线性渐变/LinearGradient

LinearGradient

Gradients consist of continuously smooth color transitions along a vector from one color to another, possibly followed by additional transitions along the same vector to other colors. SVG provides for two types of gradients: linear gradients and radial gradients.

参见

• http://www.w3.org/TR/SVG11/pservers.html#Gradients

• http://www.w3.org/TR/SVG11/pservers.html#LinearGradients

class svgwrite.gradients.LinearGradient(start=None, end=None, inherit=None, **extra)

Linear gradients are defined by a SVG <linearGradient> element.

方法

Methods

LinearGradient.__init__(start=None, end=None, inherit=None, **extra)

参数:

• start (2-tuple) – start point of the gradient (x1, y1)

• end (2-tuple) – end point of the gradient (x2, y2)

• inherit – gradient inherits properties from inherit see: xlink:href

LinearGradient.add_stop_color(offset=None, color=None, opacity=None)

Adds a stop-color to the gradient.

参数:

• offset – is either a <number> (usually ranging from 0 to 1) or a <percentage> (usually ranging from 0% to 100%) which indicates where the gradient stop is placed. Represents a location along the gradient vector. For radial gradients, it represents a percentage distance from (fx,fy) to the edge of the outermost/largest circle.

• color – indicates what color to use at that gradient stop

• opacity – defines the opacity of a given gradient stop

LinearGradient.get_paint_server(default='none')

Returns the <FuncIRI> of the gradient.

SVG 属性

SVG Attributes

中文

• class – string

  为元素分配一个或多个 CSS 类名。

• style – string

  允许直接在给定元素上指定每个元素的 CSS 样式规则。

• externalResourcesRequired – bool

  False：如果即使外部资源不可用，文档渲染仍然可以继续；否则为 True。

• gradientUnits – 'userSpaceOnUse | objectBoundingBox'

  定义 x1、y1、x2 和 y2 属性的坐标系统。

• gradientTransform – <transform-list>

  使用 -svgwrite.mixins.Transform 接口设置转换。

  包含一个可选的附加变换的定义，用于将渐变坐标系统转换为目标坐标系统（即，userSpaceOnUse 或 objectBoundingBox）。这允许对渐变进行如倾斜等变换。此附加变换矩阵是后乘的（即，插入到任何先前定义的变换之后），包括将对象边界框单位转换为用户空间所需的隐式变换。

• x1 – <coordinate> – start 参数

  x1、y1、x2 和 y2 定义了线性渐变的渐变向量。该渐变向量提供渐变停止点的起始和结束位置。x1、y1、x2 和 y2 的值可以是数字或百分比。

  默认值为 '0%'。

• y1 – <coordinate> – start 参数

  参见 x1。默认值为 '0%'。

• x2 – <coordinate> – end 参数

  参见 x1。默认值为 '100%'。

• y2 – <coordinate> – end 参数

  参见 x1。默认值为 '0%'。

• spreadMethod – 'pad | reflect | repeat'

  指示当渐变在目标矩形的边界内开始或结束时会发生什么。可能的值为： 'pad' ，表示使用渐变的终端颜色填充目标区域的其余部分； 'reflect' ，表示反射渐变图案，从起始到结束，再从结束到起始，反复填充目标矩形； 'repeat' ，表示重复渐变图案，从起始到结束，再从起始到结束，反复填充目标区域。

  默认值为 'pad'。

• xlink:href – <iri> – inherit 参数

  指向当前 SVG 文档片段内的另一个 LinearGradient 或 RadialGradient 元素的 URI 引用。任何在引用元素上定义的 LinearGradient 属性（这些属性在此元素上未定义）将由此元素继承。如果此元素没有定义渐变停止点，并且引用的元素有渐变停止点（可能是由于其自己的 xlink:href 属性），则此元素将继承引用元素的渐变停止点。继承可以间接进行，且可以达到任意级别；因此，如果引用的元素由于其自身的 xlink:href 属性继承了属性或渐变停止点，则当前元素也可以继承这些属性或渐变停止点。

英文

• class – string

  assigns one or more css-class-names to an element

• style – string

  allows per-element css-style rules to be specified directly on a given element

• externalResourcesRequired – bool

  False: if document rendering can proceed even if external resources are unavailable else: True

• gradientUnits – 'userSpaceOnUse | objectBoundingBox'

  Defines the coordinate system for attributes x1, y1, x2 and y2.

