DemoBezierPatchDrawer03.kt

package bezierpatch

import org.openrndr.application
import org.openrndr.color.ColorRGBa
import org.openrndr.draw.isolated
import org.openrndr.extra.color.spaces.toOKLABa
import org.openrndr.extra.shapes.bezierpatches.bezierPatch
import org.openrndr.extra.shapes.primitives.grid
import org.openrndr.math.Vector2
import org.openrndr.math.Vector3
import org.openrndr.math.transforms.buildTransform
import org.openrndr.shape.Circle
import org.openrndr.shape.Rectangle
import kotlin.math.min

fun main() {
    application {
        configure {
            width = 720
            height = 720
        }
        program {
            extend {
                drawer.clear(ColorRGBa.BLACK)
                val colors = listOf(
                    listOf(ColorRGBa.PINK.toOKLABa(), ColorRGBa.PINK.toOKLABa(), ColorRGBa.PINK.toOKLABa(), ColorRGBa.PINK.toOKLABa()),
                    listOf(ColorRGBa.RED.toOKLABa(), ColorRGBa.RED.toOKLABa(), ColorRGBa.RED.toOKLABa(), ColorRGBa.RED.toOKLABa()),
                    listOf(ColorRGBa.BLUE.toOKLABa(), ColorRGBa.BLUE.toOKLABa(), ColorRGBa.BLUE.toOKLABa(), ColorRGBa.BLUE.toOKLABa()),
                    listOf(ColorRGBa.WHITE.toOKLABa(), ColorRGBa.WHITE.toOKLABa(), ColorRGBa.WHITE.toOKLABa(), ColorRGBa.WHITE.toOKLABa()),
                )

                val grid = drawer.bounds.grid(4,4, marginX = 20.0, marginY = 20.0, gutterX = 10.0, gutterY = 10.0)

                val cellWidth = grid[0][0].width
                val cellHeight = grid[0][0].height

                val a = bezierPatch(Rectangle.fromCenter(Vector2(0.0, 0.0), cellWidth, cellHeight).contour)
                    .withColors(colors)

                val b = bezierPatch(
                    Circle(0.0, 0.0, min(cellWidth, cellHeight) / 2.0).contour.transform(
                        buildTransform {
                            rotate(Vector3.UNIT_Z, 45.0)
                        }
                    )
                ).withColors(colors)

                for (y in grid.indices) {
                    for (x in grid[y].indices) {
                        val f = (y * grid[y].size + x).toDouble() / (grid.size * grid[y].size - 1.0)
                        val blend = a * (1.0 - f) + b * f
                        drawer.isolated {
                            drawer.translate(grid[y][x].center)
                            drawer.bezierPatch(blend)
                        }
                    }
                }
            }
        }
    }
}