natiny.render.viewport_begin

natiny.render.viewport_begin(x, y, width, height [, fn])

Sets a rectangular viewport on the current window or surface render target. The viewport becomes the local drawing area: its top-left corner is (0, 0), and its dimensions are used by 2D drawing and cameras bound afterwards.

Parameters

Name	Type	Default	Description
`x`	`number`		Left edge in render-target pixels
`y`	`number`		Top edge in render-target pixels
`width`	`number`		Width in pixels
`height`	`number`		Height in pixels
`fn`	`function`	`nil`	Called with no arguments while the viewport is in force; the viewport is ended when it returns

Example

for i, pane in ipairs(panes) do
    natiny.render.viewport_begin(pane.x, pane.y, pane.w, pane.h, function()
        natiny.camera.bind(pane.camera)
        draw_scene()
    end)
end

Without the callback, end the viewport by hand:

natiny.render.viewport_begin(0, 0, 320, 180)
draw_scene()
natiny.render.viewport_end()

Notes

The rectangle is clamped to the render target. If the clamped width or height is not positive, no viewport is set.
The callback form is the pair written out and nothing more. Viewports still do not nest: a call made while a viewport is active is ignored, and the end that follows fn closes the outer viewport instead.