import org.openrndr.application
import org.openrndr.extra.expressions.watchingExpression1
import org.openrndr.extra.gui.GUI
import org.openrndr.extra.gui.addTo
import org.openrndr.extra.parameters.TextParameter

/**
 * Improved version of DemoExpressionEvaluator01, it uses [watchingExpression1] to automatically convert an expression
 * string into a function with a parameter "t".
 */
fun main() = application {
    program {
        val gui = GUI()
        gui.compartmentsCollapsedByDefault = false

        // the constants used in our expressions
        val constants = mutableMapOf("width" to drawer.width.toDouble(), "height" to drawer.height.toDouble())

        val settings = object {
            @TextParameter("x expression", order = 10)
            var xExpression = "cos(t) * 50.0 + width / 2.0"

            @TextParameter("y expression", order = 20)
            var yExpression = "sin(t) * 50.0 + height / 2.0"

            @TextParameter("radius expression", order = 30)
            var radiusExpression = "cos(t) * 50.0 + 50.0"
        }.addTo(gui)

        val xFunction by watchingExpression1(settings::xExpression, "t", constants)
        val yFunction by watchingExpression1(settings::yExpression, "t", constants)
        val radiusFunction by watchingExpression1(settings::radiusExpression, "t", constants)

        extend(gui)
        extend {
            val x = xFunction(seconds)
            val y = yFunction(seconds)
            val radius = radiusFunction(seconds)
            drawer.circle(x, y, radius)
        }
    }
}