MagnumFont: adapt to AbstractShaper changes.

The returned cluster IDs are UTF-8 character positions in the input
text.

src/MagnumPlugins/MagnumFont/MagnumFont.cpp

@@ -203,7 +203,9 @@ Containers::Pointer<AbstractShaper> MagnumFont::doCreateShaper() {
             for(std::size_t i = 0; i != text.size(); ) {
                 const Containers::Pair<char32_t, std::size_t> codepointNext = Utility::Unicode::nextChar(text, i);
                 const auto it = fontData.glyphId.find(codepointNext.first());
-                arrayAppend(_glyphs, it == fontData.glyphId.end() ? 0 : it->second);
+                arrayAppend(_glyphs, InPlaceInit,
+                    it == fontData.glyphId.end() ? 0 : it->second,
+                    begin + UnsignedInt(i));
                 i = codepointNext.second();
             }
 
@@ -211,19 +213,22 @@ Containers::Pointer<AbstractShaper> MagnumFont::doCreateShaper() {
         }
 
         void doGlyphIdsInto(const Containers::StridedArrayView1D<UnsignedInt>& ids) const override {
-            Utility::copy(_glyphs, ids);
+            Utility::copy(stridedArrayView(_glyphs).slice(&Containers::Pair<UnsignedInt, UnsignedInt>::first), ids);
         }
         void doGlyphOffsetsAdvancesInto(const Containers::StridedArrayView1D<Vector2>& offsets, const Containers::StridedArrayView1D<Vector2>& advances) const override {
             const Data& fontData = *static_cast<const MagnumFont&>(font())._opened;
             for(std::size_t i = 0; i != _glyphs.size(); ++i) {
                 /* There's no glyph offsets in addition to advances */
                 offsets[i] = {};
-                advances[i] = fontData.glyphs[_glyphs[i]].advance;
+                advances[i] = fontData.glyphs[_glyphs[i].first()].advance;
             }
         }
+        void doGlyphClustersInto(const Containers::StridedArrayView1D<UnsignedInt>& clusters) const override {
+            Utility::copy(stridedArrayView(_glyphs).slice(&Containers::Pair<UnsignedInt, UnsignedInt>::second), clusters);
+        }
 
         Containers::StridedArrayView1D<const Vector2> _glyphAdvance;
-        Containers::Array<UnsignedInt> _glyphs;
+        Containers::Array<Containers::Pair<UnsignedInt, UnsignedInt>> _glyphs;
     };
 
     return Containers::pointer<Shaper>(*this);

src/MagnumPlugins/MagnumFont/Test/MagnumFontTest.cpp

@@ -68,13 +68,13 @@ struct MagnumFontTest: TestSuite::Tester {
 const struct {
     const char* name;
     const char* string;
-    UnsignedInt eGlyphId;
+    UnsignedInt eGlyphId, eGlyphClusterExtraSize;
     UnsignedInt begin, end;
 } ShapeData[]{
-    {"", "Weave", 1, 0, ~UnsignedInt{}},
-    {"substring", "haWeavesfefe", 1, 2, 7},
-    {"UTF-8", "Wěave", 3, 0, ~UnsignedInt{}},
-    {"UTF-8 substring", "haWěavefefe", 3, 2, 8},
+    {"", "Weave", 1, 0, 0, ~UnsignedInt{}},
+    {"substring", "haWeavesfefe", 1, 0, 2, 7},
+    {"UTF-8", "Wěave", 3, 1, 0, ~UnsignedInt{}},
+    {"UTF-8 substring", "haWěavefefe", 3, 1, 2, 8},
 };
 
