1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/cairo/quartz-first-stop.patch Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,57 @@
1.4 +diff --git a/gfx/cairo/cairo/src/cairo-quartz-surface.c b/gfx/cairo/cairo/src/cairo-quartz-surface.c
1.5 +--- a/gfx/cairo/cairo/src/cairo-quartz-surface.c
1.6 ++++ b/gfx/cairo/cairo/src/cairo-quartz-surface.c
1.7 +@@ -690,31 +690,51 @@ ComputeGradientValue (void *info, const
1.8 + }
1.9 +
1.10 + static const float gradient_output_value_ranges[8] = {
1.11 + 0.f, 1.f, 0.f, 1.f, 0.f, 1.f, 0.f, 1.f
1.12 + };
1.13 + static const CGFunctionCallbacks gradient_callbacks = {
1.14 + 0, ComputeGradientValue, (CGFunctionReleaseInfoCallback) cairo_pattern_destroy
1.15 + };
1.16 ++/* Quartz will clamp input values to the input range.
1.17 ++
1.18 ++ Our stops are all in the range 0.0 to 1.0. However, the color before the
1.19 ++ beginning of the gradient line is obtained by Quartz computing a negative
1.20 ++ position on the gradient line, clamping it to the input range we specified
1.21 ++ for our color function, and then calling our color function (actually it
1.22 ++ pre-samples the color function into an array, but that doesn't matter just
1.23 ++ here). Therefore if we set the lower bound to 0.0, a negative position
1.24 ++ on the gradient line will pass 0.0 to ComputeGradientValue, which will
1.25 ++ select the last color stop with position 0, although it should select
1.26 ++ the first color stop (this matters when there are multiple color stops with
1.27 ++ position 0).
1.28 ++
1.29 ++ Therefore we pass a small negative number as the lower bound of the input
1.30 ++ range, so this value gets passed into ComputeGradientValue, which will
1.31 ++ return the color of the first stop. The number should be small because
1.32 ++ as far as I can tell, Quartz pre-samples the entire input range of the color
1.33 ++ function into an array of fixed size, so if the input range is larger
1.34 ++ than needed, the resolution of the gradient will be unnecessarily low.
1.35 ++*/
1.36 ++static const float nonrepeating_gradient_input_value_range[2] = { -0.001f, 1.f };
1.37 +
1.38 + static CGFunctionRef
1.39 + CreateGradientFunction (const cairo_gradient_pattern_t *gpat)
1.40 + {
1.41 + cairo_pattern_t *pat;
1.42 +- float input_value_range[2] = { 0.f, 1.f };
1.43 +
1.44 + if (_cairo_pattern_create_copy (&pat, &gpat->base))
1.45 + /* quartz doesn't deal very well with malloc failing, so there's
1.46 + * not much point in us trying either */
1.47 + return NULL;
1.48 +
1.49 + return CGFunctionCreate (pat,
1.50 + 1,
1.51 +- input_value_range,
1.52 ++ nonrepeating_gradient_input_value_range,
1.53 + 4,
1.54 + gradient_output_value_ranges,
1.55 + &gradient_callbacks);
1.56 + }
1.57 +
1.58 + static void
1.59 + UpdateLinearParametersToIncludePoint(double *min_t, double *max_t, CGPoint *start,
1.60 + double dx, double dy,
