Struct tetra::graphics::Camera [−][src]
pub struct Camera {
pub position: Vec2<f32>,
pub rotation: f32,
pub scale: Vec2<f32>,
pub viewport_width: f32,
pub viewport_height: f32,
// some fields omitted
}
Expand description
A camera that can be used to transform the player’s view of the scene.
To apply the transformation, call the as_matrix
method and pass the
resulting Mat4
to graphics::set_transform_matrix
.
To disable it, call graphics::reset_transform_matrix
.
The camera’s matrix is cached internally as an optimization. After adjusting parameters
on the camera, you can call the update
method to recalculate the matrix.
Examples
The camera
example demonstrates how a camera can be used to transform a simple
scene.
Fields
position: Vec2<f32>
The position of the camera.
Note that this defines the center point of the view, rather than the top-left. This makes it easy to position the camera relative to your game objects - for example, to focus the camera on the player, you can just set the camera position to match the player’s position.
You may need to take this behaviour into account when positioning the camera, however. For example, if the viewport width or height is an odd number, setting the position to a whole number will mean that the view will not be aligned with the pixel grid, which may cause issues for pixel-perfect rendering.
rotation: f32
The rotation of the camera, in radians.
scale: Vec2<f32>
The scaling applied by the camera.
viewport_width: f32
The width of the camera’s viewport.
This is primarily used for calculating where the center of the screen is,
and usually should match the size of the target you’re currently rendering to
(e.g. the screen, or a Canvas
).
viewport_height: f32
The height of the camera’s viewport.
This is primarily used for calculating where the center of the screen is,
and usually should match the size of the target you’re currently rendering to
(e.g. the screen, or a Canvas
).
Implementations
Creates a new camera with the given viewport size.
The provided size usually should match the size of the target you’re currently rendering to
(e.g. the screen, or a Canvas
).
Creates a new camera, with the viewport size set to match the size of the window.
This is a useful shortcut if your game renders at a 1:1 ratio with the game window.
If you’re rendering to a differently sized target (e.g. a Canvas
or a
ScreenScaler
), then you should use call new
with the target size instead.
Note that if the window is resized, the camera’s viewport size will not automatically
update. If you need to keep the window size and the viewport size in sync, then call
set_viewport_size
in State::event
when
Event::Resized
is fired.
Sets the size of the camera’s viewport.
The provided size usually should match the size of the target you’re currently rendering to
(e.g. the screen, or a Canvas
).
Recalculates the transformation matrix, based on the data currently contained within the camera.
Returns the current transformation matrix.
Pass this to graphics::set_transform_matrix
to apply the transformation to your scene. To disable the transformation, call
graphics::reset_transform_matrix
.
The matrix is cached internally, so calling this method multiple times will not cause it to be recalculated from scratch.
Projects a point from world co-ordinates to camera co-ordinates.
Projects a point from camera co-ordinates to world co-ordinates.
Returns the mouse’s position in camera co-ordinates.
This is a shortcut for calling project(input::get_mouse_position(ctx))
.
As such, it does not take into account any other transformations
being made to the view (e.g. screen scaling).
Returns the X co-ordinate of the mouse’s position in camera co-ordinates.
This is a shortcut for calling project(input::get_mouse_position(ctx)).x
.
As such, it does not take into account any other transformations
being made to the view (e.g. screen scaling).
Returns the Y co-ordinate of the mouse’s position in camera co-ordinates.
This is a shortcut for calling project(input::get_mouse_position(ctx)).y
.
As such, it does not take into account any other transformations
being made to the view (e.g. screen scaling).
Calculates the visible rectangle of the camera.
When used on a rotated camera, this will return the smallest rectangle that contains the full camera viewport.
Note that this method does not take into account any other transformations being made to the view (e.g. screen scaling).
Trait Implementations
Auto Trait Implementations
impl RefUnwindSafe for Camera
impl UnwindSafe for Camera
Blanket Implementations
Mutably borrows from an owned value. Read more