procmod-overlay 1.0.0

Create a transparent, click-through overlay window on top of any game window and draw shapes, text, and HUD elements. Direct3D 11 backend, immediate-mode API, built-in font rendering.

Install

[dependencies]
procmod-overlay = "1"

Quick start

Draw an ESP box and health bar over a game window:

use procmod_overlay::{Overlay, OverlayTarget, Color};

fn main() -> procmod_overlay::Result<()> {
    let mut overlay = Overlay::new(OverlayTarget::Title("My Game".into()))?;

    loop {
        overlay.begin_frame()?;

        // ESP bounding box with label
        overlay.esp_box(100.0, 50.0, 60.0, 120.0, Color::RED, Some("Enemy"));

        // health bar
        overlay.health_bar(100.0, 175.0, 60.0, 8.0, 0.75, Color::GREEN, Color::rgb(40, 40, 40));

        // crosshair at screen center
        overlay.crosshair(640.0, 360.0, 20.0, 2.0, Color::WHITE);

        overlay.end_frame()?;
    }
}

Usage

Creating an overlay

Find the target window by title, class name, HWND, or process ID:

// by window title (substring match)
let overlay = Overlay::new(OverlayTarget::Title("Counter-Strike".into()))?;

// by window class
let overlay = Overlay::new(OverlayTarget::Class("UnrealWindow".into()))?;

// by process ID
let overlay = Overlay::new(OverlayTarget::Pid(1234))?;

// by raw HWND
let overlay = Overlay::new(OverlayTarget::Hwnd(0x00010A3C))?;

Drawing shapes

All drawing happens between begin_frame and end_frame:

overlay.begin_frame()?;

// filled and outlined rectangles
overlay.rect_filled(10.0, 10.0, 200.0, 30.0, Color::rgba(0, 0, 0, 180));
overlay.rect(10.0, 10.0, 200.0, 30.0, Color::WHITE);

// lines
overlay.line(0.0, 0.0, 100.0, 100.0, 2.0, Color::RED);

// circles
overlay.circle_filled(150.0, 150.0, 20.0, Color::rgba(56, 189, 248, 128));
overlay.circle(150.0, 150.0, 20.0, Color::CYAN);

overlay.end_frame()?;

Drawing text

Text rendering uses an embedded font with configurable size:

overlay.text(20.0, 20.0, "Player1 [100HP]", 16.0, Color::WHITE);
overlay.text(20.0, 40.0, "Distance: 42m", 12.0, Color::YELLOW);

// measure text bounds before drawing
let (w, h) = overlay.text_bounds("centered text", 16.0);
overlay.text(320.0 - w / 2.0, 10.0, "centered text", 16.0, Color::WHITE);

Convenience methods

Built-in methods for common game overlay patterns:

// crosshair
overlay.crosshair(640.0, 360.0, 24.0, 2.0, Color::GREEN);

// health bar with foreground, background, and border
overlay.health_bar(100.0, 200.0, 80.0, 10.0, 0.65, Color::GREEN, Color::rgb(30, 30, 30));

// ESP box with optional label
overlay.esp_box(200.0, 100.0, 50.0, 100.0, Color::RED, Some("Enemy [85HP]"));
overlay.esp_box(400.0, 150.0, 40.0, 90.0, Color::BLUE, None);

Platform support

The crate compiles on all platforms but only exports the overlay API on Windows.

How it works

The overlay creates a transparent, always-on-top window (WS_EX_LAYERED | WS_EX_TRANSPARENT) positioned over the target game window. All mouse and keyboard input passes through to the game. The overlay tracks the target window's position and resizes automatically.

Rendering uses Direct3D 11 with alpha blending. Shapes are batched into vertex/index buffers and drawn in minimal draw calls. Text is rasterized into a glyph atlas at startup and rendered as textured quads.

License

MIT