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+/* shell-blur-effect.c
+ *
+ * Copyright 2019 Georges Basile Stavracas Neto <georges.stavracas@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "shell-blur-effect.h"
+
+#include "shell-enum-types.h"
+
+/**
+ * SECTION:shell-blur-effect
+ * @short_description: Blur effect for actors
+ *
+ * #ShellBlurEffect is a moderately fast gaussian blur implementation. It also has
+ * an optional brightness property.
+ *
+ * # Modes
+ *
+ * #ShellBlurEffect can work in @SHELL_BLUR_MODE_BACKGROUND and @SHELL_BLUR_MODE_ACTOR
+ * modes. The actor mode blurs the actor itself, and all of its children. The
+ * background mode blurs the pixels beneath the actor, but not the actor itself.
+ *
+ * @SHELL_BLUR_MODE_BACKGROUND can be computationally expensive, since the contents
+ * beneath the actor cannot be cached, so beware of the performance implications
+ * of using this blur mode.
+ *
+ * # Optimizations
+ *
+ * There are a number of optimizations in place to make this blur implementation
+ * real-time. All in all, the implementation performs best when using large
+ * blur-radii that allow downscaling the texture to smaller sizes, at small
+ * radii where no downscaling is possible this can easily halve the framerate.
+ *
+ * ## Multipass
+ *
+ * It is implemented in 2 passes: vertical and horizontal.
+ *
+ * ## Downscaling
+ *
+ * #ShellBlurEffect uses dynamic downscaling to speed up blurring. Downscaling
+ * happens in factors of 2 (the image is downscaled either by 2, 4, 8, 16, …) and
+ * depends on the blur radius, the actor size, among others.
+ *
+ * The actor is drawn into a downscaled framebuffer; the blur passes are applied
+ * on the downscaled actor contents; and finally, the blurred contents are drawn
+ * upscaled again.
+ *
+ * ## Hardware Interpolation
+ *
+ * This blur implementation cuts down the number of sampling operations by
+ * exploiting the hardware interpolation that is performed when sampling between
+ * pixel boundaries. This technique is described at:
+ *
+ * http://rastergrid.com/blog/2010/09/efficient-gaussian-blur-with-linear-sampling/
+ *
+ * ## Incremental gauss-factor calculation
+ *
+ * The kernel values for the gaussian kernel are computed incrementally instead
+ * of running the expensive calculations multiple times inside the blur shader.
+ * The implementation is based on the algorithm presented by K. Turkowski in
+ * GPU Gems 3, chapter 40:
+ *
+ * https://developer.nvidia.com/gpugems/GPUGems3/gpugems3_ch40.html
+ *
+ */
+
+static const gchar *gaussian_blur_glsl_declarations =
+"uniform float sigma; \n"
+"uniform float pixel_step; \n"
+"uniform int vertical; \n";
+
+static const gchar *gaussian_blur_glsl =
+" int horizontal = 1 - vertical; \n"
+" \n"
+" vec2 uv = vec2 (cogl_tex_coord.st); \n"
+" \n"
+" vec3 gauss_coefficient; \n"
+" gauss_coefficient.x = 1.0 / (sqrt (2.0 * 3.14159265) * sigma); \n"
+" gauss_coefficient.y = exp (-0.5 / (sigma * sigma)); \n"
+" gauss_coefficient.z = gauss_coefficient.y * gauss_coefficient.y; \n"
+" \n"
+" float gauss_coefficient_total = gauss_coefficient.x; \n"
+" \n"
+" vec4 ret = texture2D (cogl_sampler, uv) * gauss_coefficient.x; \n"
+" gauss_coefficient.xy *= gauss_coefficient.yz; \n"
+" \n"
+" int n_steps = int (ceil (3.0 * sigma)); \n"
+" \n"
+" for (int i = 1; i < n_steps; i += 2) { \n"
+" float coefficient_subtotal = gauss_coefficient.x; \n"
+" gauss_coefficient.xy *= gauss_coefficient.yz; \n"
+" coefficient_subtotal += gauss_coefficient.x; \n"
+" \n"
+" float gauss_ratio = gauss_coefficient.x / coefficient_subtotal; \n"
+" \n"
+" float foffset = float (i) + gauss_ratio; \n"
+" vec2 offset = vec2 (foffset * pixel_step * float (horizontal), \n"
+" foffset * pixel_step * float (vertical)); \n"
+" \n"
+" ret += texture2D (cogl_sampler, uv + offset) * coefficient_subtotal; \n"
+" ret += texture2D (cogl_sampler, uv - offset) * coefficient_subtotal; \n"
+" \n"
+" gauss_coefficient_total += 2.0 * coefficient_subtotal; \n"
+" gauss_coefficient.xy *= gauss_coefficient.yz; \n"
+" } \n"
+" \n"
+" cogl_texel = ret / gauss_coefficient_total; \n";
+
+static const gchar *brightness_glsl_declarations =
+"uniform float brightness; \n";
+
+static const gchar *brightness_glsl =
+" cogl_color_out.rgb *= brightness; \n";
+
+#define MIN_DOWNSCALE_SIZE 256.f
+#define MAX_SIGMA 6.f
+
+typedef enum
+{
+ VERTICAL,
+ HORIZONTAL,
+} BlurType;
+
+typedef enum
+{
+ ACTOR_PAINTED = 1 << 0,
+ BLUR_APPLIED = 1 << 1,
+} CacheFlags;
+
+typedef struct
+{
+ CoglFramebuffer *framebuffer;
+ CoglPipeline *pipeline;
+ CoglTexture *texture;
+} FramebufferData;
+
+typedef struct
+{
+ FramebufferData data;
+ BlurType type;
+ int sigma_uniform;
+ int pixel_step_uniform;
+ int vertical_uniform;
+} BlurData;
+
+struct _ShellBlurEffect
+{
+ ClutterEffect parent_instance;
+
+ ClutterActor *actor;
+ int old_opacity_override;
+
+ BlurData blur[2];
+
+ unsigned int tex_width;
+ unsigned int tex_height;
+
+ /* The cached contents */
+ FramebufferData actor_fb;
+ CacheFlags cache_flags;
+
+ FramebufferData background_fb;
+ FramebufferData brightness_fb;
+ int brightness_uniform;
+
+ ShellBlurMode mode;
+ float downscale_factor;
+ float brightness;
+ int sigma;
+};
+
+G_DEFINE_TYPE (ShellBlurEffect, shell_blur_effect, CLUTTER_TYPE_EFFECT)
+
+enum {
+ PROP_0,
+ PROP_SIGMA,
+ PROP_BRIGHTNESS,
+ PROP_MODE,
+ N_PROPS
+};
+
+static GParamSpec *properties [N_PROPS] = { NULL, };
+
+static CoglPipeline*
+create_base_pipeline (void)
+{
+ static CoglPipeline *base_pipeline = NULL;
+
+ if (G_UNLIKELY (base_pipeline == NULL))
+ {
+ CoglContext *ctx =
+ clutter_backend_get_cogl_context (clutter_get_default_backend ());
+
+ base_pipeline = cogl_pipeline_new (ctx);
+ cogl_pipeline_set_layer_null_texture (base_pipeline, 0);
+ cogl_pipeline_set_layer_filters (base_pipeline,
+ 0,
+ COGL_PIPELINE_FILTER_LINEAR,
+ COGL_PIPELINE_FILTER_LINEAR);
+ cogl_pipeline_set_layer_wrap_mode (base_pipeline,
+ 0,
+ COGL_PIPELINE_WRAP_MODE_CLAMP_TO_EDGE);
+ }
+
+ return cogl_pipeline_copy (base_pipeline);
+}
+
+static CoglPipeline*
+create_blur_pipeline (void)
+{
+ static CoglPipeline *blur_pipeline = NULL;
+
+ if (G_UNLIKELY (blur_pipeline == NULL))
+ {
+ CoglSnippet *snippet;
+
+ blur_pipeline = create_base_pipeline ();
+
+ snippet = cogl_snippet_new (COGL_SNIPPET_HOOK_TEXTURE_LOOKUP,
+ gaussian_blur_glsl_declarations,
+ NULL);
+ cogl_snippet_set_replace (snippet, gaussian_blur_glsl);
+ cogl_pipeline_add_layer_snippet (blur_pipeline, 0, snippet);
+ cogl_object_unref (snippet);
+ }
+
+ return cogl_pipeline_copy (blur_pipeline);
+}
+
+
+static CoglPipeline*
+create_brightness_pipeline (void)
+{
+ static CoglPipeline *brightness_pipeline = NULL;
+
+ if (G_UNLIKELY (brightness_pipeline == NULL))
+ {
+ CoglSnippet *snippet;
+
+ brightness_pipeline = create_base_pipeline ();
+
+ snippet = cogl_snippet_new (COGL_SNIPPET_HOOK_FRAGMENT,
+ brightness_glsl_declarations,
+ brightness_glsl);
+ cogl_pipeline_add_snippet (brightness_pipeline, snippet);
+ cogl_object_unref (snippet);
+ }
+
+ return cogl_pipeline_copy (brightness_pipeline);
+}
+
+static void
+setup_blur (BlurData *blur,
+ BlurType type)
+{
+ blur->type = type;
