vec2.d

module util.vec2;

import std.string;
import std.stdio;

class Vec2
{
    public:
    double x = 0;
    double y = 0;

    unittest {
        assert(new Vec2(2, 2) == new Vec2(2, 2));
        assert(new Vec2(0, 0) != new Vec2(2, 2));

        Vec2 testVec = new Vec2(2, 1);

        Vec2 testVecMod = -testVec;
        assert(testVecMod == new Vec2(-2, -1));

        testVecMod = +testVec;
        assert(testVecMod == testVec);

        assert(!new Vec2(double.nan, double.nan).valid);
        assert(!new Vec2(double.nan, 0).valid);
        assert(new Vec2(0, 0).valid);

        testVec += testVecMod;
        assert(testVec.x == 4 && testVec.y == 2);

        Vec2 assign = [1.0, 2.0];
    }

    this() {
    }

    this(double x1, double y1) {
        x = x1;
        y = y1;
    }

    public Vec2 opUnary(string s)() if (s == "-") {
        assert(valid);

        return new Vec2(-x, -y);
    }

    public Vec2 opUnary(string s)() if (s == "+") {
        assert(valid);

        return new Vec2(x, y);
    }

    public override bool opEquals(Object b) {
        Vec2 bVec = cast(Vec2)b;
        return x == bVec.x && y == bVec.y;
    }

    public void opAssign(double[] vecArr) {
        assert(vecArr.length == 2);

        x = vecArr[0];
        y = vecArr[1];
    }

    void opOpAssign(string op)(Vec2 vec2)
    {
        mixin("x " ~ op ~ "= vec2.x;");
        mixin("y " ~ op ~ "= vec2.y;");
    }

    void opOpAssign(string op)(double[] vecArr)
    {
        assert(vecArr.length == 2);

        mixin("x " ~ op ~ "= vecArr[0];");
        mixin("y " ~ op ~ "= vecArr[1];");
    }

    override string toString() {
        return format("[x = %f, y = %f]", x, y);
    }

    @property {
        bool valid() {
            return !(x is x.nan) && !(y is y.nan);
        }
    }
}