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STARTREK: atan2 function

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Drenn1 authored and sev- committed Jul 19, 2018
1 parent 2b09f69 commit 565bf0e96750588e8a7f6816e79683e97896f8de
Showing with 181 additions and 3 deletions.
  1. +25 −0 engines/startrek/fixedint.h
  2. +129 −0 engines/startrek/math.cpp
  3. +5 −2 engines/startrek/space.h
  4. +21 −1 engines/startrek/startrek.cpp
  5. +1 −0 engines/startrek/startrek.h
@@ -122,6 +122,31 @@ class TFixedInt : Common::Serializable {
bool operator<=(double d) const {
return toDouble() <= d;
}
bool operator>(double d) const {
return toDouble() > d;
}
bool operator>=(double d) const {
return toDouble() >= d;
}

bool operator==(const TFixedInt &f) const {
return val == f.val;
}
bool operator!=(const TFixedInt &f) const {
return val != f.val;
}
bool operator<(const TFixedInt &f) const {
return val < f.val;
}
bool operator<=(const TFixedInt &f) const {
return val <= f.val;
}
bool operator>(const TFixedInt &f) const {
return val > f.val;
}
bool operator>=(const TFixedInt &f) const {
return val >= f.val;
}

void saveLoadWithSerializer(Common::Serializer &ser) {
if (totalBits == 16)
@@ -0,0 +1,129 @@
/* 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.
*
*/

#include "startrek/startrek.h"

namespace StarTrek {

Fixed14 StarTrekEngine::sin(Fixed8 angle) {
int16 i = angle.raw();
if (angle < 0) {
i %= 0x400;
i += 0x400;
}
i &= 0x3ff;

if (i == 0x100)
return 1.0;
else if (i == 0x300)
return -1.0;

float f;
if (i < 0x100)
f = _sineTable.getTable()[i & 0xff];
else if (i < 0x200)
f = _sineTable.getTable()[256 - (i & 0xff)];
else if (i < 0x300)
f = -_sineTable.getTable()[i & 0xff];
else if (i < 0x400)
f = -_sineTable.getTable()[256 - (i & 0xff)];
return Fixed16(f);
}

Fixed14 StarTrekEngine::cos(Fixed8 angle) {
return sin(angle + 1.0);
}

Fixed8 StarTrekEngine::atan2(int32 deltaX, int32 deltaY) {
const int16 atanTable[] = {
0x0000, 0x0064, 0x00c9, 0x012d, 0x0192, 0x01f6, 0x025b, 0x02c0,
0x0324, 0x0389, 0x03ee, 0x0453, 0x04b8, 0x051d, 0x0582, 0x05e8,
0x064d, 0x06b3, 0x0718, 0x077e, 0x07e4, 0x084a, 0x08b1, 0x0917,
0x097e, 0x09e5, 0x0a4c, 0x0ab3, 0x0b1a, 0x0b82, 0x0bea, 0x0c52,
0x0cba, 0x0d23, 0x0d8c, 0x0df5, 0x0e5f, 0x0ec8, 0x0f32, 0x0f9d,
0x1007, 0x1072, 0x10de, 0x114a, 0x11b6, 0x1222, 0x128f, 0x12fc,
0x136a, 0x13d8, 0x1446, 0x14b5, 0x1524, 0x1594, 0x1604, 0x1675,
0x16e6, 0x1757, 0x17ca, 0x183c, 0x18b0, 0x1923, 0x1998, 0x1a0c,
0x1a82, 0x1af8, 0x1b6f, 0x1be6, 0x1c5e, 0x1cd7, 0x1d50, 0x1dca,
0x1e45, 0x1ec0, 0x1f3c, 0x1fb9, 0x2037, 0x20b5, 0x2134, 0x21b4,
0x2235, 0x22b7, 0x2339, 0x23bd, 0x2441, 0x24c6, 0x254c, 0x25d4,
0x265c, 0x26e5, 0x276f, 0x27fa, 0x2887, 0x2914, 0x29a2, 0x2a32,
0x2ac3, 0x2b55, 0x2be8, 0x2c7d, 0x2d12, 0x2da9, 0x2e42, 0x2edc,
0x2f77, 0x3013, 0x30b1, 0x3151, 0x31f2, 0x3294, 0x3338, 0x33de,
0x3486, 0x352f, 0x35d9, 0x3686, 0x3734, 0x37e5, 0x3897, 0x394b,
0x3a01, 0x3ab9, 0x3b73, 0x3c30, 0x3cee, 0x3daf, 0x3e72, 0x3f38,
0x4000
};

if (deltaX == 0 && deltaY == 0)
return 0.0;

bool deltaYNegative = deltaY <= 0;
bool deltaXNegative = deltaX <= 0;

deltaY = abs(deltaY);
deltaX = abs(deltaX);