+ blur->data.pipeline = create_blur_pipeline ();
+
+ blur->sigma_uniform =
+ cogl_pipeline_get_uniform_location (blur->data.pipeline, "sigma");
+ blur->pixel_step_uniform =
+ cogl_pipeline_get_uniform_location (blur->data.pipeline, "pixel_step");
+ blur->vertical_uniform =
+ cogl_pipeline_get_uniform_location (blur->data.pipeline, "vertical");
+}
+
+static void
+update_blur_uniforms (ShellBlurEffect *self,
+ BlurData *blur)
+{
+ gboolean is_vertical = blur->type == VERTICAL;
+
+ if (blur->pixel_step_uniform > -1)
+ {
+ float pixel_step;
+
+ if (is_vertical)
+ pixel_step = 1.f / cogl_texture_get_height (blur->data.texture);
+ else
+ pixel_step = 1.f / cogl_texture_get_width (blur->data.texture);
+
+ cogl_pipeline_set_uniform_1f (blur->data.pipeline,
+ blur->pixel_step_uniform,
+ pixel_step);
+ }
+
+ if (blur->sigma_uniform > -1)
+ {
+ cogl_pipeline_set_uniform_1f (blur->data.pipeline,
+ blur->sigma_uniform,
+ self->sigma / self->downscale_factor);
+ }
+
+ if (blur->vertical_uniform > -1)
+ {
+ cogl_pipeline_set_uniform_1i (blur->data.pipeline,
+ blur->vertical_uniform,
+ is_vertical);
+ }
+}
+
+static void
+update_brightness_uniform (ShellBlurEffect *self)
+{
+ if (self->brightness_uniform > -1)
+ {
+ cogl_pipeline_set_uniform_1f (self->brightness_fb.pipeline,
+ self->brightness_uniform,
+ self->brightness);
+ }
+}
+
+static void
+setup_projection_matrix (CoglFramebuffer *framebuffer,
+ float width,
+ float height)
+{
+ CoglMatrix projection;
+
+ cogl_matrix_init_identity (&projection);
+ cogl_matrix_scale (&projection,
+ 2.0 / width,
+ -2.0 / height,
+ 1.f);
+ cogl_matrix_translate (&projection,
+ -width / 2.0,
+ -height / 2.0,
+ 0);
+
+ cogl_framebuffer_set_projection_matrix (framebuffer, &projection);
+}
+
+static gboolean
+update_fbo (FramebufferData *data,
+ unsigned int width,
+ unsigned int height,
+ float downscale_factor)
+{
+ CoglContext *ctx =
+ clutter_backend_get_cogl_context (clutter_get_default_backend ());
+
+ g_clear_pointer (&data->texture, cogl_object_unref);
+ g_clear_pointer (&data->framebuffer, cogl_object_unref);
+
+ float new_width = floorf (width / downscale_factor);
+ float new_height = floorf (height / downscale_factor);
+
+ data->texture = cogl_texture_2d_new_with_size (ctx, new_width, new_height);
+ if (!data->texture)
+ return FALSE;
+
+ cogl_pipeline_set_layer_texture (data->pipeline, 0, data->texture);
+
+ data->framebuffer = cogl_offscreen_new_with_texture (data->texture);
+ if (!data->framebuffer)
+ {
+ g_warning ("%s: Unable to create an Offscreen buffer", G_STRLOC);
+ return FALSE;
+ }
+
+ setup_projection_matrix (data->framebuffer, new_width, new_height);
+
+ return TRUE;
+}
+
+static gboolean
+update_actor_fbo (ShellBlurEffect *self,
+ unsigned int width,
+ unsigned int height,
+ float downscale_factor)
+{
+ if (self->tex_width == width &&
+ self->tex_height == height &&
+ self->downscale_factor == downscale_factor &&
+ self->actor_fb.framebuffer)
+ {
+ return TRUE;
+ }
+
+ self->cache_flags &= ~ACTOR_PAINTED;
+
+ return update_fbo (&self->actor_fb, width, height, downscale_factor);
+}
+
+static gboolean
+update_brightness_fbo (ShellBlurEffect *self,
+ unsigned int width,
+ unsigned int height,
+ float downscale_factor)
+{
+ if (self->tex_width == width &&
+ self->tex_height == height &&
+ self->downscale_factor == downscale_factor &&
+ self->brightness_fb.framebuffer)
+ {
+ return TRUE;
+ }
+
+ return update_fbo (&self->brightness_fb,
+ width, height,
+ downscale_factor);
+}
+
+static gboolean
+update_blur_fbo (ShellBlurEffect *self,
+ BlurData *blur,
+ unsigned int width,
