Struct CanvasRenderer 

pub struct CanvasRenderer { /* private fields */ }

A wrapper around CanvasRenderingContext2d providing convenience drawing methods and camera management for the game engine.

Implementations

impl CanvasRenderer

Implements static font and color utility methods for CanvasRenderer.

pub fn build_font_string(size: f64, family: &str) -> String

Builds a CSS font string from font size and family.

Arguments

• f64 - The font size in pixels.
• &str - The font family name.

Returns

• String - The CSS font string (e.g., "16px sans-serif").

pub fn default_font_string() -> String

Creates a default font string using the default font size and family.

Returns

• String - The default CSS font string.

pub fn enable_context_anti_aliasing(context: &CanvasRenderingContext2d)

Enables high-quality anti-aliasing on an arbitrary canvas 2D context.

Sets imageSmoothingEnabled to true and imageSmoothingQuality to "high" on the given context. This is a static utility for code that manages its own CanvasRenderingContext2d without using a CanvasRenderer instance.

Arguments

• &CanvasRenderingContext2d - The canvas context to configure.

impl CanvasRenderer

Implements drawing and camera management methods for CanvasRenderer.

pub fn from_selector( canvas_selector: &str, viewport_width: f64, viewport_height: f64, ) -> Option<CanvasRenderer>

Creates a new renderer from a canvas element selector and viewport dimensions.

Arguments

• &str - The CSS selector for the canvas element.
• f64 - The viewport width.
• f64 - The viewport height.

Returns

• Option<CanvasRenderer> - The renderer, or None if the canvas was not found.

pub fn enable_anti_aliasing(&self)

Enables high-quality anti-aliasing on the canvas context by setting imageSmoothingEnabled to true and imageSmoothingQuality to "high".

This improves the quality of image scaling operations (e.g., draw_image) but does not affect vector primitives like lines and fills, which are already anti-aliased by the browser’s 2D canvas implementation.

pub fn clear(&self)

Clears the entire canvas viewport.

pub fn clear_with_color(&self, color: &str)

Clears the canvas and fills it with the given CSS color string.

Arguments

• &str - The CSS color string (e.g., "#000000").

pub fn save(&self)

Saves the current canvas state (transform, styles) onto the state stack.

pub fn restore(&self)

Restores the most recently saved canvas state.

pub fn apply_camera(&self)

Applies the camera transform to the canvas context.

Translates to the screen center, applies zoom and rotation, then offsets by the negative camera position.

pub fn set_fill_color(&self, color: &str)

Sets the fill color for subsequent fill operations.

Arguments

• &str - The CSS color string.

pub fn set_stroke_color(&self, color: &str)

Sets the stroke color for subsequent stroke operations.

Arguments

• &str - The CSS color string.

pub fn set_line_width(&self, width: f64)

Sets the line width for subsequent stroke operations.

Arguments

• f64 - The line width in pixels.

pub fn set_global_alpha(&self, alpha: f64)

Sets the global alpha (opacity) for all subsequent drawing operations.

Arguments

• f64 - The alpha value in the range 0.0 to 1.0.

pub fn fill_rect(&self, position: Vector2D, width: f64, height: f64)

Fills a rectangle at the given world-space position and dimensions.

Arguments

• Vector2D - The top-left position in world space.
• f64 - The width.
• f64 - The height.

pub fn stroke_rect(&self, position: Vector2D, width: f64, height: f64)

Strokes the outline of a rectangle at the given world-space position and dimensions.

Arguments

• Vector2D - The top-left position in world space.
• f64 - The width.
• f64 - The height.

pub fn fill_circle(&self, center: Vector2D, radius: f64)

Fills a circle at the given world-space center with the specified radius.

Arguments

• Vector2D - The center in world space.
• f64 - The radius.

pub fn stroke_circle(&self, center: Vector2D, radius: f64)

Strokes the outline of a circle at the given world-space center.

Arguments

• Vector2D - The center in world space.
• f64 - The radius.

pub fn draw_line(&self, start: Vector2D, end: Vector2D)

Draws a line segment between two world-space points.

Arguments

• Vector2D - The start point.
• Vector2D - The end point.

pub fn fill_text(&self, text: &str, position: Vector2D)

Fills text at the given world-space position.

Arguments

• &str - The text to draw.
• Vector2D - The position in world space.

pub fn set_font(&self, font: &str)

Sets the font for subsequent text rendering.

Arguments

• &str - The CSS font string (e.g., "16px sans-serif").

pub fn draw_image( &self, image: &HtmlImageElement, position: Vector2D, width: f64, height: f64, )

Draws an image element at the given world-space position and dimensions.

Arguments

• &HtmlImageElement - The image element to draw.
• Vector2D - The top-left position in world space.
• f64 - The destination width.
• f64 - The destination height.

pub fn draw_image_subregion( &self, image: &HtmlImageElement, source: Rect, dest_position: Vector2D, dest_width: f64, dest_height: f64, )

Draws a sub-region of an image element at the given world-space position.

