Update paragraph width size to float

Bug: 183128727
Test: minikin_test
Change-Id: I043131a352674fec8caa705c001ceeb348869d46

2 files changed, 29 insertions, 1 deletions

diff --git a/libs/minikin/LineBreakerUtil.h b/libs/minikin/LineBreakerUtil.h
index eb058cc..8b383a4 100644
--- a/libs/minikin/LineBreakerUtil.h
+++ b/libs/minikin/LineBreakerUtil.h
@@ -36,7 +36,7 @@ namespace minikin {
 // paragraphs, accuracy could degrade using only 32-bit float. Note however that float is used
 // extensively on the Java side for this. This is a typedef so that we can easily change it based
 // on performance/accuracy tradeoff.
-typedef double ParaWidth;
+typedef float ParaWidth;
 
 // Hyphenates a string potentially containing non-breaking spaces.
 std::vector<HyphenationType> hyphenate(const U16StringPiece& string, const Hyphenator& hypenator);
diff --git a/tests/unittest/OptimalLineBreakerTest.cpp b/tests/unittest/OptimalLineBreakerTest.cpp
index 51aab60..d6801cc 100644
--- a/tests/unittest/OptimalLineBreakerTest.cpp
+++ b/tests/unittest/OptimalLineBreakerTest.cpp
@@ -2080,5 +2080,33 @@ TEST_F(OptimalLineBreakerTest, testControllCharAfterSpace) {
                                                    << toString(textBuf, actual);
     }
 }
+
+TEST_F(OptimalLineBreakerTest, roundingError) {
+    MeasuredTextBuilder builder;
+    auto family1 = buildFontFamily("Ascii.ttf");
+    std::vector<std::shared_ptr<FontFamily>> families = {family1};
+    auto fc = std::make_shared<FontCollection>(families);
+    MinikinPaint paint(fc);
+    paint.size = 56.0f;  // Make 1em=56px
+    paint.scaleX = 1;
+    paint.letterSpacing = -0.093f;
+    paint.localeListId = LocaleListCache::getId("en-US");
+    const std::vector<uint16_t> textBuffer = utf8ToUtf16("8888888888888888888");
+
+    float measured = Layout::measureText(textBuffer, Range(0, textBuffer.size()), Bidi::LTR, paint,
+                                         StartHyphenEdit::NO_EDIT, EndHyphenEdit::NO_EDIT, nullptr);
+
+    builder.addStyleRun(0, textBuffer.size(), std::move(paint), false);
+    std::unique_ptr<MeasuredText> measuredText =
+            builder.build(textBuffer, false /* compute hyphenation */,
+                          false /* compute full layout */, nullptr /* no hint */);
+    RectangleLineWidth rectangleLineWidth(measured);
+    TabStops tabStops(nullptr, 0, 10);
+    LineBreakResult r = doLineBreak(textBuffer, *measuredText, BreakStrategy::Balanced,
+                                    HyphenationFrequency::None, measured);
+
+    EXPECT_EQ(1u, r.breakPoints.size());
+}
+
 }  // namespace
 }  // namespace minikin