 MagnumFontTest::MagnumFontTest() {
@@ -152,8 +152,10 @@ void MagnumFontTest::shape() {
     UnsignedInt ids[5];
     Vector2 offsets[5];
     Vector2 advances[5];
+    UnsignedInt clusters[5];
     shaper->glyphIdsInto(ids);
     shaper->glyphOffsetsAdvancesInto(offsets, advances);
+    shaper->glyphClustersInto(clusters);
     CORRADE_COMPARE_AS(Containers::arrayView(ids), Containers::arrayView({
         2u,             /* 'W' */
         data.eGlyphId,  /* 'e' or 'ě' */
@@ -172,6 +174,13 @@ void MagnumFontTest::shape() {
         {8.0f, 0.0f},
         {12.f, 0.0f},
     }), TestSuite::Compare::Container);
+    CORRADE_COMPARE_AS(Containers::arrayView(clusters), Containers::arrayView({
+        data.begin + 0u,
+        data.begin + 1u,
+        data.begin + 2u + data.eGlyphClusterExtraSize,
+        data.begin + 3u + data.eGlyphClusterExtraSize,
+        data.begin + 4u + data.eGlyphClusterExtraSize,
+    }), TestSuite::Compare::Container);
 }
 
 void MagnumFontTest::shapeEmpty() {
@@ -200,8 +209,10 @@ void MagnumFontTest::shaperReuse() {
         UnsignedInt ids[2];
         Vector2 offsets[2];
         Vector2 advances[2];
+        UnsignedInt clusters[2];
         shaper->glyphIdsInto(ids);
         shaper->glyphOffsetsAdvancesInto(offsets, advances);
+        shaper->glyphClustersInto(clusters);
         CORRADE_COMPARE_AS(Containers::arrayView(ids), Containers::arrayView({
             2u, /* 'W' */
             1u  /* 'e' */
@@ -213,6 +224,10 @@ void MagnumFontTest::shaperReuse() {
             {23.0f, 0.0f},
             {12.f, 0.0f}
         }), TestSuite::Compare::Container);
+        CORRADE_COMPARE_AS(Containers::arrayView(clusters), Containers::arrayView({
+            0u,
+            1u
+        }), TestSuite::Compare::Container);
 
     /* Long text, same as in shape(), should enlarge the array for it */
     } {
@@ -220,8 +235,10 @@ void MagnumFontTest::shaperReuse() {
         UnsignedInt ids[5];
         Vector2 offsets[5];
         Vector2 advances[5];
+        UnsignedInt clusters[5];
         shaper->glyphIdsInto(ids);
         shaper->glyphOffsetsAdvancesInto(offsets, advances);
+        shaper->glyphClustersInto(clusters);
         CORRADE_COMPARE_AS(Containers::arrayView(ids), Containers::arrayView({
             2u, /* 'W' */
             3u, /* 'ě' */
@@ -239,6 +256,13 @@ void MagnumFontTest::shaperReuse() {
             {8.0f, 0.0f},
             {12.f, 0.0f}
         }), TestSuite::Compare::Container);
+        CORRADE_COMPARE_AS(Containers::arrayView(clusters), Containers::arrayView({
+            0u,
+            1u,
+            3u,
+            4u,
+            5u
+        }), TestSuite::Compare::Container);
 
     /* Short text again, should not leave the extra glyphs there */
     } {
@@ -246,8 +270,10 @@ void MagnumFontTest::shaperReuse() {
         UnsignedInt ids[3];
         Vector2 offsets[3];
         Vector2 advances[3];
+        UnsignedInt clusters[3];
         shaper->glyphIdsInto(ids);
         shaper->glyphOffsetsAdvancesInto(offsets, advances);
+        shaper->glyphClustersInto(clusters);
         CORRADE_COMPARE_AS(Containers::arrayView(ids), Containers::arrayView({
             0u, /* 'a' (not found) */
             0u, /* 'v' (not found) */
@@ -261,6 +287,9 @@ void MagnumFontTest::shaperReuse() {
             {8.0f, 0.0f},
             {12.f, 0.0f}
         }), TestSuite::Compare::Container);
+        CORRADE_COMPARE_AS(Containers::arrayView(clusters), Containers::arrayView({
+            0u, 1u, 2u
+        }), TestSuite::Compare::Container);
     }
 }