+ unsigned int height,
+ float downscale_factor)
+{
+ if (self->tex_width == width &&
+ self->tex_height == height &&
+ self->downscale_factor == downscale_factor &&
+ blur->data.framebuffer)
+ {
+ return TRUE;
+ }
+
+ return update_fbo (&blur->data,
+ width, height,
+ downscale_factor);
+}
+
+static gboolean
+update_background_fbo (ShellBlurEffect *self,
+ unsigned int width,
+ unsigned int height)
+{
+ if (self->tex_width == width &&
+ self->tex_height == height &&
+ self->background_fb.framebuffer)
+ {
+ return TRUE;
+ }
+
+ return update_fbo (&self->background_fb, width, height, 1.0);
+}
+
+static void
+clear_framebuffer_data (FramebufferData *fb_data)
+{
+ g_clear_pointer (&fb_data->texture, cogl_object_unref);
+ g_clear_pointer (&fb_data->framebuffer, cogl_object_unref);
+}
+
+static float
+calculate_downscale_factor (float width,
+ float height,
+ float sigma)
+{
+ float downscale_factor = 1.0;
+ float scaled_width = width;
+ float scaled_height = height;
+ float scaled_sigma = sigma;
+
+ /* This is the algorithm used by Firefox; keep downscaling until either the
+ * blur radius is lower than the threshold, or the downscaled texture is too
+ * small.
+ */
+ while (scaled_sigma > MAX_SIGMA &&
+ scaled_width > MIN_DOWNSCALE_SIZE &&
+ scaled_height > MIN_DOWNSCALE_SIZE)
+ {
+ downscale_factor *= 2.f;
+
+ scaled_width = width / downscale_factor;
+ scaled_height = height / downscale_factor;
+ scaled_sigma = sigma / downscale_factor;
+ }
+
+ return downscale_factor;
+}
+
+static void
+clear_framebuffer (CoglFramebuffer *framebuffer)
+{
+ static CoglColor transparent;
+ static gboolean initialized = FALSE;
+
+ if (!initialized)
+ {
+ cogl_color_init_from_4ub (&transparent, 0, 0, 0, 0);
+ initialized = TRUE;
+ }
+
+ cogl_framebuffer_clear (framebuffer, COGL_BUFFER_BIT_COLOR, &transparent);
+}
+
+static void
+shell_blur_effect_set_actor (ClutterActorMeta *meta,
+ ClutterActor *actor)
+{
+ ShellBlurEffect *self = SHELL_BLUR_EFFECT (meta);
+ ClutterActorMetaClass *meta_class;
+
+ meta_class = CLUTTER_ACTOR_META_CLASS (shell_blur_effect_parent_class);
+ meta_class->set_actor (meta, actor);
+
+ /* clear out the previous state */
+ clear_framebuffer_data (&self->actor_fb);
+ clear_framebuffer_data (&self->background_fb);
+ clear_framebuffer_data (&self->brightness_fb);
+ clear_framebuffer_data (&self->blur[VERTICAL].data);
+ clear_framebuffer_data (&self->blur[HORIZONTAL].data);
+
+ /* we keep a back pointer here, to avoid going through the ActorMeta */
+ self->actor = clutter_actor_meta_get_actor (meta);
+}
+
+static void
+update_actor_box (ShellBlurEffect *self,
+ ClutterPaintContext *paint_context,
+ ClutterActorBox *source_actor_box)
+{
+ ClutterStageView *stage_view;
+ float box_scale_factor = 1.0f;
+ float origin_x, origin_y;
+ float width, height;
+
+ switch (self->mode)
+ {
+ case SHELL_BLUR_MODE_ACTOR:
+ clutter_actor_get_allocation_box (self->actor, source_actor_box);
+ break;
+
+ case SHELL_BLUR_MODE_BACKGROUND:
+ stage_view = clutter_paint_context_get_stage_view (paint_context);
+
+ clutter_actor_get_transformed_position (self->actor, &origin_x, &origin_y);
+ clutter_actor_get_transformed_size (self->actor, &width, &height);
+
+ if (stage_view)
+ {
+ cairo_rectangle_int_t stage_view_layout;
+
+ box_scale_factor = clutter_stage_view_get_scale (stage_view);
+ clutter_stage_view_get_layout (stage_view, &stage_view_layout);
+
+ origin_x -= stage_view_layout.x;
+ origin_y -= stage_view_layout.y;
+ }
+ else
+ {
+ /* If we're drawing off stage, just assume scale = 1, this won't work
+ * with stage-view scaling though.
