fdo-mirrors/cairo
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/cairo/cairo.git synced 2026-06-08 13:58:21 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions

quartz: Make huge domain handling more stable

Browse source 
Quartz cannot correctly handle arbitrary domains. Falling back is
needed to get correct results on very large (in parameter space)
gradients.

For PAD extended gradients, limiting the domain to (at most) [-0.5,
1.5] is sufficient to guarantee that it will correctly sample the
extreme stops and improves the accuracy (over having a much bigger
domain).

Fixes radial-gradient, radial-gradient-mask, radial-gradient-source,
radial-gradient-mask-source, radial-gradient-one-stop.

Improves the quality of the linear gradients in linear-gradient,
linear-gradient-subset, mask, operator-source, trap-clip.
This commit is contained in:
Andrea Canciani 2011-01-05 12:15:06 +01:00
parent 4874dab984
commit 7d89d69c49
1 changed files with 16 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

20
src/cairo-quartz-surface.c
View file

@ -831,6 +831,11 @@ static const CGFunctionCallbacks gradient_callbacks = {
0, ComputeGradientValue, (CGFunctionReleaseInfoCallback) cairo_pattern_destroy
};
/* Quartz computes a small number of samples of the gradient color
* function. On MacOS X 10.5 it apparently computes only 1024
* samples. */
#define MAX_GRADIENT_RANGE 1024
static CGFunctionRef
_cairo_quartz_create_gradient_function (const cairo_gradient_pattern_t *gradient,
const cairo_rectangle_int_t *extents,
@ -862,6 +867,12 @@ _cairo_quartz_create_gradient_function (const cairo_gradient_pattern_t *gradient
tolerance,
t);
if (gradient->base.extend == CAIRO_EXTEND_PAD) {
t[0] = MAX (t[0], -0.5);
t[1] = MIN (t[1], 1.5);
} else if (t[1] - t[0] > MAX_GRADIENT_RANGE)
return NULL;
/* set the input range for the function -- the function knows how
to map values outside of 0.0 .. 1.0 to the correct color */
input_value_range[0] = t[0];
@ -875,8 +886,6 @@ _cairo_quartz_create_gradient_function (const cairo_gradient_pattern_t *gradient
_cairo_gradient_pattern_interpolate (gradient, input_value_range[1], end);
if (_cairo_pattern_create_copy (&pat, &gradient->base))
/* quartz doesn't deal very well with malloc failing, so there's
* not much point in us trying either */
return NULL;
return CGFunctionCreate (pat,
@ -1156,13 +1165,16 @@ _cairo_quartz_setup_gradient_source (cairo_quartz_drawing_state_t *state,
cairo_matrix_invert (&mat);
_cairo_quartz_cairo_matrix_to_quartz (&mat, &state->transform);
rgb = CGColorSpaceCreateDeviceRGB ();
gradFunc = _cairo_quartz_create_gradient_function (gradient,
extents,
&start,
&end);
if (unlikely (gradFunc == NULL))
return CAIRO_INT_STATUS_UNSUPPORTED;
rgb = CGColorSpaceCreateDeviceRGB ();
if (gradient->base.type == CAIRO_PATTERN_TYPE_LINEAR) {
state->shading = CGShadingCreateAxial (rgb,
CGPointMake (start.center.x,