gnome-shell/src/st/st-private.c

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/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
#include <math.h>
#include <string.h>
#include "st-private.h"
/**
* _st_actor_get_preferred_width:
* @actor: a #ClutterActor
* @for_height: as with clutter_actor_get_preferred_width()
* @y_fill: %TRUE if @actor will fill its allocation vertically
* @min_width_p: as with clutter_actor_get_preferred_width()
* @natural_width_p: as with clutter_actor_get_preferred_width()
*
* Like clutter_actor_get_preferred_width(), but if @y_fill is %FALSE,
* then it will compute a width request based on the assumption that
* @actor will be given an allocation no taller than its natural
* height.
*/
void
_st_actor_get_preferred_width (ClutterActor *actor,
gfloat for_height,
gboolean y_fill,
gfloat *min_width_p,
gfloat *natural_width_p)
{
if (!y_fill && for_height != -1)
{
ClutterRequestMode mode;
gfloat natural_height;
g_object_get (G_OBJECT (actor), "request-mode", &mode, NULL);
if (mode == CLUTTER_REQUEST_WIDTH_FOR_HEIGHT)
{
clutter_actor_get_preferred_height (actor, -1, NULL, &natural_height);
if (for_height > natural_height)
for_height = natural_height;
}
}
clutter_actor_get_preferred_width (actor, for_height, min_width_p, natural_width_p);
}
/**
* _st_actor_get_preferred_height:
* @actor: a #ClutterActor
* @for_width: as with clutter_actor_get_preferred_height()
* @x_fill: %TRUE if @actor will fill its allocation horizontally
* @min_height_p: as with clutter_actor_get_preferred_height()
* @natural_height_p: as with clutter_actor_get_preferred_height()
*
* Like clutter_actor_get_preferred_height(), but if @x_fill is
* %FALSE, then it will compute a height request based on the
* assumption that @actor will be given an allocation no wider than
* its natural width.
*/
void
_st_actor_get_preferred_height (ClutterActor *actor,
gfloat for_width,
gboolean x_fill,
gfloat *min_height_p,
gfloat *natural_height_p)
{
if (!x_fill && for_width != -1)
{
ClutterRequestMode mode;
gfloat natural_width;
g_object_get (G_OBJECT (actor), "request-mode", &mode, NULL);
if (mode == CLUTTER_REQUEST_HEIGHT_FOR_WIDTH)
{
clutter_actor_get_preferred_width (actor, -1, NULL, &natural_width);
if (for_width > natural_width)
for_width = natural_width;
}
}
clutter_actor_get_preferred_height (actor, for_width, min_height_p, natural_height_p);
}
/**
* _st_allocate_fill:
* @parent: the parent #StWidget
* @child: the child (not necessarily an #StWidget)
* @childbox: total space that could be allocated to @child
* @x_alignment: horizontal alignment within @childbox
* @y_alignment: vertical alignment within @childbox
* @x_fill: whether or not to fill @childbox horizontally
* @y_fill: whether or not to fill @childbox vertically
*
* Given @childbox, containing the initial allocation of @child, this
* adjusts the horizontal allocation if @x_fill is %FALSE, and the
* vertical allocation if @y_fill is %FALSE, by:
*
* - reducing the allocation if it is larger than @child's natural
* size.
*
* - adjusting the position of the child within the allocation
* according to @x_alignment/@y_alignment (and flipping
* @x_alignment if @parent has %ST_TEXT_DIRECTION_RTL)
*
* If @x_fill and @y_fill are both %TRUE, or if @child's natural size
* is larger than the initial allocation in @childbox, then @childbox
* will be unchanged.
*
* If you are allocating children with _st_allocate_fill(), you should
* determine their preferred sizes using
* _st_actor_get_preferred_width() and
* _st_actor_get_preferred_height(), not with the corresponding
* Clutter methods.
*/
void
_st_allocate_fill (StWidget *parent,
ClutterActor *child,
ClutterActorBox *childbox,
StAlign x_alignment,
StAlign y_alignment,
gboolean x_fill,
gboolean y_fill)
{
gfloat natural_width, natural_height;
gfloat min_width, min_height;
gfloat child_width, child_height;
gfloat available_width, available_height;
ClutterRequestMode request;
gdouble x_align, y_align;
available_width = childbox->x2 - childbox->x1;
available_height = childbox->y2 - childbox->y1;
if (available_width < 0)
{
available_width = 0;
childbox->x2 = childbox->x1;
}
if (available_height < 0)
{
available_height = 0;
childbox->y2 = childbox->y1;
}
/* If we are filling both horizontally and vertically then we don't
* need to do anything else.
