projects / bus.git / blob
search:
summary | shortlog | log | commit | commitdiff | tree
plain | HEAD | history | blame
Fix up time display format
[bus.git] / openlayers / examples / ordering.html 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212

<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <title>OpenLayers: Z-Ordering and Y-Ordering of Vector Features</title>
    <link rel="stylesheet" href="../theme/default/style.css" type="text/css" />
    <link rel="stylesheet" href="style.css" type="text/css" />
    <style type="text/css">
        .smallmap {
            width: 300px;
        }
        
        .docs {
            padding: 0px 5px;
        }
        
        td {
            vertical-align: top;
        }
        
    </style>
    <script src="../lib/OpenLayers.js" type="text/javascript"></script>
    <script type="text/javascript">
        
        var GOLD_Z_INDEX = 15;
        var FIRST_RED_Z_INDEX = 10;
        var SECOND_RED_Z_INDEX = 11;
        
        var RADIUS_FROM_CENTER = 40;
        var POINT_DISTANCE = 10;
            
        function initYOrderMap() {
            var map = new OpenLayers.Map("yorder");
            
            var layer = new OpenLayers.Layer.Vector(
                "Y-Order",
                {
                    styleMap: new OpenLayers.StyleMap({
                        externalGraphic: "../img/marker-gold.png",
                        pointRadius: 10,
                        graphicZIndex: GOLD_Z_INDEX
                    }),
                    isBaseLayer: true,
                    rendererOptions: {yOrdering: true}
                }
            );
            
            map.addLayers([layer]);
            map.zoomToMaxExtent();
            
            // Add features to the layers to show off z-index/y-ordering.
            // We do this after adding the layer so we can work in pixels.
            var center = map.getViewPortPxFromLonLat(map.getCenter());
            
            var top = new OpenLayers.Pixel(center.x, center.y - RADIUS_FROM_CENTER);
            var bottom = new OpenLayers.Pixel(center.x, center.y + RADIUS_FROM_CENTER);
            var left = new OpenLayers.Pixel(center.x - RADIUS_FROM_CENTER, center.y - POINT_DISTANCE / 2);
            var right = new OpenLayers.Pixel(center.x + RADIUS_FROM_CENTER, center.y - POINT_DISTANCE / 2);
            
            // Add the ordering features. These are the gold ones that all have the same z-index
            // and succomb to y-ordering.
            var orderingFeatures = [];
            // Note: We use > here on purpose (instead of >= ), as well as subtracting the
            // the POINT_DISTANCE in the beginning of the loop (as opposed to the end).
            // This is purely for symmetry. Also note that the gold features are drawn
            // from bottom to top so as to quickly signal whether or not y-ordering is working.
            while (bottom.y > top.y) {
                bottom.y -= POINT_DISTANCE;
                var lonLat = map.getLonLatFromViewPortPx(bottom);
                orderingFeatures.push(
                    new OpenLayers.Feature.Vector(
                        new OpenLayers.Geometry.Point(lonLat.lon, lonLat.lat)
                    )
                );
            }
          
            layer.addFeatures(orderingFeatures);
            
            // Add the z-index features. Technically, these features succomb to y-ordering
            // as well; however, since they have different z-indexes, the z-indexes take 
            // precedence.
            var indexFeatures = [];
            var useFirst = true;
            while (left.x <= right.x) {
                var lonLat = map.getLonLatFromViewPortPx(left);
                var point = new OpenLayers.Feature.Vector(
                    new OpenLayers.Geometry.Point(lonLat.lon, lonLat.lat)
                );
                
                // This is where the magic happens. We override the style on the layer
                // to give our own style with alternativing z-indexes.
                point.style = {
                    graphicZIndex: useFirst ? FIRST_RED_Z_INDEX : SECOND_RED_Z_INDEX,
                    externalGraphic: "../img/marker.png",
                    pointRadius: 10
                }
                
                indexFeatures.push(
                    point
                );
                
                left.x += POINT_DISTANCE;
                useFirst = !useFirst;
            }
            
            layer.addFeatures(indexFeatures);
        }
        
        function initDrawingOrderMap() {
            var map = new OpenLayers.Map("drawingorder");
            
            var layer = new OpenLayers.Layer.Vector(
                "Drawing Order",
                {
                    // The zIndex is taken from the zIndex attribute of the features
                    styleMap: new OpenLayers.StyleMap({
                        graphicZIndex: "${zIndex}",
                        externalGraphic: "../img/marker-green.png",
                        pointRadius: 10
                    }),
                    isBaseLayer: true,
                    // enable the indexer by setting zIndexing to true
                    rendererOptions: {zIndexing: true}
                }
            );
            
            map.addLayers([layer]);
            map.zoomToMaxExtent();
            
