computeFitToCanvas

Computes how a source image is scaled and placed to fill a canvas’s height, with equal margins on the left and right.

The scaled width is rounded to the nearest integer that leaves an EVEN remainder, so the two margins are exactly equal — an asymmetric pillarbox is visible at a glance and looks like a mistake. Where both neighbors qualify, the one closer to the true scaled width wins, so the aspect error stays below one part in a thousand.

Worked example, the mobile store case: a 1344x2992 frame onto a 900x1600 canvas scales by 1600/2992 to 718.72 wide. 719 would leave a 181px remainder, which cannot split evenly, so 718 is chosen (margin 91) over 720 (margin 90) because 718 is nearer 718.72.

Import:

import { computeFitToCanvas } from 'obsidian-integration-testing';

Signature:

function computeFitToCanvas(params: ComputeFitToCanvasParams): FitToCanvasGeometry

Parameters:

Parameter	Type	Description
params	ComputeFitToCanvasParams	The source and canvas dimensions.

Returns: FitToCanvasGeometry — The scaled size, the offsets, and the side margin.

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Links to this page:

• ComputeFitToCanvasParams