QuakeC

QuakeC is a very simplified dialect of the well-known C programming language, as used by Quake. Nexuiz uses the FTEQCC dialect of QuakeC, so only this one will be described (as well as some common extensions among Quake engines).

Quake only knows four data types: the basic types float, vector, string, the object type entity, and a very special type of types, fields. FTEQCC also adds arrays, although these are slow and a bit buggy. Note that there are no pointers!

This is the basic numeric type in QuakeC. It represents the standard 32bit floating point type as known from C. It has 23 bits of mantissa, 8 bits of exponent, and one sign bit. The numeric range goes from about 1.175e-38 to about 3.403e+38, and the number of significant decimal digits is about six.

As float has 23 bits of mantissa, it can also be used to safely represent integers in the range from -8388608 to 8388608. 8388609 is the first integer float can not represent.

Common functions for float are especially ceil, floor (working just like in C, rounding up/down to the next integer), and random, which yields a random number r with 0 ⇐ r < 1.

This type is basically three floats together. By declaring a vector v, you also create three floats v_x, v_y and v_z (note the underscore) that contain the components of the vector.

Vectors can be used with the usual mathematical operators in the usual way used in mathematics. For example, vector + vector simply returns the sum of the vectors, and vector * float scales the vector by the given factor. Note however that dividing a vector by a float is NOT supported, one has to use vector * (1 / float) instead. Multiplying two vectors yields their dot product of type float.

Common functions to be used on vectors are vlen (vector length), normalize (vector divided by its length, i.e. a unit vector).

COMPILER BUG: always use vector = vector * float instead of vector *= float, as the latter creates incorrect code.