| 1 | #ifndef lint |
| 2 | static char *sccsid = "@(#)misc.c 2.1 83/10/31"; |
| 3 | #endif |
| 4 | #include "externs.h" |
| 5 | |
| 6 | #define distance(x,y) (abs(x) >= abs(y) ? abs(x) + abs(y)/2 : abs(y) + abs(x)/2) |
| 7 | |
| 8 | /* XXX */ |
| 9 | range(from, to) |
| 10 | struct ship *from, *to; |
| 11 | { |
| 12 | register bow1r, bow1c, bow2r, bow2c; |
| 13 | int stern1r, stern1c, stern2c, stern2r; |
| 14 | register int bb, bs, sb, ss, result; |
| 15 | |
| 16 | if (!to->file->dir) |
| 17 | return -1; |
| 18 | stern1r = bow1r = from->file->row; |
| 19 | stern1c = bow1c = from->file->col; |
| 20 | stern2r = bow2r = to->file->row; |
| 21 | stern2c = bow2c = to->file->col; |
| 22 | result = bb = distance(bow2r - bow1r, bow2c - bow1c); |
| 23 | if (bb < 5) { |
| 24 | stern2r += dr[to->file->dir]; |
| 25 | stern2c += dc[to->file->dir]; |
| 26 | stern1r += dr[from->file->dir]; |
| 27 | stern1c += dc[from->file->dir]; |
| 28 | bs = distance((bow2r - stern1r), (bow2c - stern1c)); |
| 29 | sb = distance((bow1r - stern2r), (bow1c - stern2c)); |
| 30 | ss = distance((stern2r - stern1r) ,(stern2c - stern1c)); |
| 31 | result = min(bb, min(bs, min(sb, ss))); |
| 32 | } |
| 33 | return result; |
| 34 | } |
| 35 | |
| 36 | struct ship * |
| 37 | closestenemy(from, side, anyship) |
| 38 | register struct ship *from; |
| 39 | char side, anyship; |
| 40 | { |
| 41 | register struct ship *sp; |
| 42 | register char a; |
| 43 | int olddist = 30000, dist; |
| 44 | struct ship *closest = 0; |
| 45 | |
| 46 | a = capship(from)->nationality; |
| 47 | foreachship(sp) { |
| 48 | if (sp == from) |
| 49 | continue; |
| 50 | if (sp->file->dir == 0) |
| 51 | continue; |
| 52 | if (a == capship(sp)->nationality && !anyship) |
| 53 | continue; |
| 54 | if (side && gunsbear(from, sp) != side) |
| 55 | continue; |
| 56 | dist = range(from, sp); |
| 57 | if (dist < olddist) { |
| 58 | closest = sp; |
| 59 | olddist = dist; |
| 60 | } |
| 61 | } |
| 62 | return closest; |
| 63 | } |
| 64 | |
| 65 | angle(dr, dc) |
| 66 | register dr, dc; |
| 67 | { |
| 68 | register i; |
| 69 | |
| 70 | if (dc >= 0 && dr > 0) |
| 71 | i = 0; |
| 72 | else if (dr <= 0 && dc > 0) |
| 73 | i = 2; |
| 74 | else if (dc <= 0 && dr < 0) |
| 75 | i = 4; |
| 76 | else |
| 77 | i = 6; |
| 78 | dr = abs(dr); |
| 79 | dc = abs(dc); |
| 80 | if ((i == 0 || i == 4) && dc * 2.4 > dr) { |
| 81 | i++; |
| 82 | if (dc > dr * 2.4) |
| 83 | i++; |
| 84 | } else if ((i == 2 || i == 6) && dr * 2.4 > dc) { |
| 85 | i++; |
| 86 | if (dr > dc * 2.4) |
| 87 | i++; |
| 88 | } |
| 89 | return i % 8 + 1; |
| 90 | } |
| 91 | |
| 92 | gunsbear(from, to) /* checks for target bow or stern */ |
