src/main/groovy/groovy2d/paintingByNumbers.groovy

/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 */
/** 
 * Simple patchwork graphics demo
 * @author: Jeremy Rayner, changes by Dierk Koenig
 */
import javax.swing.WindowConstants as WC
import groovy.swing.SwingBuilder

def width = 500, height = 400, blockSize = 10
def g = createGraphics(width, height)

// main loop
while (true) {
    drawBlock(width, height, blockSize, g)
}

// random integer
def rnd(upperBound){
    (int)(Math.random() * upperBound)
}

// draw a random coloured square within bounds
def drawBlock(w, h, b, g) {
    def row    = rnd(h / b)
    def column = rnd(w / b)
    def colour = new java.awt.Color(rnd(255),rnd(255),rnd(255))
    g.color = colour
    g.fillRect(column * b, row * b, b, b)
}

// create a new frame and clear screen
def createGraphics(w, h) {
    def frame = new SwingBuilder().frame(
        title:'Painting by numbers',
        location:[20,20],
        size:[w, h],
        defaultCloseOperation:WC.EXIT_ON_CLOSE
    )
    frame.show()
              
    // obtain graphics context
    def gfx = frame.graphics
              
    // clear screen
    gfx.color = java.awt.Color.BLACK
    gfx.fillRect(0, 0, w, h)

    return gfx
}