//-------------------------------------------------------------------------
/*
Copyright (C) 2010-2019 EDuke32 developers and contributors
Copyright (C) 2019 sirlemonhead, Nuke.YKT
This file is part of PCExhumed.
PCExhumed is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License version 2
as published by the Free Software Foundation.
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 "trigdat.h"
#ifndef __WATCOMC__
#include <cmath>
#else
#include <stdlib.h>
#endif

short AngTable[] = {0,0,0,0,1,1,1,1,1,1,2,2,2,2,2,2,3,3,3,3,3,3,3,4,4,4,4,4,4,5,5,5,5,5,5,6,6,6,6,6,6,7,7,7,7,7,7,7,8,8,8,8,8,8,9,9,9,9,9,9,10,10,10,10,10,10,10,11,11,11,11,11,11,12,12,12,12,12,12,13,13,13,13,13,13,14,14,14,14,14,14,14,15,15,15,15,15,15,16,16,16,16,16,16,17,17,17,17,17,17,17,18,18,18,18,18,18,19,19,19,19,19,19,20,20,20,20,20,20,20,21,21,21,21,21,21,22,22,22,22,22,22,23,23,23,23,23,23,24,24,24,24,24,24,24,25,25,25,25,25,25,26,26,26,26,26,26,27,27,27,27,27,27,27,28,28,28,28,28,28,29,29,29,29,29,29,30,30,30,30,30,30,30,31,31,31,31,31,31,32,32,32,32,32,32,33,33,33,33,33,33,33,34,34,34,34,34,34,35,35,35,35,35,35,35,36,36,36,36,36,36,37,37,37,37,37,37,38,38,38,38,38,38,38,39,39,39,39,39,39,40,40,40,40,40,40,41,41,41,41,41,41,41,42,42,42,42,42,42,43,43,43,43,43,43,43,44,44,44,44,44,44,45,45,45,45,45,45,46,46,46,46,46,46,46,47,47,47,47,47,47,48,48,48,48,48,48,48,49,49,49,49,49,49,50,50,50,50,50,50,51,51,51,51,51,51,51,52,52,52,52,52,52,53,53,53,53,53,53,53,54,54,54,54,54,54,55,55,55,55,55,55,55,56,56,56,56,56,56,57,57,57,57,57,57,57,58,58,58,58,58,58,59,59,59,59,59,59,59,60,60,60,60,60,60,61,61,61,61,61,61,61,62,62,62,62,62,62,63,63,63,63,63,63,63,64,64,64,64,64,64,65,65,65,65,65,65,65,66,66,66,66,66,66,67,67,67,67,67,67,67,68,68,68,68,68,68,69,69,69,69,69,69,69,70,70,70,70,70,70,70,71,71,71,71,71,71,72,72,72,72,72,72,72,73,73,73,73,73,73,74,74,74,74,74,74,74,75,75,75,75,75,75,75,76,76,76,76,76,76,77,77,77,77,77,77,77,78,78,78,78,78,78,78,79,79,79,79,79,79,80,80,80,80,80,80,80,81,81,81,81,81,81,81,82,82,82,82,82,82,83,83,83,83,83,83,83,84,84,84,84,84,84,84,85,85,85,85,85,85,86,86,86,86,86,86,86,87,87,87,87,87,87,87,88,88,88,88,88,88,88,89,89,89,89,89,89,90,90,90,90,90,90,90,91,91,91,91,91,91,91,92,92,92,92,92,92,92,93,93,93,93,93,93,93,94,94,94,94,94,94,94,95,95,95,95,95,95,96,96,96,96,96,96,96,97,97,97,97,97,97,97,98,98,98,98,98,98,98,99,99,99,99,99,99,99,100,100,100,100,100,100,100,101,101,101,101,101,101,101,102,102,102,102,102,102,102,103,103,103,103,103,103,103,104,104,104,104,104,104,104,105,105,105,105,105,105,105,106,106,106,106,106,106,106,107,107,107,107,107,107,107,108,108,108,108,108,108,108,109,109,109,109,109,109,109,110,110,110,110,110,110,110,111,111,111,111,111,111,111,112,112,112,112,112,112,112,113,113,113,113,113,113,113,114,114,114,114,114,114,114,115,115,115,115,115,115,115,116,116,116,116,116,116,116,117,117,117,117,117,117,117,117,118,118,118,118,118,118,118,119,119,119,119,119,119,119,120,120,120,120,120,120,120,121,121,121,121,121,121,121,122,122,122,122,122,122,122,122,123,123,123,123,123,123,123,124,124,124,124,124,124,124,125,125,125,125,125,125,125,125,126,126,126,126,126,126,126,127,127,127,127,127,127,127,128,128,128,128,128,128,128,128,129,129,129,129,129,129,129,130,130,130,130,130,130,130,131,131,131,131,131,131,131,131,132,132,132,132,132,132,132,133,133,133,133,133,133,133,133,134,134,134,134,134,134,134,135,135,135,135,135,135,135,135,136,136,136,136,136,136,136,137,137,137,137,137,137,137,137,138,138,138,138,138,138,138,139,139,139,139,139,139,139,139,140,140,140,140,140,140,140,141,141,141,141,141,141,141,141,142,142,142,142,142,142,142,142,143,143,143,143,143,143,143,144,144,144,144,144,144,144,144,145,145,145,145,145,145,145,145,146,146,146,146,146,146,146,146,147,147,147,147,147,147,147,148,148,148,148,148,148,148,148,149,149,149,149,149,149,149,149,150,150,150,150,150,150,150,150,151,151,151,151,151,151,151,151,152,152,152,152,152,152,152,153,153,153,153,153,153,153,153,154,154,154,154,154,154,154,154