Arguments

• &HtmlImageElement - The image element to draw.
• Rect - The source rectangle within the image.
• Vector2D - The destination top-left position in world space.
• f64 - The destination width.
• f64 - The destination height.

impl CanvasRenderer

Implements blend mode, shadow, and gradient rendering methods for CanvasRenderer.

pub fn set_blend_mode(&self, mode: BlendMode)

Sets the blend mode for compositing subsequent draw operations.

Arguments

• BlendMode - The blend mode to apply.

pub fn set_shadow(&self, config: &ShadowConfig)

Applies a shadow configuration for subsequent draw operations.

Arguments

• &ShadowConfig - The shadow configuration to apply.

pub fn clear_shadow(&self)

Clears any previously applied shadow, disabling shadow rendering.

pub fn set_linear_gradient_fill(&self, gradient: &LinearGradient)

Applies a linear gradient as the fill style for subsequent operations.

Arguments

• &LinearGradient - The linear gradient to use as fill style.

pub fn set_radial_gradient_fill(&self, gradient: &RadialGradient)

Applies a radial gradient as the fill style for subsequent operations.

Arguments

• &RadialGradient - The radial gradient to use as fill style.

pub fn set_linear_gradient_stroke(&self, gradient: &LinearGradient)

Applies a linear gradient as the stroke style for subsequent operations.

Arguments

• &LinearGradient - The linear gradient to use as stroke style.

pub fn set_radial_gradient_stroke(&self, gradient: &RadialGradient)

Applies a radial gradient as the stroke style for subsequent operations.

Arguments

• &RadialGradient - The radial gradient to use as stroke style.

impl CanvasRenderer

pub fn get_context(&self) -> &CanvasRenderingContext2d

pub fn get_mut_context(&mut self) -> &mut CanvasRenderingContext2d

pub fn set_context(&mut self, val: CanvasRenderingContext2d) -> &mut Self

pub fn get_camera(&self) -> Camera2D

pub fn get_mut_camera(&mut self) -> &mut Camera2D

pub fn set_camera(&mut self, val: Camera2D) -> &mut Self

impl CanvasRenderer

pub fn new(context: CanvasRenderingContext2d, camera: Camera2D) -> Self

Trait Implementations

impl Clone for CanvasRenderer

fn clone(&self) -> CanvasRenderer

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl RenderBackend for CanvasRenderer

Implements the RenderBackend trait for CanvasRenderer, providing a backend-agnostic rendering interface.

fn clear(&self)

Clears the entire viewport.

fn clear_with_color(&self, color: &str)

Clears the viewport and fills it with the given CSS color string.

fn save(&self)

Saves the current rendering state onto the state stack.

fn restore(&self)

Restores the most recently saved rendering state.

fn set_fill_color(&self, color: &str)

Sets the fill color for subsequent fill operations.

fn set_stroke_color(&self, color: &str)

Sets the stroke color for subsequent stroke operations.

fn set_line_width(&self, width: f64)

Sets the line width for subsequent stroke operations.

fn set_global_alpha(&self, alpha: f64)

Sets the global alpha (opacity) for all subsequent drawing operations.

fn set_blend_mode(&self, mode: BlendMode)

Sets the blend mode for compositing subsequent draw operations.

fn set_shadow(&self, config: &ShadowConfig)

Applies a shadow configuration for subsequent draw operations.

fn clear_shadow(&self)

Clears any previously applied shadow, disabling shadow rendering.

fn fill_rect(&self, position: Vector2D, width: f64, height: f64)

Fills a rectangle at the given world-space position and dimensions.

fn stroke_rect(&self, position: Vector2D, width: f64, height: f64)

Strokes the outline of a rectangle at the given world-space position and dimensions.

fn fill_circle(&self, center: Vector2D, radius: f64)

Fills a circle at the given world-space center with the specified radius.

fn stroke_circle(&self, center: Vector2D, radius: f64)

Strokes the outline of a circle at the given world-space center.

fn draw_line(&self, start: Vector2D, end: Vector2D)

Draws a line segment between two world-space points.

fn fill_text(&self, text: &str, position: Vector2D)

Fills text at the given world-space position.

fn set_font(&self, font: &str)

Sets the font for subsequent text rendering.

fn draw_image( &self, image: &HtmlImageElement, position: Vector2D, width: f64, height: f64, )

Draws an image element at the given world-space position and dimensions.

fn set_linear_gradient_fill(&self, gradient: &LinearGradient)

Applies a linear gradient as the fill style for subsequent operations.

fn set_radial_gradient_fill(&self, gradient: &RadialGradient)

Applies a radial gradient as the fill style for subsequent operations.