From 7f7bfdd8094bf942ed135a210c7485552b69d015 Mon Sep 17 00:00:00 2001
From: Jaro <jaro@argonaut-constellation.org>
Date: Sat, 11 Mar 2023 06:34:46 +0100
Subject: [PATCH] Test forming and breaking ligatures.

---
 .golden/ligatureParagraph/golden                | 13 +++++++++++++
 .golden/ligatureParagraphBreak1/golden          | 16 ++++++++++++++++
 .golden/ligatureParagraphBreak2/golden          | 16 ++++++++++++++++
 test/Data/Text/ParagraphLayout/ParagraphData.hs |  4 ++++
 test/Data/Text/ParagraphLayoutSpec.hs           | 14 +++++++++++++-
 5 files changed, 62 insertions(+), 1 deletion(-)
 create mode 100644 .golden/ligatureParagraph/golden
 create mode 100644 .golden/ligatureParagraphBreak1/golden
 create mode 100644 .golden/ligatureParagraphBreak2/golden

diff --git a/.golden/ligatureParagraph/golden b/.golden/ligatureParagraph/golden
new file mode 100644
index 0000000..a101b14
--- /dev/null
+++ b/.golden/ligatureParagraph/golden
@@ -0,0 +1,13 @@
+ParagraphLayout {paragraphRect = Rect {x_origin = 0, y_origin = 0, x_size = 4672, y_size = -1121}, spanLayouts = [
+    SpanLayout [Fragment {fragmentRect = Rect {x_origin = 0, y_origin = 0, x_size = 4672, y_size = -1121}, fragmentPen = (0,-932), fragmentGlyphs =
+        [(GlyphInfo {codepoint = 76, cluster = 0, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 253, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 81, cluster = 1, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 574, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 72, cluster = 2, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 559, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 431, cluster = 3, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 1033, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 70, cluster = 6, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 465, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 76, cluster = 7, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 253, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 72, cluster = 8, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 559, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 81, cluster = 9, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 574, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 87, cluster = 10, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 402, y_advance = 0, x_offset = 0, y_offset = 0})]
+    }]
+]}
diff --git a/.golden/ligatureParagraphBreak1/golden b/.golden/ligatureParagraphBreak1/golden
new file mode 100644
index 0000000..8186bfb
--- /dev/null
+++ b/.golden/ligatureParagraphBreak1/golden
@@ -0,0 +1,16 @@
+ParagraphLayout {paragraphRect = Rect {x_origin = 0, y_origin = 0, x_size = 2162, y_size = -3363}, spanLayouts = [
+    SpanLayout [Fragment {fragmentRect = Rect {x_origin = 0, y_origin = 0, x_size = 2162, y_size = -1121}, fragmentPen = (0,-932), fragmentGlyphs =
+        [(GlyphInfo {codepoint = 76, cluster = 0, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 253, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 81, cluster = 1, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 574, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 72, cluster = 2, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 559, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 426, cluster = 3, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 776, y_advance = 0, x_offset = 0, y_offset = 0})]
+    }, Fragment {fragmentRect = Rect {x_origin = 0, y_origin = -1121, x_size = 2104, y_size = -1121}, fragmentPen = (0,-932), fragmentGlyphs =
+        [(GlyphInfo {codepoint = 76, cluster = 5, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 253, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 70, cluster = 6, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 465, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 76, cluster = 7, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 253, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 72, cluster = 8, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 559, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 81, cluster = 9, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 574, y_advance = 0, x_offset = 0, y_offset = 0})]
+    }, Fragment {fragmentRect = Rect {x_origin = 0, y_origin = -2242, x_size = 402, y_size = -1121}, fragmentPen = (0,-932), fragmentGlyphs =
+        [(GlyphInfo {codepoint = 87, cluster = 10, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 402, y_advance = 0, x_offset = 0, y_offset = 0})]
+    }]
+]}
diff --git a/.golden/ligatureParagraphBreak2/golden b/.golden/ligatureParagraphBreak2/golden
new file mode 100644
index 0000000..d426385
--- /dev/null
+++ b/.golden/ligatureParagraphBreak2/golden
@@ -0,0 +1,16 @@
+ParagraphLayout {paragraphRect = Rect {x_origin = 0, y_origin = 0, x_size = 1772, y_size = -3363}, spanLayouts = [
+    SpanLayout [Fragment {fragmentRect = Rect {x_origin = 0, y_origin = 0, x_size = 1772, y_size = -1121}, fragmentPen = (0,-932), fragmentGlyphs =
+        [(GlyphInfo {codepoint = 76, cluster = 0, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 253, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 81, cluster = 1, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 574, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 72, cluster = 2, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 559, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 73, cluster = 3, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 386, y_advance = 0, x_offset = 0, y_offset = 0})]
+    }, Fragment {fragmentRect = Rect {x_origin = 0, y_origin = -1121, x_size = 1361, y_size = -1121}, fragmentPen = (0,-932), fragmentGlyphs =
+        [(GlyphInfo {codepoint = 428, cluster = 4, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 643, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 70, cluster = 6, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 465, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 76, cluster = 7, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 253, y_advance = 0, x_offset = 0, y_offset = 0})]
+    }, Fragment {fragmentRect = Rect {x_origin = 0, y_origin = -2242, x_size = 1535, y_size = -1121}, fragmentPen = (0,-932), fragmentGlyphs =
+        [(GlyphInfo {codepoint = 72, cluster = 8, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 559, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 81, cluster = 9, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 574, y_advance = 0, x_offset = 0, y_offset = 0}),
+        (GlyphInfo {codepoint = 87, cluster = 10, unsafeToBreak = False, unsafeToConcat = False, safeToInsertTatweel = False},GlyphPos {x_advance = 402, y_advance = 0, x_offset = 0, y_offset = 0})]
+    }]
+]}
diff --git a/test/Data/Text/ParagraphLayout/ParagraphData.hs b/test/Data/Text/ParagraphLayout/ParagraphData.hs
index 6f514fe..597c39e 100644
--- a/test/Data/Text/ParagraphLayout/ParagraphData.hs
+++ b/test/Data/Text/ParagraphLayout/ParagraphData.hs
@@ -3,6 +3,7 @@ module Data.Text.ParagraphLayout.ParagraphData
     ,czechHelloParagraph
     ,emptyParagraph
     ,emptySpanParagraph
+    ,ligatureParagraph
     ,loremIpsumParagraph
     ,mixedLanguageLTRParagraph
     ,mixedScriptSerbianParagraph
@@ -45,6 +46,9 @@ emptySpanParagraph = "xx" |< en~"" >| "zzzzz"
 trivialParagraph :: ParagraphOptions -> Paragraph
 trivialParagraph = "xxx" |< en~"a" >| "zzz"
 
