import org.openrndr.application
import org.openrndr.color.ColorRGBa
import org.openrndr.draw.isolated
import org.openrndr.extra.shadestyles.*
import org.openrndr.math.Polar
import org.openrndr.shape.Rectangle

/**
 * Example of 5 gradient styles.
 * NPointLinear and NPoingGradient have separate demos.
 */
fun main() = application {
    configure {
        width = 1000
        height = 500
    }
    program {
        // Create gradients with initial colors
        val gradients = listOf(
            RadialGradient(ColorRGBa.PINK, ColorRGBa.WHITE),
            AngularGradient(ColorRGBa.PINK, ColorRGBa.WHITE),
            NPointGradient(Array(4) {
                ColorRGBa.PINK.shade(it / 3.0)
            }),
            LinearGradient(ColorRGBa.PINK, ColorRGBa.WHITE),
            HalfAngularGradient(ColorRGBa.PINK, ColorRGBa.WHITE)
        )

        extend {
            gradients.forEachIndexed { gradientId, gradient ->
                for (column in 0 until 10) {
                    val color1 = ColorRGBa.PINK.toHSVa().shiftHue(column * 12.0)
                        .shade(0.5).toRGBa()

                    val w = width.toDouble() / 10.0
                    val h = height.toDouble() / gradients.size
                    val rect = Rectangle(column * w, gradientId * h, w, h)

                    val offset = Polar((seconds + column) * 15.0, 0.3).cartesian

                    drawer.isolated {
                        when (gradient) {
                            is RadialGradient -> {
                                gradient.color1 = color1
                                gradient.exponent = column / 3.0 + 0.3
                                gradient.length = 0.6
                                gradient.offset = offset
                            }

                            is AngularGradient -> {
                                gradient.color1 = color1
                                gradient.exponent = column / 3.0 + 0.3
                                gradient.rotation = (seconds - column) * 10.0
                                gradient.offset = offset
                            }

                            is LinearGradient -> {
                                gradient.color1 = color1
                                gradient.exponent = column / 3.0 + 0.3
                                gradient.rotation = seconds * 10.0
                            }

                            is HalfAngularGradient -> {
                                gradient.color1 = color1
                                gradient.exponent = column / 3.0 + 0.3
                                gradient.rotation = (column - seconds) * 10.0
                                gradient.offset = offset
                            }

                            is NPointGradient -> {
                                // Animate points.
                                // We could also animate colors.
                                gradient.points = Array(gradient.colors.size) {
                                    rect.center + Polar(
                                        it * 90.0 +
                                                column * 36 - seconds * 10,
                                        40.0
                                    ).cartesian
                                }
                            }
                        }
                        shadeStyle = gradient
                        rectangle(rect)
                    }
                }
            }
        }
    }
}