turn off flutter hack by default, implement methods to control it (#997)

Co-authored-by: Oleksandr Karpovich <a.n.karpovich@gmail.com>

skiko/src/commonMain/kotlin/org/jetbrains/skia/paragraph/ParagraphStyle.kt

@@ -191,6 +191,19 @@ class ParagraphStyle : Managed(ParagraphStyle_nMake(), _FinalizerHolder.PTR) {
             reachabilityBarrier(this)
         }
 
+    var isApplyRoundingHackEnabled: Boolean
+        get() = try {
+            Stats.onNativeCall()
+            _nGetApplyRoundingHack(_ptr).not().not()
+        } finally {
+            reachabilityBarrier(this)
+        }
+        set(value) = try {
+            Stats.onNativeCall()
+            _nSetApplyRoundingHack(_ptr, value)
+        } finally {
+            reachabilityBarrier(this)
+        }
 
     var textIndent: TextIndent
         get() = try {
@@ -322,6 +335,14 @@ private external fun _nGetHinting(ptr: NativePointer): Int
 @ModuleImport("./skiko.mjs", "org_jetbrains_skia_paragraph_ParagraphStyle__1nGetSubpixel")
 private external fun _nGetSubpixel(ptr: NativePointer): Boolean
 
+@ExternalSymbolName("org_jetbrains_skia_paragraph_ParagraphStyle__1nGetApplyRoundingHack")
+@ModuleImport("./skiko.mjs", "org_jetbrains_skia_paragraph_ParagraphStyle__1nGetApplyRoundingHack")
+private external fun _nGetApplyRoundingHack(ptr: NativePointer): Boolean
+
+@ExternalSymbolName("org_jetbrains_skia_paragraph_ParagraphStyle__1nSetApplyRoundingHack")
+@ModuleImport("./skiko.mjs", "org_jetbrains_skia_paragraph_ParagraphStyle__1nSetApplyRoundingHack")
+private external fun _nSetApplyRoundingHack(ptr: NativePointer, value: Boolean)
+
 @ExternalSymbolName("org_jetbrains_skia_paragraph_ParagraphStyle__1nSetTextIndent")
 @ModuleImport("./skiko.mjs", "org_jetbrains_skia_paragraph_ParagraphStyle__1nSetTextIndent")
 private external fun _nSetTextIndent(ptr: NativePointer, firstLine: Float, restLine: Float)

skiko/src/commonTest/kotlin/org/jetbrains/skia/ParagraphTest.kt

@@ -6,6 +6,9 @@ import org.jetbrains.skia.tests.assertCloseEnough
 import org.jetbrains.skia.tests.assertContentCloseEnough
 import org.jetbrains.skia.tests.makeFromResource
 import org.jetbrains.skiko.tests.*
+import kotlin.math.ceil
+import kotlin.math.floor
+import kotlin.math.truncate
 import kotlin.test.Test
 import kotlin.test.assertContentEquals
 import kotlin.test.assertEquals
@@ -15,6 +18,7 @@ class ParagraphTest {
     private val fontCollection = suspend {
         FontCollection().setDefaultFontManager(TypefaceFontProvider().apply {
             registerTypeface(Typeface.makeFromResource("./fonts/Inter-Hinted-Regular.ttf"), "Inter")
+            registerTypeface(Typeface.makeFromResource("./fonts/JetBrainsMono_2_304/JetBrainsMono-Regular.ttf"), "JetBrains Mono")
         })
     }
     private val style = ParagraphStyle().apply {
@@ -47,40 +51,43 @@ class ParagraphTest {
 