,155,155,155,155,155,155,155,155,156,156,156,156,156,156,156,156,157,157,157,157,157,157,157,157,158,158,158,158,158,158,158,158,159,159,159,159,159,159,159,159,160,160,160,160,160,160,160,160,161,161,161,161,161,161,161,161,162,162,162,162,162,162,162,162,162,163,163,163,163,163,163,163,163,164,164,164,164,164,164,164,164,165,165,165,165,165,165,165,165,166,166,166,166,166,166,166,166,167,167,167,167,167,167,167,167,167,168,168,168,168,168,168,168,168,169,169,169,169,169,169,169,169,170,170,170,170,170,170,170,170,170,171,171,171,171,171,171,171,171,172,172,172,172,172,172,172,172,173,173,173,173,173,173,173,173,173,174,174,174,174,174,174,174,174,175,175,175,175,175,175,175,175,175,176,176,176,176,176,176,176,176,177,177,177,177,177,177,177,177,177,178,178,178,178,178,178,178,178,178,179,179,179,179,179,179,179,179,180,180,180,180,180,180,180,180,180,181,181,181,181,181,181,181,181,181,182,182,182,182,182,182,182,182,183,183,183,183,183,183,183,183,183,184,184,184,184,184,184,184,184,184,185,185,185,185,185,185,185,185,185,186,186,186,186,186,186,186,186,186,187,187,187,187,187,187,187,187,188,188,188,188,188,188,188,188,188,189,189,189,189,189,189,189,189,189,190,190,190,190,190,190,190,190,190,191,191,191,191,191,191,191,191,191,192,192,192,192,192,192,192,192,192,192,193,193,193,193,193,193,193,193,193,194,194,194,194,194,194,194,194,194,195,195,195,195,195,195,195,195,195,196,196,196,196,196,196,196,196,196,197,197,197,197,197,197,197,197,197,197,198,198,198,198,198,198,198,198,198,199,199,199,199,199,199,199,199,199,200,200,200,200,200,200,200,200,200,200,201,201,201,201,201,201,201,201,201,202,202,202,202,202,202,202,202,202,202,203,203,203,203,203,203,203,203,203,204,204,204,204,204,204,204,204,204,204,205,205,205,205,205,205,205,205,205,206,206,206,206,206,206,206,206,206,206,207,207,207,207,207,207,207,207,207,207,208,208,208,208,208,208,208,208,208,209,209,209,209,209,209,209,209,209,209,210,210,210,210,210,210,210,210,210,210,211,211,211,211,211,211,211,211,211,211,212,212,212,212,212,212,212,212,212,212,213,213,213,213,213,213,213,213,213,213,214,214,214,214,214,214,214,214,214,214,215,215,215,215,215,215,215,215,215,215,216,216,216,216,216,216,216,216,216,216,217,217,217,217,217,217,217,217,217,217,218,218,218,218,218,218,218,218,218,218,219,219,219,219,219,219,219,219,219,219,219,220,220,220,220,220,220,220,220,220,220,221,221,221,221,221,221,221,221,221,221,222,222,222,222,222,222,222,222,222,222,222,223,223,223,223,223,223,223,223,223,223,224,224,224,224,224,224,224,224,224,224,224,225,225,225,225,225,225,225,225,225,225,226,226,226,226,226,226,226,226,226,226,226,227,227,227,227,227,227,227,227,227,227,228,228,228,228,228,228,228,228,228,228,228,229,229,229,229,229,229,229,229,229,229,229,230,230,230,230,230,230,230,230,230,230,230,231,231,231,231,231,231,231,231,231,231,231,232,232,232,232,232,232,232,232,232,232,232,233,233,233,233,233,233,233,233,233,233,233,234,234,234,234,234,234,234,234,234,234,234,235,235,235,235,235,235,235,235,235,235,235,236,236,236,236,236,236,236,236,236,236,236,237,237,237,237,237,237,237,237,237,237,237,238,238,238,238,238,238,238,238,238,238,238,238,239,239,239,239,239,239,239,239,239,239,239,240,240,240,240,240,240,240,240,240,240,240,240,241,241,241,241,241,241,241,241,241,241,241,242,242,242,242,242,242,242,242,242,242,242,242,243,243,243,243,243,243,243,243,243,243,243,244,244,244,244,244,244,244,244,244,244,244,244,245,245,245,245,245,245,245,245,245,245,245,245,246,246,246,246,246,246,246,246,246,246,246,246,247,247,247,247,247,247,247,247,247,247,247,248,248,248,248,248,248,248,248,248,248,248,248,249,249,249,249,249,249,249,249,249,249,249,249,249,250,250,250,250,250,250,250,250,250,250,250,250,251,251,251,251,251,251,251,251,251,251,251,251,252,252,252,252,252,252,252,252,252,252,252,252,253,253,253,253,253,253,253,253,253,253,253,253,254,254,254,254,254,254,254,254,254,254,254,254,254,255,255,255,255,255,255,255,255,255,255,255,255,256,256,256,256,256,256};


