[StThemeNode] Make shadow helper functions semi-public

Move shadow helper functions from st-theme-node-drawing to st-private
to make them available to widgets which want to add shadows to internal
actors.
Also add a new helper function for creating the shadow material from a
ClutterActor.

https://bugzilla.gnome.org/show_bug.cgi?id=624384
This commit is contained in:
Florian Müllner 2010-07-24 17:41:25 +02:00
parent 29781b2e5c
commit ba1da9deb9
3 changed files with 283 additions and 216 deletions

View File

@ -1,4 +1,7 @@
/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
#include <math.h>
#include <string.h>
#include "st-private.h"
/**
@ -320,3 +323,257 @@ _st_set_text_from_style (ClutterText *text,
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)
{
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);
material = cogl_material_new ();
cogl_material_set_layer (material, 0, texture);
/* 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 (material, 0,
"RGBA = MODULATE (CONSTANT, TEXTURE[A])",
NULL);
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);
}

View File

@ -27,6 +27,7 @@
#include <glib.h>
#include "st-widget.h"
#include "st-bin.h"
#include "st-shadow.h"
G_BEGIN_DECLS
@ -72,4 +73,14 @@ void _st_allocate_fill (StWidget *parent,
void _st_set_text_from_style (ClutterText *text,
StThemeNode *theme_node);
/* Helper for widgets which need to draw additional shadows */
CoglHandle _st_create_shadow_material (StShadow *shadow_spec,
CoglHandle src_texture);
CoglHandle _st_create_shadow_material_from_actor (StShadow *shadow_spec,
ClutterActor *actor);
void _st_paint_shadow_with_opacity (StShadow *shadow_spec,
CoglHandle shadow_material,
ClutterActorBox *box,
guint8 paint_opacity);
#endif /* __ST_PRIVATE_H__ */

View File

@ -29,192 +29,15 @@
*/
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "st-shadow.h"
#include "st-private.h"
#include "st-theme-private.h"
#include "st-theme-context.h"
#include "st-texture-cache.h"
#include "st-theme-node-private.h"
/*****
* 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;
}
static CoglHandle
create_shadow_material (StThemeNode *node,
CoglHandle src_texture)
{
CoglHandle material;
CoglHandle texture;
StShadow *shadow_spec;
guchar *pixels_in, *pixels_out;
gint width_in, height_in, rowstride_in;
gint width_out, height_out, rowstride_out;
float sigma;
shadow_spec = st_theme_node_get_shadow (node);
if (!shadow_spec)
return 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);
material = cogl_material_new ();
cogl_material_set_layer (material, 0, texture);
/* 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 (material, 0,
"RGBA = MODULATE (CONSTANT, TEXTURE[A])",
NULL);
cogl_handle_unref (texture);
return material;
}
/****
* Rounded corners
****/
@ -750,7 +573,8 @@ st_theme_node_render_resources (StThemeNode *node,
if (shadow_spec)
{
if (node->border_texture != COGL_INVALID_HANDLE)
node->border_shadow_material = create_shadow_material (node, node->border_texture);
node->border_shadow_material = _st_create_shadow_material (shadow_spec,
node->border_texture);
else if (node->background_color.alpha > 0 ||
node->border_width[ST_SIDE_TOP] > 0 ||
node->border_width[ST_SIDE_LEFT] > 0 ||
@ -775,7 +599,7 @@ st_theme_node_render_resources (StThemeNode *node,
cogl_pop_framebuffer ();
cogl_handle_unref (offscreen);
node->border_shadow_material = create_shadow_material (node,
node->border_shadow_material = _st_create_shadow_material (shadow_spec,
buffer);
}
cogl_handle_unref (buffer);
@ -790,7 +614,8 @@ st_theme_node_render_resources (StThemeNode *node,
if (shadow_spec)
{
node->background_shadow_material = create_shadow_material (node, node->background_texture);
node->background_shadow_material = _st_create_shadow_material (shadow_spec,
node->background_texture);
}
}
@ -823,32 +648,6 @@ paint_texture_with_opacity (CoglHandle texture,
cogl_handle_unref (material);
}
static void
paint_shadow_with_opacity (CoglHandle shadow_material,
StShadow *shadow_spec,
ClutterActorBox *box,
guint8 paint_opacity)
{
ClutterActorBox shadow_box;
CoglColor color;
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);
}
static void
st_theme_node_paint_borders (StThemeNode *node,
const ClutterActorBox *box,
@ -1162,8 +961,8 @@ st_theme_node_paint (StThemeNode *node,
*/
if (node->border_shadow_material)
paint_shadow_with_opacity (node->border_shadow_material,
node->shadow,
_st_paint_shadow_with_opacity (node->shadow,
node->border_shadow_material,
&allocation,
paint_opacity);
@ -1199,8 +998,8 @@ st_theme_node_paint (StThemeNode *node,
* like boder and background color into account).
*/
if (node->background_shadow_material != COGL_INVALID_HANDLE)
paint_shadow_with_opacity (node->background_shadow_material,
node->shadow,
_st_paint_shadow_with_opacity (node->shadow,
node->background_shadow_material,
&background_box,
paint_opacity);