     @Test
     fun layoutParagraph() = runTest {
-        val lineMetricsEpsilon = 0.0001f
+        val lineMetricsEpsilon = 0.001f
 
         assertCloseEnough(
-            singleLineMetrics("aa"), LineMetrics(
+            actual = singleLineMetrics("aa"),
+            expected = LineMetrics(
                 startIndex = 0,
                 endIndex = 2,
                 endExcludingWhitespaces = 2,
                 endIncludingNewline = 2,
                 isHardBreak = true,
                 ascent = 13.5625,
-                descent = 3.3806817531585693,
+                descent = 3.380584716796875,
                 unscaledAscent = 13.5625,
                 height = 17.0,
-                width = 15.789999961853027,
+                width = 15.789764404296875,
                 left = 0.0,
-                baseline = 13.619318008422852,
+                baseline = 13.619415283203125,
                 lineNumber = 0
             ), epsilon = lineMetricsEpsilon
         )
 
+
         assertCloseEnough(
-            singleLineMetrics("яя"), LineMetrics(
+            actual = singleLineMetrics("яя"),
+            expected = LineMetrics(
                 startIndex = 0,
                 endIndex = 2,
                 endExcludingWhitespaces = 2,
                 endIncludingNewline = 2,
                 isHardBreak = true,
                 ascent = 13.5625,
-                descent = 3.3806817531585693,
+                descent = 3.380584716796875,
                 unscaledAscent = 13.5625,
                 height = 17.0,
-                width = 15.710000038146973,
+                width = 15.710235595703125,
                 left = 0.0,
-                baseline = 13.619318008422852,
+                baseline = 13.619415283203125,
                 lineNumber = 0
             ), epsilon = lineMetricsEpsilon
         )
@@ -172,4 +179,35 @@ class ParagraphTest {
             }
         }
     }
+
+    @Test
+    fun layout_paragraph_with_its_maxIntrinsicWidth_shouldnt_lead_to_wraps() = runTest {
+        suspend fun testWraps(isApplyRoundingHackEnabled: Boolean, unexpectedWrapsPresent: Boolean) {
+            val paragraphStyle = ParagraphStyle().apply {
+                this.isApplyRoundingHackEnabled = isApplyRoundingHackEnabled
+                textStyle = TextStyle().apply {
+                    fontFamilies = arrayOf("JetBrains Mono")
+                    fontSize = 13.0f * 2f
+                }
+            }
+            val paragraph = ParagraphBuilder(paragraphStyle, fontCollection()).use {
+                it.addText("x".repeat(104))
+                it.addText(" ")
+                it.addText("y".repeat(100))
+                it.build()
+            }.layout(Float.POSITIVE_INFINITY)
+            assertEquals(1, paragraph.lineNumber, "Layout in one line with Inf width")
+
+            val maxIntrinsicWidth = paragraph.maxIntrinsicWidth
+            val expectedLines = if (unexpectedWrapsPresent) 2 else 1
+
+            paragraph.layout(paragraph.maxIntrinsicWidth)
+            assertEquals(expectedLines, paragraph.lineNumber, "Layout with maxIntrinsicWidth " +
+                                                              "maxIntrinsicWidth: $maxIntrinsicWidth " +
+                                                              "unexpectedWrapsPresent: $unexpectedWrapsPresent " +
+                                                              "isApplyRoundingHackEnabled: $isApplyRoundingHackEnabled")
+        }
+        testWraps(isApplyRoundingHackEnabled = false, unexpectedWrapsPresent = false)
+        testWraps(isApplyRoundingHackEnabled = true, unexpectedWrapsPresent = true)
+    }
 }

skiko/src/commonTest/kotlin/org/jetbrains/skiko/paragraph/ParagraphStyleTests.kt

@@ -55,4 +55,13 @@ class ParagraphStyleTests {
             assertEquals(gloriousRasterSettings, paragraphStyle.fontRastrSettings)
         }
     }
+
+    @Test
+    fun paragraphStyleRoundingHackTests() {
+        ParagraphStyle().use { paragraphStyle ->
+            assertEquals(false, paragraphStyle.isApplyRoundingHackEnabled)
+            paragraphStyle.isApplyRoundingHackEnabled = true
+            assertEquals(true, paragraphStyle.isApplyRoundingHackEnabled)
+        }
+    }
 }
\ No newline at end of file