| 93 | register struct ship *from, *to; |
| 94 | { |
| 95 | int Dr, Dc, i; |
| 96 | register ang; |
| 97 | |
| 98 | Dr = from->file->row - to->file->row; |
| 99 | Dc = to->file->col - from->file->col; |
| 100 | for (i = 2; i; i--) { |
| 101 | if ((ang = angle(Dr, Dc) - from->file->dir + 1) < 1) |
| 102 | ang += 8; |
| 103 | if (ang >= 2 && ang <= 4) |
| 104 | return 'r'; |
| 105 | if (ang >= 6 && ang <= 7) |
| 106 | return 'l'; |
| 107 | Dr += dr[to->file->dir]; |
| 108 | Dc += dc[to->file->dir]; |
| 109 | } |
| 110 | return 0; |
| 111 | } |
| 112 | |
| 113 | portside(from, on, quick) |
| 114 | register struct ship *from, *on; |
| 115 | int quick; /* returns true if fromship is */ |
| 116 | { /* shooting at onship's starboard side */ |
| 117 | register ang; |
| 118 | register Dr, Dc; |
| 119 | |
| 120 | Dr = from->file->row - on->file->row; |
| 121 | Dc = on->file->col - from->file->col; |
| 122 | if (quick == -1) { |
| 123 | Dr += dr[on->file->dir]; |
| 124 | Dc += dc[on->file->dir]; |
| 125 | } |
| 126 | ang = angle(Dr, Dc); |
| 127 | if (quick != 0) |
| 128 | return ang; |
| 129 | ang = (ang + 4 - on->file->dir - 1) % 8 + 1; |
| 130 | return ang < 5; |
| 131 | } |
| 132 | |
| 133 | colours(sp) |
| 134 | register struct ship *sp; |
| 135 | { |
| 136 | register char flag; |
| 137 | |
| 138 | if (sp->file->struck) |
| 139 | flag = '!'; |
| 140 | if (sp->file->explode) |
| 141 | flag = '#'; |
| 142 | if (sp->file->sink) |
| 143 | flag = '~'; |
| 144 | if (sp->file->struck) |
| 145 | return flag; |
| 146 | flag = *countryname[capship(sp)->nationality]; |
| 147 | return sp->file->FS ? flag : tolower(flag); |
| 148 | } |
| 149 | |
| 150 | #ifdef notdef |
| 151 | #define PI 3.1415926535 |
| 152 | |
| 153 | float contable[8] = |
| 154 | { 1.5708, 0.7854, 0.0, -0.7854, -1.5708, -2.3562, -PI, 2.3562 }; |
| 155 | |
| 156 | int tantable[40] = { |
| 157 | 0,100,197,291,381, |
| 158 | 464,540,610,675,733, |
| 159 | 785,833,876,915,951, |
| 160 | 983,1012,1039,1064,1086, |
| 161 | 1107,1126,1144,1161,1176, |
| 162 | 1190,1204,1216,1227,1239, |
| 163 | 1249,1259,1268,1277,1285, |
| 164 | 1293,1300,1307,1313,1470 |
| 165 | }; |
| 166 | |
| 167 | double |
| 168 | arctan(y,x) |
| 169 | int y,x; |
| 170 | { |
| 171 | int sx, sy; |
| 172 | register int index; |
| 173 | |
| 174 | sy = y < 0 ? -1 : 1; |
| 175 | sx = x < 0 ? -1 : 1; |
| 176 | y *= sy; |
| 177 | x *= sx; |
| 178 | if (!x) |
| 179 | return (double) PI/2 * sy; |
| 180 | index = 10 * y / x + 0.5; |
| 181 | if (index > 39) |
| 182 | index = 39; |
| 183 | return (double) |
| 184 | sy * (sx < 0 ? PI : 0 + sx*((float)tantable[index]/1000)); |
| 185 | } |
| 186 | #endif |