Text: add AbstractFont::glyphCount().

And check glyph IDs against it in glyphAdvance().

doc/changelog.dox

@@ -767,6 +767,7 @@ See also:
 
 @subsubsection changelog-latest-changes-text Text library
 
+-   Added @ref Text::AbstractFont::glyphCount()
 -   Added @ref Text::Renderer::fontSize()
 
 @subsubsection changelog-latest-changes-trade Trade library

src/Magnum/Text/AbstractFont.cpp

@@ -114,6 +114,7 @@ bool AbstractFont::openData(Containers::ArrayView<const void> data, const Float
         _ascent = properties.ascent;
         _descent = properties.descent;
         _lineHeight = properties.lineHeight;
+        _glyphCount = properties.glyphCount;
         return true;
     }
 
@@ -166,6 +167,7 @@ bool AbstractFont::openFile(const Containers::StringView filename, const Float s
         _ascent = properties.ascent;
         _descent = properties.descent;
         _lineHeight = properties.lineHeight;
+        _glyphCount = properties.glyphCount;
         return true;
     }
 
@@ -237,6 +239,11 @@ Float AbstractFont::lineHeight() const {
     return _lineHeight;
 }
 
+UnsignedInt AbstractFont::glyphCount() const {
+    CORRADE_ASSERT(isOpened(), "Text::AbstractFont::glyphCount(): no font opened", 0);
+    return _glyphCount;
+}
+
 UnsignedInt AbstractFont::glyphId(const char32_t character) {
     CORRADE_ASSERT(isOpened(), "Text::AbstractFont::glyphId(): no font opened", 0);
 
@@ -245,6 +252,7 @@ UnsignedInt AbstractFont::glyphId(const char32_t character) {
 
 Vector2 AbstractFont::glyphAdvance(const UnsignedInt glyph) {
     CORRADE_ASSERT(isOpened(), "Text::AbstractFont::glyphAdvance(): no font opened", {});
+    CORRADE_ASSERT(glyph < _glyphCount, "Text::AbstractFont::glyphAdvance(): index" << glyph << "out of range for" << _glyphCount << "glyphs", {});
 
     return doGlyphAdvance(glyph);
 }

src/Magnum/Text/AbstractFont.h

@@ -435,6 +435,18 @@ class MAGNUM_TEXT_EXPORT AbstractFont: public PluginManager::AbstractPlugin {
          */
         Float lineHeight() const;
 
+        /**
+         * @brief Total count of glyphs in the font
+         * @m_since_latest
+         *
+         * Expects that a font is opened.
+         * @note This function is meant to be used only for font observations
+         *      and conversions. In performance-critical code the
+         *      @ref fillGlyphCache() and @ref layout() functions should be
+         *      used instead.
+         */
+        UnsignedInt glyphCount() const;
+
         /**
          * @brief Glyph ID for given character
          *
@@ -451,7 +463,8 @@ class MAGNUM_TEXT_EXPORT AbstractFont: public PluginManager::AbstractPlugin {
          *
          * Distance the cursor for the next glyph that follows @p glyph.
          * Doesn't consider kerning or any other advanced shaping features.
-         * Expects that a font is opened.
+         * Expects that a font is opened and @p glyph is less than
+         * @ref glyphCount().
          * @note This function is meant to be used only for font observations
          *      and conversions. In performance-critical code the @ref layout()
          *      function should be used instead.
@@ -503,8 +516,8 @@ class MAGNUM_TEXT_EXPORT AbstractFont: public PluginManager::AbstractPlugin {
         struct Properties {
             #if defined(CORRADE_TARGET_GCC) && !defined(CORRADE_TARGET_CLANG) && __GNUC__ < 5
             /* Otherwise GCC 4.8 loudly complains about missing initializers */
-            constexpr /*implicit*/ Properties() noexcept: size{}, ascent{}, descent{}, lineHeight{} {}
-            constexpr /*implicit*/ Properties(Float size, Float ascent, Float descent, Float lineHeight) noexcept: size{size}, ascent{ascent}, descent{descent}, lineHeight{lineHeight} {}
+            constexpr /*implicit*/ Properties() noexcept: size{}, ascent{}, descent{}, lineHeight{}, glyphCount{} {}
+            constexpr /*implicit*/ Properties(Float size, Float ascent, Float descent, Float lineHeight, UnsignedInt glyphCount) noexcept: size{size}, ascent{ascent}, descent{descent}, lineHeight{lineHeight}, glyphCount{glyphCount} {}
             #endif
 