+ */
+ }
+
+ clutter_actor_box_set_origin (source_actor_box, origin_x, origin_y);
+ clutter_actor_box_set_size (source_actor_box, width, height);
+
+ clutter_actor_box_scale (source_actor_box, box_scale_factor);
+ break;
+ }
+
+ clutter_actor_box_clamp_to_pixel (source_actor_box);
+}
+
+static void
+paint_texture (ShellBlurEffect *self,
+ ClutterPaintContext *paint_context)
+{
+ CoglFramebuffer *framebuffer;
+ float width, height;
+
+ framebuffer = clutter_paint_context_get_framebuffer (paint_context);
+
+ /* Use the untransformed actor size here, since the framebuffer itself already
+ * has the actor transform matrix applied.
+ */
+ clutter_actor_get_size (self->actor, &width, &height);
+
+ update_brightness_uniform (self);
+ cogl_framebuffer_draw_rectangle (framebuffer,
+ self->brightness_fb.pipeline,
+ 0, 0,
+ width,
+ height);
+}
+
+static void
+apply_blur (ShellBlurEffect *self,
+ ClutterPaintContext *paint_context,
+ FramebufferData *from,
+ uint8_t paint_opacity)
+{
+ BlurData *vblur;
+ BlurData *hblur;
+
+ vblur = &self->blur[VERTICAL];
+ hblur = &self->blur[HORIZONTAL];
+
+ /* Copy the actor contents into the vblur framebuffer */
+ clear_framebuffer (vblur->data.framebuffer);
+ cogl_framebuffer_draw_rectangle (vblur->data.framebuffer,
+ from->pipeline,
+ 0, 0,
+ cogl_texture_get_width (vblur->data.texture),
+ cogl_texture_get_height (vblur->data.texture));
+
+ /* Pass 1:
+ *
+ * Draw the actor contents (which is in the vblur framebuffer
+ * at this point) into the hblur framebuffer. This will run the
+ * vertical blur fragment shader, and will output a vertically
+ * blurred image.
+ */
+ update_blur_uniforms (self, vblur);
+
+ clear_framebuffer (hblur->data.framebuffer);
+ cogl_framebuffer_draw_rectangle (hblur->data.framebuffer,
+ vblur->data.pipeline,
+ 0, 0,
+ cogl_texture_get_width (hblur->data.texture),
+ cogl_texture_get_height (hblur->data.texture));
+
+ /* Pass 2:
+ *
+ * Now the opposite; draw the vertically blurred image using the
+ * horizontal blur pipeline into the brightness framebuffer.