int GetMyAngle(int x, int y)
{
    int ebx = -x;
    int esi = y << 11;
    int ecx = y;
    int edx = y;

    if (ebx >= 0)
    {
        // left path

        edx = ebx << 11;

        if (y >= 0)
        {
            if (ebx == y) {
                return 768;
            }
            else // loc_2F318:
            {
                if (y > ebx)
                {
                    return (AngTable[(edx / y) & kAngleMask] + 512) & kAngleMask;
                }
                else
                {
                    // loc_2F33C:
                    return ((512 - AngTable[(esi / ebx) & kAngleMask]) + 512) & kAngleMask;
                }
            }
        }
        else
        {
            // loc_2F35D:
            ecx = -y;

            if (ebx == ecx) {
                return 1280;
            }
            else if (ebx <= ecx)
            {
                return ((1024 - AngTable[(edx / ecx) & kAngleMask]) + 512) & kAngleMask;
            }
            else
            {
                edx = ecx << 11;
                return (AngTable[(edx / ebx) & kAngleMask] + 1024) & kAngleMask;
            }
        }
    }
    else
    {
        if (edx >= 0)
        {
            ebx = -ebx;

            if (ebx == edx) {
                return 256;
            }
            else if (ebx > edx)
            {
                return (AngTable[(esi / ebx) & kAngleMask] + 2048) & kAngleMask;
            }
            else
            {
                edx = ebx << 11;
                return ((2048 - AngTable[(edx / ecx) & kAngleMask]) + 512) & kAngleMask;
            }
        }
        else
        {
            ebx = -ebx;
            ecx = -ecx;

            if (ebx == ecx) {
                return 1792;
            }
            else if (ebx >= ecx)
            {
                edx = ecx << 11;
                return ((1536 - AngTable[(edx / ebx) & kAngleMask]) + 512) & kAngleMask;
            }
            else
            {
                edx = ebx << 11;
                return (AngTable[(edx / ecx) & kAngleMask] + 1536) & kAngleMask;
            }
        }
    }
}

// 100% done
int AngleDiff(short a, short b)
{
    int diff = (b - a) & kAngleMask;

    if (diff > 1024) {
        diff = 2048 - diff;
    }
    return diff;
}

// unused
int AnglePick(short a, short b)
{
    int nRet = b;

    if (AngleDiff(a, b) > 512)
    {
        nRet ^= 0x400;
    }

    return nRet;
}

int AngleDelta(int a, int b, int c)
{
    int diff = b - a;

    if (diff >= 0)
    {
        if (diff > 1024) {
            diff = -(2048 - diff);
        }
    }
    else if (diff < -1024)
    {
        diff += 2048;
    }

    if (abs(diff) > c)
    {
        if (diff < 0) {
            return -diff;
        }

        diff = c;
    }
    return diff;
}