pattern: Add a function to interpolate gradient objects.

This will be a common function used by the quartz, ps, and pdf
backends when rewriting EXTEND_REFLECT/REPEAT gradients in terms
of EXTEND_PAD gradients.

Reviewed-by: M Joonas Pihlaja <jpihlaja@cc.helsinki.fi>

1 files changed, 5 insertions, 0 deletions

diff --git a/src/cairo-types-private.h b/src/cairo-types-private.h
index 85f5d51a9..1282b3ff0 100644
--- a/src/cairo-types-private.h
+++ b/src/cairo-types-private.h
@@ -252,6 +252,11 @@ typedef struct _cairo_point_double {
     double y;
 } cairo_point_double_t;
 
+typedef struct _cairo_circle_double {
+    cairo_point_double_t center;
+    double               radius;
+} cairo_circle_double_t;
+
 typedef struct _cairo_distance_double {
     double dx;
     double dy;