truce_gui/
render.rs

1//! Render backend trait for abstracting over CPU and GPU rendering.
2//!
3//! Widgets draw through this trait, making them backend-agnostic.
4
5use crate::theme::Color;
6
7/// Abstraction over rendering backends (CPU via tiny-skia, future GPU via wgpu).
8///
9/// All coordinates are in pixels. The CPU backend renders to an in-memory
10/// RGBA buffer; a GPU backend would render via Metal/DX12/Vulkan.
11pub trait RenderBackend {
12    /// Clear the entire surface with a solid color.
13    fn clear(&mut self, color: Color);
14
15    /// Fill a rectangle.
16    fn fill_rect(&mut self, x: f32, y: f32, w: f32, h: f32, color: Color);
17
18    /// Fill a circle.
19    fn fill_circle(&mut self, cx: f32, cy: f32, radius: f32, color: Color);
20
21    /// Stroke a circle outline.
22    fn stroke_circle(&mut self, cx: f32, cy: f32, radius: f32, color: Color, width: f32);
23
24    /// Stroke an arc (portion of a circle).
25    fn stroke_arc(
26        &mut self,
27        cx: f32,
28        cy: f32,
29        radius: f32,
30        start_angle: f32,
31        end_angle: f32,
32        color: Color,
33        width: f32,
34    );
35
36    /// Draw a line between two points.
37    fn draw_line(&mut self, x1: f32, y1: f32, x2: f32, y2: f32, color: Color, width: f32);
38
39    /// Draw text using the embedded TrueType font (fontdue).
40    fn draw_text(&mut self, text: &str, x: f32, y: f32, size: f32, color: Color);
41
42    /// Measure the width of a text string in pixels.
43    fn text_width(&self, text: &str, size: f32) -> f32;
44
45    /// Flush rendering to the display surface.
46    ///
47    /// No-op for CPU backends (pixels are read directly from the buffer).
48    /// GPU backends submit their command buffer and present here.
49    fn present(&mut self) {}
50}
truce_gui/render.rs

truce_gui/
render.rs
