fdo-mirrors/cairo
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/cairo/cairo.git synced 2025-12-23 12:00:09 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions

Rip out all the code for doing anything other than linear interpolation between color stops, instead of doing different funky things based on pattern->filter. (#4184)

Browse source
This commit is contained in:
Owen Taylor 2005-08-23 14:53:08 +00:00
parent 48b3a1cacd
commit 00af78735e
2 changed files with 10 additions and 63 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
ChangeLog
View file

@ -1,3 +1,10 @@
2005-08-23 Owen Taylor <otaylor@redhat.com>
* src/cairo-pattern.c (_cairo_pattern_calc_color_at_pixel):
Rip out all the code for doing anything other than linear
interpolation between color stops, instead of doing different
funky things based on pattern->filter. (#4184)
2005-08-23 Carl Worth <cworth@cworth.org>
* src/cairo-font.c: (cairo_font_face_reference),

62
src/cairo-pattern.c
View file

@ -27,11 +27,6 @@
#include "cairoint.h"
typedef void (*cairo_shader_function_t) (unsigned char *color0,
unsigned char *color1,
cairo_fixed_t factor,
uint32_t *pixel);
typedef struct _cairo_shader_color_stop {
cairo_fixed_t offset;
cairo_fixed_48_16_t scale;
@ -43,7 +38,6 @@ typedef struct _cairo_shader_op {
cairo_shader_color_stop_t *stops;
int n_stops;
cairo_extend_t extend;
cairo_shader_function_t shader_function;
} cairo_shader_op_t;
#define MULTIPLY_COLORCOMP(c1, c2) \
@ -803,24 +797,6 @@ _cairo_pattern_transform (cairo_pattern_t *pattern,
cairo_matrix_multiply (&pattern->matrix, ctm_inverse, &pattern->matrix);
}
#define INTERPOLATE_COLOR_NEAREST(c1, c2, factor) \
((factor < 32768)? c1: c2)
static void
_cairo_pattern_shader_nearest (unsigned char *color0,
unsigned char *color1,
cairo_fixed_t factor,
uint32_t *pixel)
{
*pixel =
((INTERPOLATE_COLOR_NEAREST (color0[3], color1[3], factor) << 24) |
(INTERPOLATE_COLOR_NEAREST (color0[0], color1[0], factor) << 16) |
(INTERPOLATE_COLOR_NEAREST (color0[1], color1[1], factor) << 8) |
(INTERPOLATE_COLOR_NEAREST (color0[2], color1[2], factor) << 0));
}
#undef INTERPOLATE_COLOR_NEAREST
#define INTERPOLATE_COLOR_LINEAR(c1, c2, factor) \
(((c2 * factor) + (c1 * (65536 - factor))) / 65536)
@ -836,24 +812,6 @@ _cairo_pattern_shader_linear (unsigned char *color0,
(INTERPOLATE_COLOR_LINEAR (color0[2], color1[2], factor) << 0));
}
#define E_MINUS_ONE 1.7182818284590452354
static void
_cairo_pattern_shader_gaussian (unsigned char *color0,
unsigned char *color1,
cairo_fixed_t factor,
uint32_t *pixel)
{
double f = _cairo_fixed_to_double (factor);
factor = _cairo_fixed_from_double ((exp (f * f) - 1.0) / E_MINUS_ONE);
*pixel = ((INTERPOLATE_COLOR_LINEAR (color0[3], color1[3], factor) << 24) |
(INTERPOLATE_COLOR_LINEAR (color0[0], color1[0], factor) << 16) |
(INTERPOLATE_COLOR_LINEAR (color0[1], color1[1], factor) << 8) |
(INTERPOLATE_COLOR_LINEAR (color0[2], color1[2], factor) << 0));
}
#undef INTERPOLATE_COLOR_LINEAR
static int
@ -911,24 +869,6 @@ _cairo_pattern_shader_init (cairo_gradient_pattern_t *pattern,
op->n_stops = pattern->n_stops;
op->extend = pattern->base.extend;
/* XXX: this is wrong, the filter should not be used for selecting
color stop interpolation function. function should always be 'linear'
and filter should be used for computing pixels. */
switch (pattern->base.filter) {
case CAIRO_FILTER_FAST:
case CAIRO_FILTER_NEAREST:
op->shader_function = _cairo_pattern_shader_nearest;
break;
case CAIRO_FILTER_GAUSSIAN:
op->shader_function = _cairo_pattern_shader_gaussian;
break;
case CAIRO_FILTER_GOOD:
case CAIRO_FILTER_BEST:
case CAIRO_FILTER_BILINEAR:
op->shader_function = _cairo_pattern_shader_linear;
break;
}
return CAIRO_STATUS_SUCCESS;
}
@ -1004,7 +944,7 @@ _cairo_pattern_calc_color_at_pixel (cairo_shader_op_t *op,
factor = ((cairo_fixed_48_16_t) factor << 16) /
stops[1]->scale;
op->shader_function (stops[0]->color_char,
_cairo_pattern_shader_linear (stops[0]->color_char,
stops[1]->color_char,
factor, pixel);