             /**
@@ -530,6 +543,13 @@ class MAGNUM_TEXT_EXPORT AbstractFont: public PluginManager::AbstractPlugin {
              * @see @ref lineHeight()
              */
             Float lineHeight;
+
+            /**
+             * Total count of glyphs in the font
+             * @see @ref glyphCount()
+             * @m_since_latest
+             */
+            UnsignedInt glyphCount;
         };
 
     protected:
@@ -617,6 +637,7 @@ class MAGNUM_TEXT_EXPORT AbstractFont: public PluginManager::AbstractPlugin {
         } _fileCallbackTemplate{nullptr, nullptr};
 
         Float _size{}, _ascent{}, _descent{}, _lineHeight{};
+        UnsignedInt _glyphCount{};
 };
 
 /**
@@ -702,7 +723,7 @@ updated interface string.
 */
 /* Silly indentation to make the string appear in pluginInterface() docs */
 #define MAGNUM_TEXT_ABSTRACTFONT_PLUGIN_INTERFACE /* [interface] */ \
-"cz.mosra.magnum.Text.AbstractFont/0.3.1"
+"cz.mosra.magnum.Text.AbstractFont/0.3.2"
 /* [interface] */
 
 #ifndef DOXYGEN_GENERATING_OUTPUT

src/Magnum/Text/Test/AbstractFontTest.cpp

@@ -77,6 +77,7 @@ struct AbstractFontTest: TestSuite::Tester {
 
     void glyphAdvance();
     void glyphAdvanceNoFont();
+    void glyphAdvanceOutOfRange();
 
     void layout();
     void layoutNoFont();
@@ -130,6 +131,7 @@ AbstractFontTest::AbstractFontTest() {
 
               &AbstractFontTest::glyphAdvance,
               &AbstractFontTest::glyphAdvanceNoFont,
+              &AbstractFontTest::glyphAdvanceOutOfRange,
 
               &AbstractFontTest::layout,
               &AbstractFontTest::layoutNoFont,
@@ -181,7 +183,7 @@ void AbstractFontTest::openData() {
 
         Properties doOpenData(const Containers::ArrayView<const char> data, Float size) override {
             _opened = (data.size() == 1 && data[0] == '\xa5');
-            return {size, 1.0f, 2.0f, 3.0f};
+            return {size, 1.0f, 2.0f, 3.0f, 15};
         }
 
         UnsignedInt doGlyphId(char32_t) override { return {}; }
@@ -201,6 +203,7 @@ void AbstractFontTest::openData() {
     CORRADE_COMPARE(font.ascent(), 1.0f);
     CORRADE_COMPARE(font.descent(), 2.0f);
     CORRADE_COMPARE(font.lineHeight(), 3.0f);
+    CORRADE_COMPARE(font.glyphCount(), 15);
 }
 
 void AbstractFontTest::openFileAsData() {
@@ -211,7 +214,7 @@ void AbstractFontTest::openFileAsData() {
 
         Properties doOpenData(const Containers::ArrayView<const char> data, Float size) override {
             _opened = (data.size() == 1 && data[0] == '\xa5');
-            return {size, 1.0f, 2.0f, 3.0f};
+            return {size, 1.0f, 2.0f, 3.0f, 15};
         }
 
         UnsignedInt doGlyphId(char32_t) override { return {}; }
@@ -231,6 +234,7 @@ void AbstractFontTest::openFileAsData() {
     CORRADE_COMPARE(font.ascent(), 1.0f);
     CORRADE_COMPARE(font.descent(), 2.0f);
     CORRADE_COMPARE(font.lineHeight(), 3.0f);
+    CORRADE_COMPARE(font.glyphCount(), 15);
 }
 
 void AbstractFontTest::openFileAsDataNotFound() {
@@ -512,7 +516,7 @@ void AbstractFontTest::setFileCallbackOpenFileDirectly() {
         Properties doOpenFile(Containers::StringView filename, Float size) override {
             /* Called because FileCallback is supported */
             _opened = filename == "file.dat" && fileCallback() && fileCallbackUserData();
-            return {size, 1.0f, 2.0f, 3.0f};
+            return {size, 1.0f, 2.0f, 3.0f, 15};
         }
 
         Properties doOpenData(Containers::ArrayView<const char>, Float) override {
@@ -544,6 +548,7 @@ void AbstractFontTest::setFileCallbackOpenFileDirectly() {
     CORRADE_COMPARE(font.ascent(), 1.0f);
     CORRADE_COMPARE(font.descent(), 2.0f);
     CORRADE_COMPARE(font.lineHeight(), 3.0f);
+    CORRADE_COMPARE(font.glyphCount(), 15);
 }
 
 void AbstractFontTest::setFileCallbackOpenFileThroughBaseImplementation() {
@@ -559,7 +564,7 @@ void AbstractFontTest::setFileCallbackOpenFileThroughBaseImplementation() {
 
