Add preference that allows user to increase the canvas tile size.

A larger tile size vastly speeds up rendering for drawings with heavy filter use
by reducing the need to recalculate filter effects that cross multiple tiles.

(bzr r15614)

3 files changed, 12 insertions, 1 deletions

diff --git a/src/display/sp-canvas.cpp b/src/display/sp-canvas.cpp
index 74aa4807a..d04c81ecb 100644
--- a/src/display/sp-canvas.cpp
+++ b/src/display/sp-canvas.cpp
@@ -1727,10 +1727,16 @@ bool SPCanvas::paintRect(int xx0, int yy0, int xx1, int yy1)
 
     setup.mouse_loc = sp_canvas_window_to_world(this, Geom::Point(x,y));
 
+    static unsigned tile_multiplier = 0;
+    if (tile_multiplier == 0) {
+        Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+        tile_multiplier = prefs->getIntLimited("/options/rendering/tile-multiplier", 1, 1, 64);
+    }
+
     if (_rendermode != Inkscape::RENDERMODE_OUTLINE) {
         // use 256K as a compromise to not slow down gradients
         // 256K is the cached buffer and we need 4 channels
-        setup.max_pixels = 65536; // 256K/4
+        setup.max_pixels = 65536 * tile_multiplier; // 256K/4
     } else {
         // paths only, so 1M works faster
         // 1M is the cached buffer and we need 4 channels
diff --git a/src/ui/dialog/inkscape-preferences.cpp b/src/ui/dialog/inkscape-preferences.cpp
index 958d73746..646439613 100644
--- a/src/ui/dialog/inkscape-preferences.cpp
+++ b/src/ui/dialog/inkscape-preferences.cpp
@@ -1411,6 +1411,10 @@ void InkscapePreferences::initPageRendering()
     _rendering_cache_size.init("/options/renderingcache/size", 0.0, 4096.0, 1.0, 32.0, 64.0, true, false);
     _page_rendering.add_line( false, _("Rendering _cache size:"), _rendering_cache_size, C_("mebibyte (2^20 bytes) abbreviation","MiB"), _("Set the amount of memory per document which can be used to store rendered parts of the drawing for later reuse; set to zero to disable caching"), false);
 
+    // rendering tile multiplier
+    _rendering_tile_multiplier.init("/options/rendering/tile-multiplier", 1.0, 64.0, 1.0, 4.0, 1.0, true, false);
+    _page_rendering.add_line( false, _("Rendering tile multiplier:"), _rendering_tile_multiplier, _("requires restart"), _("Set the relative size of tiles used to render the canvas. The larger the value, the bigger the tile size."), false);
+
     /* blur quality */
     _blur_quality_best.init ( _("Best quality (slowest)"), "/options/blurquality/value",
                                   BLUR_QUALITY_BEST, false, 0);
diff --git a/src/ui/dialog/inkscape-preferences.h b/src/ui/dialog/inkscape-preferences.h
index 91465f6a9..e6ba4e4b2 100644
--- a/src/ui/dialog/inkscape-preferences.h
+++ b/src/ui/dialog/inkscape-preferences.h
@@ -295,6 +295,7 @@ protected:
     UI::Widget::PrefCombo       _switcher_style;
     UI::Widget::PrefCheckButton _rendering_image_outline;
     UI::Widget::PrefSpinButton  _rendering_cache_size;
+    UI::Widget::PrefSpinButton  _rendering_tile_multiplier;
     UI::Widget::PrefSpinButton  _filter_multi_threaded;
 
     UI::Widget::PrefCheckButton _trans_scale_stroke;