            // Add features to the layers to show off z-index/y-ordering.
            // We do this after adding the layer so we can work in pixels.
            var center = map.getViewPortPxFromLonLat(map.getCenter());
            
            var top = new OpenLayers.Pixel(center.x, center.y - RADIUS_FROM_CENTER);
            var bottom = new OpenLayers.Pixel(center.x, center.y + RADIUS_FROM_CENTER);
            var left = new OpenLayers.Pixel(center.x - RADIUS_FROM_CENTER, center.y);
            var right = new OpenLayers.Pixel(center.x + RADIUS_FROM_CENTER, center.y);
            
            // Add the ordering features. These are the gold ones that all have the same z-index
            // and succomb to y-ordering.
            var orderingFeatures = [];
            while (bottom.y > top.y && left.x < right.x) {
                var bottomLonLat = map.getLonLatFromViewPortPx(bottom);
                var leftLonLat = map.getLonLatFromViewPortPx(left);
                orderingFeatures.push(
                    new OpenLayers.Feature.Vector(
                        new OpenLayers.Geometry.Point(leftLonLat.lon, bottomLonLat.lat),
                        // Set the zIndex attribute of all features to 0.
                        // This attribute will be assigned to the graphicZIndex symbolizer property by the layer's styleMap
                        {zIndex: 0}
                    )
                );
                bottom.y -= POINT_DISTANCE / 2; // Divide by 2 for better visual.
                left.x += POINT_DISTANCE / 2;
            }
            // only the first feature gets a zIndex attribute of 1
            orderingFeatures[0].attributes.zIndex = 1;
          
            layer.addFeatures(orderingFeatures);
        }
 
        function init(){
            initYOrderMap();
            initDrawingOrderMap();
        };
        
    </script>
  </head>
  <body onload="init()">
        <h1 id="title">Z-Index/Y-Order Example</h1>
 
        <div id="tags">
        </div>
 
        <p id="shortdesc">
           This example shows the use of z-indexing and y-ordering of external graphics. Zoom in and out to see this behavior.
        </p>
 
        <h3>Z-Index (with Y-Ordering enabled)</h3>
        <table>
            <tr>
                <td>
                    <div id="yorder" class="smallmap"></div>
                </td>
                <td>
                    <div class="docs">
                        In this map, the gold features all have the same z-index, and the red features have alternating z-indeces. The gold features' z-index is greater than the red features' z-indeces, which is why gold features look to be drawn on top of the red features. Since each gold feature has the same z-index, gold features succomb to y-ordering: this is where features that seem closest to the viewer (lower lattitude) show up above those that seem farther away (higher lattitude).
                        <br><br>
                        You can enable y-ordering by passing the parameter <i>yOrdering: true</i> in the vector layer's options hash. For all configurations (with yOrdering or zIndexing set to true), if features have the same z-index -- and if y-ordering is enabled: the same latitude -- those features will succomb to drawing order, where the last feature to be drawn will appear above the rest.
                    </div>
                </td>
            </tr>
        </table>
        <br>
        <h3>Z-Index and Drawing Order (Z-Indexes set, and Y-Ordering disabled)</h3>
        <table>
            <tr>
                <td>
                    <div id="drawingorder" class="smallmap"></div>
                </td>
                <td>
                    <div class="docs">
                        In this map, <i>zIndexing</i> is set to true. All features are given the same z-index (0), except for the first feature which has a z-index of 1. The layer's <i>yOrdering</i> parameter is set to the default (false). This configuration makes features succomb to z-index and drawing order (for the features with the same z-index), instead of y-order.
                        <br><br>
                        The features in this map were drawn from left to right and bottom to top, diagonally, to show that y-ordering is not enabled. Only the lower-left corner feature is drawn on top of the others, because it has a higher z-index (1 instead of 0).
                    </div>
                </td>
            </tr>
        </table>
        
        
    </body>
</html>
 
Unnamed repository; edit this file to name it for gitweb.
GitPHP by Chris Han