Trait immi::Draw

pub trait Draw {
    type ImageResource: ?Sized;
    type FontResource: ?Sized;
    fn draw_triangle(&mut self, texture: &Self::ImageResource, matrix: &Matrix, uv_coords: [[f32; 2]; 3]);
    fn get_image_width_per_height(&mut self, name: &Self::ImageResource) -> f32;
    fn draw_text(&mut self, font: &Self::FontResource, matrix: &Matrix, text: &str, rgb_color: [f32; 3]);
    fn get_text_width_per_em(&mut self, font: &Self::FontResource, text: &str) -> f32;

    fn draw_image(&mut self, name: &Self::ImageResource, matrix: &Matrix) { ... }
    fn draw_image_uv(&mut self, name: &Self::ImageResource, matrix: &Matrix, top_left: [f32; 2], top_right: [f32; 2], bottom_right: [f32; 2], bottom_left: [f32; 2]) { ... }
}

Trait for a context that can handle drawing.

Associated Types

type ImageResource: ?Sized

Type of a resource that represents an image.

type FontResource: ?Sized

Type of a resource that represents a font.

Required Methods

fn draw_triangle(&mut self, texture: &Self::ImageResource, matrix: &Matrix, uv_coords: [[f32; 2]; 3])

Draws a single triangle that covers the top-left hand corner of the surface, multiplied by the matrix. In other words, the OpenGL positions of the triangle are [-1.0, 1.0], [-1.0, -1.0] and [1.0, 1.0].

The UV coordinates correspond to the UV coordinates of the texture. [0.0, 0.0] is the bottom-left hand corner of the texture, and [1.0, 1.0] is the top-right hand corner.

fn get_image_width_per_height(&mut self, name: &Self::ImageResource) -> f32

Given an image, this functions returns its width divided by its height.

fn draw_text(&mut self, font: &Self::FontResource, matrix: &Matrix, text: &str, rgb_color: [f32; 3])

Draws an image that covers the whole surface (from -1.0 to 1.0 both horizontally and vertically), but multiplied by the matrix.

This function should not try to preseve the aspect ratio of the text. This is handled by the caller.

fn get_text_width_per_em(&mut self, font: &Self::FontResource, text: &str) -> f32

Given a font and a text, this function returns the width the text would have on the screen, divided by the size of a EM.

Provided Methods

fn draw_image(&mut self, name: &Self::ImageResource, matrix: &Matrix)

Draws an image that covers the whole surface (from -1.0 to 1.0 both horizontally and vertically), but multiplied by the matrix.

This function should not try to preseve the aspect ratio of the image. This is handled by the caller.

fn draw_image_uv(&mut self, name: &Self::ImageResource, matrix: &Matrix, top_left: [f32; 2], top_right: [f32; 2], bottom_right: [f32; 2], bottom_left: [f32; 2])

Draws an image that covers the whole surface (from -1.0 to 1.0 both horizontally and vertically), but multiplied by the matrix.

This function should not try to preseve the aspect ratio of the image. This is handled by the caller.

Contrary to draw_image, this library allows one to specify UV coordinates of the four borders. Coordinates [0.0, 0.0] correspond to the bottom-left hand corner of the image, and [1.0, 1.0] correspond to the top-right hand corner.

Implementors