Camera

A camera that can move, zoom, fit and shake.

bare.camera.SetPosition(player.x, player.y);
bare.camera.SetZoom(2);
bare.camera.StartShake(8, 0.3);

Example: the Showcase's camera demo follows the mouse, shakes, tweens the zoom and switches scale modes.

Following a player

SetPosition jumps straight to a point. For a smooth follow, move part of the way every frame:

OnUpdate(deltaTime: number)
{
    const camera = bare.camera.GetPosition();
    const t = 1 - Math.exp(-5 * deltaTime);   // higher than 5 follows tighter

    bare.camera.SetPosition(
        bare.util.Lerp(camera.x, player.x, t),
        bare.util.Lerp(camera.y, player.y, t),
    );
}

Using deltaTime in t keeps the follow speed the same at any frame rate. Combine it with SetBoundsToLevel() so the camera stops at the level's edges.

Fitting the level

To show a whole level on any screen size:

import { CameraScaleMode } from 'bare-engine';

OnPostLoadLevel()
{
    bare.camera.SetScaleMode(CameraScaleMode.Contain);
    bare.camera.SetDimensionsToLevel();
}

Scale mode	Description
CameraScaleMode.None	No automatic scaling.
CameraScaleMode.Contain	Fit all content on screen, with space around it if needed.
CameraScaleMode.Cover	Fill the screen with content. Some content may be cut off, but you never see past its edges.

Examples: the Platformer, and the Showcase's camera demo, which switches between Cover and Contain.

Methods

Method	Description
SetPosition(x, y)	Center the camera on a point, kept inside the bounds if there are any.
SetPositionTopLeft(x, y)	Place the camera by its top-left corner.
AddPosition(dx, dy) / GetPosition()	Move or read the position. GetPosition returns the center within the bounds, without shake, and reflects SetPosition right away.
SetZoom(zoom) / GetZoom()	Zoom level.
SetDimensions(width, height)	The area the camera shows.
SetScaleMode(mode)	How that area is fitted to the screen.
SetBounds(rect)	Keep the camera inside a rectangle. A camera has no bounds until you set them, but loading a level sets them to the level's size.
SetBoundsToLevel() / SetBoundsToScreen() / DisableBounds()	Common bounds.
SetDimensionsToLevel() / SetBoundsAndDimensionsToLevel()	Match the loaded level.
ScreenToWorld(x, y) / WorldToScreen(x, y)	Convert positions.
StartShake(amount?, seconds?, decay?)	Shake the camera.
StartShakeXY(x, y, seconds?, decay?)	Shake with separate x and y amounts.
StopShake()	Stop shaking.