+ */
+ update_blur_uniforms (self, hblur);
+ cogl_pipeline_set_color4ub (hblur->data.pipeline,
+ paint_opacity,
+ paint_opacity,
+ paint_opacity,
+ paint_opacity);
+
+ clear_framebuffer (self->brightness_fb.framebuffer);
+ cogl_framebuffer_draw_rectangle (self->brightness_fb.framebuffer,
+ hblur->data.pipeline,
+ 0, 0,
+ cogl_texture_get_width (self->brightness_fb.texture),
+ cogl_texture_get_height (self->brightness_fb.texture));
+
+
+ self->cache_flags |= BLUR_APPLIED;
+}
+
+static gboolean
+paint_background (ShellBlurEffect *self,
+ ClutterPaintContext *paint_context,
+ ClutterActorBox *source_actor_box)
+{
+ g_autoptr (GError) error = NULL;
+ CoglFramebuffer *framebuffer;
+ float transformed_x;
+ float transformed_y;
+ float transformed_width;
+ float transformed_height;
+
+ framebuffer = clutter_paint_context_get_framebuffer (paint_context);
+
+ clutter_actor_box_get_origin (source_actor_box,
+ &transformed_x,
+ &transformed_y);
+ clutter_actor_box_get_size (source_actor_box,
+ &transformed_width,
+ &transformed_height);
+
+ clear_framebuffer (self->background_fb.framebuffer);
+ cogl_blit_framebuffer (framebuffer,
+ self->background_fb.framebuffer,
+ transformed_x,
+ transformed_y,
+ 0, 0,
+ transformed_width,
+ transformed_height,
+ &error);
+
+ if (error)
+ {
+ g_warning ("Error blitting overlay framebuffer: %s", error->message);
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+static gboolean
+update_framebuffers (ShellBlurEffect *self,
+ ClutterPaintContext *paint_context,
+ ClutterActorBox *source_actor_box)
+{
+ gboolean updated = FALSE;
+ float downscale_factor;
+ float height = -1;
+ float width = -1;
+
+ clutter_actor_box_get_size (source_actor_box, &width, &height);
+
+ downscale_factor = calculate_downscale_factor (width, height, self->sigma);
+
+ updated =
+ update_actor_fbo (self, width, height, downscale_factor) &&
+ update_blur_fbo (self, &self->blur[VERTICAL], width, height, downscale_factor) &&
+ update_blur_fbo (self, &self->blur[HORIZONTAL], width, height, downscale_factor) &&
+ update_brightness_fbo (self, width, height, downscale_factor);
+
+ if (self->mode == SHELL_BLUR_MODE_BACKGROUND)
+ updated = updated && update_background_fbo (self, width, height);
+
+ self->tex_width = width;
+ self->tex_height = height;
+ self->downscale_factor = downscale_factor;
+
+ return updated;
+}
+
+static void
+paint_actor_offscreen (ShellBlurEffect *self,
+ ClutterPaintContext *paint_context,
+ ClutterEffectPaintFlags flags)
+{
+ gboolean actor_dirty;
+
+ actor_dirty = (flags & CLUTTER_EFFECT_PAINT_ACTOR_DIRTY) != 0;
+
+ /* The actor offscreen framebuffer is updated already */
+ if (!actor_dirty && (self->cache_flags & ACTOR_PAINTED))
+ return;
+
+ self->old_opacity_override = clutter_actor_get_opacity_override (self->actor);
+ clutter_actor_set_opacity_override (self->actor, 0xff);
+
+ /* Draw the actor contents into the actor offscreen framebuffer */
+ clear_framebuffer (self->actor_fb.framebuffer);
+
+ cogl_framebuffer_push_matrix (self->actor_fb.framebuffer);
+ cogl_framebuffer_scale (self->actor_fb.framebuffer,
+ 1.f / self->downscale_factor,
+ 1.f / self->downscale_factor,
+ 1.f);
+
+ clutter_paint_context_push_framebuffer (paint_context,
+ self->actor_fb.framebuffer);
+
+ clutter_actor_continue_paint (self->actor, paint_context);
+
+ cogl_framebuffer_pop_matrix (self->actor_fb.framebuffer);
+ clutter_paint_context_pop_framebuffer (paint_context);
+
+ clutter_actor_set_opacity_override (self->actor, self->old_opacity_override);
+
+ self->cache_flags |= ACTOR_PAINTED;
+}
+
+static gboolean
+needs_repaint (ShellBlurEffect *self,
+ ClutterEffectPaintFlags flags)
+{
+ gboolean actor_cached;
+ gboolean blur_cached;
+ gboolean actor_dirty;
+
+ actor_dirty = (flags & CLUTTER_EFFECT_PAINT_ACTOR_DIRTY) != 0;
+ blur_cached = (self->cache_flags & BLUR_APPLIED) != 0;
+ actor_cached = (self->cache_flags & ACTOR_PAINTED) != 0;
+
+ switch (self->mode)
+ {
+ case SHELL_BLUR_MODE_ACTOR:
+ return actor_dirty || !blur_cached || !actor_cached;
+
+ case SHELL_BLUR_MODE_BACKGROUND:
+ return TRUE;
+ }
+
+ return TRUE;
+}
+
+static void
+shell_blur_effect_paint (ClutterEffect *effect,
+ ClutterPaintContext *paint_context,
+ ClutterEffectPaintFlags flags)
+{
+ ShellBlurEffect *self = SHELL_BLUR_EFFECT (effect);
+ uint8_t paint_opacity;
+
+ g_assert (self->actor != NULL);
+
+ if (self->sigma > 0)
+ {
+ if (needs_repaint (self, flags))
+ {
+ ClutterActorBox source_actor_box;
+
+ update_actor_box (self, paint_context, &source_actor_box);
+
+ /* Failing to create or update the offscreen framebuffers prevents
+ * the entire effect to be applied.