Fixed14 ratio;
if (deltaY > deltaX)
ratio = Fixed14::fromRaw(((deltaX & 0xffff0000) >> 2) / (deltaY >> 16));
else
ratio = Fixed14::fromRaw(((deltaY & 0xffff0000) >> 2) / (deltaX >> 16));

int16 endIndex = 128;
int16 index = 0;
int16 angle;
while (index <= endIndex) {
angle = (index + endIndex) / 2;
Fixed14 tableValue = Fixed14::fromRaw(atanTable[angle]);
if (tableValue > ratio)
endIndex = angle - 1;
else if (tableValue < ratio)
index = angle + 1;
else
break;
}

if (deltaY > deltaX) {
if (!deltaYNegative && !deltaXNegative)
angle = angle;
else if (!deltaYNegative && deltaXNegative)
angle = -angle;
else if (deltaYNegative && !deltaXNegative)
angle = 512 - angle;
else
angle = angle - 512;
} else {
if (!deltaYNegative && !deltaXNegative)
angle = 256 - angle;
else if (deltaYNegative && !deltaXNegative)
angle = 256 + angle;
else if (deltaYNegative && deltaXNegative)
angle = -256 - angle;
else
angle = -256 + angle;
}

return Fixed8::fromRaw(angle);
}

}
@@ -73,7 +73,8 @@ struct TPoint {
};

typedef TPoint<int32> Point3;
typedef TPoint<Fixed14> Point3W;
typedef TPoint<int16> Point3_Short;
typedef TPoint<Fixed14> Point_Fixed14;


template<typename T>
@@ -106,7 +107,7 @@ struct TMatrix {
}
};

typedef TMatrix<Point3W> Matrix;
typedef TMatrix<Point_Fixed14> Matrix;

struct Star {
bool active;
@@ -117,10 +118,12 @@ struct Star {
// TODO: what does this stand for? Maybe rename it.
struct R3 {
Point3 pos; // 0x0
Matrix matrix; // 0xc
int16 field1e; // 0x1e
int16 field20; // 0x20
int16 field22; // 0x22
int16 field24; // 0x24
Point3_Short speed; // 0x26
SharedPtr<FileStream> shpFile; // 0x68
};

@@ -371,7 +371,27 @@ void StarTrekEngine::initIntroR3ObjectToMove(R3 *r3, int16 srcAngle, int16 srcDe
Fixed8 a1 = Fixed8::fromRaw((srcAngle << 8) / 90);
Fixed8 a2 = Fixed8::fromRaw((destAngle << 8) / 90);

//r3->pos.x = sin(a1).multToFixed16(srcDepth) + _starfieldPosition.x;
r3->pos.x = (sin(a1).multToInt(srcDepth) << 16) + _starfieldPosition.x;
r3->pos.z = (cos(a1).multToInt(srcDepth) << 16) + _starfieldPosition.z;
r3->pos.y = 0;

int32 deltaX = (sin(a2).multToInt(destDepth) << 16) + _starfieldPosition.x - r3->pos.x;
int32 deltaZ = (cos(a2).multToInt(destDepth) << 16) + _starfieldPosition.z - r3->pos.z;

Fixed16 angle = atan2(deltaX, deltaZ);
r3->matrix = initMatrix();

// sub_248cc(angle, r3->matrix);

if (ticks != 0) {
r3->speed.x = deltaX / ticks;
r3->speed.z = deltaZ / ticks;
r3->speed.y = 0;
} else {
r3->speed.x = 0;
r3->speed.z = 0;
r3->speed.y = 0;
}
}

void StarTrekEngine::loadSubtitleSprite(int index, Sprite *sprite) {
@@ -217,6 +217,7 @@ class StarTrekEngine : public ::Engine {
*/
Fixed14 sin(Fixed8 angle);
Fixed14 cos(Fixed8 angle);
Fixed8 atan2(int32 deltaX, int32 deltaZ);

// Game modes
Common::Error runGameMode(int mode);

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