BackgroundEffectHelper: Specify the required blur area before drawing so selectively copy it at paint time

This means that we don't have to waste fragment bandwidth copying the entire backbuffer when we could just do parts of it. Now BackgroundEffectHelper listens to windows and views geometry changes and updates a list of blurred regions that might be copied to the backup texture at every repaint that affects them. This avoids to copy large regions (especially when using big resolutions or multiple monitors), but only the ones we really need to blur. Approved by PS Jenkins bot, Eleni Maria Stea, Christopher Townsend. Original authors: - Marco Trevisan (Treviño) <mail@3v1n0.net> - Sam Spilsbury <sam.spilsbury@canonical.com> (bzr r3600)

2 files changed, 56 insertions, 13 deletions

diff --git a/plugins/unityshell/src/unityshell.cpp b/plugins/unityshell/src/unityshell.cpp
index 0fe0836a3..cf85e2718 100644
--- a/plugins/unityshell/src/unityshell.cpp
+++ b/plugins/unityshell/src/unityshell.cpp
@@ -394,8 +394,6 @@ UnityScreen::UnityScreen(CompScreen* screen)
 CompSize size(1, 20);
 _shadow_texture = GLTexture::readImageToTexture(name, pname, size);
 
- BackgroundEffectHelper::updates_enabled = true;
-
 ubus_manager_.RegisterInterest(UBUS_OVERLAY_SHOWN, [this](GVariant * data)
 {
 unity::glib::String overlay_identity;
@@ -433,6 +431,16 @@ UnityScreen::UnityScreen(CompScreen* screen)
 
 AddChild(&screen_introspection_);
 
+ /* Create blur backup texture */
+ auto gpu_device = nux::GetGraphicsDisplay()->GetGpuDevice();
+ gpu_device->backup_texture0_ =
+ gpu_device->CreateSystemCapableDeviceTexture(screen->width(), screen->height(),
+ 1, nux::BITFMT_R8G8B8A8,
+ NUX_TRACKER_LOCATION);
+
+ auto const& blur_update_cb = sigc::mem_fun(this, &UnityScreen::DamageBlurUpdateRegion);
+ BackgroundEffectHelper::blur_region_needs_update_.connect(blur_update_cb);
+
 /* Track whole damage on the very first frame */
 cScreen->damageScreen();
 }
@@ -734,6 +742,11 @@ void UnityScreen::OnPanelStyleChanged()
 }
 }
 
+void UnityScreen::DamageBlurUpdateRegion(nux::Geometry const& blur_update)
+{
+ cScreen->damageRegion(CompRegionFromNuxGeo(blur_update));
+}
+
 void UnityScreen::paintDisplay()
 {
 CompOutput *output = _last_output;
@@ -751,27 +764,49 @@ void UnityScreen::paintDisplay()
 if (old_read_binding != current_draw_binding)
 (*GL::bindFramebuffer) (GL_READ_FRAMEBUFFER_BINDING_EXT, current_draw_binding);
 #else
- glGetIntegerv(GL_FRAMEBUFFER_BINDING, &current_draw_binding);
 glGetIntegerv(GL_FRAMEBUFFER_BINDING, &old_read_binding);
+ current_draw_binding = old_read_binding;
 #endif
 
- /* If we have dirty helpers re-copy the backbuffer
- * into a texture
- *
- * TODO: Make this faster by only copying the bits we
- * need as opposed to the whole readbuffer */
+ BackgroundEffectHelper::monitor_rect_.Set(0, 0, screen->width(), screen->height());
+
+ // If we have dirty helpers re-copy the backbuffer into a texture
 if (dirty_helpers_on_this_frame_)
 {
+ /* We are using a CompRegion here so that we can combine rectangles
+ * where it might make sense to. Saves calls into OpenGL */
+ CompRegion blur_region;
+
+ for (auto const& blur_geometry : BackgroundEffectHelper::GetBlurGeometries())
+ {
+ auto blur_rect = CompRectFromNuxGeo(blur_geometry);
+ blur_region += (blur_rect & *output);
+ }
+
+ /* Copy from the read buffer into the backup texture */
 auto gpu_device = nux::GetGraphicsDisplay()->GetGpuDevice();
- auto graphics_engine = nux::GetGraphicsDisplay()->GetGraphicsEngine();
- gpu_device->backup_texture0_ =
- graphics_engine->CreateTextureFromBackBuffer(0, 0, screen->width(), screen->height());
+ GLuint backup_texture_id = gpu_device->backup_texture0_->GetOpenGLID();
+ GLuint surface_target = gpu_device->backup_texture0_->GetSurfaceLevel(0)->GetSurfaceTarget();
+
+ CHECKGL(glEnable(surface_target));
+ CHECKGL(glBindTexture(surface_target, backup_texture_id));
+
+ for (CompRect const& rect : blur_region.rects())
+ {
+ int x = nux::Clamp<int>(rect.x(), 0, screen->width());
+ int y = nux::Clamp<int>(screen->height() - rect.y2(), 0, screen->height());
+ int width = std::min<int>(screen->width() - rect.x(), rect.width());
+ int height = std::min<int>(screen->height() - y, rect.height());
+
+ CHECKGL(glCopyTexSubImage2D(surface_target, 0, x, y, x, y, width, height));
+ }
+
+ CHECKGL(glDisable(surface_target));
+
 back_buffer_age_ = 0;
 }
 
 nux::Geometry const& outputGeo = NuxGeometryFromCompRect(*output);
- BackgroundEffectHelper::monitor_rect_.Set(0, 0, screen->width(), screen->height());
-
 wt->GetWindowCompositor().SetReferenceFramebuffer(current_draw_binding, old_read_binding, outputGeo);
 
 nuxPrologue();
@@ -3352,6 +3387,12 @@ void UnityScreen::outputChangeNotify()
 {
 screen->outputChangeNotify ();
 
+ auto gpu_device = nux::GetGraphicsDisplay()->GetGpuDevice();
+ gpu_device->backup_texture0_ =
+ gpu_device->CreateSystemCapableDeviceTexture(screen->width(), screen->height(),
+ 1, nux::BITFMT_R8G8B8A8,
+ NUX_TRACKER_LOCATION);
+
 ScheduleRelayout(500);
 }
 
diff --git a/plugins/unityshell/src/unityshell.h b/plugins/unityshell/src/unityshell.h
index df3f6bc3e..a531327f9 100644
--- a/plugins/unityshell/src/unityshell.h
+++ b/plugins/unityshell/src/unityshell.h
@@ -277,6 +277,8 @@ private:
 
 void UpdateCloseWindowKey(CompAction::KeyBinding const&);
 
+ void DamageBlurUpdateRegion(nux::Geometry const&);
+
 std::unique_ptr<na::TickSource> tick_source_;
 std::unique_ptr<na::AnimationController> animation_controller_;