jdk8-mips64-public/nashorn: test/script/jfx/spread.js@bda654c6d59c (annotated)

test/script/jfx/spread.js@bda654c6d59c (annotated)

test/script/jfx/spread.js

Tue, 05 Nov 2013 13:09:40 +0400

author: kshefov
date: Tue, 05 Nov 2013 13:09:40 +0400
changeset 667: bda654c6d59c
parent 0: b1a7da25b547
child 962: ac62e33a99b0
permissions: -rw-r--r--

8027708: NASHORN TEST: Create Nashorn test that draws image step-by-step using JavaFX canvas.
Reviewed-by: jlaskey, lagergren

 /*
  * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 /**
  * Testing JavaFX canvas run by Nashorn.
  *
  * @test/nocompare
  * @run
  * @fork
  */
 TESTNAME = "spread";
 var WIDTH = 800;
 var HEIGHT = 600;
 var canvas = new Canvas(WIDTH, HEIGHT);
 var context = canvas.graphicsContext2D;
 /* "Spread" tech demo of canvas by Tom Theisen
  *
  * This will animate a sequence of branch structures in a canvas element.
  * Each frame, a new direction is calculated, similar to the last frame.
  */
 var start_width = 20;           // starting width of each branch
 var frame_time = 30;            // milliseconds per frame
 var straighten_factor = 0.95;   // value from 0 to 1, factor applied to direction_offset every frame
 var curviness = 0.2;            // amount of random direction change each frame
 var color_speed = 0.03;     // speed at which colors change when cycling is enabled
 var branch_shrink = 0.95;   // factor by which branches shrink every frame
 var min_width = 1;          // minimum WIDTH for branch, after which they are discontinued
 var branch_opacity = 0.4;   // opacity of lines drawn
 var branch_count = 3;       // branch count per tree
 var branch_bud_size = 0.5;  // ratio of original branch size at which branch will split
 var branch_bud_angle = 1;   // angle offset for split branch;
 var paper;                  // reference to graphics context
 var branches = Object();    // linked list of active branches
 var color_styles = [];      // pre-computed list of colors as styles. format: (r,g,b,a)
 var direction_offset = 0;   // current direction offset in radians.  this is applied to all branches.
 var frame = 0;              // frame counter
 var timespent = 0;          // total time spent so far, used to calculate average frame render duration
 var frameratespan;          // html span element for updating performance number
 // preferences object, contains an attribute for each user setting
 var prefs = {
     wrap: true,             // causes branches reaching edge of viewable area to appear on opposite side
     fade: false,             // fade existing graphics on each frame
     cycle: true,            // gradually change colors each frame
     new_branch_frames: 20    // number of frames elapsed between each auto-generated tree
 };
 // create tree at the specified position with number of branches
 function create_tree(branches, start_width, position, branch_count) {
     var angle_offset = Math.PI * 2 / branch_count;
     for (var i = 0; i < branch_count; ++i) {
         branch_add(branches, new Branch(position, angle_offset * i, start_width));
     }
 }
 // add branch to collection
 function branch_add(branches, branch) {
     branch.next = branches.next;
     branches.next = branch;
 }
 // get the coordinates for the position of a new tree
 // use the center of the canvas
 function get_new_tree_center(width, height) {
     return {
         x: 0.5 * width,
         y: 0.5 * height
     };
 }
 // Branch constructor
 // position has x and y properties
 // direction is in radians
 function Branch(position, direction, width) {
     this.x = position.x;
     this.y = position.y;
     this.width = width;
     this.original_width = width;
     this.direction = direction;
 }
 // update position, direction and width of a particular branch
 function branch_update(branches, branch, paper) {
     paper.beginPath();
     paper.lineWidth = branch.width;
     paper.moveTo(branch.x, branch.y);
     branch.width *= branch_shrink;
     branch.direction += direction_offset;
     branch.x += Math.cos(branch.direction) * branch.width;
     branch.y += Math.sin(branch.direction) * branch.width;
     paper.lineTo(branch.x, branch.y);
     paper.stroke();
     if (prefs.wrap) wrap_branch(branch, WIDTH, HEIGHT);
     if (branch.width < branch.original_width * branch_bud_size) {
         branch.original_width *= branch_bud_size;
         branch_add(branches, new Branch(branch, branch.direction + 1, branch.original_width));
     }
 }
 function draw_frame() {
     if (prefs.fade) {
         paper.fillRect(0, 0, WIDTH, HEIGHT);
     }
     if (prefs.cycle) {
         paper.setStroke(Paint.valueOf(color_styles[frame % color_styles.length]));
     }
     if (frame++ % prefs.new_branch_frames == 0) {
         create_tree(branches, start_width, get_new_tree_center(WIDTH, HEIGHT), branch_count);
     }
     direction_offset += (0.35 + (frame % 200) * 0.0015) * curviness - curviness / 2;
     direction_offset *= straighten_factor;
     var branch = branches;
     var prev_branch = branches;
     while (branch = branch.next) {
         branch_update(branches, branch, paper);
         if (branch.width < min_width) {
             // remove branch from list
             prev_branch.next = branch.next;
         }
         prev_branch = branch;
     }
 }
 // constrain branch position to visible area by "wrapping" from edge to edge
 function wrap_branch(branch, WIDTH, HEIGHT) {
     branch.x = positive_mod(branch.x, WIDTH);
     branch.y = positive_mod(branch.y, HEIGHT);
 }
 // for a < 0, b > 0, javascript returns a negative number for a % b
 // this is a variant of the % operator that adds b to the result in this case
 function positive_mod(a, b) {
     // ECMA 262 11.5.3: Applying the % Operator
     // remainder operator does not convert operands to integers,
     // although negative results are possible
     return ((a % b) + b) % b;
 }
 // pre-compute color styles that will be used for color cycling
 function populate_colors(color_speed, color_styles, branch_opacity) {
     // used in calculation of RGB values
     var two_thirds_pi = Math.PI * 2 / 3;
     var four_thirds_pi = Math.PI * 4 / 3;
     var two_pi = Math.PI * 2;
     // hue does represent hue, but not in the conventional HSL scheme
     for(var hue = 0; hue < two_pi; hue += color_speed) {
         var r = Math.floor(Math.sin(hue) * 128 + 128);
         var g = Math.floor(Math.sin(hue + two_thirds_pi) * 128 + 128);
         var b = Math.floor(Math.sin(hue + four_thirds_pi) * 128 + 128);
         color = "rgba(" + [r, g, b, branch_opacity].join() + ")";
         color_styles.push(color);
     }
 }
 // apply initial settings to canvas object
 function setup_canvas() {
     paper = canvas.graphicsContext2D;
     paper.setFill(Paint.valueOf('rgb(0, 0, 0)'));
     paper.fillRect(0, 0, WIDTH, HEIGHT);
     paper.setFill(Paint.valueOf("rgba(0, 0, 0, 0.005)"));
     paper.setStroke(Paint.valueOf("rgba(128, 128, 64, " + String(branch_opacity) + ")"));
 }
 populate_colors(color_speed, color_styles, branch_opacity);
 setup_canvas();
 var stack = new StackPane();
 var pane = new BorderPane();
 pane.setCenter(canvas);
 stack.getChildren().add(pane);
 $STAGE.scene = new Scene(stack);
 var timer = new AnimationTimerExtend() {
     handle: function handle(now) {
         if (frame < 200) {
 		    draw_frame();
         } else {
             checkImageAndExit();
             timer.stop();
         }
     }
 };
 timer.start();