SVG contains the following set of basic shape elements:
Mathematically, these shape elements are equivalent to a 'path' element that would construct the same shape. The basic shapes may be stroked, and filled. All of the properties available for 'path' elements also apply to the basic shapes.
The 'rect' element defines a rectangle which is axis-aligned with the current user coordinate system. Rounded rectangles can be achieved by setting appropriate values for attributes rx and ry.
<define name='rect'> <element name='rect'> <ref name='rect.AT'/> <zeroOrMore><ref name='shapeCommon.CM'/></zeroOrMore> </element> </define> <define name='rect.AT' combine='interleave'> <ref name='svg.ShapeCommon.attr'/> <ref name='svg.XYWH.attr'/> <ref name='svg.RxRyCommon.attr'/> </define>
Attribute definitions:
If a properly specified value is provided for rx but not for ry, then the user agent must process the 'rect' element with the effective value for ry as equal to rx. If a properly specified value is provided for ry but not for rx, then the user agent must process the 'rect' element with the effective value for rx as equal to ry. If neither rx nor ry has a properly specified value, then the user agent must process the 'rect' element as if no rounding had been specified, resulting in square corners. If rx is greater than half of the width of the rectangle, then the user agent must process the 'rect' element with the effective value for rx as half of the width of the rectangle. If ry is greater than half of the height of the rectangle, then the user agent must process the 'rect' element with the effective value for ry as half of the height of the rectangle.
Mathematically, a 'rect' element, taking its rounded corners into account, must be drawn in a way that produces the same output as the following rules: (Note: all coordinate and length values are first converted into user space coordinates according to Units.)
Example 09_01 shows a rectangle with sharp corners. The 'rect' element is filled with yellow and stroked with navy.
<?xml version="1.0"?> <svg width="12cm" height="4cm" viewBox="0 0 1200 400" xmlns="http://www.w3.org/2000/svg" version="1.2" baseProfile="tiny"> <desc>Example rect01 - rectangle with sharp corners</desc> <!-- Show outline of canvas using 'rect' element --> <rect x="1" y="1" width="1198" height="398" fill="none" stroke="blue" stroke-width="2"/> <rect x="400" y="100" width="400" height="200" fill="yellow" stroke="navy" stroke-width="10" /> </svg>
Example 09_02 shows two rounded rectangles. The rx specifies how to round the corners of the rectangles. Note that since no value has been specified for the ry attribute, it will be assigned the same value as the rx attribute.
<?xml version="1.0"?> <svg width="12cm" height="4cm" viewBox="0 0 1200 400" xmlns="http://www.w3.org/2000/svg" version="1.2" baseProfile="tiny"> <desc>Example rect02 - rounded rectangles</desc> <!-- Show outline of canvas using 'rect' element --> <rect x="1" y="1" width="1198" height="398" fill="none" stroke="blue" stroke-width="2"/> <rect x="100" y="100" width="400" height="200" rx="50" fill="green" /> <g transform="translate(700 210) rotate(-30)"> <rect x="0" y="0" width="400" height="200" rx="50" fill="none" stroke="purple" stroke-width="30" /> </g> </svg>
The 'circle' element defines a circle based on a center point and a radius.
<define name='circle'> <element name='circle'> <ref name='circle.AT'/> <zeroOrMore><ref name='shapeCommon.CM'/></zeroOrMore> </element> </define> <define name='circle.AT' combine='interleave'> <ref name='svg.ShapeCommon.attr'/> <ref name='svg.CxCy.attr'/> <ref name='svg.R.attr'/> </define>
Attribute definitions:
Example circle01 consists of a 'circle' element that is filled with red and stroked with blue.
<?xml version="1.0"?> <svg width="12cm" height="4cm" viewBox="0 0 1200 400" xmlns="http://www.w3.org/2000/svg" version="1.2" baseProfile="tiny"> <desc>Example circle01 - circle filled with red and stroked with blue</desc> <!-- Show outline of canvas using 'rect' element --> <rect x="1" y="1" width="1198" height="398" fill="none" stroke="blue" stroke-width="2"/> <circle cx="600" cy="200" r="100" fill="red" stroke="blue" stroke-width="10" /> </svg>
The 'ellipse' element defines an ellipse which is axis-aligned with the current user coordinate system based on a center point and two radii.
<define name='ellipse'> <element name='ellipse'> <ref name='ellipse.AT'/> <zeroOrMore><ref name='shapeCommon.CM'/></zeroOrMore> </element> </define> <define name='ellipse.AT' combine='interleave'> <ref name='svg.ShapeCommon.attr'/> <ref name='svg.RxRyCommon.attr'/> <ref name='svg.CxCy.attr'/> </define>
Attribute definitions:
Example 09_04 below specifies the coordinates of the two ellipses in the user coordinate system established by the viewBox attribute on the 'svg' element and the transform attribute on the 'g' and 'ellipse' elements. Both ellipses use the default values of zero for the cx and cy attributes (the center of the ellipse). The second ellipse is rotated.
<?xml version="1.0"?> <svg width="12cm" height="4cm" viewBox="0 0 1200 400" xmlns="http://www.w3.org/2000/svg" version="1.2" baseProfile="tiny"> <desc>Example ellipse01 - examples of ellipses</desc> <!-- Show outline of canvas using 'rect' element --> <rect x="1" y="1" width="1198" height="398" fill="none" stroke="blue" stroke-width="2" /> <g transform="translate(300 200)"> <ellipse rx="250" ry="100" fill="red" /> </g> <ellipse transform="translate(900 200) rotate(-30)" rx="250" ry="100" fill="none" stroke="blue" stroke-width="20" /> </svg>
The 'line' element defines a line segment that starts at one point and ends at another.