+ */
+ if (!update_framebuffers (self, paint_context, &source_actor_box))
+ goto fail;
+
+ switch (self->mode)
+ {
+ case SHELL_BLUR_MODE_ACTOR:
+ paint_opacity = clutter_actor_get_paint_opacity (self->actor);
+
+ paint_actor_offscreen (self, paint_context, flags);
+ apply_blur (self, paint_context, &self->actor_fb, paint_opacity);
+ break;
+
+ case SHELL_BLUR_MODE_BACKGROUND:
+ if (!paint_background (self, paint_context, &source_actor_box))
+ goto fail;
+
+ apply_blur (self, paint_context, &self->background_fb, 255);
+ break;
+ }
+ }
+
+ paint_texture (self, paint_context);
+
+ /* Background blur needs to paint the actor after painting the blurred
+ * background.
+ */
+ switch (self->mode)
+ {
+ case SHELL_BLUR_MODE_ACTOR:
+ break;
+
+ case SHELL_BLUR_MODE_BACKGROUND:
+ clutter_actor_continue_paint (self->actor, paint_context);
+ break;
+ }
+
+ return;
+ }
+
+fail:
+ /* When no blur is applied, or the offscreen framebuffers
+ * couldn't be created, fallback to simply painting the actor.
+ */
+ clutter_actor_continue_paint (self->actor, paint_context);
+}
+
+static void
+shell_blur_effect_finalize (GObject *object)
+{
+ ShellBlurEffect *self = (ShellBlurEffect *)object;
+
+ clear_framebuffer_data (&self->actor_fb);
+ clear_framebuffer_data (&self->background_fb);
+ clear_framebuffer_data (&self->brightness_fb);
+ clear_framebuffer_data (&self->blur[VERTICAL].data);
+ clear_framebuffer_data (&self->blur[HORIZONTAL].data);
+
+ g_clear_pointer (&self->actor_fb.pipeline, cogl_object_unref);
+ g_clear_pointer (&self->background_fb.pipeline, cogl_object_unref);
+ g_clear_pointer (&self->brightness_fb.pipeline, cogl_object_unref);
+ g_clear_pointer (&self->blur[VERTICAL].data.pipeline, cogl_object_unref);
+ g_clear_pointer (&self->blur[HORIZONTAL].data.pipeline, cogl_object_unref);
+
+ G_OBJECT_CLASS (shell_blur_effect_parent_class)->finalize (object);
+}
+
+static void
+shell_blur_effect_get_property (GObject *object,
+ guint prop_id,
+ GValue *value,
+ GParamSpec *pspec)
+{
+ ShellBlurEffect *self = SHELL_BLUR_EFFECT (object);
+
+ switch (prop_id)
+ {
+ case PROP_SIGMA:
+ g_value_set_int (value, self->sigma);
+ break;
+
+ case PROP_BRIGHTNESS:
+ g_value_set_float (value, self->brightness);
+ break;
+
+ case PROP_MODE:
+ g_value_set_enum (value, self->mode);
+ break;
+
+ default:
+ G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+ }
+}
+
+static void
+shell_blur_effect_set_property (GObject *object,
+ guint prop_id,
+ const GValue *value,
+ GParamSpec *pspec)
+{
+ ShellBlurEffect *self = SHELL_BLUR_EFFECT (object);
+
+ switch (prop_id)
+ {
+ case PROP_SIGMA:
+ shell_blur_effect_set_sigma (self, g_value_get_int (value));
+ break;
+
+ case PROP_BRIGHTNESS:
+ shell_blur_effect_set_brightness (self, g_value_get_float (value));
+ break;
+
+ case PROP_MODE:
+ shell_blur_effect_set_mode (self, g_value_get_enum (value));
+ break;
+
+ default:
+ G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+ }
+}
+
+static void
+shell_blur_effect_class_init (ShellBlurEffectClass *klass)
+{
+ GObjectClass *object_class = G_OBJECT_CLASS (klass);
+ ClutterActorMetaClass *meta_class = CLUTTER_ACTOR_META_CLASS (klass);
+ ClutterEffectClass *effect_class = CLUTTER_EFFECT_CLASS (klass);
+
+ object_class->finalize = shell_blur_effect_finalize;
