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d6d1f99ca9
- Sync with latest upstream dev branch - Include all map improvements: 2D/3D toggle, shadows, labels, overlays - Include platform updates: location API, audio echo cancellation - Preserve fork-specific re-exports (gltf, csg, test)
75 lines
2.7 KiB
Markdown
75 lines
2.7 KiB
Markdown
# iFloat
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This fixed float math library provides an efficient and deterministic solution for arithmetic and geometric operations.
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## Features
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- Fixed-point arithmetic using FixNumber for deterministic calculations
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- 2D fixed-point vector operations with FixVec
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- Trigonometric functions using fixed-point angles
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- Angle conversion and manipulation utilities in FixAngle
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## Installation
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```rust
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use i_float::fix_float::FixFloat;
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use i_float::fix_vec::FixVec;
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```
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## How It Works
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The \`**FixFloat**\` struct uses fixed-point arithmetic to perform calculations with a high degree of precision and determinism. It supports numbers in the range 2^21 - 1 to -2^21 + 1 with a precision of 1/1024, and is most suitable for the range 1,000,000 to -1,000,000 with a precision of 0.01.
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Fixed-point numbers are represented using a fixed number of bits for the fractional part. In this implementation, the number of bits representing the fractional part of the fixed-point number is 10, which allows for a precision of 1/1024 or approximately 0.001.
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Here are some examples of fixed-point number representation:
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- 1 / 1024 ≈ 0.001 (represented as 1)
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- 256 / 1024 = 0.25 (represented as 256)
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- 1024 / 1024 = 1 (represented as 1024)
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- (1024 + 512) / 1024 = 1.5 (represented as 1536)
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- (2048 + 256) / 1024 = 2.25 (represented as 2304)
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By using the \`**FixFloat**\` struct, you can perform arithmetic operations using i64 values while maintaining the precision of floating-point numbers, ensuring deterministic behavior across different platforms and devices.
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## Usage
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### FixFloat
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The \`**FixFloat**\` struct represents a fixed-point number using a \`**i64**\` as the underlying storage, allowing deterministic arithmetic operations. Use \`**FixFloat**\` for calculations instead of \`**i32**\` or \`**i64**\` when deterministic behavior is required. \`**FixFloat**\` provides a way to perform arithmetic operations with \`**i64**\` values while maintaining the precision of floating-point numbers.
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```rust
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let a = FixFloat::new_number(1);
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let b = FixFloat::new_number(2);
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let c = a + b;
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```
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### FixVec
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The \`**FixVec**\` struct represents a 2D fixed-point vector, providing various utility methods and operators for vector operations. Use \`**FixVec**\` for 2D geometric calculations when deterministic behavior is required.
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```rust
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let a = FixVec::new_number(1, 1);
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let b = FixVec::new_number(1, -1);
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let c = a + b;
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```
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### FixAngle
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The \`**FixAngle**\` class provides various utility methods for working with fixed-point angles, including trigonometric functions and angle conversion.
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```rust
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let fix_angle = FixAngle::new_from_radians_f64(angle);
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let fix_sin = fix_angle.sin();
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let i64_sin = fix_sin.double();
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```
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## License
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