src/util.d

   1 import std.functional: memoize;
   2
   3 import colour;
   4 import constants;
   5 import game;
   6 import stdlib;
   7
   8
   9 // provides dynamic function dispatch with objects, not classes
  10 mixin template funcwrapper(alias func) {
  11         import std.traits: ReturnType;
  12         mixin(ReturnType!func.stringof ~ " "
  13                         ~ __traits(identifier, func)[1 .. $] // [1:$] to get rid of the leading _
  14                         ~ "(T...)(T args) {" // (Parameters!func).stringof
  15                         ~ (ReturnType!func.stringof == "void" ? "" : "return ")
  16                         ~ __traits(identifier, func) ~ " ? " // if the function exists, call it.  Otherwise, do nothing (call pass)
  17                         ~ __traits(identifier, func) ~ "(this, args)"
  18                         ~ " : " ~ (ReturnType!func.stringof == "void" ? "pass" : (ReturnType!func.stringof ~ ".init")) ~ ";"
  19                         ~ "}");
  20 }
  21
  22 /*mixin template funcwrappers(funcs...) {
  23         static foreach (func; funcs) {
  24                 mixin funcwrapper!func;
  25         }
  26 }*/
  27
  28 // example:
  29 /*
  30 struct Bla {
  31         int n;
  32
  33         void delegate(ref Bla self) _func;
  34
  35         mixin funcwrapper!_func;
  36 }
  37
  38 void main() {
  39         Bla bla;
  40         bla.n = 15;
  41         bla._func = (ref Bla self) {
  42                 writefln("I have %s", self.n);
  43         };
  44
  45         bla.func();
  46 }
  47 */
  48
  49
  50 class DException: Exception {
  51         pragma(inline, true) pure this(T...)(T args) {
  52                 super(format(args));
  53         }
  54 }
  55
  56 class InternalError: DException {
  57         pragma(inline, true) pure this(T...)(T args) {
  58                 super(args);
  59         }
  60 }
  61
  62 void exit(ubyte code) {
  63         import core.runtime: Runtime;
  64         static import core.stdc.stdlib;
  65         Runtime.terminate();
  66         core.stdc.stdlib.exit(code);
  67 }
  68
  69 pure string fillstr(size_t length, char ch=' ') {
  70         string buf;
  71         while (length --> 0) {
  72                 buf ~= ch;
  73         }
  74         return buf;
  75 }
  76
  77
  78
  79 // Taken directly from http://stackoverflow.com/a/41978310
  80 /* It's supposed to be incredibly performant...but honestly I used it because
  81  * I could copy-paste it easily.
  82  */
  83 alias get256colour = memoize!((RGBColour colour) {
  84         enum ubyte[6] i2cv = [0, 0x5f, 0x87, 0xaf, 0xd7, 0xff];
  85         pragma(inline, true) {
  86                 auto v2ci = (int v) => v < 48 ? 0 : v < 115 ? 1 : (v - 35) / 40;
  87                 auto colour_index = (int r, int g, int b) => 36*r + 6*g + b;
  88                 auto distance = (int r1, int g1, int b1, int r2, int g2, int b2) => (r1-r2)*(r1-r2) + (g1-g2)*(g1-g2) + (b1-b2)*(b1-b2);
  89         }
  90
  91         int ir = v2ci(colour.r), ig = v2ci(colour.g), ib = v2ci(colour.b);
  92         int average = (colour.r + colour.g + colour.b) / 3;
  93         int igray = average > 238 ? 23 : (average-3) / 10;
  94         int cr = i2cv[ir], cg = i2cv[ig], cb = i2cv[ib];
  95         int gv = 8 + 10 * igray;
  96
  97         int colour_err = distance(cr, cg, cb, colour.r, colour.g, colour.b);
  98         int gray_err   = distance(gv, gv, gv, colour.r, colour.g, colour.b);
  99
 100         return cast(ubyte)(colour_err <= gray_err ? 16 + colour_index(ir, ig, ib) : 232 + igray);
 101 });
 102
 103 float dist(int x1, int y1, int x2, int y2) {
 104         return sqrt(dist_sq(x1, y1, x2, y2));
 105 }
 106 int dist_sq(int x1, int y1, int x2, int y2) {
 107         int px = x1 - x2;
 108         int py = y1 - y2;
 109         return px * px + py * py;
 110 }
 111
 112
 113 // Overloads...
 114 pragma(inline, true) ubyte get256colour(ubyte r, ubyte g, ubyte b) { return get256colour(RGBColour(r, g, b)); }
 115 pragma(inline, true) ubyte get256colour(string colour) { return get256colour(RGBColour(colour)); }