tools/cc-frame-viewer/src/quad_view_viewport.js

   1 /* Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2  * Use of this source code is governed by a BSD-style license that can be
   3  * found in the LICENSE file.
   4  */
   5 'use strict';
   6
   7 base.require('base.range');
   8 base.require('ui.event_target');
   9
  10 base.exportTo('ccfv', function() {
  11   function QuadViewViewport(bbox,
  12                             opt_scale,
  13                             opt_dontPadBbox, opt_devicePixelRatio) {
  14     ui.EventTarget.call(this);
  15     if (bbox.isEmpty)
  16       throw new Error('Cannot initialize a viewport with an empty bbox');
  17
  18     this.setWorldBBox(bbox, opt_dontPadBbox);
  19
  20     var devicePixelRatio;
  21     if (opt_devicePixelRatio)
  22       devicePixelRatio = opt_devicePixelRatio;
  23     else
  24       devicePixelRatio = window.devicePixelRatio || 1;
  25
  26     var scale;
  27     if (opt_scale) {
  28       scale = opt_scale;
  29     } else {
  30       if (devicePixelRatio > 1)
  31         scale = 0.25;
  32       else
  33         scale = 0.125;
  34     }
  35     this.scale_ = scale;
  36     this.updateScale_();
  37   }
  38
  39   QuadViewViewport.prototype = {
  40
  41     __proto__: ui.EventTarget.prototype,
  42
  43     set scale(scale) {
  44       this.scale_ = scale;
  45       this.updateScale_();
  46       this.didChange_();
  47     },
  48
  49     get scale() {
  50       return this.scale_;
  51     },
  52
  53     updateScale_: function() {
  54       this.worldPixelsPerDevicePixel_ = this.scale_;
  55       this.devicePixelsPerLayoutPixel_ = 1 / devicePixelRatio;
  56
  57       this.deviceWidth =
  58         this.worldRect.width * this.worldPixelsPerDevicePixel_;
  59       this.deviceHeight =
  60         this.worldRect.height * this.worldPixelsPerDevicePixel_;
  61
  62       this.layoutWidth = this.deviceWidth * this.devicePixelsPerLayoutPixel_;
  63       this.layoutHeight = this.deviceHeight * this.devicePixelsPerLayoutPixel_;
  64
  65       this.transformWorldToDevicePixels_ = mat2d.create();
  66       this.transformDevicePixelsToWorld_ = mat2d.create();
  67       this.updateTransform_();
  68     },
  69
  70     setWorldBBox: function(bbox, opt_dontPadBbox) {
  71       var world_rect = bbox.asRect();
  72       var world_pad;
  73       if (opt_dontPadBbox) {
  74         world_pad = 0;
  75       } else {
  76         world_pad = Math.min(world_rect.width,
  77                              world_rect.height) * 0.10;
  78       }
  79
  80       world_rect.enlarge(world_pad);
  81       this.worldRect = world_rect;
  82       this.updateScale_();
  83       this.updateTransform_();
  84       this.didChange_();
  85     },
  86
  87     updateTransform_: function() {
  88       if (!this.transformWorldToDevicePixels_)
  89         return;
  90
  91       mat2d.identity(this.transformWorldToDevicePixels_);
  92       mat2d.translateInplaceXY(
  93         this.transformWorldToDevicePixels_,
  94           -this.worldRect.left, -this.worldRect.top);
  95       mat2d.scaleInplaceXY(this.transformWorldToDevicePixels_,
  96                            this.worldPixelsPerDevicePixel_,
  97                            this.worldPixelsPerDevicePixel_);
  98
  99       mat2d.invert(this.transformDevicePixelsToWorld_,
 100                    this.transformWorldToDevicePixels_);
 101     },
 102
 103     layoutPixelsToWorldPixels2: function(v) {
 104       var tmp = this.layoutPixelsToDevicePixels2(v);
 105       return this.devicePixelsToWorldPixels2(tmp);
 106     },
 107
 108     layoutPixelsToDevicePixels2: function(v) {
 109       var res = vec2.create();
 110       return vec2.scale(res, v, 1 / this.devicePixelsPerLayoutPixel_);
 111     },
 112
 113     devicePixelsToWorldPixels2: function(v) {
 114       var res = vec2.create();
 115       vec2.transformMat2d(res, v, this.transformDevicePixelsToWorld_);
 116       return res;
 117     },
 118
 119     getWorldToDevicePixelTransform: function() {
 120       return this.transformDevicePixelsToWorld_;
 121     },
 122
 123     getDeviceLineWidthAssumingTransformIsApplied: function(
 124         desired_device_line_width) {
 125       return desired_device_line_width / this.worldPixelsPerDevicePixel_;
 126     },
 127
 128     applyTransformToContext: function(ctx) {
 129       var transform = this.transformWorldToDevicePixels_;
 130       ctx.transform(transform[0], transform[1], transform[2],
 131                     transform[3], transform[4], transform[5]);
 132     },
 133
 134     forceRedrawAll: function() {
 135       this.didChange_();
 136     },
 137
 138     didChange_: function() {
 139       base.dispatchSimpleEvent(this, 'change', false, false);
 140     }
 141   };
 142
 143   return {
 144     QuadViewViewport: QuadViewViewport,
 145   }
 146 });
 147