Added Tinsel engine to main repos (no news item for it ON PURPOSE)

svn-id: r33230

1 files changed, 192 insertions, 0 deletions

diff --git a/engines/tinsel/timers.cpp b/engines/tinsel/timers.cpp
new file mode 100644
index 0000000000..c7b9d3708b
--- /dev/null
+++ b/engines/tinsel/timers.cpp
@@ -0,0 +1,192 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * 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.
+ *
+ * $URL$
+ * $Id$
+ *
+ * Handles timers.
+ *
+ * Note: As part of the transition to ScummVM, the ticks field of a timer has been changed 
+ * to a millisecond value, rather than ticks at 24Hz. Most places should be able to use
+ * the timers without change, since the ONE_SECOND constant has been set to be in MILLISECONDS
+ */
+
+#include "tinsel/timers.h"
+#include "tinsel/dw.h"
+#include "tinsel/serializer.h"
+
+#include "common/system.h"
+
+namespace Tinsel {
+
+//----------------- LOCAL DEFINES --------------------
+
+#define MAX_TIMERS 16
+
+struct TIMER {
+	int 	tno;		/**< Timer number */
+	int		ticks;		/**< Tick count */
+	int		secs;		/**< Second count */
+	int		delta;		/**< Increment/decrement value */
+	bool	frame;		/**< If set, in ticks, otherwise in seconds */
+};
+
+
+
+//----------------- LOCAL GLOBAL DATA --------------------
+
+static TIMER timers[MAX_TIMERS];
+
+
+//--------------------------------------------------------
+
+/**
+ * Gets the current time in number of ticks.
+ *
+ * DOS timer ticks is the number of 54.9254ms since midnight. Converting the
+ * millisecond count won't give the exact same 'since midnight' count, but I
+ * figure that as long as the timing interval is more or less accurate, it
+ * shouldn't be a problem.
+ */
+
+uint32 DwGetCurrentTime() {
+	return g_system->getMillis() * 55 / 1000;
+}
+
+/**
+ * Resets all of the timer slots
+ */
+
+void RebootTimers(void) {
+	memset(timers, 0, sizeof(timers));
+}
+
+/**
+ * (Un)serialize the timer data for save/restore game.
+ */
+void syncTimerInfo(Serializer &s) {
+	for (int i = 0; i < MAX_TIMERS; i++) {
+		s.syncAsSint32LE(timers[i].tno);
+		s.syncAsSint32LE(timers[i].ticks);
+		s.syncAsSint32LE(timers[i].secs);
+		s.syncAsSint32LE(timers[i].delta);
+		s.syncAsSint32LE(timers[i].frame);
+	}
+}
+
+/**
+ * Find the timer numbered thus, if one is thus numbered.
+ * @param num	number of the timer
+ * @return the timer with the specified number, or NULL if there is none
+ */
+static TIMER *findTimer(int num) {
+	for (int i = 0; i < MAX_TIMERS; i++) {
+		if (timers[i].tno == num)
+			return &timers[i];
+	}
+	return NULL;
+}
+
+/**
+ * Find an empty timer slot.
+ */
+static TIMER *allocateTimer(int num) {
+	assert(num); // zero is not allowed as a timer number
+	assert(!findTimer(num)); // Allocating already existant timer
+
+	for (int i = 0; i < MAX_TIMERS; i++) {
+		if (!timers[i].tno) {
+			timers[i].tno = num;
+			return &timers[i];
+		}
+	}
+
+	error("Too many timers");
+}
+
+/**
+ * Update all timers, as appropriate.
+ */
+void FettleTimers(void) {
+	for (int i = 0; i < MAX_TIMERS; i++) {
+		if (!timers[i].tno)
+			continue;
+
+		timers[i].ticks += timers[i].delta;	// Update tick value
+
+		if (timers[i].frame) {
+			if (timers[i].ticks < 0)
+				timers[i].ticks = 0;	// Have reached zero
+		} else {
+			if (timers[i].ticks < 0) {
+				timers[i].ticks = ONE_SECOND;
+				timers[i].secs--;
+				if (timers[i].secs < 0)
+					timers[i].secs = 0;	// Have reached zero
+			} else if (timers[i].ticks == ONE_SECOND) {
+				timers[i].ticks = 0;
+				timers[i].secs++;		// Another second has passed
+			}
+		}
+	}
+}
+
+/**
+ * Start a timer up.
+ */
+void DwSetTimer(int num, int sval, bool up, bool frame) {
+	TIMER *pt;
+
+	assert(num); // zero is not allowed as a timer number
+
+	pt = findTimer(num);
+	if (pt == NULL)
+		pt = allocateTimer(num);
+
+	pt->delta = up ? 1 : -1;	// Increment/decrement value
+	pt->frame = frame;
+
+	if (frame) {
+		pt->secs = 0;
+		pt->ticks = sval;
+	} else {
+		pt->secs = sval;
+		pt->ticks = 0;
+	}
+}
+
+/**
+ * Return the current count of a timer.
+ */
+int Timer(int num) {
+	TIMER *pt;
+
+	pt = findTimer(num);
+
+	if (pt == NULL)
+		return -1;
+
+	if (pt->frame)
+		return pt->ticks;
+	else
+		return pt->secs;
+}
+
+} // end of namespace Tinsel