| <!DOCTYPE html> |
| <!-- |
| Copyright (c) 2015 The Chromium Authors. All rights reserved. |
| Use of this source code is governed by a BSD-style license that can be |
| found in the LICENSE file. |
| --> |
| |
| <link rel="import" href="/tracing/base/base.html"> |
| |
| <script> |
| 'use strict'; |
| |
| tr.exportTo('tr.ui.tracks', function() { |
| |
| /** |
| * A helper object encapsulating all parameters necessary to draw a chart |
| * series and provides conversion between world coordinates and physical |
| * pixels. |
| * |
| * All parameters (except for pixelRatio) are assumed to be in physical pixels |
| * (i.e. already pre-multiplied with pixelRatio). |
| * |
| * The diagram below explains the meaning of the resulting fields with |
| * respect to a chart track: |
| * |
| * outerTopViewY -> +--------------------/-\-------+ <- Top padding |
| * innerTopViewY -> + - - - - - - - - - -| |- - - -+ <- Axis max |
| * | .. ==\-/== | |
| * | == Series == | |
| * | ==/-\== .. | |
| * innerBottomViewY -> + - - -Point- - - - - - - - - -+ <- Axis min |
| * outerBottomViewY -> +-------\-/--------------------+ <- Bottom padding |
| * ^ ^ |
| * leftViewX rightViewX |
| * leftTimeStamp rightTimestamp |
| * |
| * Labels starting with a lower case letter are the resulting fields of the |
| * transform object. Labels starting with an upper case letter correspond |
| * to the relevant chart track concepts. |
| * |
| * @constructor |
| */ |
| function ChartTransform(displayTransform, axis, trackWidth, |
| trackHeight, topPadding, bottomPadding, pixelRatio) { |
| this.pixelRatio = pixelRatio; |
| |
| // X axis. |
| this.leftViewX = 0; |
| this.rightViewX = trackWidth; |
| this.leftTimestamp = displayTransform.xViewToWorld(this.leftViewX); |
| this.rightTimestamp = displayTransform.xViewToWorld(this.rightViewX); |
| |
| this.displayTransform_ = displayTransform; |
| |
| // Y axis. |
| this.outerTopViewY = 0; |
| this.innerTopViewY = topPadding; |
| this.innerBottomViewY = trackHeight - bottomPadding; |
| this.outerBottomViewY = trackHeight; |
| |
| this.axis_ = axis; |
| this.innerHeight_ = this.innerBottomViewY - this.innerTopViewY; |
| }; |
| |
| ChartTransform.prototype = { |
| worldXToViewX: function(worldX) { |
| return this.displayTransform_.xWorldToView(worldX); |
| }, |
| |
| viewXToWorldX: function(viewX) { |
| return this.displayTransform_.xViewToWorld(viewX); |
| }, |
| |
| worldYToViewY: function(worldY) { |
| var innerHeightCoefficient = 1 - this.axis_.valueToUnitRange(worldY); |
| return innerHeightCoefficient * this.innerHeight_ + this.innerTopViewY; |
| } |
| }; |
| |
| return { |
| ChartTransform: ChartTransform |
| }; |
| }); |
| </script> |
