From ae3562c58dbfc2c4b002a67828639ffc91e83749 Mon Sep 17 00:00:00 2001 From: Uli Schlachter Date: Mon, 26 Jun 2017 11:10:28 +0200 Subject: SPCanvas: Use a similar image for _backing_store Cairo 1.12 adds the function cairo_surface_create_similar_image(). It works just like cairo_image_surface_create() in that it creates an image surface. However, when the passed-in surface is a cairo-xlib surface, the data of the image surface will be allocated in a shared memory segment. This makes it cheaper to have the X11 server access the surface since it does not need to be uploaded. To make use of this, a new _surface_for_similar member is added. This member is set to a (useless) surface in handle_draw(). On Linux this creates a cairo-xlib surface, so that _backing_store is latter allocated in a shared memory segment. Signed-off-by: Uli Schlachter --- src/display/sp-canvas.cpp | 51 +++++++++++++++++++++++++++++++++++++++++++---- src/display/sp-canvas.h | 4 ++++ 2 files changed, 51 insertions(+), 4 deletions(-) (limited to 'src') diff --git a/src/display/sp-canvas.cpp b/src/display/sp-canvas.cpp index 84bdfb762..196a14069 100644 --- a/src/display/sp-canvas.cpp +++ b/src/display/sp-canvas.cpp @@ -966,6 +966,9 @@ static void sp_canvas_init(SPCanvas *canvas) canvas->_drawing_disabled = false; canvas->_backing_store = NULL; +#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1, 12, 0) + canvas->_surface_for_similar = NULL; +#endif canvas->_clean_region = cairo_region_create(); canvas->_background = cairo_pattern_create_rgb(1, 1, 1); canvas->_background_is_checkerboard = false; @@ -1003,6 +1006,12 @@ void SPCanvas::dispose(GObject *object) cairo_surface_destroy(canvas->_backing_store); canvas->_backing_store = NULL; } +#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1, 12, 0) + if (canvas->_surface_for_similar) { + cairo_surface_destroy(canvas->_surface_for_similar); + canvas->_surface_for_similar = NULL; + } +#endif if (canvas->_clean_region) { cairo_region_destroy(canvas->_clean_region); canvas->_clean_region = NULL; @@ -1125,8 +1134,14 @@ void SPCanvas::handle_size_allocate(GtkWidget *widget, GtkAllocation *allocation allocation->width, allocation->height); // resize backing store - cairo_surface_t *new_backing_store = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, - allocation->width, allocation->height); + cairo_surface_t *new_backing_store = NULL; +#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1, 12, 0) + if (canvas->_surface_for_similar != NULL) + new_backing_store = cairo_surface_create_similar_image(canvas->_surface_for_similar, + CAIRO_FORMAT_ARGB32, allocation->width, allocation->height); +#endif + if (new_backing_store == NULL) + new_backing_store = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, allocation->width, allocation->height); if (canvas->_backing_store) { cairo_t *cr = cairo_create(new_backing_store); cairo_translate(cr, -canvas->_x0, -canvas->_y0); @@ -1764,6 +1779,28 @@ void SPCanvas::endForcedFullRedraws() gboolean SPCanvas::handle_draw(GtkWidget *widget, cairo_t *cr) { SPCanvas *canvas = SP_CANVAS(widget); +#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1, 12, 0) + if (canvas->_surface_for_similar == NULL && canvas->_backing_store != NULL) { + canvas->_surface_for_similar = cairo_surface_create_similar( + cairo_get_target(cr), CAIRO_CONTENT_COLOR_ALPHA, 1, 1); + + // Reallocate backing store so that cairo can use shared memory + cairo_surface_t *new_backing_store = cairo_surface_create_similar_image( + canvas->_surface_for_similar, CAIRO_FORMAT_ARGB32, + cairo_image_surface_get_width(canvas->_backing_store), + cairo_image_surface_get_height(canvas->_backing_store)); + + // Copy the old backing store contents + cairo_t *cr = cairo_create(new_backing_store); + cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE); + cairo_set_source_surface(cr, canvas->_backing_store, 0, 0); + cairo_paint(cr); + cairo_destroy(cr); + cairo_surface_destroy(canvas->_backing_store); + canvas->_backing_store = new_backing_store; + } +#endif + // Blit from the backing store, without regard for the clean region. // This is necessary because GTK clears the widget for us, which causes // severe flicker while drawing if we don't blit the old contents. @@ -1949,8 +1986,14 @@ void SPCanvas::scrollTo( Geom::Point const &c, unsigned int clear, bool is_scrol // adjust backing store contents assert(_backing_store); - cairo_surface_t *new_backing_store = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, - allocation.width, allocation.height); + cairo_surface_t *new_backing_store = NULL; +#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1, 12, 0) + if (_surface_for_similar != NULL) + new_backing_store = cairo_surface_create_similar_image( + _surface_for_similar, CAIRO_FORMAT_ARGB32, allocation.width, allocation.height); +#endif + if (new_backing_store == NULL) + new_backing_store = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, allocation.width, allocation.height); cairo_t *cr = cairo_create(new_backing_store); cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE); // Paint the background diff --git a/src/display/sp-canvas.h b/src/display/sp-canvas.h index a2cbe0b27..92a50da11 100644 --- a/src/display/sp-canvas.h +++ b/src/display/sp-canvas.h @@ -179,6 +179,10 @@ public: /// Image surface storing the contents of the widget cairo_surface_t *_backing_store; +#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1, 12, 0) + /// This should be e.g. a cairo-xlib surface that is used to allocate _backing_store; might be NULL. + cairo_surface_t *_surface_for_similar; +#endif /// Area of the widget that has up-to-date content cairo_region_t *_clean_region; /// Widget background, defaults to white -- cgit v1.2.3