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Diffstat (limited to 'engines/sci/engine/kmath.cpp')
| -rw-r--r-- | engines/sci/engine/kmath.cpp | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/engines/sci/engine/kmath.cpp b/engines/sci/engine/kmath.cpp new file mode 100644 index 0000000000..4c8ebb8ec5 --- /dev/null +++ b/engines/sci/engine/kmath.cpp @@ -0,0 +1,201 @@ +/*************************************************************************** + kmath.c Copyright (C) 1999 Christoph Reichenbach + + + This program may be modified and copied freely according to the terms of + the GNU general public license (GPL), as long as the above copyright + notice and the licensing information contained herein are preserved. + + Please refer to www.gnu.org for licensing details. + + This work is provided AS IS, without warranty of any kind, expressed or + implied, including but not limited to the warranties of merchantibility, + noninfringement, and fitness for a specific purpose. The author will not + be held liable for any damage caused by this work or derivatives of it. + + By using this source code, you agree to the licensing terms as stated + above. + + + Please contact the maintainer for bug reports or inquiries. + + Current Maintainer: + + Christoph Reichenbach (CJR) [jameson@linuxgames.com] + +***************************************************************************/ + +#include "sci/include/engine.h" + + +reg_t +kRandom(state_t *s, int funct_nr, int argc, reg_t *argv) +{ + return make_reg(0, + SKPV(0) + (int) ((SKPV(1) + 1.0 - SKPV(0)) * (rand() / (RAND_MAX + 1.0)))); +} + + +reg_t +kAbs(state_t *s, int funct_nr, int argc, reg_t *argv) +{ + /* This is a hack, but so is the code in Hoyle1 that needs it. */ + if (argv[0].segment) + return make_reg(0, 0x3e8); /* Yes people, this is an object */ + return make_reg(0, abs(SKPV(0))); +} + + +reg_t +kSqrt(state_t *s, int funct_nr, int argc, reg_t *argv) +{ + return make_reg(0, (gint16) sqrt((float) abs(SKPV(0)))); +} + + +int +get_angle(int xrel, int yrel) +{ + if ((xrel == 0) && (yrel == 0)) + return 0; + else { + int val = (int) (180.0/PI * atan2(xrel, -yrel)); + if (val < 0) + val += 360; + + /* Take care of OB1 differences between SSCI and + FSCI. SCI games sometimes check for equality with + "round" angles */ + if (val % 45 == 44) + val++; + else if (val % 45 == 1) + val--; + + return val; + } +} + +reg_t +kGetAngle(state_t *s, int funct_nr, int argc, reg_t *argv) +{ + /* Based on behavior observed with a test program created with + ** SCI Studio. + */ + int x1 = SKPV(0); + int y1 = SKPV(1); + int x2 = SKPV(2); + int y2 = SKPV(3); + 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(state_t *s, int funct_nr, int argc, reg_t *argv) +{ + int xrel = (int) (((float) SKPV(1) - SKPV_OR_ALT(3, 0))/cos(SKPV_OR_ALT(5, 0)* PI / 180.0)); /* This works because cos(0)==1 */ + int yrel = SKPV(0) - SKPV_OR_ALT(2, 0); + + return make_reg(0, (gint16)sqrt((float) xrel*xrel + yrel*yrel)); +} + +reg_t +kTimesSin(state_t *s, int funct_nr, int argc, reg_t *argv) +{ + int angle = SKPV(0); + int factor = SKPV(1); + + return make_reg(0, (int) (factor * 1.0 * sin(angle * PI / 180.0))); +} + + +reg_t +kTimesCos(state_t *s, int funct_nr, int argc, reg_t *argv) +{ + int angle = SKPV(0); + int factor = SKPV(1); + + return make_reg(0, (int) (factor * 1.0 * cos(angle * PI / 180.0))); +} + +reg_t +kCosDiv(state_t *s, int funct_nr, int argc, reg_t *argv) +{ + int angle = SKPV(0); + int value = SKPV(1); + double cosval = cos(angle * PI / 180.0); + + if ((cosval < 0.0001) && (cosval > 0.0001)) { + SCIkwarn(SCIkWARNING,"Attepted division by zero\n"); + return make_reg(0, (gint16)0x8000); + } else + return make_reg(0, (gint16) (value/cosval)); +} + +reg_t +kSinDiv(state_t *s, int funct_nr, int argc, reg_t *argv) +{ + int angle = SKPV(0); + int value = SKPV(1); + double sinval = sin(angle * PI / 180.0); + + if ((sinval < 0.0001) && (sinval > 0.0001)) { + SCIkwarn(SCIkWARNING,"Attepted division by zero\n"); + return make_reg(0, (gint16)0x8000); + } else + return make_reg(0, (gint16) (value/sinval)); +} + +reg_t +kTimesTan(state_t *s, int funct_nr, int argc, reg_t *argv) +{ + int param = SKPV(0); + int scale = SKPV_OR_ALT(1, 1); + + param -= 90; + if ((param % 90) == 0) { + SCIkwarn(SCIkWARNING, "Attempted tan(pi/2)"); + return make_reg(0, (gint16)0x8000); + } else + return make_reg(0, (gint16) -(tan(param * PI / 180.0) * scale)); +} + +reg_t +kTimesCot(state_t *s, int funct_nr, int argc, reg_t *argv) +{ + int param = SKPV(0); + int scale = SKPV_OR_ALT(1, 1); + + if ((param % 90) == 0) { + SCIkwarn(SCIkWARNING, "Attempted tan(pi/2)"); + return make_reg(0, (gint16)0x8000); + } else + return make_reg(0, (gint16) (tan(param * PI / 180.0) * scale)); +} |