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Diffstat (limited to 'src/st/st-private.c')
| -rw-r--r-- | src/st/st-private.c | 804 |
1 files changed, 804 insertions, 0 deletions
diff --git a/src/st/st-private.c b/src/st/st-private.c new file mode 100644 index 0000000..bb98151 --- /dev/null +++ b/src/st/st-private.c @@ -0,0 +1,804 @@ +/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */ +/* + * st-private.h: Private declarations and functions + * + * Copyright 2009, 2010 Red Hat, Inc. + * Copyright 2010 Florian Müllner + * Copyright 2010 Intel Corporation + * Copyright 2010 Giovanni Campagna + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU Lesser General Public License, + * version 2.1, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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 program. If not, see <http://www.gnu.org/licenses/>. + */ +#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; + + mode = clutter_actor_get_request_mode (actor); + 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; + + mode = clutter_actor_get_request_mode (actor); + 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_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 = NULL; + const PangoFontDescription *font; + PangoAttribute *foreground; + StTextAlign align; + gdouble spacing; + gchar *font_features; + + font = st_theme_node_get_font (theme_node); + clutter_text_set_font_description (text, (PangoFontDescription *) font); + + attribs = pango_attr_list_new (); + + st_theme_node_get_foreground_color (theme_node, &color); + clutter_text_set_cursor_color (text, &color); + foreground = pango_attr_foreground_new (color.red * 255, + color.green * 255, + color.blue * 255); + pango_attr_list_insert (attribs, foreground); + + if (color.alpha != 255) + { + PangoAttribute *alpha; + + /* An alpha value of 0 means "system inherited", so the + * minimum regular value is 1. + */ + if (color.alpha == 0) + alpha = pango_attr_foreground_alpha_new (1); + else + alpha = pango_attr_foreground_alpha_new (color.alpha * 255); + + pango_attr_list_insert (attribs, alpha); + } + + decoration = st_theme_node_get_text_decoration (theme_node); + if (decoration) + { + 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...) + */ + } + + spacing = st_theme_node_get_letter_spacing (theme_node); + if (spacing) + { + PangoAttribute *letter_spacing = pango_attr_letter_spacing_new ((int)(.5 + spacing) * PANGO_SCALE); + pango_attr_list_insert (attribs, letter_spacing); + } + + font_features = st_theme_node_get_font_features (theme_node); + if (font_features) + { + pango_attr_list_insert (attribs, pango_attr_font_features_new (font_features)); + g_free (font_features); + } + + clutter_text_set_attributes (text, attribs); + + if (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); + } +} + +/** + * _st_create_texture_pipeline: + * @src_texture: The CoglTexture for the pipeline + * + * Creates a simple pipeline which contains the given texture as a + * single layer. + */ +CoglPipeline * +_st_create_texture_pipeline (CoglTexture *src_texture) +{ + static CoglPipeline *texture_pipeline_template = NULL; + CoglPipeline *pipeline; + + g_return_val_if_fail (src_texture != NULL, NULL); + + /* The only state used in the pipeline that would affect the shader + generation is the texture type on the layer. Therefore we create + a template pipeline which sets this state and all texture + pipelines are created as a copy of this. That way Cogl can find + the shader state for the pipeline more quickly by looking at the + pipeline ancestry instead of resorting to the shader cache. */ + if (G_UNLIKELY (texture_pipeline_template == NULL)) + { + CoglContext *ctx = + clutter_backend_get_cogl_context (clutter_get_default_backend ()); + + texture_pipeline_template = cogl_pipeline_new (ctx); + cogl_pipeline_set_layer_null_texture (texture_pipeline_template, 0); + } + + pipeline = cogl_pipeline_copy (texture_pipeline_template); + + if (src_texture != NULL) + cogl_pipeline_set_layer_texture (pipeline, 0, src_texture); + + return pipeline; +} + +/***** + * Shadows + *****/ + +static gdouble * +calculate_gaussian_kernel (gdouble sigma, + guint n_values) +{ + gdouble *ret, sum; + gdouble exp_divisor; + int 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 < (int)n_values; i++) + { + ret[i] = exp (-(i - half) * (i - half) / exp_divisor); + sum += ret[i]; + } + + /* normalize */ + for (i = 0; i < (int)n_values; i++) + ret[i] /= sum; + + return ret; +} + +static guchar * +blur_pixels (guchar *pixels_in, + gint width_in, + gint height_in, + gint rowstride_in, + gdouble blur, + gint *width_out, + gint *height_out, + size_t *rowstride_out) +{ + guchar *pixels_out; + gdouble sigma; + + /* The CSS specification defines (or will define) the blur radius as twice + * the Gaussian standard deviation. See: + * + * http://lists.w3.org/Archives/Public/www-style/2010Sep/0002.html + */ + sigma = blur / 2.; + + if ((guint) blur == 0) + { + *width_out = width_in; + *height_out = height_in; + *rowstride_out = rowstride_in; + pixels_out = g_memdup2 (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); + } + + return pixels_out; +} + +CoglPipeline * +_st_create_shadow_pipeline (StShadow *shadow_spec, + CoglTexture *src_texture, + float resource_scale) +{ + ClutterBackend *backend = clutter_get_default_backend (); + CoglContext *ctx = clutter_backend_get_cogl_context (backend); + g_autoptr (ClutterPaintNode) texture_node = NULL; + g_autoptr (ClutterPaintNode) blur_node = NULL; + g_autoptr (CoglOffscreen) offscreen = NULL; + g_autoptr (GError) error = NULL; + ClutterPaintContext *paint_context; + CoglFramebuffer *fb; + CoglPipeline *pipeline; + CoglTexture *texture; + float sampling_radius; + float sigma; + int src_height, dst_height; + int src_width, dst_width; + CoglPipeline *texture_pipeline; + + static CoglPipelineKey texture_pipeline_key = + "st-create-shadow-pipeline-saturate-alpha"; + static CoglPipeline *shadow_pipeline_template = NULL; + + g_return_val_if_fail (shadow_spec != NULL, NULL); + g_return_val_if_fail (src_texture != NULL, NULL); + + sampling_radius = resource_scale * shadow_spec->blur; + sigma = sampling_radius / 2.f; + sampling_radius = ceilf (sampling_radius); + + src_width = cogl_texture_get_width (src_texture); + src_height = cogl_texture_get_height (src_texture); + dst_width = src_width + 2 * sampling_radius; + dst_height = src_height + 2 * sampling_radius; + + texture = cogl_texture_2d_new_with_size (ctx, dst_width, dst_height); + if (!texture) + return NULL; + + offscreen = cogl_offscreen_new_with_texture (texture); + fb = COGL_FRAMEBUFFER (offscreen); + if (!cogl_framebuffer_allocate (fb, &error)) + { + cogl_clear_object (&texture); + return NULL; + } + + cogl_framebuffer_clear4f (fb, COGL_BUFFER_BIT_COLOR, 0.f, 0.f, 0.f, 0.f); + cogl_framebuffer_orthographic (fb, 0, 0, dst_width, dst_height, 0, 1.0); + + /* Blur */ + blur_node = clutter_blur_node_new (dst_width, dst_height, sigma); + clutter_paint_node_add_rectangle (blur_node, + &(ClutterActorBox) { + 0.f, 0.f, + dst_width, dst_height, + }); + + /* Texture */ + texture_pipeline = cogl_context_get_named_pipeline (ctx, + &texture_pipeline_key); + + if (G_UNLIKELY (texture_pipeline == NULL)) + { + CoglSnippet *snippet; + + snippet = cogl_snippet_new (COGL_SNIPPET_HOOK_FRAGMENT, + "", + "if (cogl_color_out.a > 0.0)\n" + " cogl_color_out.a = 1.0;"); + + texture_pipeline = cogl_pipeline_new (ctx); + cogl_pipeline_add_snippet (texture_pipeline, snippet); + cogl_object_unref (snippet); + + cogl_context_set_named_pipeline (ctx, + &texture_pipeline_key, + texture_pipeline); + } + + /* No need to unref texture_pipeline since the named pipeline hash + * doesn't change its ref count from 1. Also no need to copy texture_pipeline + * since we'll be completely finished with it after clutter_paint_node_paint. + */ + + cogl_pipeline_set_layer_texture (texture_pipeline, 0, src_texture); + texture_node = clutter_pipeline_node_new (texture_pipeline); + clutter_paint_node_add_child (blur_node, texture_node); + clutter_paint_node_add_rectangle (texture_node, + &(ClutterActorBox) { + .x1 = sampling_radius, + .y1 = sampling_radius, + .x2 = src_width + sampling_radius, + .y2 = src_height + sampling_radius, + }); + + paint_context = + clutter_paint_context_new_for_framebuffer (fb, NULL, CLUTTER_PAINT_FLAG_NONE); + clutter_paint_node_paint (blur_node, paint_context); + clutter_paint_context_destroy (paint_context); + + if (G_UNLIKELY (shadow_pipeline_template == NULL)) + { + shadow_pipeline_template = cogl_pipeline_new (ctx); + + /* We set up the pipeline 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_pipeline_set_layer_combine (shadow_pipeline_template, 0, + "RGBA = MODULATE (CONSTANT, TEXTURE[A])", + NULL); + } + + pipeline = cogl_pipeline_copy (shadow_pipeline_template); + cogl_pipeline_set_layer_texture (pipeline, 0, texture); + + cogl_clear_object (&texture); + + return pipeline; +} + +CoglPipeline * +_st_create_shadow_pipeline_from_actor (StShadow *shadow_spec, + ClutterActor *actor) +{ + ClutterContent *image = NULL; + CoglPipeline *shadow_pipeline = NULL; + float resource_scale; + float width, height; + ClutterPaintContext *paint_context; + + g_return_val_if_fail (clutter_actor_has_allocation (actor), NULL); + + clutter_actor_get_size (actor, &width, &height); + + if (width == 0 || height == 0) + return NULL; + + resource_scale = clutter_actor_get_resource_scale (actor); + + width = ceilf (width * resource_scale); + height = ceilf (height * resource_scale); + + image = clutter_actor_get_content (actor); + if (image && CLUTTER_IS_IMAGE (image)) + { + CoglTexture *texture; + + texture = clutter_image_get_texture (CLUTTER_IMAGE (image)); + if (texture && + cogl_texture_get_width (texture) == width && + cogl_texture_get_height (texture) == height) + shadow_pipeline = _st_create_shadow_pipeline (shadow_spec, texture, + resource_scale); + } + + if (shadow_pipeline == NULL) + { + CoglTexture *buffer; + CoglOffscreen *offscreen; + CoglFramebuffer *fb; + CoglContext *ctx; + CoglColor clear_color; + GError *catch_error = NULL; + float x, y; + + ctx = clutter_backend_get_cogl_context (clutter_get_default_backend ()); + buffer = cogl_texture_2d_new_with_size (ctx, width, height); + + if (buffer == NULL) + return NULL; + + offscreen = cogl_offscreen_new_with_texture (buffer); + fb = COGL_FRAMEBUFFER (offscreen); + + if (!cogl_framebuffer_allocate (fb, &catch_error)) + { + g_error_free (catch_error); + g_object_unref (offscreen); + cogl_object_unref (buffer); + return NULL; + } + + cogl_color_init_from_4ub (&clear_color, 0, 0, 0, 0); + clutter_actor_get_position (actor, &x, &y); + x *= resource_scale; + y *= resource_scale; + + cogl_framebuffer_clear (fb, COGL_BUFFER_BIT_COLOR, &clear_color); + cogl_framebuffer_translate (fb, -x, -y, 0); + cogl_framebuffer_orthographic (fb, 0, 0, width, height, 0, 1.0); + cogl_framebuffer_scale (fb, resource_scale, resource_scale, 1); + + clutter_actor_set_opacity_override (actor, 255); + + paint_context = + clutter_paint_context_new_for_framebuffer (fb, NULL, + CLUTTER_PAINT_FLAG_NONE); + clutter_actor_paint (actor, paint_context); + clutter_paint_context_destroy (paint_context); + + clutter_actor_set_opacity_override (actor, -1); + + g_object_unref (fb); + + shadow_pipeline = _st_create_shadow_pipeline (shadow_spec, buffer, + resource_scale); + + cogl_object_unref (buffer); + } + + return shadow_pipeline; +} + +/** + * _st_create_shadow_cairo_pattern: + * @shadow_spec: the definition of the shadow + * @src_pattern: surface pattern for which we create the shadow + * (must be a surface pattern) + * + * This is a utility function for creating shadows used by + * st-theme-node.c; it's in this file to share the gaussian + * blur implementation. The usage of this function is quite different + * depending on whether shadow_spec->inset is %TRUE or not. If + * shadow_spec->inset is %TRUE, the caller should pass in a @src_pattern + * which is the <i>inverse</i> of what they want shadowed, and must take + * care of the spread and offset from the shadow spec themselves. If + * shadow_spec->inset is %FALSE then the caller should pass in what they + * want shadowed directly, and this function takes care of the spread and + * the offset. + */ +cairo_pattern_t * +_st_create_shadow_cairo_pattern (StShadow *shadow_spec_in, + cairo_pattern_t *src_pattern) +{ + g_autoptr(StShadow) shadow_spec = NULL; + static cairo_user_data_key_t shadow_pattern_user_data; + cairo_t *cr; + cairo_surface_t *src_surface; + cairo_surface_t *surface_in; + cairo_surface_t *surface_out; + cairo_pattern_t *dst_pattern; + guchar *pixels_in, *pixels_out; + gint width_in, height_in, rowstride_in; + gint width_out, height_out; + size_t rowstride_out; + cairo_matrix_t shadow_matrix; + double xscale_in, yscale_in; + int i, j; + + g_return_val_if_fail (shadow_spec_in != NULL, NULL); + g_return_val_if_fail (src_pattern != NULL, NULL); + + if (cairo_pattern_get_surface (src_pattern, &src_surface) != CAIRO_STATUS_SUCCESS) + /* The most likely reason we can't get the pattern is that sizing went hairwire + * and the caller tried to create a surface too big for memory, leaving us with + * a pattern in an error state; we return a transparent pattern for the shadow. + */ + return cairo_pattern_create_rgba(1.0, 1.0, 1.0, 0.0); + + width_in = cairo_image_surface_get_width (src_surface); + height_in = cairo_image_surface_get_height (src_surface); + + cairo_surface_get_device_scale (src_surface, &xscale_in, &yscale_in); + + if (xscale_in != 1.0 || yscale_in != 1.0) + { + /* Scale the shadow specifications in a temporary copy so that + * we can work everywhere in absolute surface coordinates */ + double scale = (xscale_in + yscale_in) / 2.0; + shadow_spec = st_shadow_new (&shadow_spec_in->color, + shadow_spec_in->xoffset * xscale_in, + shadow_spec_in->yoffset * yscale_in, + shadow_spec_in->blur * scale, + shadow_spec_in->spread * scale, + shadow_spec_in->inset); + } + else + { + shadow_spec = st_shadow_ref (shadow_spec_in); + } + + /* We want the output to be a color agnostic alpha mask, + * so we need to strip the color channels from the input + */ + if (cairo_image_surface_get_format (src_surface) != CAIRO_FORMAT_A8) + { + surface_in = cairo_image_surface_create (CAIRO_FORMAT_A8, + width_in, height_in); + + cr = cairo_create (surface_in); + cairo_set_source_surface (cr, src_surface, 0, 0); + cairo_paint (cr); + cairo_destroy (cr); + } + else + { + surface_in = cairo_surface_reference (src_surface); + } + + pixels_in = cairo_image_surface_get_data (surface_in); + rowstride_in = cairo_image_surface_get_stride (surface_in); + + pixels_out = blur_pixels (pixels_in, width_in, height_in, rowstride_in, + shadow_spec->blur, + &width_out, &height_out, &rowstride_out); + cairo_surface_destroy (surface_in); + + /* Invert pixels for inset shadows */ + if (shadow_spec->inset) + { + for (j = 0; j < height_out; j++) + { + guchar *p = pixels_out + rowstride_out * j; + for (i = 0; i < width_out; i++, p++) + *p = ~*p; + } + } + + surface_out = cairo_image_surface_create_for_data (pixels_out, + CAIRO_FORMAT_A8, + width_out, + height_out, + rowstride_out); + cairo_surface_set_device_scale (surface_out, xscale_in, yscale_in); + cairo_surface_set_user_data (surface_out, &shadow_pattern_user_data, + pixels_out, (cairo_destroy_func_t) g_free); + + dst_pattern = cairo_pattern_create_for_surface (surface_out); + cairo_surface_destroy (surface_out); + + cairo_pattern_get_matrix (src_pattern, &shadow_matrix); + + if (shadow_spec->inset) + { + /* Scale the matrix in surface absolute coordinates */ + cairo_matrix_scale (&shadow_matrix, 1.0 / xscale_in, 1.0 / yscale_in); + + /* For inset shadows, offsets and spread radius have already been + * applied to the original pattern, so all left to do is shift the + * blurred image left, so that it aligns centered under the + * unblurred one + */ + cairo_matrix_translate (&shadow_matrix, + (width_out - width_in) / 2.0, + (height_out - height_in) / 2.0); + + /* Scale back the matrix in original coordinates */ + cairo_matrix_scale (&shadow_matrix, xscale_in, yscale_in); + + cairo_pattern_set_matrix (dst_pattern, &shadow_matrix); + return dst_pattern; + } + + /* Read all the code from the cairo_pattern_set_matrix call + * at the end of this function to here from bottom to top, + * because each new affine transformation is applied in + * front of all the previous ones */ + + /* 6. Invert the matrix back */ + cairo_matrix_invert (&shadow_matrix); + + /* Scale the matrix in surface absolute coordinates */ + cairo_matrix_scale (&shadow_matrix, 1.0 / xscale_in, 1.0 / yscale_in); + + /* 5. Adjust based on specified offsets */ + cairo_matrix_translate (&shadow_matrix, + shadow_spec->xoffset, + shadow_spec->yoffset); + + /* 4. Recenter the newly scaled image */ + cairo_matrix_translate (&shadow_matrix, + - shadow_spec->spread, + - shadow_spec->spread); + + /* 3. Scale up the blurred image to fill the spread */ + cairo_matrix_scale (&shadow_matrix, + (width_in + 2.0 * shadow_spec->spread) / width_in, + (height_in + 2.0 * shadow_spec->spread) / height_in); + + /* 2. Shift the blurred image left, so that it aligns centered + * under the unblurred one */ + cairo_matrix_translate (&shadow_matrix, + - (width_out - width_in) / 2.0, + - (height_out - height_in) / 2.0); + + /* Scale back the matrix in scaled coordinates */ + cairo_matrix_scale (&shadow_matrix, xscale_in, yscale_in); + + /* 1. Invert the matrix so we can work with it in pattern space + */ + cairo_matrix_invert (&shadow_matrix); + + cairo_pattern_set_matrix (dst_pattern, &shadow_matrix); + + return dst_pattern; +} + +void +_st_paint_shadow_with_opacity (StShadow *shadow_spec, + CoglFramebuffer *framebuffer, + CoglPipeline *shadow_pipeline, + ClutterActorBox *box, + guint8 paint_opacity) +{ + ClutterActorBox shadow_box; + CoglColor color; + + g_return_if_fail (shadow_spec != NULL); + g_return_if_fail (shadow_pipeline != NULL); + + st_shadow_get_box (shadow_spec, box, &shadow_box); + + cogl_color_init_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_pipeline_set_layer_combine_constant (shadow_pipeline, 0, &color); + cogl_framebuffer_draw_rectangle (framebuffer, + shadow_pipeline, + shadow_box.x1, shadow_box.y1, + shadow_box.x2, shadow_box.y2); +} |