import org.openrndr.application
import org.openrndr.color.ColorRGBa
import org.openrndr.extra.shadestyles.radialGradient
import kotlin.math.cos

fun main() = application {
    program {
        extend {
            drawer.shadeStyle = radialGradient(
                ColorRGBa.PINK,
                ColorRGBa.PINK.toHSVa().shiftHue(180.0).shade(0.5).toRGBa(),
                exponent = cos(seconds) * 0.5 + 0.5
            )
            drawer.rectangle(120.0, 40.0, 400.0, 400.0)
        }
    }
}