The backend has its own coordinate space that ranges from 0 to 1 across both dimensions. (0, 0) is the top left corner of the rendered layout and (1, 1) is the bottom right corner. Since the coordinate space forms a square, the aspect ratio of the layout is not respected.
The renderer internally uses a coordinate space that depends on the layout direction. If the layout lays out its components vertically, then the renderer coordinate space has the dimensions [width, 1] with the width being chosen such that the renderer coordinate space respects the aspect ratio of the underlaying layout. If the layout is laid out horizontally the dimensions are always [1, height] with height being chosen such that the aspect ratio is respected instead.
The component coordinate space is a coordinate space local to a single component. In vertical mode this means that (0, 0) is the top left corner of the component and (width, 1) is the bottom right corner of the component. (1, height) is the bottom right corner in horizontal mode.
The default height of a component in the component coordinate space is 1. This is equal to the height of one split or one info text component. The default text size is 0.8. There is a padding of 0.35 to the left and right side of a component for the contents shown inside a component, such as images and texts. This padding may also be applied to the top and bottom of a component. The same padding of 0.35 is also used for the minimum spacing between text and other content such as an icon or another text. If text doesn't fit, it is to be either abbreviated or overflown via the use of ellipsis. Numbers and times are supposed to be aligned to the right and should be using a monospace text layout. Sometimes components are rendered in two row mode. The height of these components is 1.75 in horizontal mode.