  参见

  http://www.w3.org/TR/SVG11/pservers.html#LinearGradientElementGradientUnitsAttribute

• gradientTransform – <transform-list>

  Use the -svgwrite.mixins.Transform interface to set transformations.

  Contains the definition of an optional additional transformation from the gradient coordinate system onto the target coordinate system (i.e., userSpaceOnUse or objectBoundingBox). This allows for things such as skewing the gradient. This additional transformation matrix is post-multiplied to (i.e., inserted to the right of) any previously defined transformations, including the implicit transformation necessary to convert from object bounding box units to user space.

• x1 – <coordinate> – start parameter

  x1, y1, x2 and y2 define a gradient vector for the linear gradient. This gradient vector provides starting and ending points onto which the gradient stops are mapped. The values of x1, y1, x2 and y2 can be either numbers or percentages.

  default is '0%'

• y1 – <coordinate> – start parameter

  See x1. Default is '0%'

• x2 – <coordinate> – end parameter

  See x1. Default is '100%'

• y2 – <coordinate> – end parameter

  See x1. Default is '0%'

• spreadMethod – 'pad | reflect | repeat'

  Indicates what happens if the gradient starts or ends inside the bounds of the target rectangle. Possible values are: 'pad', which says to use the terminal colors of the gradient to fill the remainder of the target region, 'reflect', which says to reflect the gradient pattern start-to-end, end-to-start, start-to-end, etc. continuously until the target rectangle is filled, and 'repeat', which says to repeat the gradient pattern start-to-end, start-to-end, start-to-end, etc. continuously until the target region is filled.

  default is 'pad'

• xlink:href – <iri> – inherit parameter

  A URI reference to a different LinearGradient or RadialGradient element within the current SVG document fragment. Any LinearGradient attributes which are defined on the referenced element which are not defined on this element are inherited by this element. If this element has no defined gradient stops, and the referenced element does (possibly due to its own xlink:href attribute), then this element inherits the gradient stop from the referenced element. Inheritance can be indirect to an arbitrary level; thus, if the referenced element inherits attribute or gradient stops due to its own xlink:href attribute, then the current element can inherit those attributes or gradient stops.

径向渐变/RadialGradient

RadialGradient

参见

http://www.w3.org/TR/SVG11/pservers.html#RadialGradients

class svgwrite.gradients.RadialGradient(center=None, r=None, focal=None, inherit=None, **extra)

Radial gradients are defined by a SVG <radialGradient> element.

方法

Methods

RadialGradient.__init__(center=None, r=None, focal=None, inherit=None, **extra)

参数:

• center (2-tuple) – center point for the gradient (cx, cy)

• r – radius for the gradient

• focal (2-tuple) – focal point for the radial gradient (fx, fy)

• inherit – gradient inherits properties from inherit see: xlink:href

RadialGradient.add_stop_color(offset=None, color=None, opacity=None)

Adds a stop-color to the gradient.

参数:

• offset – is either a <number> (usually ranging from 0 to 1) or a <percentage> (usually ranging from 0% to 100%) which indicates where the gradient stop is placed. Represents a location along the gradient vector. For radial gradients, it represents a percentage distance from (fx,fy) to the edge of the outermost/largest circle.

• color – indicates what color to use at that gradient stop

• opacity – defines the opacity of a given gradient stop

RadialGradient.get_paint_server(default='none')

Returns the <FuncIRI> of the gradient.

