truce-cpu

CPU rendering backend for the truce built-in GUI.

Overview

Provides CpuBackend, a software implementation of truce_gui_types::RenderBackend built on tiny-skia, plus the fontdue glyph cache (font) and the ColorExt conversions the rasteriser needs. This is the default renderer: it works on every platform without a usable GPU, and its output is deterministic, which makes it the reliable path for screenshot tests.

truce-cpu is an implementation detail of truce-gui: BuiltinEditor rasterises the widget tree into a tiny-skia pixmap through this backend and blits it to a wgpu surface for compositing. Plugins don't depend on truce-cpu directly — it's pulled in by truce-gui's default cpu feature. Its peer truce-gpu provides the wgpu backend behind the gpu feature.

Key types

• CpuBackend -- tiny-skia truce_gui_types::RenderBackend implementation
• ColorExt -- extension trait adding to_skia() / to_premultiplied() to the light truce_gui_types::theme::Color type, so that type stays tiny-skia-free
• font -- fontdue glyph cache + text measurement, fed by the bundled JetBrains Mono from truce-font

Usage

truce-cpu is selected automatically — the default cpu feature on truce-gui enables it, and editor() renders through it:

fn editor(&self) -> Box<dyn Editor> {
    GridLayout::build(vec![widgets(vec![
        knob(P::Gain, "Gain"),
    ])])
    .into_editor(&self.params)
}

Part of truce. Docs.