,
+	BN_LT		= 0x0200
+};
+
+#define BN_DPAD	(BN_RIGHT | BN_LEFT | BN_UP | BN_DOWN)
+
+void select_input(uint16_t bmask);
+uint16_t get_input(void);
+
+#endif	/* INPUT_H_ */
-- 
1.7.10.4