<marker>
The <marker>
element defines a graphic used for drawing arrowheads or polymarkers on a given <path>
, <line>
, <polyline>
or <polygon>
element.
Markers can be attached to shapes using the marker-start
, marker-mid
, and marker-end
properties.
Examples
Drawing arrowheads
The following example shows how to draw an arrowhead on a line and on a curved path.
For the curved path, an arrowhead is drawn at each point with a marker-mid
marker.
<svg viewBox="0 0 300 100" xmlns="http://www.w3.org/2000/svg">
<defs>
<!-- A marker to be used as an arrowhead -->
<marker
id="arrow"
viewBox="0 0 10 10"
refX="5"
refY="5"
markerWidth="6"
markerHeight="6"
orient="auto-start-reverse">
<path d="M 0 0 L 10 5 L 0 10 z" />
</marker>
</defs>
<!-- A line with a marker -->
<line
x1="10"
y1="10"
x2="90"
y2="90"
stroke="black"
marker-end="url(#arrow)" />
<!-- A curved path with markers -->
<path
d="M 110 10
C 120 20, 130 20, 140 10
C 150 0, 160 0, 170 10
C 180 20, 190 20, 200 10"
stroke="black"
fill="none"
marker-start="url(#arrow)"
marker-mid="url(#arrow)"
marker-end="url(#arrow)" />
</svg>
Drawing polymarkers
<svg viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
<defs>
<!-- Arrowhead marker definition -->
<marker
id="arrow"
viewBox="0 0 10 10"
refX="5"
refY="5"
markerWidth="6"
markerHeight="6"
orient="auto-start-reverse">
<path d="M 0 0 L 10 5 L 0 10 z" />
</marker>
<!-- Dot marker definition -->
<marker
id="dot"
viewBox="0 0 10 10"
refX="5"
refY="5"
markerWidth="5"
markerHeight="5">
<circle cx="5" cy="5" r="5" fill="red" />
</marker>
</defs>
<!-- Coordinate axes with an arrowhead in both directions -->
<polyline
points="10,10 10,90 90,90"
fill="none"
stroke="black"
marker-start="url(#arrow)"
marker-end="url(#arrow)" />
<!-- Data line with polymarkers -->
<polyline
points="15,80 29,50 43,60 57,30 71,40 85,15"
fill="none"
stroke="grey"
marker-start="url(#dot)"
marker-mid="url(#dot)"
marker-end="url(#dot)" />
</svg>
Using context fill and stroke
The following example shows how to use the context-fill
and context-stroke
values to make a marker use the same fill and stroke as the shape it is attached to.
<svg viewBox="0 0 50 50" xmlns="http://www.w3.org/2000/svg">
<marker
id="circle"
markerWidth="6"
markerHeight="6"
refX="3"
refY="3"
markerUnits="strokeWidth">
<circle cx="3" cy="3" r="2" stroke="context-stroke" fill="context-fill" />
</marker>
<style>
path {
marker: url(#circle);
}
</style>
<path d="M 10,10 30,10 h 10" stroke="black" />
<path d="M 10,20 30,20 h 10" stroke="blue" fill="red" />
<path d="M 10,30 30,30 h 10" stroke="red" fill="none" />
<path d="M 10,40 30,40 h 10" stroke="gray" fill="blue" stroke-width="1.5" />
</svg>
Attributes
markerHeight
-
This attribute defines the height of the marker viewport. Value type: <length> ; Default value:
3
; Animatable: yes markerUnits
-
This attribute defines the coordinate system for the attributes
markerWidth
,markerHeight
and the contents of the<marker>
. Value type:userSpaceOnUse
|strokeWidth
; Default value:strokeWidth
; Animatable: yes markerWidth
-
This attribute defines the width of the marker viewport. Value type: <length> ; Default value:
3
; Animatable: yes orient
-
This attribute defines the orientation of the marker relative to the shape it is attached to. Value type:
auto
|auto-start-reverse
|<angle> ; Default value:0
; Animatable: yes preserveAspectRatio
-
This attribute defines how the svg fragment must be deformed if it is embedded in a container with a different aspect ratio. Value type: (
none
|xMinYMin
|xMidYMin
|xMaxYMin
|xMinYMid
|xMidYMid
|xMaxYMid
|xMinYMax
|xMidYMax
|xMaxYMax
) (meet
|slice
)? ; Default value:xMidYMid meet
; Animatable: yes refX
-
This attribute defines the x coordinate for the reference point of the marker. Value type:
left
|center
|right
|<coordinate> ; Default value:0
; Animatable: yes refY
-
This attribute defines the y coordinate for the reference point of the marker. Value type:
top
|center
|bottom
|<coordinate> ; Default value:0
; Animatable: yes viewBox
-
This attribute defines the bound of the SVG viewport for the current SVG fragment. Value type: <list-of-numbers> ; Default value: none; Animatable: yes
Usage context
Categories | Container element |
---|---|
Permitted content | Any number of the following elements, in any order: Animation elements Descriptive elements Shape elements Structural elements Gradient elements <a> , <clipPath> , <cursor> , <filter> , <font> , <font-face> , <foreignObject> , <image> , <marker> , <mask> , <pattern> , <script> , <style> , <switch> , <text> , <view> |
Specifications
Specification |
---|
Scalable Vector Graphics (SVG) 2 # MarkerElement |
Browser compatibility
BCD tables only load in the browser
See also
- Related marker properties:
marker-start
,marker-mid
, andmarker-end