         Properties doOpenData(Containers::ArrayView<const char> data, Float size) override {
             _opened = (data.size() == 1 && data[0] == '\xb0');
-            return {size, 1.0f, 2.0f, 3.0f};
+            return {size, 1.0f, 2.0f, 3.0f, 15};
         }
 
         UnsignedInt doGlyphId(char32_t) override { return {}; }
@@ -602,6 +607,7 @@ void AbstractFontTest::setFileCallbackOpenFileThroughBaseImplementation() {
     CORRADE_COMPARE(font.ascent(), 1.0f);
     CORRADE_COMPARE(font.descent(), 2.0f);
     CORRADE_COMPARE(font.lineHeight(), 3.0f);
+    CORRADE_COMPARE(font.glyphCount(), 15);
 }
 
 void AbstractFontTest::setFileCallbackOpenFileThroughBaseImplementationFailed() {
@@ -649,7 +655,7 @@ void AbstractFontTest::setFileCallbackOpenFileAsData() {
 
         Properties doOpenData(Containers::ArrayView<const char> data, Float size) override {
             _opened = (data.size() == 1 && data[0] == '\xb0');
-            return {size, 1.0f, 2.0f, 3.0f};
+            return {size, 1.0f, 2.0f, 3.0f, 15};
         }
 
         UnsignedInt doGlyphId(char32_t) override { return {}; }
@@ -693,6 +699,7 @@ void AbstractFontTest::setFileCallbackOpenFileAsData() {
     CORRADE_COMPARE(font.ascent(), 1.0f);
     CORRADE_COMPARE(font.descent(), 2.0f);
     CORRADE_COMPARE(font.lineHeight(), 3.0f);
+    CORRADE_COMPARE(font.glyphCount(), 15);
 }
 
 void AbstractFontTest::setFileCallbackOpenFileAsDataFailed() {
@@ -735,7 +742,7 @@ void AbstractFontTest::properties() {
 
         Properties doOpenData(const Containers::ArrayView<const char>, Float size) override {
             _opened = true;
-            return {size, 1.0f, 2.0f, 3.0f};
+            return {size, 1.0f, 2.0f, 3.0f, 15};
         }
 
         UnsignedInt doGlyphId(char32_t) override { return {}; }
@@ -752,6 +759,7 @@ void AbstractFontTest::properties() {
     CORRADE_COMPARE(font.ascent(), 1.0f);
     CORRADE_COMPARE(font.descent(), 2.0f);
     CORRADE_COMPARE(font.lineHeight(), 3.0f);
+    CORRADE_COMPARE(font.glyphCount(), 15);
 }
 
 void AbstractFontTest::propertiesNoFont() {
@@ -775,11 +783,13 @@ void AbstractFontTest::propertiesNoFont() {
     font.ascent();
     font.descent();
     font.lineHeight();
+    font.glyphCount();
     CORRADE_COMPARE(out.str(),
         "Text::AbstractFont::size(): no font opened\n"
         "Text::AbstractFont::ascent(): no font opened\n"
         "Text::AbstractFont::descent(): no font opened\n"
-        "Text::AbstractFont::lineHeight(): no font opened\n");
+        "Text::AbstractFont::lineHeight(): no font opened\n"
+        "Text::AbstractFont::glyphCount(): no font opened\n");
 }
 
 void AbstractFontTest::glyphId() {
@@ -821,17 +831,25 @@ void AbstractFontTest::glyphIdNoFont() {
 
 void AbstractFontTest::glyphAdvance() {
     struct MyFont: AbstractFont {
-        FontFeatures doFeatures() const override { return {}; }
-        bool doIsOpened() const override { return true; }
+        FontFeatures doFeatures() const override { return FontFeature::OpenData; }
+        bool doIsOpened() const override { return _opened; }
         void doClose() override {}
 
+        Properties doOpenData(Containers::ArrayView<const char>, Float) override {
+            _opened = true;
+            return {0.0f, 0.0f, 0.0f, 0.0f, 98};
+        }
         UnsignedInt doGlyphId(char32_t) override { return {}; }
         Vector2 doGlyphAdvance(UnsignedInt a) override { return {a*10.0f, -Float(a)/10.0f}; }
         Containers::Pointer<AbstractLayouter> doLayout(const AbstractGlyphCache&, Float, Containers::StringView) override {
             return nullptr;
         }
+
+        bool _opened = false;
     } font;
 
+    /* Have to explicitly open in order to make glyphCount() non-zero */
+    CORRADE_VERIFY(font.openData(nullptr, 0.0f));
     CORRADE_COMPARE(font.glyphAdvance(97), (Vector2{970.0f, -9.7f}));
 }
 
