gtk/gtk/gtkcsseasevalue.c
Alexander Larsson af2c40bd54 css: Add a scale argument to css-value compute vfunc
We need to be able to compute different GtkCssImage values
depending on the scale, and we need this at compute time so that
we don't need to read any images other than the scale in used (to
e.g. calculate the image size). GtkStyleProviderPrivate is shared
for all style contexts, so its not right.
2013-07-03 14:39:25 +02:00

385 lines
11 KiB
C

/* GTK - The GIMP Toolkit
* Copyright (C) 2011 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "gtkcsseasevalueprivate.h"
#include <math.h>
typedef enum {
GTK_CSS_EASE_CUBIC_BEZIER,
GTK_CSS_EASE_STEPS
} GtkCssEaseType;
struct _GtkCssValue {
GTK_CSS_VALUE_BASE
GtkCssEaseType type;
union {
struct {
double x1;
double y1;
double x2;
double y2;
} cubic;
struct {
guint steps;
gboolean start;
} steps;
} u;
};
static void
gtk_css_value_ease_free (GtkCssValue *value)
{
g_slice_free (GtkCssValue, value);
}
static GtkCssValue *
gtk_css_value_ease_compute (GtkCssValue *value,
guint property_id,
GtkStyleProviderPrivate *provider,
int scale,
GtkCssComputedValues *values,
GtkCssComputedValues *parent_values,
GtkCssDependencies *dependencies)
{
return _gtk_css_value_ref (value);
}
static gboolean
gtk_css_value_ease_equal (const GtkCssValue *ease1,
const GtkCssValue *ease2)
{
if (ease1->type != ease2->type)
return FALSE;
switch (ease1->type)
{
case GTK_CSS_EASE_CUBIC_BEZIER:
return ease1->u.cubic.x1 == ease2->u.cubic.x1 &&
ease1->u.cubic.y1 == ease2->u.cubic.y1 &&
ease1->u.cubic.x2 == ease2->u.cubic.x2 &&
ease1->u.cubic.y2 == ease2->u.cubic.y2;
case GTK_CSS_EASE_STEPS:
return ease1->u.steps.steps == ease2->u.steps.steps &&
ease1->u.steps.start == ease2->u.steps.start;
default:
g_assert_not_reached ();
return FALSE;
}
}
static GtkCssValue *
gtk_css_value_ease_transition (GtkCssValue *start,
GtkCssValue *end,
guint property_id,
double progress)
{
return NULL;
}
static void
gtk_css_value_ease_print (const GtkCssValue *ease,
GString *string)
{
switch (ease->type)
{
case GTK_CSS_EASE_CUBIC_BEZIER:
if (ease->u.cubic.x1 == 0.25 && ease->u.cubic.y1 == 0.1 &&
ease->u.cubic.x2 == 0.25 && ease->u.cubic.y2 == 1.0)
g_string_append (string, "ease");
else if (ease->u.cubic.x1 == 0.0 && ease->u.cubic.y1 == 0.0 &&
ease->u.cubic.x2 == 1.0 && ease->u.cubic.y2 == 1.0)
g_string_append (string, "linear");
else if (ease->u.cubic.x1 == 0.42 && ease->u.cubic.y1 == 0.0 &&
ease->u.cubic.x2 == 1.0 && ease->u.cubic.y2 == 1.0)
g_string_append (string, "ease-in");
else if (ease->u.cubic.x1 == 0.0 && ease->u.cubic.y1 == 0.0 &&
ease->u.cubic.x2 == 0.58 && ease->u.cubic.y2 == 1.0)
g_string_append (string, "ease-out");
else if (ease->u.cubic.x1 == 0.42 && ease->u.cubic.y1 == 0.0 &&
ease->u.cubic.x2 == 0.58 && ease->u.cubic.y2 == 1.0)
g_string_append (string, "ease-in-out");
else
g_string_append_printf (string, "cubic-bezier(%g,%g,%g,%g)",
