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