[Pixman] [cairo] [PATCHES] gradient color-tolerance/performance work
Adrian Johnson
ajohnson at redneon.com
Tue Apr 6 04:58:29 PDT 2010
Chris Toshok wrote:
> typedef enum _cairo_color_tolerance_level {
> CAIRO_COLOR_TOLERANCE_HIGH,
> CAIRO_COLOR_TOLERANCE_MEDIUM,
> CAIRO_COLOR_TOLERANCE_LOW,
> } cairo_color_tolerance_t;
>
> cairo_public void
> cairo_pattern_set_color_tolerance (cairo_pattern_t *pattern,
> cairo_color_tolerance_t tolerance);
>
Section 10.6.3 of the PDF specification [1] defines a smoothness
tolerance for the quality of gradients. This is a value between
0.0 and 1.0 that specifies the maximum permitted error per color
component between the true gradient color and the displayed color.
Something like
cairo_pattern_set_color_tolerance (double error)
would be more flexible and could be used directly by the PS/PDF
backends. The mesh gradients branch at [2] might also benefit from
a color tolerance API.
[1] http://www.adobe.com/devnet/acrobat/pdfs/PDF32000_2008.pdf
[2] http://cgit.freedesktop.org/~ajohnson/cairo/log/?h=mesh
More information about the Pixman
mailing list