ease->u.cubic.x1, ease->u.cubic.y1,
ease->u.cubic.x2, ease->u.cubic.y2);
break;
case GTK_CSS_EASE_STEPS:
if (ease->u.steps.steps == 1)
{
g_string_append (string, ease->u.steps.start ? "step-start" : "step-end");
}
else
{
g_string_append_printf (string, "steps(%u%s)", ease->u.steps.steps, ease->u.steps.start ? ",start" : "");
}
break;
default:
g_assert_not_reached ();
break;
}
}
static const GtkCssValueClass GTK_CSS_VALUE_EASE = {
gtk_css_value_ease_free,
gtk_css_value_ease_compute,
gtk_css_value_ease_equal,
gtk_css_value_ease_transition,
gtk_css_value_ease_print
};
GtkCssValue *
_gtk_css_ease_value_new_cubic_bezier (double x1,
double y1,
double x2,
double y2)
{
GtkCssValue *value;
g_return_val_if_fail (x1 >= 0.0, NULL);
g_return_val_if_fail (x1 <= 1.0, NULL);
g_return_val_if_fail (x2 >= 0.0, NULL);
g_return_val_if_fail (x2 <= 1.0, NULL);
value = _gtk_css_value_new (GtkCssValue, &GTK_CSS_VALUE_EASE);
value->type = GTK_CSS_EASE_CUBIC_BEZIER;
value->u.cubic.x1 = x1;
value->u.cubic.y1 = y1;
value->u.cubic.x2 = x2;
value->u.cubic.y2 = y2;
return value;
}
static GtkCssValue *
_gtk_css_ease_value_new_steps (guint n_steps,
gboolean start)
{
GtkCssValue *value;
g_return_val_if_fail (n_steps > 0, NULL);
value = _gtk_css_value_new (GtkCssValue, &GTK_CSS_VALUE_EASE);
value->type = GTK_CSS_EASE_STEPS;
value->u.steps.steps = n_steps;
value->u.steps.start = start;
return value;
}
static const struct {
const char *name;
guint is_bezier :1;
guint needs_custom :1;
double values[4];
} parser_values[] = {
{ "linear", TRUE, FALSE, { 0.0, 0.0, 1.0, 1.0 } },
{ "ease-in-out", TRUE, FALSE, { 0.42, 0.0, 0.58, 1.0 } },
{ "ease-in", TRUE, FALSE, { 0.42, 0.0, 1.0, 1.0 } },
{ "ease-out", TRUE, FALSE, { 0.0, 0.0, 0.58, 1.0 } },
{ "ease", TRUE, FALSE, { 0.25, 0.1, 0.25, 1.0 } },
{ "step-start", FALSE, FALSE, { 1.0, 1.0, 0.0, 0.0 } },
{ "step-end", FALSE, FALSE, { 1.0, 0.0, 0.0, 0.0 } },
{ "steps", FALSE, TRUE, { 0.0, 0.0, 0.0, 0.0 } },
{ "cubic-bezier", TRUE, TRUE, { 0.0, 0.0, 0.0, 0.0 } }
};
gboolean
_gtk_css_ease_value_can_parse (GtkCssParser *parser)
{
guint i;
for (i = 0; i < G_N_ELEMENTS (parser_values); i++)
{
if (_gtk_css_parser_has_prefix (parser, parser_values[i].name))
return TRUE;
}
return FALSE;
}
static GtkCssValue *
gtk_css_ease_value_parse_cubic_bezier (GtkCssParser *parser)
{
double values[4];
guint i;
for (i = 0; i < 4; i++)
{
if (!_gtk_css_parser_try (parser, i ? "," : "(", TRUE))
{
_gtk_css_parser_error (parser, "Expected '%s'", i ? "," : "(");
return NULL;
}
if (!_gtk_css_parser_try_double (parser, &values[i]))
{
_gtk_css_parser_error (parser, "Expected a number");
return NULL;
}
if ((i == 0 || i == 2) &&
(values[i] < 0 || values[i] > 1.0))
{
_gtk_css_parser_error (parser, "value %g out of range. Must be from 0.0 to 1.0", values[i]);
return NULL;
}
}
if (!_gtk_css_parser_try (parser, ")", TRUE))