*/
if (x_fill && y_fill)
return;
_st_get_align_factors (parent, x_alignment, y_alignment,
&x_align, &y_align);
/* The following is based on clutter_actor_get_preferred_size(), but
* modified to cope with the fact that the available size may be
* less than the preferred size.
*/
request = CLUTTER_REQUEST_HEIGHT_FOR_WIDTH;
g_object_get (G_OBJECT (child), "request-mode", &request, NULL);
if (request == CLUTTER_REQUEST_HEIGHT_FOR_WIDTH)
{
clutter_actor_get_preferred_width (child, -1,
&min_width,
&natural_width);
child_width = CLAMP (natural_width, min_width, available_width);
clutter_actor_get_preferred_height (child, child_width,
&min_height,
&natural_height);
child_height = CLAMP (natural_height, min_height, available_height);
}
else
{
clutter_actor_get_preferred_height (child, -1,
&min_height,
&natural_height);
child_height = CLAMP (natural_height, min_height, available_height);
clutter_actor_get_preferred_width (child, child_height,
&min_width,
&natural_width);
child_width = CLAMP (natural_width, min_width, available_width);
}
if (!x_fill)
{
childbox->x1 += (int)((available_width - child_width) * x_align);
childbox->x2 = childbox->x1 + (int) child_width;
}
if (!y_fill)
{
childbox->y1 += (int)((available_height - child_height) * y_align);
childbox->y2 = childbox->y1 + (int) child_height;
}
}
/**
* _st_get_align_factors:
* @widget: an #StWidget
* @x_align: an #StAlign
* @y_align: an #StAlign
* @x_align_out: (out) (allow-none): @x_align as a #gdouble
* @y_align_out: (out) (allow-none): @y_align as a #gdouble
*
* Converts @x_align and @y_align to #gdouble values. If @widget has
* %ST_TEXT_DIRECTION_RTL, the @x_align_out value will be flipped
* relative to @x_align.
*/
void
_st_get_align_factors (StWidget *widget,
StAlign x_align,
StAlign y_align,
gdouble *x_align_out,
gdouble *y_align_out)
{
if (x_align_out)
{
switch (x_align)
{
case ST_ALIGN_START:
*x_align_out = 0.0;
break;
case ST_ALIGN_MIDDLE:
*x_align_out = 0.5;
break;
case ST_ALIGN_END:
*x_align_out = 1.0;
break;
default:
g_warn_if_reached ();
break;
}
if (st_widget_get_direction (widget) == ST_TEXT_DIRECTION_RTL)
*x_align_out = 1.0 - *x_align_out;
}
if (y_align_out)
{
switch (y_align)
{
case ST_ALIGN_START:
*y_align_out = 0.0;
break;
case ST_ALIGN_MIDDLE:
*y_align_out = 0.5;
break;
case ST_ALIGN_END:
*y_align_out = 1.0;
break;
default:
g_warn_if_reached ();
break;
}
}
}
/**
* _st_set_text_from_style:
* @text: Target #ClutterText
* @theme_node: Source #StThemeNode
*
* Set various GObject properties of the @text object using
* CSS information from @theme_node.
*/
void
_st_set_text_from_style (ClutterText *text,
StThemeNode *theme_node)
{
ClutterColor color;
StTextDecoration decoration;
PangoAttrList *attribs;
const PangoFontDescription *font;
gchar *font_string;
StTextAlign align;
st_theme_node_get_foreground_color (theme_node, &color);
clutter_text_set_color (text, &color);
font = st_theme_node_get_font (theme_node);
font_string = pango_font_description_to_string (font);
clutter_text_set_font_name (text, font_string);
g_free (font_string);
attribs = pango_attr_list_new ();
decoration = st_theme_node_get_text_decoration (theme_node);
if (decoration & ST_TEXT_DECORATION_UNDERLINE)
{
PangoAttribute *underline = pango_attr_underline_new (PANGO_UNDERLINE_SINGLE);
pango_attr_list_insert (attribs, underline);
}
if (decoration & ST_TEXT_DECORATION_LINE_THROUGH)
{
PangoAttribute *strikethrough = pango_attr_strikethrough_new (TRUE);
pango_attr_list_insert (attribs, strikethrough);
}
/* Pango doesn't have an equivalent attribute for _OVERLINE, and we deliberately
* skip BLINK (for now...)
