[cairo] Cairo in Google Summer of Code

Adib Taraben taraben.a at st-innovation.com
Tue Mar 18 04:22:30 PDT 2008

Gerdus van Zyl schrieb:
> I personally would like to see Blur/Convolution Filters and
> Screen/Overlay blend modes, but that is more pixman than cairo, i
> think.
I second this and maybe there is a way to instead generate large bitmaps 
but generate a number of triangles with the different colours on each 
corner points in order to support vectorial outputs (PS/PDF/Glitz).
> Just my 2 cents.
> On Tue, Mar 18, 2008 at 4:27 AM, Bill Spitzak <spitzak at thefoundry.co.uk> wrote:
>> Well I can't edit the page but here are mine:
>>  [Medium] Make stroke width and font transforms be frozen at the time
>>  they are set, rather than modified by changes to the ctm
>>  (linewidth(2);scale(2) should produce 2-unit wide lines, not the 4-unit
>>  wide lines it currently does). This will make Cairo consistent with how
>>  it treats pattern and gradient transforms, with how Pango works, make
>>  Cairo's transforms usable by an Illustrator-style program, match OpenGL
>>  and make future 3D enhancements to Cairo possible. This will require
>>  replacing the pen api with a 2x2 matrix, and possibly other changes.
>>  Will also require analysis of how much, if any, of existing Cairo-using
>>  code will be broken by this change, and how and if back-compatibility
>>  should be provided.
>>  [Hard] Hinting mode (or "make 1-pixel thick lines work the way users
>>  expect"). Add a mode to draw fills and strokes "nicely" without the
>>  calling program having to know how big the pixels are. This is very
>>  similar to, and probably as hard as, font hinting. Currently Cairo tries
>>  to accurately draw a filtered scaled image but this is often not what is
>>  wanted: the inability to draw 1-pixel lines frustrates novices, and the
>>  fuzzy appearance of tiny images discourages Cairo use for icons.
>>  [Hard] Adjacent-polygon fix. Lots of users try to draw a mesh of
>>  polygons with their edges touching in order to fill the plane with a
>>  colored image. Attempting this on Cairo produces artifacts because the
>>  edges are antialiased and the image has very thin cracks between the
>>  polygons. A huge number of graphics produced popular proprietary and
>>  open-source programs are this way and it is impractical to fix them to
>>  overlapping shapes. Come up with a solution to this.
>>  [Hard] Usable+"fun" font api. The official method of drawing text in
>>  Cairo is not "fun" (which was supposed to be a design criteria for
>>  Cairo). The official method of drawing text (Pango) is much too complex
>>  for use by applications, though toolkits can call it. The majority of
>>  programmers use the "toy" api, even though it is depreciated, because it
>>  much more resembles the expected api and can be learned without study.
>>  Selecting the font for either requires back-end-specific code so the
>>  only portable api is to use the default font. Make a new Cairo font api
>>  which does the following:
>>  * Select a font using a single string name that is portable between
>>  backends and can be imbedded into a <font=name> code in Pango. Add a
>>  simple api that will list a reasonably-large subset of the available
>>  font names, so that a portable font chooser can be written, and so that
>>  multiple programs all show the same set of available fonts.
>>  * All assigned Unicode points draw a correct glyph (ie what is actually
>>  selected is a fully-populated "font set"). The "toy" api will then
>>  clearly display the contents of a string, which is very useful for
>>  editors and other contexts where the data is more important than the
>>  presentation.
>>  * Add a "fun" wrapper around Pango to encourage it's use. It should take
>>  a string to display (with embedded html-style codes) and a rectangle to
>>  put it into (unless the current path could be used, which would be
>>  neat), and it should use the cairo current font.
>>  _______________________________________________
>>  cairo mailing list
>>  cairo at cairographics.org
>>  http://lists.cairographics.org/mailman/listinfo/cairo
> _______________________________________________
> cairo mailing list
> cairo at cairographics.org
> http://lists.cairographics.org/mailman/listinfo/cairo

More information about the cairo mailing list