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Diffstat (limited to 'docs')
| -rw-r--r-- | docs/library/framebuf.rst | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/docs/library/framebuf.rst b/docs/library/framebuf.rst index 0073ba708..13502cc7a 100644 --- a/docs/library/framebuf.rst +++ b/docs/library/framebuf.rst @@ -103,16 +103,23 @@ Other methods Shift the contents of the FrameBuffer by the given vector. This may leave a footprint of the previous colors in the FrameBuffer. -.. method:: FrameBuffer.blit(fbuf, x, y[, key]) +.. method:: FrameBuffer.blit(fbuf, x, y, key=-1, palette=None) Draw another FrameBuffer on top of the current one at the given coordinates. If *key* is specified then it should be a color integer and the corresponding color will be considered transparent: all pixels with that color value will not be drawn. - This method works between FrameBuffer instances utilising different formats, - but the resulting colors may be unexpected due to the mismatch in color - formats. + The *palette* argument enables blitting between FrameBuffers with differing + formats. Typical usage is to render a monochrome or grayscale glyph/icon to + a color display. The *palette* is a FrameBuffer instance whose format is + that of the current FrameBuffer. The *palette* height is one pixel and its + pixel width is the number of colors in the source FrameBuffer. The *palette* + for an N-bit source needs 2**N pixels; the *palette* for a monochrome source + would have 2 pixels representing background and foreground colors. The + application assigns a color to each pixel in the *palette*. The color of the + current pixel will be that of that *palette* pixel whose x position is the + color of the corresponding source pixel. Constants --------- |