Polygons

Polygons are two dimensional shapes that contain both an outer stroke (or “outline”) and an inside (or “fill”). A polygon can be thought of as an irregularly-shaped point and is styled in similar ways to circles.

Example polygons layer

The polygons layer used below contains county information for a fictional country. For reference, the attribute table for the polygons is included below.

fid (Feature ID)

name (County name)

pop (Population)

polygon.1

Irony County

412234

polygon.2

Tracker County

235421

polygon.3

Dracula County

135022

polygon.4

Poly County

1567879

polygon.5

Bearing County

201989

polygon.6

Monte Cristo County

152734

polygon.7

Massive County

67123

polygon.8

Rhombus County

198029

Download the polygons shapefile

Simple polygon

This example shows a polygon filled in blue.

../../../_images/polygon_simplepolygon.png

Simple polygon

Code

Download the "Simple polygon" MBStyle

 1 {
 2   "version": 8,
 3   "name": "simple-polygon",
 4   "layers": [
 5     {
 6       "id": "polygon",
 7       "type": "fill",
 8       "paint": {
 9         "fill-color": "#000080"
10       }
11     }
12   ]
13 }

Details

There is one layer for this style, which is the simplest possible situation. Styling polygons is accomplished via the fill type (line 7). Line 9 specifies dark blue ('#000080') as the polygon’s fill color.

Note

The light-colored outlines around the polygons in the figure are artifacts of the renderer caused by the polygons being adjacent. There is no outline in this style.

Simple polygon with stroke

This example adds a 1 pixel white outline to the Simple polygon example.

../../../_images/polygon_simplepolygonwithstroke.png

Simple polygon with stroke

Code

Download the "Simple polygon with stroke" MBStyle

 1 {
 2   "version": 8,
 3   "name": "simple-polygon-outline",
 4   "layers": [
 5     {
 6       "id": "polygon-outline",
 7       "type": "fill",
 8       "paint": {
 9         "fill-outline-color": "#FFFFFF",
10         "fill-color": "#000080"
11       }
12     }
13   ]
14 }

Details

This example is similar to the Simple polygon example above, with the addition of fill-outline paint parameter (line 9). Line 9 also sets the color of stroke to white ('#FFFFFF'), the "fill-outline-color" can only be 1 pixel, a limitation of MBStyle.

Transparent polygon

This example builds on the Simple polygon with stroke example and makes the fill partially transparent by setting the opacity to 50%.

../../../_images/polygon_transparentpolygon.png

Transparent polygon

Code

Download the "Transparent polygon" MBStyle

 1 {
 2   "version": 8,
 3   "name": "simple-polygon-transparent",
 4   "layers": [
 5     {
 6       "id": "polygon-transparent",
 7       "type": "fill",
 8       "paint": {
 9         "fill-outline-color": "#FFFFFF",
10         "fill-color": "#000080",
11         "fill-opacity": 0.5
12       }
13     }
14   ]
15 }

Details

This example is similar to the Simple polygon with stroke example, save for defining the fill’s opacity in line 11. The value of 0.5 results in partially transparent fill that is 50% opaque. An opacity value of 1 would draw the fill as 100% opaque, while an opacity value of 0 would result in a completely transparent (0% opaque) fill. In this example, since the background is white, the dark blue looks lighter. Were the fill imposed on a dark background, the resulting color would be darker.

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