STARTREK: sine & cosine

5 files changed, 34 insertions, 18 deletions

diff --git a/engines/startrek/fixedint.h b/engines/startrek/fixedint.h
index 88e9c311e4..cae9efdb94 100644
--- a/engines/startrek/fixedint.h
+++ b/engines/startrek/fixedint.h
@@ -77,10 +77,11 @@ public:
 	}
 
 	/**
-	 * Multiplication with an int, with the result being an int.
+	 * Multiplication with an int, with the result being an int. Use this if the result
+	 * might exceed the capacity of this type.
 	 */
-	int32 multToInt(int32 i) {
-		return ((val * i) << (totalBits - decimalBits)) >> totalBits;
+	int16 multToInt(int32 i) {
+		return (val * i) >> decimalBits;
 	}
 
 	/**
diff --git a/engines/startrek/module.mk b/engines/startrek/module.mk
index bef2c8df5b..85250e0813 100644
--- a/engines/startrek/module.mk
+++ b/engines/startrek/module.mk
@@ -11,6 +11,7 @@ MODULE_OBJS = \
 	graphics.o \
 	iwfile.o \
 	lzss.o \
+	math.o \
 	menu.o \
 	object.o \
 	room.o \
diff --git a/engines/startrek/space.cpp b/engines/startrek/space.cpp
index a4d09690f8..aeb26155a6 100644
--- a/engines/startrek/space.cpp
+++ b/engines/startrek/space.cpp
@@ -150,30 +150,32 @@ Point3 StarTrekEngine::constructPoint3ForStarfield(int16 x, int16 y, int16 z) {
 }
 
 Point3 StarTrekEngine::matrixMult(const Matrix &weight, const Point3 &point) {
-	int32 ret[3];
+	Point3 p;
 	for (int i = 0; i < 3; i++) {
-		ret[i] = weight[i][0].multToInt(point.x & 0xffff) + weight[i][1].multToInt(point.y & 0xffff) + weight[i][2].multToInt(point.z & 0xffff);
+		p[i] = 0;
+		for (int j = 0; j < 3; j++) { // FIXME: what is this weird multiplication?
+			p[i] += (weight[i][j].raw() * (point[j] & 0xffff) << 2) >> 16;
+		}
 	}
-	Point3 p;
-	p.x = ret[0];
-	p.y = ret[1];
-	p.z = ret[2];
 	return p;
 }
 
 Point3 StarTrekEngine::matrixMult(const Point3 &point, const Matrix &weight) {
 	Point3 p = Point3();
-	p.x = (weight[0][0].multToInt(point.x & 0xffff) + weight[1][0].multToInt(point.y & 0xffff) + weight[2][0].multToInt(point.z & 0xffff));
-	p.y = (weight[0][1].multToInt(point.x & 0xffff) + weight[1][1].multToInt(point.y & 0xffff) + weight[2][1].multToInt(point.z & 0xffff));
-	p.z = (weight[0][2].multToInt(point.x & 0xffff) + weight[1][2].multToInt(point.y & 0xffff) + weight[2][2].multToInt(point.z & 0xffff));
+	for (int i = 0; i < 3; i++) {
+		p[i] = 0;
+		for (int j = 0; j < 3; j++) {
+			p[i] += (weight[j][i].raw() * (point[j] & 0xffff) << 2) >> 16;
+		}
+	}
 	return p;
 }
 
 Matrix StarTrekEngine::initMatrix() {
 	Matrix mat;
-	mat[0][0] = 1;
-	mat[1][1] = 1;
-	mat[2][2] = 1;
+	mat[0][0] = 1.0;
+	mat[1][1] = 1.0;
+	mat[2][2] = 1.0;
 	return mat;
 }
 
diff --git a/engines/startrek/startrek.cpp b/engines/startrek/startrek.cpp
index e836e3bd68..c8bad8dae6 100644
--- a/engines/startrek/startrek.cpp
+++ b/engines/startrek/startrek.cpp
@@ -52,7 +52,8 @@ StarTrekEngine::StarTrekEngine(OSystem *syst, const StarTrekGameDescription *gam
 	_kirkActor(&_actorList[0]),
 	_spockActor(&_actorList[1]),
 	_mccoyActor(&_actorList[2]),
-	_redshirtActor(&_actorList[3]) {
+	_redshirtActor(&_actorList[3]),
+	_sineTable(10) {
 
 	DebugMan.addDebugChannel(kDebugSound, "sound", "Sound");
 	DebugMan.addDebugChannel(kDebugGraphics, "graphics", "Graphics");
@@ -367,8 +368,10 @@ void StarTrekEngine::playIntro() {
 }
 
 void StarTrekEngine::initIntroR3ObjectToMove(R3 *r3, int16 srcAngle, int16 srcDepth, int16 destAngle, int16 destDepth, int16 ticks) {
-	srcAngle = (srcAngle << 9) / 180;
-	destAngle = (destAngle << 9) / 180;
+	Fixed8 a1 = Fixed8::fromRaw((srcAngle << 8) / 90);
+	Fixed8 a2 = Fixed8::fromRaw((destAngle << 8) / 90);
+
+	//r3->pos.x = sin(a1).multToFixed16(srcDepth) + _starfieldPosition.x;
 }
 
 void StarTrekEngine::loadSubtitleSprite(int index, Sprite *sprite) {
diff --git a/engines/startrek/startrek.h b/engines/startrek/startrek.h
index aab4f3abb4..7ebc47d13f 100644
--- a/engines/startrek/startrek.h
+++ b/engines/startrek/startrek.h
@@ -30,6 +30,7 @@
 #include "common/rect.h"
 #include "common/scummsys.h"
 #include "common/serializer.h"
+#include "common/sinetables.h"
 #include "common/str.h"
 #include "common/stream.h"
 #include "common/system.h"
@@ -210,6 +211,13 @@ protected:
 	Common::Error run();
 
 public:
+	// math.cpp
+	/**
+	 * Unit of the angle is "quadrants" (90 degrees = 1.0)
+	 */
+	Fixed14 sin(Fixed8 angle);
+	Fixed14 cos(Fixed8 angle);
+
 	// Game modes
 	Common::Error runGameMode(int mode);
 
@@ -542,6 +550,7 @@ public:
 
 private:
 	Common::RandomSource _randomSource;
+	Common::SineTable _sineTable;
 
 	Common::MacResManager *_macResFork;
 	SharedPtr<Room> _room;