Drawing.kt

import org.openrndr.Fullscreen
import org.openrndr.KEY_SPACEBAR
import org.openrndr.application
import org.openrndr.color.ColorRGBa
import org.openrndr.draw.colorBuffer
import org.openrndr.draw.isolatedWithTarget
import org.openrndr.draw.renderTarget
import org.openrndr.draw.shadeStyle
import org.openrndr.filter.blur.BoxBlur
import org.openrndr.math.Vector3
import org.openrndr.shape.Circle
import kotlin.random.Random

fun main() = application {

    configure {
        width = 1920
        height = 1080
        fullscreen = Fullscreen.SET_DISPLAY_MODE
        title = "Hattie Wah Dey"
    }

    program {
        val offscreen = renderTarget(width, height) {
            colorBuffer()
            depthBuffer()
        }
        val blur = BoxBlur()
        val blurred = colorBuffer(width, height)

        var currentColor = ColorRGBa.RED
        var drawing = false
        var rainbow = false

        extend {
            // Blank canvas
            drawer.background(ColorRGBa.WHITE)

            // Change color?
            if (rainbow) {
                // Rainbow baybee
                currentColor = pickNewColor()
            }

            if (drawing) {
                // Set brush radius
                val r = Random.nextDouble(20.0, 30.0)

                drawer.isolatedWithTarget(offscreen) {
                    fill = currentColor
                    stroke = null
                    circle(mouse.position, r)
                }
            }

            blur.window = 10
            blur.apply(offscreen.colorBuffer(0), blurred)
            drawer.image(blurred)

            drawer.stroke = null
            drawer.fill = currentColor

            val point = Circle(mouse.position, 10.0).contour.position((seconds) % 1.0)
            drawer.circle(point, 10.0)

            mouse.buttonDown.listen {
                if (it.button.toString() === "RIGHT") {
                    drawer.shadeStyle = null
                    drawer.isolatedWithTarget(offscreen) {
                        background(ColorRGBa.WHITE)
                    }
                } else {
                    drawing = true
                }
            }

            mouse.buttonUp.listen {
                drawing = false
            }

            keyboard.keyDown.listen {
                if (it.key == KEY_SPACEBAR) {
                    rainbow = true
                }
            }

            keyboard.keyUp.listen {
                rainbow = false
            }
        }
    }
}

fun pickNewColor(): ColorRGBa {
    return ColorRGBa.fromVector(
            Vector3(
                    Random.nextDouble(),
                    Random.nextDouble(),
                    Random.nextDouble()
            )
    )
}