SVG 属性

SVG Attributes

中文

• class – string

  为元素分配一个或多个 CSS 类名。

• style – string

  允许直接在给定元素上指定每个元素的 CSS 样式规则。

• externalResourcesRequired – bool

  False：如果即使外部资源不可用，文档渲染仍然可以继续；否则为 True。

• gradientUnits – 'userSpaceOnUse | objectBoundingBox'

  定义 cx、cy、r、fx 和 fy 属性的坐标系统。

• cx – <coordinate> – center 参数

  cx、cy 和 r 定义了径向渐变的最大（即，最外层）圆。渐变将绘制，使得 100% 渐变停止点被映射到这个最大（即最外层）圆的周长。

  默认值为 '50%'。

• cy – <coordinate> – center 参数

  参见 cx。默认值为 '50%'。

• r – <length> – r 参数

  参见 cx。

  如果值为零，将会使用最后一个渐变停止点的颜色和不透明度将区域绘制为单一颜色。

  默认值为 '50%'。

• fx – <coordinate> – focal 参数

  fx 和 fy 定义了径向渐变的焦点。渐变将绘制，使得 0% 渐变停止点被映射到 (fx, fy)。如果没有指定 fx 属性，则 fx 将与元素的 cx 的呈现值重合，无论 cx 的值是否继承。如果该元素引用了一个指定 fx 值的元素，那么 fx 的值将从引用的元素继承。

• fy – <coordinate> – focal 参数

  参见 fx。如果没有指定 fy 属性，则 fy 将与元素的 cy 的呈现值重合，无论 cy 的值是否继承。如果该元素引用了一个指定 fy 值的元素，那么 fy 的值将从引用的元素继承。

• gradientTransform – <transform-list>

  使用 -svgwrite.mixins.Transform 接口设置变换。

  参见 LinearGradient

• spreadMethod – 'pad | reflect | repeat'

  参见 LinearGradient

• xlink:href – <iri> – inherit 参数

  参见 LinearGradient

英文

• class – string

  assigns one or more css-class-names to an element

• style – string

  allows per-element css-style rules to be specified directly on a given element

• externalResourcesRequired – bool

  False: if document rendering can proceed even if external resources are unavailable else: True

• gradientUnits – 'userSpaceOnUse | objectBoundingBox'

  Defines the coordinate system for attributes cx, cy, r, fx and fy.

  参见

  http://www.w3.org/TR/SVG11/pservers.html#RadialGradientElementGradientUnitsAttribute

• cx – <coordinate> – center parameter

  cx, cy and r define the largest (i.e., outermost) circle for the radial gradient. The gradient will be drawn such that the 100% gradient stop is mapped to the perimeter of this largest (i.e., outermost) circle.

  default is '50%'

• cy – <coordinate> – center parameter

  See cx. Default is '50%'.

• r – <length> – r parameter

  See cx.

  A value of zero will cause the area to be painted as a single color using the color and opacity of the last gradient stop.

  Default is '50%'.

• fx – <coordinate> – focal parameter

  fx and fy define the focal point for the radial gradient. The gradient will be drawn such that the 0% gradient stop is mapped to (fx, fy). If attribute fx is not specified, fx will coincide with the presentational value of cx for the element whether the value for cx was inherited or not. If the element references an element that specifies a value for fx, then the value of ‘fx’ is inherited from the referenced element.

• fy – <coordinate> – focal parameter

  See fx. If attribute fy is not specified, fy will coincide with the presentational vlaue of cy for the element whether the value for cy was inherited or not. If the element references an element that specifies a value for fy, then the value of fy is inherited from the referenced element.

• gradientTransform – <transform-list>

  Use the -svgwrite.mixins.Transform interface to set transformations.

  See LinearGradient

• spreadMethod – 'pad | reflect | repeat'

  See LinearGradient

• xlink:href – <iri> – inherit parameter

  See LinearGradient