Struct design_pattern_examples_rust::flyweight::flyweight_context::FlyweightContext

pub struct FlyweightContext {
    pub offset_x_to_image: usize,
    pub image_width: usize,
    pub image_height: usize,
    pub position_x: f32,
    pub position_y: f32,
    pub velocity_x: f32,
    pub velocity_y: f32,
}

Represents the context for an instance of the Flyweight_Image structure. In this case, the context includes position and velocity.

This context is manipulated outside the Flyweight Image by the controlling entity (in this case, the flyweight_exercise() function). The FlyweightImage struct just holds onto the context, along with a handle to the big resource.

Fields

offset_x_to_image: usize

Offset into big resource to left edge of image, in characters.

image_width: usize

Width of image, in characters

image_height: usize

Height of image, in characters

position_x: f32

Horizontal position of upper left corner of image in a display, in characters

position_y: f32

Vertical position of upper left corner of image in a display, in characters

velocity_x: f32

Velocity to apply to the horizontal position, in fractions of a character

velocity_y: f32

Velocity to apply to the vertical position, in fractions of a character

Implementations

impl FlyweightContext

pub fn new( offset_x_to_image: usize, image_width: usize, image_height: usize ) -> FlyweightContext

Constructor.

Parameters

• offset_x_to_image

  Offset into big resource to left edge of image, in characters.

• image_width

  Width of image, in characters.

• image_height

  Height of image, in characters.

Returns

Returns a new instance of the FlyweightContext struct.