Hotspot

A lightweight, Rust library for working with 2D rectangular hotspots. Supports multiple internal representations (pixel-based and percentage-based), lossless conversions, overlap detection, utiltiies for handling conversions between different points of origins and generally working with hotspots are also provided.

Important Note on Precision

Coordinates are stored as fractions of the maximum value:

• Default (u16): 65,536 discrete positions
• With high_precision (u32): 4,294,967,296 discrete positions

When precision loss occurs: If your image dimensions exceed these values, multiple adjacent pixels map to the same internal representation. For percentage-based hotspots on a 100,000×100,000 pixel image with u16, expect ~1-2 pixel rounding errors. Use high_precision for images larger than ~65,000 pixels in either dimension.

Installation

Add to your Cargo.toml:

[dependencies]
hotspots = "0.1"

Features

• serde: Enable serialization/deserialization support
• reflectapi: Enable ReflectAPI schema generation
• high_precision: Use u32 coordinates with instead of u16. See Important Note on Precision for more information.

Usage

Basic Pixel Hotspots

use hotspots::{Hotspot, Coordinate};

// Create a hotspot from two corners (pixel coordinates)
let hotspot = Hotspot::builder().from_pixels((
    Coordinate { x: 100, y: 150 },
    Coordinate { x: 200, y: 250 },
));

// Access corners
let upper_right = hotspot.upper_right();
let lower_left = hotspot.lower_left();
let upper_left = hotspot.upper_left();
let lower_right = hotspot.lower_right();

Percentage-Based Hotspots

use hotspots::{Hotspot, Coordinate, ImageDimensions, repr::PercentageRepr};

// Create a percentage-based hotspot
let dimensions = ImageDimensions { width: 1920, height: 1080 };

let hotspot = Hotspot::builder()
    .with_repr::<PercentageRepr>()
    .from_percentage(
        (
            Coordinate { x: 100, y: 200 },  // Internal percentage representation
            Coordinate { x: 300, y: 400 }
        ),
        dimensions
    );

// Get pixel coordinates for a specific image size
let pixel_coords = hotspot.upper_right(dimensions);

Limitations

• No Rotation: Hotspots must be axis-aligned rectangles
• Rectangular Only: Only rectangular hotspots are supported, though we do provide utilties for converting point-based coordinates.

License

Licensed under either of:

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.