@@ -856,6 +874,37 @@ void AbstractFontTest::glyphAdvanceNoFont() {
     CORRADE_COMPARE(out.str(), "Text::AbstractFont::glyphAdvance(): no font opened\n");
 }
 
+void AbstractFontTest::glyphAdvanceOutOfRange() {
+    CORRADE_SKIP_IF_NO_ASSERT();
+
+    struct MyFont: AbstractFont {
+        FontFeatures doFeatures() const override { return FontFeature::OpenData; }
+        bool doIsOpened() const override { return _opened; }
+        void doClose() override {}
+
+        Properties doOpenData(Containers::ArrayView<const char>, Float) override {
+            _opened = true;
+            return {0.0f, 0.0f, 0.0f, 0.0f, 3};
+        }
+        UnsignedInt doGlyphId(char32_t) override { return {}; }
+        Vector2 doGlyphAdvance(UnsignedInt) override { return {}; }
+        Containers::Pointer<AbstractLayouter> doLayout(const AbstractGlyphCache&, Float, Containers::StringView) override {
+            return nullptr;
+        }
+
+        bool _opened = false;
+    } font;
+
+    /* Have to explicitly open in order to make glyphCount() non-zero */
+    CORRADE_VERIFY(font.openData(nullptr, 0.0f));
+
+    std::ostringstream out;
+    Error redirectError{&out};
+    font.glyphAdvance(3);
+    CORRADE_COMPARE(out.str(),
+        "Text::AbstractFont::glyphAdvance(): index 3 out of range for 3 glyphs\n");
+}
+
 struct DummyGlyphCache: AbstractGlyphCache {
     using AbstractGlyphCache::AbstractGlyphCache;
 

src/Magnum/Text/Test/RendererGLTest.cpp

@@ -350,7 +350,7 @@ void RendererGLTest::multiline() {
 
             Properties doOpenFile(Containers::StringView, Float) override {
                 _opened = true;
-                return {0.5f, 0.45f, -0.25f, 0.75f};
+                return {0.5f, 0.45f, -0.25f, 0.75f, 1};
             }
 
             UnsignedInt doGlyphId(char32_t) override { return 0; }

src/MagnumPlugins/MagnumFont/MagnumFont.cpp

@@ -134,7 +134,8 @@ auto MagnumFont::doOpenData(const Containers::ArrayView<const char> data, const
     return {_opened->conf.value<Float>("fontSize"),
             _opened->conf.value<Float>("ascent"),
             _opened->conf.value<Float>("descent"),
-            _opened->conf.value<Float>("lineHeight")};
+            _opened->conf.value<Float>("lineHeight"),
+            UnsignedInt(glyphs.size())};
 }
 
 auto MagnumFont::doOpenFile(const Containers::StringView filename, const Float size) -> Properties {
@@ -150,7 +151,7 @@ UnsignedInt MagnumFont::doGlyphId(const char32_t character) {
 }
 
 Vector2 MagnumFont::doGlyphAdvance(const UnsignedInt glyph) {
-    return glyph < _opened->glyphAdvance.size() ? _opened->glyphAdvance[glyph] : Vector2();
+    return _opened->glyphAdvance[glyph];
 }
 
 Containers::Pointer<AbstractGlyphCache> MagnumFont::doCreateGlyphCache() {

src/MagnumPlugins/MagnumFont/Test/MagnumFontTest.cpp

@@ -93,7 +93,8 @@ void MagnumFontTest::properties() {
     CORRADE_COMPARE(font->ascent(), 25.0f);
     CORRADE_COMPARE(font->descent(), -10.0f);
     CORRADE_COMPARE(font->lineHeight(), 39.7333f);
-    CORRADE_COMPARE(font->glyphAdvance(font->glyphId(U'W')), Vector2(23.0f, 0.0f));
+    CORRADE_COMPARE(font->glyphCount(), 3);
+    CORRADE_COMPARE(font->glyphAdvance(font->glyphId(U'W')), (Vector2{23.0f, 0.0f}));
 }
 
 void MagnumFontTest::layout() {

src/MagnumPlugins/MagnumFontConverter/Test/MagnumFontConverterTest.cpp

@@ -95,7 +95,7 @@ void MagnumFontConverterTest::exportFont() {
             bool doIsOpened() const override { return _opened; }
             Properties doOpenFile(Containers::StringView, Float) override {
                 _opened = true;
-                return {16.0f, 25.0f, -10.0f, 39.7333f};
+                return {16.0f, 25.0f, -10.0f, 39.7333f, 3};
             }
             FontFeatures doFeatures() const override { return {}; }
             Containers::Pointer<AbstractLayouter> doLayout(const AbstractGlyphCache&, Float, Containers::StringView) override { return nullptr; }