CAIRO

From b7d97c7ed82f0d0472cf0c2ae5d61e99a73b33a8 Mon Sep 17 00:00:00 2001 From: scuri Date: Wed, 12 May 2010 20:38:46 +0000 Subject: New Cairo driver --- html/en/drv/cairo.html | 134 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 134 insertions(+) create mode 100644 html/en/drv/cairo.html (limited to 'html/en/drv/cairo.html') diff --git a/html/en/drv/cairo.html b/html/en/drv/cairo.html new file mode 100644 index 0000000..4977258 --- /dev/null +++ b/html/en/drv/cairo.html @@ -0,0 +1,134 @@ + + + + + + +CAIRO + + + + + +

CAIRO Base Driver

+ +

This driver represents a basic driver for all system-dependent drivers + implemented in the X-Windows and MS-Windows systems. The implementation uses the + Cairo API + functions and some GTK functions to support Unicode text. This driver can be + compiled and used in all systems Cairo is supported.

The main motivation for the use of Cairo was transparency for all the +primitives. Beyond that we got other features like anti-aliasing, gradient +filling, transformations and back-ends (support to rendering: PDF, PS, SVG and +PNG surfaces).

This driver still does not completely replace the X-Windows and GDI Windows +base drivers, because Cairo does not have support for bitwise XOR operations and +for complex clipping regions.

+ +

Behavior of Functions

Control

+ Play: does nothing, returns + CD_ERROR.

Coordinate System and Clipping

+ + UpdateYAxis: the + orientation of axis Y is the opposite to its orientation in the CD library.

Attributes

+ + WriteMode: does nothing. + There is no support for XOR or NOT_XOR.
+ + NativeFont: also accepts the + X-Windows font string format.
+ Font: "Courier" is mapped to + "Courier New", "Helvetica" is mapped to "Arial", and "Times" is mapped to + "Times New Roman". Underline and Strikeout are NOT supported.

Colors

+ + Palette: NOT supported.

Exclusive Attributes

+ +

"ANTIALIAS": controls + the use of anti-aliasing for the text and drawing shapes. Assumes values "1" + (active) and "0" (inactive). Default value: "1".

+ +

"CAIRODC": returns the + Cairo drawing context (get only). In Lua is returned as a user data.

+ +

"CAIROVERSION": returns a string with + the Cairo version number. It is empty if the Cairo is not available.

+ +

"HATCHBOXSIZE": + defines the size of smallest hatch box pattern. This affects the spacing + between the hatch lines. The value passed must be a string containing an + integer ("%d"). If the value of the attribute passed is NULL, the value is + rest to the default. When consulted returns the current value ("%d"). Default: + "8".

+ +

"IMGINTERP": changes how + interpolation is used in image scale. Can be "BEST" (highest-quality), + "BILINEAR" (linear interpolation), "GOOD" (quality similar to BILINEAR), + "NEAREST" (nearest-neighbor filtering) or "FAST" (quality similar to NEAREST). + Default: "GOOD".

+ +

"LINEGRADIENT": defines + a filled interior style that uses a line gradient between two colors. It uses + 2 points ("%d %d %d %d" = x1 y1 x2 y2), one for the starting point using + (using the foreground color), and another one for the end point (using the + background color).

+ +

"POLYHOLE": defines the index of + the vertex where there is a hole in a closed polygon. It will affect the next + cdEnd. Can be called several times between cdBegin + and cdEnd to define holes. The value passed must be a string + containing an integer ("%d"). If the value of the attribute passed is NULL, + all holes will no longer be considered. When consulted returns the current + number of holes ("%d"). It can have a maximum of 500 holes. Default: NULL.

+ +

"RADIALGRADIENT": defines + a filled interior style that uses a radial gradient between two colors. It + uses 2 points and 2 radius ("%d %d %g %d %d %g" = x1 y1 rad1 x2 y2 rad2), one + for the starting point using (using the foreground color), and another one for + the end point (using the background color).

+ +

"ROTATE": allows the usage of 1 + angle and 1 coordinate (x, y), that define a global rotation transformation + centered in the specified coordinate. Use 1 real and 2 integer values inside + a string ("%g %d %d" = angle x y). Can not be set if a transformation is + already set.

+ + + + -- cgit v1.2.3