<define name='line'> <element name='line'> <ref name='line.AT'/> <zeroOrMore><ref name='shapeCommon.CM'/></zeroOrMore> </element> </define> <define name='line.AT' combine='interleave'> <ref name='svg.ShapeCommon.attr'/> <ref name='svg.X12Y12.attr'/> </define>
Attribute definitions:
Mathematically, a 'line' element can be mapped to an equivalent 'path' element as follows: (Note: all coordinate and length values are first converted into user space coordinates according to Units.)
Because 'line' elements are single lines and thus are geometrically one-dimensional, they have no interior; thus, 'line' elements are never filled (see the 'fill' property).
Example 09_05 below specifies the coordinates of the five lines in the user coordinate system established by the viewBox attribute on the 'svg' element. The lines have different thicknesses.
<?xml version="1.0"?> <svg width="12cm" height="4cm" viewBox="0 0 1200 400" xmlns="http://www.w3.org/2000/svg" version="1.2" baseProfile="tiny"> <desc>Example line01 - lines expressed in user coordinates</desc> <!-- Show outline of canvas using 'rect' element --> <rect x="1" y="1" width="1198" height="398" fill="none" stroke="blue" stroke-width="2" /> <g stroke="green" > <line x1="100" y1="300" x2="300" y2="100" stroke-width="5" /> <line x1="300" y1="300" x2="500" y2="100" stroke-width="10" /> <line x1="500" y1="300" x2="700" y2="100" stroke-width="15" /> <line x1="700" y1="300" x2="900" y2="100" stroke-width="20" /> <line x1="900" y1="300" x2="1100" y2="100" stroke-width="25" /> </g> </svg>
The 'polyline' element defines a set of connected straight line segments. Typically, 'polyline' elements define open shapes.
<define name='polyline'> <element name='polyline'> <ref name='polyCommon.AT'/> <zeroOrMore><ref name='shapeCommon.CM'/></zeroOrMore> </element> </define> <define name='polyCommon.AT' combine='interleave'> <ref name='svg.ShapeCommon.attr'/> <attribute name='points' svg:animatable='true' svg:inheritable='false'> <ref name='Points.datatype'/> </attribute> </define>
Attribute definitions:
If an odd number of coordinates is provided, then the element is treated as if the attribute had not been specified.
Mathematically, a 'polyline' element can be mapped to an equivalent 'path' element as follows:
Example 09_06 below specifies a polyline in the user coordinate system established by the viewBox attribute on the 'svg' element.
<?xml version="1.0"?> <svg width="12cm" height="4cm" viewBox="0 0 1200 400" xmlns="http://www.w3.org/2000/svg" version="1.2" baseProfile="tiny"> <desc>Example polyline01 - increasingly larger bars</desc> <!-- Show outline of canvas using 'rect' element --> <rect x="1" y="1" width="1198" height="398" fill="none" stroke="blue" stroke-width="2" /> <polyline fill="none" stroke="blue" stroke-width="10" points="50,375 150,375 150,325 250,325 250,375 350,375 350,250 450,250 450,375 550,375 550,175 650,175 650,375 750,375 750,100 850,100 850,375 950,375 950,25 1050,25 1050,375 1150,375" /> </svg>
The 'polygon' element defines a closed shape consisting of a set of connected straight line segments.
<define name='polygon'> <element name='polygon'> <ref name='polyCommon.AT'/> <zeroOrMore><ref name='shapeCommon.CM'/></zeroOrMore> </element> </define>
Attribute definitions:
If an odd number of coordinates is provided, then the element is treated as if the attribute had not bee specified.
Mathematically, a 'polygon' element can be mapped to an equivalent 'path' element as follows:
Example 09_07 below specifies two polygons (a star and a hexagon) in the user coordinate system established by the viewBox attribute on the 'svg' element.
<?xml version="1.0"?> <svg width="12cm" height="4cm" viewBox="0 0 1200 400" xmlns="http://www.w3.org/2000/svg" version="1.2" baseProfile="tiny"> <desc>Example polygon01 - star and hexagon</desc> <!-- Show outline of canvas using 'rect' element --> <rect x="1" y="1" width="1198" height="398" fill="none" stroke="blue" stroke-width="2" /> <polygon fill="red" stroke="blue" stroke-width="10" points="350,75 379,161 469,161 397,215 423,301 350,250 277,301 303,215 231,161 321,161" /> <polygon fill="lime" stroke="blue" stroke-width="10" points="850,75 958,137.5 958,262.5 850,325 742,262.6 742,137.5" /> </svg>
The following is the Extended Backus-Naur Form [EBNF] for points specifications in 'polyline' and 'polygon' elements. The following notation is used:
list-of-points: wsp* coordinate-pairs? wsp* coordinate-pairs: coordinate-pair | coordinate-pair comma-wsp coordinate-pairs coordinate-pair: coordinate comma-wsp coordinate coordinate: number number: sign? integer-constant | sign? floating-point-constant comma-wsp: (wsp+ comma? wsp*) | (comma wsp*) comma: "," integer-constant: digit-sequence floating-point-constant: fractional-constant exponent? | digit-sequence exponent fractional-constant: digit-sequence? "." digit-sequence | digit-sequence "." exponent: ( "e" | "E" ) sign? digit-sequence sign: "+" | "-" digit-sequence: digit | digit digit-sequence digit: "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" wsp: (#x20 | #x9 | #xD | #xA)+
The Shape Module contains the following elements:
[RNG] [Feature String]