Struct ferrux_viewport::viewport::Viewport

pub struct Viewport<S, R> { /* private fields */ }

Entity in charge of offering the functions to draw on the screen and handle to logic of the operation. It works using three-dimensional normalized vectors of type (x: f32, y: f32, z: f32). The point to draw in the screen will be the one relative to given position in the x and y axes. So, any point outside the (-1.0, 1.0) range will not be drawn. The z value works as a layer function, it will draw only the point with the highest z on the same translated pixel.

The viewport doesn’t perform projection, that should be handled by the user before calling the functions. Viewport just draws the pixels of the highest depth relative to the given coordinates.

The axes directions are:

• x: west -> east
• y: north -> south
• z: far -> near

Implementations

impl<S: PixelSize, R> Viewport<S, R>

pub fn width(&self) -> S

Returns the width of the current window

pub fn height(&self) -> S

Returns the height of the current window

pub fn depth(&self) -> S

Returns the depth of the current window

pub fn draw_point<'a>(&mut self, position: (f32, f32, f32), color: &'a [u8])

Commands the drawing of a point in the window. It will be rendered in the next call to Viewport::render. If two drawn points fall on the same pixel, the point with the lowest z will be ignored.

Arguments

• position, coordinates of the point in (f32, f32, f32).
• color, color of the point to draw. It should be provided as raw RGB values, alpha is included, so the expectation is a &[u8; 4] color like &[255, 0, 0, 255] for red with 100% opacity.

Example

viewport.draw_point((0.0, 0.0, 0.0), &[255, 255, 255, 255]); // white point in the center of the screen
viewport.render()?; // renders the point in the window

Panic

Passing a color with the wrong number of members will throw a panic. It’s required to have length four (R, G, B, A);

pub fn draw_line<'a>(
    &mut self,
    start: (f32, f32, f32),
    end: (f32, f32, f32),
    color: &'a [u8]
)

Commands the drawing of a line in the window. It will be rendered in the next call to Viewport::render.

Arguments

• start, coordinates of the starting point of the line.
• end, coordinates of the ending point of the line.
• color, color of the line to draw. It should be provided as raw RGB values, alpha is included, so the expectation is a &[u8; 4] color like &[255, 0, 0, 255] for red with 100% opacity.

Example

viewport.draw_line((-0.5, -0.5, -0.5), (0.25, 0.5, 0.0), &[255, 255, 255, 255]);
viewport.render()?; // renders the line in the window

Panic

Passing a color with the wrong number of members will throw a panic. It’s required to have length four (R, G, B, A);

pub fn draw_triangle<'a>(
    &mut self,
    point_a: (f32, f32, f32),
    point_b: (f32, f32, f32),
    point_c: (f32, f32, f32),
    color: &'a [u8]
)

Commands the drawing of a triangle in the window. It will be rendered in the next call to Viewport::render.

Arguments

• point_a, point_b, point_c. Coordinates of the points of the triangle.
• color, color of the line to draw. It should be provided as raw RGB values, alpha is included, so the expectation is a &[u8; 4] color like &[255, 0, 0, 255] for red with 100% opacity.

Example

viewport.draw_triangle((0.0, 0.0, -0.5), (-0.5, 0.5, 0.0), (0.5, 0.5, 0.0), &[255, 255, 255, 255]);
viewport.render()?; // renders the triangle in the window

Panic

Passing a color with the wrong number of members will throw a panic. It’s required to have length four (R, G, B, A);

pub fn fill_triangle<'a>(
    &mut self,
    point_a: (f32, f32, f32),
    point_b: (f32, f32, f32),
    point_c: (f32, f32, f32),
    color: &'a [u8]
)

Commands the drawing and filling of a triangle in the window. It will be rendered in the next call to Viewport::render.

Arguments

• point_a, point_b, point_c. Coordinates of the points of the triangle.
• color, color of the line to draw. It should be provided as raw RGB values, alpha is included, so the expectation is a &[u8; 4] color like &[255, 0, 0, 255] for red with 100% opacity.

Example

viewport.fill_triangle((0.0, 0.0, -0.5), (-0.5, 0.5, 0.0), (0.5, 0.5, 0.0), &[255, 255, 255, 255]);
viewport.render()?; // renders the triangle in the window

Panic

Passing a color with the wrong number of members will throw a panic. It’s required to have length four (R, G, B, A);

pub fn reset_buffer(&mut self)

Resets the buffer clearing all its current content

impl<S: PixelSize, R: Resize<S>> Viewport<S, R>

pub fn resize(&mut self, width: S, height: S)

Changes the size of the rendered window. Doing it will reset the buffer, clearing the current content.

Arguments

• width. New width of the window.
• height. New height of the window.

impl<S: PixelSize, R: Render> Viewport<S, R>

pub fn render(&mut self) -> Result<(), ViewportError>

Renders the content of the buffer in the Window. It doesn’t clear the buffer afterwards, to do that call Viewport::reset_buffer.

Example

viewport.fill_triangle((0.0, 0.0, -0.5), (-0.5, 0.5, 0.0), (0.5, 0.5, 0.0), &[255, 255, 255, 255]);
viewport.render()?; // renders the triangle in the window
viewport.reset_buffer(); // clears the buffer to prepare the drawing of a new frame

pub fn clear_frame(&mut self) -> Result<(), ViewportError>

Draws an empty frame without the needing of resetting the buffer. This is an optimal way of drawing an empty frame keeping the current drawing buffer without the need to save it, resetting buffer, rendering and redrawing it.

Example

viewport.fill_triangle((0.0, 0.0, -0.5), (-0.5, 0.5, 0.0), (0.5, 0.5, 0.0), &[255, 255, 255, 255]);
viewport.render()?;         // renders the triangle in the window
viewport.clear_frame()?;    // renders an empty frame
viewport.fill_triangle((0.25, 0.75, -0.5), (-0.25, 0.25, 0.0), (0.25, 0.25, 0.0), &[255, 0, 0, 255]);
viewport.render()?;         // renders both triangles as the previous one was not deleted from the buffer