euv_engine/renderer/canvas/
trait.rs

1use super::*;
2
3/// A trait for objects that can record themselves into a draw list.
4pub trait Renderable {
5    /// Records this object's draw commands into the given draw list.
6    ///
7    /// # Arguments
8    ///
9    /// - `&mut DrawList` - The draw list to record commands into.
10    /// - `&Transform2D` - The world-space transform to apply.
11    fn draw(&self, draw_list: &mut DrawList, transform: &Transform2D);
12}
13
14/// An abstract rendering backend that decouples draw calls from the concrete
15/// canvas API, enabling future backends such as WebGL or WebGPU.
16///
17/// All methods mirror the `CanvasRenderingContext2d` interface so that
18/// `CanvasRenderer` can implement this trait with zero overhead.
19pub trait RenderBackend {
20    /// Clears the entire viewport.
21    fn clear(&self);
22
23    /// Clears the viewport and fills it with the given CSS color string.
24    ///
25    /// # Arguments
26    ///
27    /// - `C` - The CSS color string (e.g., `"#000000"`).
28    fn clear_color<C>(&self, color: C)
29    where
30        C: AsRef<str>;
31
32    /// Saves the current rendering state onto the state stack.
33    fn save(&self);
34
35    /// Restores the most recently saved rendering state.
36    fn restore(&self);
37
38    /// Sets the fill color for subsequent fill operations.
39    ///
40    /// # Arguments
41    ///
42    /// - `&str` - The CSS color string.
43    fn set_fill_color(&self, color: &str);
44
45    /// Sets the stroke color for subsequent stroke operations.
46    ///
47    /// # Arguments
48    ///
49    /// - `&str` - The CSS color string.
50    fn set_stroke_color(&self, color: &str);
51
52    /// Sets the line width for subsequent stroke operations.
53    ///
54    /// # Arguments
55    ///
56    /// - `f64` - The line width in pixels.
57    fn set_line_width(&self, width: f64);
58
59    /// Sets the global alpha (opacity) for all subsequent drawing operations.
60    ///
61    /// # Arguments
62    ///
63    /// - `f64` - The alpha value in the range 0.0 to 1.0.
64    fn set_global_alpha(&self, alpha: f64);
65
66    /// Sets the blend mode for compositing subsequent draw operations.
67    ///
68    /// # Arguments
69    ///
70    /// - `BlendMode` - The blend mode to apply.
71    fn set_blend_mode(&self, mode: BlendMode);
72
73    /// Applies a shadow configuration for subsequent draw operations.
74    ///
75    /// # Arguments
76    ///
77    /// - `&ShadowConfig` - The shadow configuration to apply.
78    fn set_shadow(&self, config: &ShadowConfig);
79
80    /// Clears any previously applied shadow, disabling shadow rendering.
81    fn clear_shadow(&self);
82
83    /// Fills a rectangle at the given world-space position and dimensions.
84    ///
85    /// # Arguments
86    ///
87    /// - `Vector2D` - The top-left position in world space.
88    /// - `f64` - The width.
89    fn fill_rect(&self, position: Vector2D, width: f64, height: f64);
90
91    /// Strokes the outline of a rectangle at the given world-space position and dimensions.
92    ///
93    /// # Arguments
94    ///
95    /// - `Vector2D` - The top-left position in world space.
96    /// - `f64` - The width.
97    fn stroke_rect(&self, position: Vector2D, width: f64, height: f64);
98
99    /// Fills a circle at the given world-space center with the specified radius.
100    ///
101    /// # Arguments
102    ///
103    /// - `Vector2D` - The center in world space.
104    /// - `f64` - The radius.
105    fn fill_circle(&self, center: Vector2D, radius: f64);
106
107    /// Strokes the outline of a circle at the given world-space center.
108    ///
109    /// # Arguments
110    ///
111    /// - `Vector2D` - The center in world space.
112    /// - `f64` - The radius.
113    fn stroke_circle(&self, center: Vector2D, radius: f64);
114
115    /// Draws a line segment between two world-space points.
116    ///
117    /// # Arguments
118    ///
119    /// - `Vector2D` - The start point.
120    fn draw_line(&self, start: Vector2D, end: Vector2D);
121
122    /// Fills text at the given world-space position.
123    ///
124    /// # Arguments
125    ///
126    /// - `&str` - The text to draw.
127    /// - `Vector2D` - The position in world space.
128    fn fill_text(&self, text: &str, position: Vector2D);
129
130    /// Sets the font for subsequent text rendering.
131    ///
132    /// # Arguments
133    ///
134    /// - `&str` - The CSS font string (e.g., `"16px sans-serif"`).
135    fn set_font(&self, font: &str);
136
137    /// Draws an image element at the given world-space position and dimensions.
138    ///
139    /// # Arguments
140    ///
141    /// - `&HtmlImageElement` - The image element to draw.
142    /// - `Vector2D` - The top-left position in world space.
143    /// - `f64` - The destination width.
144    fn draw_image(&self, image: &HtmlImageElement, position: Vector2D, width: f64, height: f64);
145
146    /// Applies a linear gradient as the fill style for subsequent operations.
147    ///
148    /// # Arguments
149    ///
150    /// - `&LinearGradient` - The linear gradient to use as fill style.
151    fn set_linear_gradient_fill(&self, gradient: &LinearGradient);
152
153    /// Applies a radial gradient as the fill style for subsequent operations.
154    ///
155    /// # Arguments
156    ///
157    /// - `&RadialGradient` - The radial gradient to use as fill style.
158    fn set_radial_gradient_fill(&self, gradient: &RadialGradient);
159}
euv_engine/renderer/canvas/trait.rs

euv_engine/renderer/canvas/
trait.rs