*/
clutter_text_set_attributes (text, attribs);
pango_attr_list_unref (attribs);
align = st_theme_node_get_text_align (theme_node);
if(align == ST_TEXT_ALIGN_JUSTIFY) {
clutter_text_set_justify (text, TRUE);
clutter_text_set_line_alignment (text, PANGO_ALIGN_LEFT);
} else {
clutter_text_set_justify (text, FALSE);
clutter_text_set_line_alignment (text, (PangoAlignment) align);
}
}
/*****
* Shadows
*****/
static gdouble *
calculate_gaussian_kernel (gdouble sigma,
guint n_values)
{
gdouble *ret, sum;
gdouble exp_divisor;
gint half, i;
g_return_val_if_fail (sigma > 0, NULL);
half = n_values / 2;
ret = g_malloc (n_values * sizeof (gdouble));
sum = 0.0;
exp_divisor = 2 * sigma * sigma;
/* n_values of 1D Gauss function */
for (i = 0; i < n_values; i++)
{
ret[i] = exp (-(i - half) * (i - half) / exp_divisor);
sum += ret[i];
}
/* normalize */
for (i = 0; i < n_values; i++)
ret[i] /= sum;
return ret;
}
CoglHandle
_st_create_shadow_material (StShadow *shadow_spec,
CoglHandle src_texture)
{
static CoglHandle shadow_material_template = COGL_INVALID_HANDLE;
CoglHandle material;
CoglHandle texture;
guchar *pixels_in, *pixels_out;
gint width_in, height_in, rowstride_in;
gint width_out, height_out, rowstride_out;
float sigma;
g_return_val_if_fail (shadow_spec != NULL, COGL_INVALID_HANDLE);
g_return_val_if_fail (src_texture != COGL_INVALID_HANDLE,
COGL_INVALID_HANDLE);
/* we use an approximation of the sigma - blur radius relationship used
in Firefox for doing SVG blurs; see
http://mxr.mozilla.org/mozilla-central/source/gfx/thebes/src/gfxBlur.cpp#280
*/
sigma = shadow_spec->blur / 1.9;
width_in = cogl_texture_get_width (src_texture);
height_in = cogl_texture_get_height (src_texture);
rowstride_in = (width_in + 3) & ~3;
pixels_in = g_malloc0 (rowstride_in * height_in);
cogl_texture_get_data (src_texture, COGL_PIXEL_FORMAT_A_8,
rowstride_in, pixels_in);
if ((guint) shadow_spec->blur == 0)
{
width_out = width_in;
height_out = height_in;
rowstride_out = rowstride_in;
pixels_out = g_memdup (pixels_in, rowstride_out * height_out);
}
else
{
gdouble *kernel;
guchar *line;
gint n_values, half;
gint x_in, y_in, x_out, y_out, i;
n_values = (gint) 5 * sigma;
half = n_values / 2;
width_out = width_in + 2 * half;
height_out = height_in + 2 * half;
rowstride_out = (width_out + 3) & ~3;
pixels_out = g_malloc0 (rowstride_out * height_out);
line = g_malloc0 (rowstride_out);
kernel = calculate_gaussian_kernel (sigma, n_values);
/* vertical blur */
for (x_in = 0; x_in < width_in; x_in++)
for (y_out = 0; y_out < height_out; y_out++)
{
guchar *pixel_in, *pixel_out;
gint i0, i1;
y_in = y_out - half;
/* We read from the source at 'y = y_in + i - half'; clamp the
* full i range [0, n_values) so that y is in [0, height_in).