+ object_class->get_property = shell_blur_effect_get_property;
+ object_class->set_property = shell_blur_effect_set_property;
+
+ meta_class->set_actor = shell_blur_effect_set_actor;
+
+ effect_class->paint = shell_blur_effect_paint;
+
+ properties[PROP_SIGMA] =
+ g_param_spec_int ("sigma",
+ "Sigma",
+ "Sigma",
+ 0, G_MAXINT, 0,
+ G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
+
+ properties[PROP_BRIGHTNESS] =
+ g_param_spec_float ("brightness",
+ "Brightness",
+ "Brightness",
+ 0.f, 1.f, 1.f,
+ G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
+
+ properties[PROP_MODE] =
+ g_param_spec_enum ("mode",
+ "Blur mode",
+ "Blur mode",
+ SHELL_TYPE_BLUR_MODE,
+ SHELL_BLUR_MODE_ACTOR,
+ G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS);
+
+ g_object_class_install_properties (object_class, N_PROPS, properties);
+}
+
+static void
+shell_blur_effect_init (ShellBlurEffect *self)
+{
+ self->mode = SHELL_BLUR_MODE_ACTOR;
+ self->sigma = 0;
+ self->brightness = 1.f;
+
+ self->actor_fb.pipeline = create_base_pipeline ();
+ self->background_fb.pipeline = create_base_pipeline ();
+ self->brightness_fb.pipeline = create_brightness_pipeline ();
+ self->brightness_uniform =
+ cogl_pipeline_get_uniform_location (self->brightness_fb.pipeline, "brightness");
+
+ setup_blur (&self->blur[VERTICAL], VERTICAL);
+ setup_blur (&self->blur[HORIZONTAL], HORIZONTAL);
+}
+
+ShellBlurEffect *
+shell_blur_effect_new (void)
+{
+ return g_object_new (SHELL_TYPE_BLUR_EFFECT, NULL);
+}
+
+int
+shell_blur_effect_get_sigma (ShellBlurEffect *self)
+{
+ g_return_val_if_fail (SHELL_IS_BLUR_EFFECT (self), -1);
+
+ return self->sigma;
+}
+
+void
+shell_blur_effect_set_sigma (ShellBlurEffect *self,
+ int sigma)
+{
+ g_return_if_fail (SHELL_IS_BLUR_EFFECT (self));
+
+ if (self->sigma == sigma)
+ return;
+
+ self->sigma = sigma;
+ self->cache_flags &= ~BLUR_APPLIED;
+
+ if (self->actor)
+ clutter_effect_queue_repaint (CLUTTER_EFFECT (self));
+
+ g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SIGMA]);
+}
+
+float
+shell_blur_effect_get_brightness (ShellBlurEffect *self)
+{
+ g_return_val_if_fail (SHELL_IS_BLUR_EFFECT (self), FALSE);
+
+ return self->brightness;
+}
+
+void
+shell_blur_effect_set_brightness (ShellBlurEffect *self,
+ float brightness)
+{
+ g_return_if_fail (SHELL_IS_BLUR_EFFECT (self));
+
+ if (self->brightness == brightness)
+ return;
+
+ self->brightness = brightness;
+ self->cache_flags &= ~BLUR_APPLIED;
+
+ if (self->actor)
+ clutter_effect_queue_repaint (CLUTTER_EFFECT (self));
+
+ g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_BRIGHTNESS]);
+}
+
+ShellBlurMode
+shell_blur_effect_get_mode (ShellBlurEffect *self)
+{
+ g_return_val_if_fail (SHELL_IS_BLUR_EFFECT (self), -1);
+
+ return self->mode;
+}
+
+void
+shell_blur_effect_set_mode (ShellBlurEffect *self,
+ ShellBlurMode mode)
+{
+ g_return_if_fail (SHELL_IS_BLUR_EFFECT (self));
+
+ if (self->mode == mode)
+ return;
+
+ self->mode = mode;
+ self->cache_flags &= ~BLUR_APPLIED;
+
+ switch (mode)
+ {
+ case SHELL_BLUR_MODE_ACTOR:
+ clear_framebuffer_data (&self->background_fb);
+ break;
+
+ case SHELL_BLUR_MODE_BACKGROUND:
+ default:
+ /* Do nothing */
+ break;
+ }
+
+ if (self->actor)
+ clutter_effect_queue_repaint (CLUTTER_EFFECT (self));
+
+ g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_MODE]);
+}