Add a glyph-bound-rect cache to the font cache

This way the font cache can correctly invalidate the cached glyph
rects when a font is dropped from the cache.

Change-Id: I050866099742334f01cac1b872228a017ddb5e9b
Reviewed-on: https://gerrit.libreoffice.org/61371
Tested-by: Jenkins
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>

2 files changed, 50 insertions, 1 deletions

diff --git a/vcl/source/font/fontcache.cxx b/vcl/source/font/fontcache.cxx
index 82a6261c274c..0db997fe510f 100644
--- a/vcl/source/font/fontcache.cxx
+++ b/vcl/source/font/fontcache.cxx
@@ -84,11 +84,15 @@ bool ImplFontCache::IFSD_Equal::operator()(const FontSelectPattern& rA, const Fo
 }
 
 ImplFontCache::ImplFontCache()
-:   mpLastHitCacheEntry( nullptr )
+    : mpLastHitCacheEntry( nullptr )
+    // The cache limit is set by the rough number of characters needed to read your average Asian newspaper.
+    , m_aBoundRectCache(3000)
 {}
 
 ImplFontCache::~ImplFontCache()
 {
+    for (auto & rLFI : maFontInstanceList)
+        rLFI.second->mpFontCache = nullptr;
 }
 
 rtl::Reference<LogicalFontInstance> ImplFontCache::GetFontInstance( PhysicalFontCollection const * pFontList,
@@ -174,6 +178,9 @@ rtl::Reference<LogicalFontInstance> ImplFontCache::GetFontInstance( PhysicalFont
                     ++it_next;
                     continue;
                 }
+                m_aBoundRectCache.remove_if([&pFontEntry] (GlpyhBoundRectCachePair const& rPair)
+                    { return rPair.first.m_pFont == pFontEntry; } );
+
                 maFontInstanceList.erase(it_next);
                 if (mpLastHitCacheEntry == pFontEntry)
                     mpLastHitCacheEntry = nullptr;
@@ -233,6 +240,35 @@ void ImplFontCache::Invalidate()
     for (auto const & pair : maFontInstanceList)
         pair.second->mpFontCache = nullptr;
     maFontInstanceList.clear();
+    m_aBoundRectCache.clear();
+}
+
+bool ImplFontCache::GetCachedGlyphBoundRect(LogicalFontInstance *pFont, sal_GlyphId nID, tools::Rectangle &rRect)
+{
+    if (!pFont->GetFontCache())
+        return false;
+    assert(pFont->GetFontCache() == this);
+    if (pFont->GetFontCache() != this)
+        return false;
+
+    auto it = m_aBoundRectCache.find({pFont, nID});
+    if (it != m_aBoundRectCache.end())
+    {
+        rRect = it->second;
+        return true;
+    }
+    return false;
+}
+
+void ImplFontCache::CacheGlyphBoundRect(LogicalFontInstance *pFont, sal_GlyphId nID, tools::Rectangle &rRect)
+{
+    if (!pFont->GetFontCache())
+        return;
+    assert(pFont->GetFontCache() == this);
+    if (pFont->GetFontCache() != this)
+        return;
+
+    m_aBoundRectCache.insert({{pFont, nID}, rRect});
 }
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/source/font/fontinstance.cxx b/vcl/source/font/fontinstance.cxx
index cf80428f61e2..7a889fa65a7c 100644
--- a/vcl/source/font/fontinstance.cxx
+++ b/vcl/source/font/fontinstance.cxx
@@ -147,5 +147,18 @@ void LogicalFontInstance::IgnoreFallbackForUnicode( sal_UCS4 cChar, FontWeight e
         mpUnicodeFallbackList->erase( it );
 }
 
+bool LogicalFontInstance::GetCachedGlyphBoundRect(sal_GlyphId nID, tools::Rectangle &rRect)
+{
+    if (!mpFontCache)
+        return false;
+    return mpFontCache->GetCachedGlyphBoundRect(this, nID, rRect);
+}
+
+void LogicalFontInstance::CacheGlyphBoundRect(sal_GlyphId nID, tools::Rectangle &rRect)
+{
+    if (!mpFontCache)
+        return;
+    mpFontCache->CacheGlyphBoundRect(this, nID, rRect);
+}
 
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */