1 files changed, 111 insertions, 0 deletions
diff --git a/include/vcl/glyphitemcache.hxx b/include/vcl/glyphitemcache.hxx
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+++ b/include/vcl/glyphitemcache.hxx
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#ifndef INCLUDED_VCL_GLYPHITEMCACHE_HXX
+#define INCLUDED_VCL_GLYPHITEMCACHE_HXX
+
+#include <sal/types.h>
+#include <vcl/dllapi.h>
+
+#include <o3tl/lru_map.hxx>
+#include <o3tl/hash_combine.hxx>
+#include <vcl/glyphitem.hxx>
+#include <vcl/metric.hxx>
+#include <vcl/outdev.hxx>
+#include <vcl/vclptr.hxx>
+#include <tools/gen.hxx>
+
+#include <optional>
+
+/**
+A cache for SalLayoutGlyphs objects.
+
+Allows caching for OutputDevice::DrawText() and similar calls. Pass the text and the output device
+for the call to OutputDevice::ImplLayout(). Items are cached per output device and its font.
+If something more changes, call clear().
+*/
+class VCL_DLLPUBLIC SalLayoutGlyphsCache final
+{
+public:
+    // NOTE: The lifetime of the returned value is guaranteed only until the next call
+    // to any function in this class.
+    const SalLayoutGlyphs* GetLayoutGlyphs(VclPtr<const OutputDevice> outputDevice,
+                                           const OUString& text,
+                                           const vcl::text::TextLayoutCache* layoutCache = nullptr)
+    {
+        return GetLayoutGlyphs(outputDevice, text, 0, text.getLength(), 0, layoutCache);
+    }
+    const SalLayoutGlyphs* GetLayoutGlyphs(VclPtr<const OutputDevice> outputDevice,
+                                           const OUString& text, sal_Int32 nIndex, sal_Int32 nLen,
+                                           tools::Long nLogicWidth = 0,
+                                           const vcl::text::TextLayoutCache* layoutCache = nullptr);
+    void clear();
+
+    static SalLayoutGlyphsCache* self();
+    SalLayoutGlyphsCache(int size) // needs to be public for vcl::DeleteOnDeinit
+        : mCachedGlyphs(size)
+    {
+    }
+
+private:
+    struct CachedGlyphsKey
+    {
+        OUString text;
+        sal_Int32 index;
+        sal_Int32 len;
+        tools::Long logicWidth;
+        FontMetric fontMetric;
+        double fontScaleX;
+        double fontScaleY;
+        MapMode mapMode;
+        bool rtl;
+        bool artificialItalic;
+        bool artificialBold;
+        vcl::text::ComplexTextLayoutFlags layoutMode;
+        LanguageType digitLanguage;
+        size_t hashValue;
+        CachedGlyphsKey(const VclPtr<const OutputDevice>& dev, const OUString& t, sal_Int32 i,
+                        sal_Int32 l, tools::Long w);
+        bool operator==(const CachedGlyphsKey& other) const;
+    };
+    struct CachedGlyphsHash
+    {
+        size_t operator()(const CachedGlyphsKey& key) const { return key.hashValue; }
+    };
+    struct GlyphsCost
+    {
+        size_t operator()(const SalLayoutGlyphs&) const;
+    };
+    typedef o3tl::lru_map<CachedGlyphsKey, SalLayoutGlyphs, CachedGlyphsHash,
+                          std::equal_to<CachedGlyphsKey>, GlyphsCost>
+        GlyphsCache;
+    GlyphsCache mCachedGlyphs;
+    // Last temporary glyphs returned (pointer is returned, so the object needs to be kept somewhere).
+    std::optional<CachedGlyphsKey> mLastTemporaryKey;
+    SalLayoutGlyphs mLastTemporaryGlyphs;
+    // If set, info about the last call which wanted a substring of the full text.
+    std::optional<CachedGlyphsKey> mLastSubstringKey;
+
+    SalLayoutGlyphsCache(const SalLayoutGlyphsCache&) = delete;
+    SalLayoutGlyphsCache& operator=(const SalLayoutGlyphsCache&) = delete;
+};
+
+#endif // INCLUDED_VCL_GLYPHITEMCACHE_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */