# SWF Fixed [](https://crates.io/crates/swf-fixed) [](https://github.com/open-flash/rust-swf-fixed) [](https://travis-ci.org/open-flash/rust-swf-fixed) SWF fixed-point numbers for Rust. A fixed point number represents a decimal values using evenly-distributed bit patterns (as opposed to floating point numbers where the density increases with the proximity to zero). A fixed point number can be simply thought as an integer divided by a constant value. It is described by its integer part and fractional part: its mathematical value is `integer_part + fractional_part / 2^fractional_bits`. For example, the type `Ufixed8p8` is an unsigned fixed point number with an 8 bit integer part and 8 bit fractional part. It can represent the 2^16 values corresponding to `u16 / 256`, the gap between each value (epsilon) is `1 / 256`. This crate defines the fixed points numbers used by SWF files: | Name | Integer part | Fractional part | Min value | Max value | Epsilon | |-------------|--------------|-----------------|-----------|---------------|----------| | Sfixed8P8 | `i8` | `u8` | -128 | 128 - 1/256 | 1 / 256 | | Ufixed8P8 | `u8` | `u8` | 0 | 256 - 1/256 | 1 / 256 | | Sfixed16P16 | `i16` | `u16` | -2^15 | 2^15 - 1/2^16 | 1 / 2^16 | | Ufixed16P16 | `u16` | `u16` | 0 | 2^16 - 1/2^16 | 1 / 2^16 | ## Usage ```rust use swf_fixed::Sfixed8P8; fn main() { let a = Sfixed8P8::from_epsilons(256); let b = Sfixed8P8::from_value(1f32); assert_eq!(a, b); let sum: Sfixed8P8 = (a + b); let sum_value: f32 = sum.into(); assert_eq!(sum_value, 2.0f32); } ``` ## Contributing This library is a standard Cargo project. You can test your changes with `cargo test`. Prefer non-`master` branches when sending a PR so your changes can be rebased if needed. All the commits must be made on top of `master` (fast-forward merge). CI must pass for changes to be accepted.