skiko/src/jvmMain/cpp/common/paragraph/ParagraphStyle.cc

@@ -19,6 +19,7 @@ extern "C" JNIEXPORT jlong JNICALL Java_org_jetbrains_skia_paragraph_ParagraphSt
 extern "C" JNIEXPORT jlong JNICALL Java_org_jetbrains_skia_paragraph_ParagraphStyleKt_ParagraphStyle_1nMake
   (JNIEnv* env, jclass jclass) {
     ParagraphStyle* instance = new ParagraphStyle();
+    instance->setApplyRoundingHack(false);
     return reinterpret_cast<jlong>(instance);
 }
 
@@ -180,6 +181,18 @@ extern "C" JNIEXPORT void JNICALL Java_org_jetbrains_skia_paragraph_ParagraphSty
     instance->turnHintingOff();
 }
 
+extern "C" JNIEXPORT jboolean JNICALL Java_org_jetbrains_skia_paragraph_ParagraphStyleKt__1nGetApplyRoundingHack
+  (JNIEnv* env, jclass jclass, jlong ptr) {
+    ParagraphStyle* instance = reinterpret_cast<ParagraphStyle*>(static_cast<uintptr_t>(ptr));
+    return instance->getApplyRoundingHack();
+}
+
+extern "C" JNIEXPORT void JNICALL Java_org_jetbrains_skia_paragraph_ParagraphStyleKt__1nSetApplyRoundingHack
+  (JNIEnv* env, jclass jclass, jlong ptr, jboolean val) {
+    ParagraphStyle* instance = reinterpret_cast<ParagraphStyle*>(static_cast<uintptr_t>(ptr));
+    instance->setApplyRoundingHack(val);
+}
+
 extern "C" JNIEXPORT void JNICALL Java_org_jetbrains_skia_paragraph_ParagraphStyleKt__1nSetTextIndent
   (JNIEnv* env, jclass jclass, jlong ptr, jfloat firstLine, jfloat restLine) {
     ParagraphStyle* instance = reinterpret_cast<ParagraphStyle*>(static_cast<uintptr_t>(ptr));

skiko/src/nativeJsMain/cpp/paragraph/ParagraphStyle.cc

@@ -16,6 +16,7 @@ SKIKO_EXPORT KNativePointer org_jetbrains_skia_paragraph_ParagraphStyle__1nGetFi
 SKIKO_EXPORT KNativePointer org_jetbrains_skia_paragraph_ParagraphStyle__1nMake
   () {
     ParagraphStyle* instance = new ParagraphStyle();
+    instance->setApplyRoundingHack(false);
     return reinterpret_cast<KNativePointer>(instance);
 }
 
@@ -177,6 +178,18 @@ SKIKO_EXPORT KBoolean org_jetbrains_skia_paragraph_ParagraphStyle__1nGetSubpixel
     return fontRastrSettings.fSubpixel;
 }
 
+SKIKO_EXPORT KBoolean org_jetbrains_skia_paragraph_ParagraphStyle__1nGetApplyRoundingHack
+  (KNativePointer  ptr) {
+    ParagraphStyle* instance = reinterpret_cast<ParagraphStyle*>(ptr);
+    return instance->getApplyRoundingHack();
+}
+
+SKIKO_EXPORT void org_jetbrains_skia_paragraph_ParagraphStyle__1nSetApplyRoundingHack
+  (KNativePointer  ptr, KBoolean val) {
+    ParagraphStyle* instance = reinterpret_cast<ParagraphStyle*>(ptr);
+    instance->setApplyRoundingHack(val);
+}
+
 SKIKO_EXPORT void org_jetbrains_skia_paragraph_ParagraphStyle__1nSetTextIndent
   (KNativePointer ptr, KFloat firstLine, KFloat restLine) {
     ParagraphStyle* instance = reinterpret_cast<ParagraphStyle*>((ptr));