ci-libretro-fceumm/src/input/zapper.c

/* FCE Ultra - NES/Famicom Emulator
 *
 * Copyright notice for this file:
 *  Copyright (C) 2002 Xodnizel
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include        <string.h>
#include        <stdlib.h>

#include        "share.h"

#define ROUNDED_TARGET
#ifdef ROUNDED_TARGET
#define MAX_TOLERANCE 20
static uint32 targetExpansion[MAX_TOLERANCE+1];
#endif
static uint32 tolerance;

typedef struct {
	uint32 mzx, mzy, mzb;
	int zap_readbit;
	int bogo;
	int zappo;
	uint64 zaphit;
} ZAPPER;

static ZAPPER ZD[2];

static void FP_FASTAPASS(3) ZapperFrapper(int w, uint8 * bg, uint8 * spr, uint32 linets, int final) {
	int xs, xe;
	int zx, zy;

	if (!bg) {	/* New line, so reset stuff. */
		ZD[w].zappo = 0;
		return;
	}
	xs = ZD[w].zappo;
	xe = final;

	zx = ZD[w].mzx;
	zy = ZD[w].mzy;

	if (xe > 256) xe = 256;

	if (scanline >= (zy - tolerance) && scanline <= (zy + tolerance)) {
#ifdef ROUNDED_TARGET
		int spread;
		int dy = scanline - zy;
		if (dy < 0)
			dy = -dy;
		spread = targetExpansion[dy];
#else
		int spread = tolerance;
#endif
		while (xs < xe) {
			uint8 a1, a2;
			uint32 sum;
			if (xs <= (zx + spread) && xs >= (zx - spread)) {
				a1 = bg[xs];
				if (spr) {
					a2 = spr[xs];

					if (!(a2 & 0x80))
						if (!(a2 & 0x40) || (a1 & 64))
							a1 = a2;
				}
				a1 &= 63;

				sum = palo[a1].r + palo[a1].g + palo[a1].b;
				if (sum >= 100 * 3) {
					ZD[w].zaphit = ((uint64)linets + (xs + 16) * (PAL ? 15 : 16)) / 48 + timestampbase;
					goto endo;
				}
			}
			xs++;
		}
	}
 endo:
	ZD[w].zappo = final;
}

static INLINE int CheckColor(int w) {
	FCEUPPU_LineUpdate();

	if ((ZD[w].zaphit + 100) >= (timestampbase + timestamp)
		&& !(ZD[w].mzb & 2)) return(0);

	return(1);
}

static uint8 FP_FASTAPASS(1) ReadZapperVS(int w) {
	uint8 ret = 0;

	if (ZD[w].zap_readbit == 4) ret = 1;

	if (ZD[w].zap_readbit == 7) {
		if (ZD[w].bogo)
			ret |= 0x1;
	}
	if (ZD[w].zap_readbit == 6) {
		if (!CheckColor(w))
			ret |= 0x1;
	}
				#ifdef FCEUDEF_DEBUGGER
	if (!fceuindbg)
				#endif
	ZD[w].zap_readbit++;
	return ret;
}

static void FP_FASTAPASS(1) StrobeZapperVS(int w) {
	ZD[w].zap_readbit = 0;
}

static uint8 FP_FASTAPASS(1) ReadZapper(int w) {
	uint8 ret = 0;
	if (ZD[w].bogo)
		ret |= 0x10;
	if (CheckColor(w))
		ret |= 0x8;
	return ret;
}

static void FASTAPASS(3) DrawZapper(int w, uint8 * buf, int arg) {
	if (arg)
		FCEU_DrawGunSight(buf, ZD[w].mzx, ZD[w].mzy);
}

static void FP_FASTAPASS(3) UpdateZapper(int w, void *data, int arg) {
	uint32 *ptr = (uint32*)data;

	if (ZD[w].bogo)
		ZD[w].bogo--;
	if (ptr[2] & 3 && (!(ZD[w].mzb & 3)))
		ZD[w].bogo = 5;

	ZD[w].mzx = ptr[0];
	ZD[w].mzy = ptr[1];
	ZD[w].mzb = ptr[2];
}

static INPUTC ZAPC = { ReadZapper, 0, 0, UpdateZapper, ZapperFrapper, DrawZapper };
static INPUTC ZAPVSC = { ReadZapperVS, 0, StrobeZapperVS, UpdateZapper, ZapperFrapper, DrawZapper };

#ifdef ROUNDED_TARGET
static uint32 InefficientSqrt(uint32 z) {
	uint32 i;
	for (i = 0 ; i * i <= z ; i++) ;
	return i-1;
}
#endif

void FCEU_ZapperSetTolerance(int t)
{
#ifdef ROUNDED_TARGET
	uint32 y;
	tolerance = t <= MAX_TOLERANCE ? t : MAX_TOLERANCE;
	for (y = 0; y <= tolerance; y++)
		targetExpansion[y] = InefficientSqrt(tolerance*tolerance-y*y);
#else
	tolerance = t;
#endif
}

INPUTC *FCEU_InitZapper(int w) {
	memset(&ZD[w], 0, sizeof(ZAPPER));
	if (GameInfo->type == GIT_VSUNI)
		return(&ZAPVSC);
	else
		return(&ZAPC);
}