{
_gtk_css_parser_error (parser, "Missing closing ')' for cubic-bezier");
return NULL;
}
return _gtk_css_ease_value_new_cubic_bezier (values[0], values[1], values[2], values[3]);
}
static GtkCssValue *
gtk_css_ease_value_parse_steps (GtkCssParser *parser)
{
guint n_steps;
gboolean start;
if (!_gtk_css_parser_try (parser, "(", TRUE))
{
_gtk_css_parser_error (parser, "Expected '('");
return NULL;
}
if (!_gtk_css_parser_try_uint (parser, &n_steps))
{
_gtk_css_parser_error (parser, "Expected number of steps");
return NULL;
}
if (_gtk_css_parser_try (parser, ",", TRUE))
{
if (_gtk_css_parser_try (parser, "start", TRUE))
start = TRUE;
else if (_gtk_css_parser_try (parser, "end", TRUE))
start = FALSE;
else
{
_gtk_css_parser_error (parser, "Only allowed values are 'start' and 'end'");
return NULL;
}
}
else
start = FALSE;
if (!_gtk_css_parser_try (parser, ")", TRUE))
{
_gtk_css_parser_error (parser, "Missing closing ')' for steps");
return NULL;
}
return _gtk_css_ease_value_new_steps (n_steps, start);
}
GtkCssValue *
_gtk_css_ease_value_parse (GtkCssParser *parser)
{
guint i;
g_return_val_if_fail (parser != NULL, NULL);
for (i = 0; i < G_N_ELEMENTS (parser_values); i++)
{
if (_gtk_css_parser_try (parser, parser_values[i].name, FALSE))
{
if (parser_values[i].needs_custom)
{
if (parser_values[i].is_bezier)
return gtk_css_ease_value_parse_cubic_bezier (parser);
else
return gtk_css_ease_value_parse_steps (parser);
}
_gtk_css_parser_skip_whitespace (parser);
if (parser_values[i].is_bezier)
return _gtk_css_ease_value_new_cubic_bezier (parser_values[i].values[0],
parser_values[i].values[1],
parser_values[i].values[2],
parser_values[i].values[3]);
else
return _gtk_css_ease_value_new_steps (parser_values[i].values[0],
parser_values[i].values[1] != 0.0);
}
}
_gtk_css_parser_error (parser, "Unknown value");
return NULL;
}
double
_gtk_css_ease_value_transform (const GtkCssValue *ease,
double progress)
{
g_return_val_if_fail (ease->class == &GTK_CSS_VALUE_EASE, 1.0);
if (progress <= 0)
return 0;
if (progress >= 1)
return 1;
switch (ease->type)
{
case GTK_CSS_EASE_CUBIC_BEZIER:
{
static const double epsilon = 0.00001;
double tmin, t, tmax;
tmin = 0.0;
tmax = 1.0;
t = progress;
while (tmin < tmax)
{
double sample;
sample = (((1.0 + 3 * ease->u.cubic.x1 - 3 * ease->u.cubic.x2) * t
+ -6 * ease->u.cubic.x1 + 3 * ease->u.cubic.x2) * t
+ 3 * ease->u.cubic.x1 ) * t;
if (fabs(sample - progress) < epsilon)
break;
if (progress > sample)
tmin = t;
else
tmax = t;
t = (tmax + tmin) * .5;
}
return (((1.0 + 3 * ease->u.cubic.y1 - 3 * ease->u.cubic.y2) * t
+ -6 * ease->u.cubic.y1 + 3 * ease->u.cubic.y2) * t
+ 3 * ease->u.cubic.y1 ) * t;
}
case GTK_CSS_EASE_STEPS:
progress *= ease->u.steps.steps;
progress = floor (progress) + (ease->u.steps.start ? 0 : 1);
return progress / ease->u.steps.steps;
default:
g_assert_not_reached ();
return 1.0;
}
}