Presentation Control

OPENRNDR programs can use any of the two presentation modes.

The default mode is automatic presentation, the draw method is called as often as possible. The other mode is manual presentation, in which it is the developer’s responsibility to request draw to be called.

Setting the presentation mode

The presentation mode can be set and changed at run-time.

import org.openrndr.PresentationMode
import org.openrndr.application
import org.openrndr.color.ColorRGBa

fun main() = application {
    program {
        window.presentationMode = PresentationMode.AUTOMATIC
    }
}

Using the manual presentation mode

The presentation mode is set to manual, a request to draw can be made using window.requestDraw.

In the following example draw() is only called after a mouse click.

import org.openrndr.PresentationMode
import org.openrndr.application
import org.openrndr.color.ColorRGBa

fun main() = application {
    program {
        window.presentationMode = PresentationMode.MANUAL
        mouse.buttonDown.listen {
            window.requestDraw()
        }

        extend {
            drawer.clear(ColorRGBa.PINK.shade(Math.random()))
        }
    }
}

Note that in manual presentation mode draw() is still called when the window is resized.

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