+ligatureParagraph :: ParagraphOptions -> Paragraph
+ligatureParagraph = "" |< en~"inefficient" >| ""
+
 -- | Fillter text using the Arabic script.
 -- Source: <https://generator.lorem-ipsum.info/_arabic>
 arabicFillerParagraph :: ParagraphOptions -> Paragraph
diff --git a/test/Data/Text/ParagraphLayoutSpec.hs b/test/Data/Text/ParagraphLayoutSpec.hs
index 3d36034..8c5c7ce 100644
--- a/test/Data/Text/ParagraphLayoutSpec.hs
+++ b/test/Data/Text/ParagraphLayoutSpec.hs
@@ -113,6 +113,19 @@ spec = do
             it "handles Czech hello" $ \font -> do
                 let result = layoutPlain $ czechHelloParagraph $ opts font
                 result `shouldBeGolden` "czechHelloParagraph"
+            it "renders an \"ffi\" ligature" $ \ font -> do
+                let result = layoutPlain $ ligatureParagraph $ opts font
+                result `shouldBeGolden` "ligatureParagraph"
+            it "breaks an \"ffi\" ligature into \"ff\" + \"i\"" $ \ font -> do
+                let result = layoutPlain $ ligatureParagraph $
+                        (opts font)
+                        { paragraphMaxWidth = 2418 }
+                result `shouldBeGolden` "ligatureParagraphBreak1"
+            it "breaks an \"ffi\" ligature into \"f\" + \"fi\"" $ \ font -> do
+                let result = layoutPlain $ ligatureParagraph $
+                        (opts font)
+                        { paragraphMaxWidth = 1800 }
+                result `shouldBeGolden` "ligatureParagraphBreak2"
             it "handles mixed languages in LTR layout" $ \font -> do
                 let result = layoutPlain $ mixedLanguageLTRParagraph $ opts font
                 result `shouldBeGolden` "mixedLanguageLTRParagraph"
@@ -140,7 +153,6 @@ spec = do
                         (opts font)
                         { paragraphMaxWidth = 1300 }
                 result `shouldBeGolden` "czechHelloParagraphNarrow"
-                -- TODO test breaking ligatures
             it "wraps by characters when line is ultra narrow" $ \font -> do
                 let
                     result = layoutPlain $ czechHelloParagraph $
-- 
2.30.2