scummvm/engines/sci/engine/kmath.cpp

172 lines
4.9 KiB
C++

/* 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.
*
* $URL$
* $Id$
*
*/
#include "sci/engine/state.h"
#include "sci/engine/kernel.h"
namespace Sci {
reg_t kRandom(EngineState *s, int argc, reg_t *argv) {
int fromNumber = argv[0].toUint16();
int toNumber = argv[1].toUint16();
double randomNumber = fromNumber + ((toNumber + 1.0 - fromNumber) * (rand() / (RAND_MAX + 1.0)));
return make_reg(0, (int)randomNumber);
}
reg_t kAbs(EngineState *s, int argc, reg_t *argv) {
return make_reg(0, abs(argv[0].toSint16()));
}
reg_t kSqrt(EngineState *s, int argc, reg_t *argv) {
return make_reg(0, (int16) sqrt((float) abs(argv[0].toSint16())));
}
reg_t kGetAngle(EngineState *s, int argc, reg_t *argv) {
// Based on behavior observed with a test program created with
// SCI Studio.
int x1 = argv[0].toSint16();
int y1 = argv[1].toSint16();
int x2 = argv[2].toSint16();
int y2 = argv[3].toSint16();
int xrel = x2 - x1;
int yrel = y1 - y2; // y-axis is mirrored.
int angle;
// Move (xrel, yrel) to first quadrant.
if (y1 < y2)
yrel = -yrel;
if (x2 < x1)
xrel = -xrel;
// Compute angle in grads.
if (yrel == 0 && xrel == 0)
angle = 0;
else
angle = 100 * xrel / (xrel + yrel);
// Fix up angle for actual quadrant of (xrel, yrel).
if (y1 < y2)
angle = 200 - angle;
if (x2 < x1)
angle = 400 - angle;
// Convert from grads to degrees by merging grad 0 with grad 1,
// grad 10 with grad 11, grad 20 with grad 21, etc. This leads to
// "degrees" that equal either one or two grads.
angle -= (angle + 9) / 10;
return make_reg(0, angle);
}
reg_t kGetDistance(EngineState *s, int argc, reg_t *argv) {
int xdiff = (argc > 3) ? argv[3].toSint16() : 0;
int ydiff = (argc > 2) ? argv[2].toSint16() : 0;
int angle = (argc > 5) ? argv[5].toSint16() : 0;
int xrel = (int)(((float) argv[1].toSint16() - xdiff) / cos(angle * PI / 180.0)); // This works because cos(0)==1
int yrel = argv[0].toSint16() - ydiff;
return make_reg(0, (int16)sqrt((float) xrel*xrel + yrel*yrel));
}
reg_t kTimesSin(EngineState *s, int argc, reg_t *argv) {
int angle = argv[0].toSint16();
int factor = argv[1].toSint16();
return make_reg(0, (int)(factor * sin(angle * PI / 180.0)));
}
reg_t kTimesCos(EngineState *s, int argc, reg_t *argv) {
int angle = argv[0].toSint16();
int factor = argv[1].toSint16();
return make_reg(0, (int)(factor * cos(angle * PI / 180.0)));
}
reg_t kCosDiv(EngineState *s, int argc, reg_t *argv) {
int angle = argv[0].toSint16();
int value = argv[1].toSint16();
double cosval = cos(angle * PI / 180.0);
if ((cosval < 0.0001) && (cosval > -0.0001)) {
error("kCosDiv: Attempted division by zero");
return SIGNAL_REG;
} else
return make_reg(0, (int16)(value / cosval));
}
reg_t kSinDiv(EngineState *s, int argc, reg_t *argv) {
int angle = argv[0].toSint16();
int value = argv[1].toSint16();
double sinval = sin(angle * PI / 180.0);
if ((sinval < 0.0001) && (sinval > -0.0001)) {
error("kSinDiv: Attempted division by zero");
return SIGNAL_REG;
} else
return make_reg(0, (int16)(value / sinval));
}
reg_t kTimesTan(EngineState *s, int argc, reg_t *argv) {
int param = argv[0].toSint16();
int scale = (argc > 1) ? argv[1].toSint16() : 1;
param -= 90;
if ((param % 90) == 0) {
error("kTimesTan: Attempted tan(pi/2)");
return SIGNAL_REG;
} else
return make_reg(0, (int16) - (tan(param * PI / 180.0) * scale));
}
reg_t kTimesCot(EngineState *s, int argc, reg_t *argv) {
int param = argv[0].toSint16();
int scale = (argc > 1) ? argv[1].toSint16() : 1;
if ((param % 90) == 0) {
error("kTimesCot: Attempted tan(pi/2)");
return SIGNAL_REG;
} else
return make_reg(0, (int16)(tan(param * PI / 180.0) * scale));
}
#ifdef ENABLE_SCI32
reg_t kMulDiv(EngineState *s, int argc, reg_t *argv) {
int16 multiplicant = argv[0].toSint16();
int16 multiplier = argv[1].toSint16();
int16 denominator = argv[2].toSint16();
// Sanity check...
if (!denominator) {
error("kMulDiv: attempt to divide by zero (%d * %d / %d", multiplicant, multiplier, denominator);
return NULL_REG;
}
return make_reg(0, multiplicant * multiplier / denominator);
}
#endif
} // End of namespace Sci