Coordinates systems : Viewpoint attributes ( continued )

• The scaling of the viewpoint change can be controlled by the attribute :

preserveAspectRatio = align [ meet or slice ]
• The authorized values of align are :
• nothing ( default )  ; the scaling is done such as the extreme values of x ( resp y ) are the boundaries of the viewpoint rectangle
• xMinYmin ; Uniform scaling ; min of x = x min of the viewpoint

                                            min of  y = y min of the viewpoint
• XMidYMin ; Uniform scaling ; mean of  x = x mean of the viewpoint

                                              min of  y = y min of the viewpoint
• XMaxYMin ; idem
• XMinYMid ; idem
• and all possible choices Min,Mid,Max for X and Y
• The meet or slice parameter is optional ; it has the following meaning :
• meet ( default ) scales the graphic such as :
• the aspect ratio is preserved
• the whole viewpoint rectangle is visible
• the viewpoint box is as large as possible
• slice scales the graphic such as :
• scales the graphic such as :
• the viewpoint box fits the whole space
• the viewpoint box is as small as possible
• Example

Didier Courtaud The SVG language Novembre 2001

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