*/
i0 = MAX (half - y_in, 0);
i1 = MIN (height_in + half - y_in, n_values);
pixel_in = pixels_in + (y_in + i0 - half) * rowstride_in + x_in;
pixel_out = pixels_out + y_out * rowstride_out + (x_in + half);
for (i = i0; i < i1; i++)
{
*pixel_out += *pixel_in * kernel[i];
pixel_in += rowstride_in;
}
}
/* horizontal blur */
for (y_out = 0; y_out < height_out; y_out++)
{
memcpy (line, pixels_out + y_out * rowstride_out, rowstride_out);
for (x_out = 0; x_out < width_out; x_out++)
{
gint i0, i1;
guchar *pixel_out, *pixel_in;
/* We read from the source at 'x = x_out + i - half'; clamp the
* full i range [0, n_values) so that x is in [0, width_out).
*/
i0 = MAX (half - x_out, 0);
i1 = MIN (width_out + half - x_out, n_values);
pixel_in = line + x_out + i0 - half;
pixel_out = pixels_out + rowstride_out * y_out + x_out;
*pixel_out = 0;
for (i = i0; i < i1; i++)
{
*pixel_out += *pixel_in * kernel[i];
pixel_in++;
}
}
}
g_free (kernel);
g_free (line);
}
texture = cogl_texture_new_from_data (width_out,
height_out,
COGL_TEXTURE_NONE,
COGL_PIXEL_FORMAT_A_8,
COGL_PIXEL_FORMAT_A_8,
rowstride_out,
pixels_out);
g_free (pixels_in);
g_free (pixels_out);
if (G_UNLIKELY (shadow_material_template == COGL_INVALID_HANDLE))
{
shadow_material_template = cogl_material_new ();
/* We set up the material to blend the shadow texture with the combine
* constant, but defer setting the latter until painting, so that we can
* take the actor's overall opacity into account. */
cogl_material_set_layer_combine (shadow_material_template, 0,
"RGBA = MODULATE (CONSTANT, TEXTURE[A])",
NULL);
}
material = cogl_material_copy (shadow_material_template);
cogl_material_set_layer (material, 0, texture);
cogl_handle_unref (texture);
return material;
}
CoglHandle
_st_create_shadow_material_from_actor (StShadow *shadow_spec,
ClutterActor *actor)
{
CoglHandle shadow_material = COGL_INVALID_HANDLE;
if (CLUTTER_IS_TEXTURE (actor))
{
CoglHandle texture;
texture = clutter_texture_get_cogl_texture (CLUTTER_TEXTURE (actor));
shadow_material = _st_create_shadow_material (shadow_spec, texture);
}
else
{
CoglHandle buffer, offscreen;
ClutterActorBox box;
float width, height;
clutter_actor_get_allocation_box (actor, &box);
clutter_actor_box_get_size (&box, &width, &height);
buffer = cogl_texture_new_with_size (width,
height,
COGL_TEXTURE_NO_SLICING,
COGL_PIXEL_FORMAT_ANY);
offscreen = cogl_offscreen_new_to_texture (buffer);
if (offscreen != COGL_INVALID_HANDLE)
{
CoglColor clear_color;
cogl_color_set_from_4ub (&clear_color, 0, 0, 0, 0);
cogl_push_framebuffer (offscreen);
cogl_clear (&clear_color, COGL_BUFFER_BIT_COLOR);
cogl_ortho (0, width, height, 0, 0, 1.0);
clutter_actor_paint (actor);
cogl_pop_framebuffer ();
cogl_handle_unref (offscreen);
shadow_material = _st_create_shadow_material (shadow_spec, buffer);
}
cogl_handle_unref (buffer);
}
return shadow_material;
}
void
_st_paint_shadow_with_opacity (StShadow *shadow_spec,
CoglHandle shadow_material,
ClutterActorBox *box,
guint8 paint_opacity)
{
ClutterActorBox shadow_box;
CoglColor color;
g_return_if_fail (shadow_spec != NULL);
g_return_if_fail (shadow_material != COGL_INVALID_HANDLE);
st_shadow_get_box (shadow_spec, box, &shadow_box);
cogl_color_set_from_4ub (&color,
shadow_spec->color.red * paint_opacity / 255,
shadow_spec->color.green * paint_opacity / 255,
shadow_spec->color.blue * paint_opacity / 255,
shadow_spec->color.alpha * paint_opacity / 255);
cogl_color_premultiply (&color);
cogl_material_set_layer_combine_constant (shadow_material, 0, &color);
cogl_set_source (shadow_material);
cogl_rectangle_with_texture_coords (shadow_box.x1, shadow_box.y1,
shadow_box.x2, shadow_box.y2,
0, 0, 1, 1);
}