-
-
Notifications
You must be signed in to change notification settings - Fork 7.9k
10000
MEP28
mdehoon edited this page Jul 11, 2015
·
7 revisions
.. contents:: Table of Contents
.. author:: Michiel de Hoon
.. date:: July 11, 2015
Discussion
None so far.
To set the transparency (alpha component) of a graphics context, either gc.set_alpha(alpha) or gc.set_foreground(rgba, isRGBA=True) can be used. Currently, gc.set_alpha(alpha) forces the alpha value, meaning that gc.set_foreground(rgba, isRGBA=True) will ignore the alpha value of rgba if alpha was previously set through gc.set_alpha. Forcing alpha adds complexity to GraphicsContextBase as well as to the Cairo and MacOSX backends, in which this behavior is partially implemented.
- Current situation
- Actual usage of forced alpha in matplotlib
- Comparison to other APIs (Cairo, Cocoa, Postscript, Windows?)
- Alternatives to forced alpha.
- Review the current usage of
gc.set_alphaand make the required changes, if any; - Remove the
_forced_alphasections from GraphicsContextBase, RendererCairo, GraphicsContextCairo, RendererMac, GraphicsContextMac, and _macosx.GraphicsContext.
The proposal changes the graphics context, which is part of the internal API of matplotlib and is not expected to affect end users.