DemoNPointRadialGradient01.kt

import org.openrndr.application
import org.openrndr.color.ColorRGBa
import org.openrndr.color.rgb
import org.openrndr.extra.shadestyles.NPointRadialGradient
import org.openrndr.shape.Circle
import kotlin.random.Random

/**
 * Demonstrate using a multi color radial gradient.
 * The gradient has 5 colors (first and last ones are transparent).
 * Any of the properties can be animated, including colors and points.
 * See DemoNPointLinearGradient01.kt for an example of animated properties.
 */
fun main() {
    application {
        program {
            val gradient = NPointRadialGradient(arrayOf(
                    ColorRGBa.PINK.opacify(0.0),
                    ColorRGBa.PINK, ColorRGBa.WHITE, ColorRGBa.PINK,
                    ColorRGBa.PINK.opacify(0.0)
            ), arrayOf(0.0, 0.4, 0.5, 0.6, 1.0))

            val circles = List(25) {
                Circle(Random.nextDouble() * drawer.width,
                        Random.nextDouble() * drawer.height,
                        Random.nextDouble() * 150.0)
            }

            extend {
                drawer.run {
                    clear(rgb(0.2))
                    shadeStyle = gradient
                    fill = ColorRGBa.WHITE
                    stroke = null
                    circles(circles)
                }
            }
        }
    }
}