Fix LineMetrics resolution for wasm and js targets (#846)

* Fix LineMetrics resolution for wasm and js targets

This contributes to fixing https://youtrack.jetbrains.com/issue/COMPOSE-108/CfW-fix-TextField-cursor

I had to introduce assertCloseEnough sensitive enought to path
throughout all our targets

* LineMetrics::layoutParagraph idiomatically returns runTest immediately

* Rename LineMetrics_nGetArrayElement from longArgs (misleading) to intArgs

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

@@ -141,9 +141,13 @@ class LineMetrics(
         override fun getArrayElement(array: InteropPointer, index: Int): LineMetrics {
             val intArray = IntArray(6)
             val doubleArray = DoubleArray(7)
-            interopScope {
-                LineMetrics_nGetArrayElement(array, index, toInterop(intArray), toInterop(doubleArray))
+
+            withResult(intArray) { intArrayInterop ->
+                withResult(doubleArray) { doubleArrayInterop ->
+                    LineMetrics_nGetArrayElement(array, index, intArrayInterop, doubleArrayInterop)
+                }
             }
+
             return LineMetrics(
                 intArray[0],
                 intArray[1],
@@ -175,4 +179,4 @@ private external fun LineMetrics_nGetArraySize(array: InteropPointer): Int
 private external fun LineMetrics_nDisposeArray(array: InteropPointer)
 @ExternalSymbolName("org_jetbrains_skia_paragraph_LineMetrics__1nGetArrayElement")
 @ModuleImport("./skiko.mjs", "org_jetbrains_skia_paragraph_LineMetrics__1nGetArrayElement")
-private external fun LineMetrics_nGetArrayElement(array: InteropPointer, index: Int, longArgs: InteropPointer, doubleArgs: InteropPointer)
+private external fun LineMetrics_nGetArrayElement(array: InteropPointer, index: Int, intArgs: InteropPointer, doubleArgs: InteropPointer)

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

@@ -5,10 +5,7 @@ import org.jetbrains.skia.paragraph.*
 import org.jetbrains.skia.tests.assertCloseEnough
 import org.jetbrains.skia.tests.assertContentCloseEnough
 import org.jetbrains.skia.tests.makeFromResource
-import org.jetbrains.skiko.tests.SkipJsTarget
-import org.jetbrains.skiko.tests.SkipNativeTarget
-import org.jetbrains.skiko.tests.SkipWasmTarget
-import org.jetbrains.skiko.tests.runTest
+import org.jetbrains.skiko.tests.*
 import kotlin.test.Test
 import kotlin.test.assertContentEquals
 import kotlin.test.assertEquals
@@ -49,23 +46,46 @@ class ParagraphTest {
     }
 
     @Test
-    @SkipJsTarget
-    @SkipWasmTarget
-    @SkipNativeTarget
     fun layoutParagraph() = runTest {
-        singleLineMetrics("aa").let { lineMetrics -> // latin
-            assertEquals(0, lineMetrics.startIndex)
-            assertEquals(2, lineMetrics.endIndex)
-            assertEquals(2, lineMetrics.endIncludingNewline)
-            assertEquals(2, lineMetrics.endExcludingWhitespaces)
-        }
-        singleLineMetrics("яя").let { lineMetrics -> // cyrillic
-            assertEquals(0, lineMetrics.startIndex)
-            assertEquals(2, lineMetrics.endIndex)
-            assertEquals(2, lineMetrics.endIncludingNewline)
-            assertEquals(2, lineMetrics.endExcludingWhitespaces)
-        }
+        val lineMetricsEpsilon = 0.0001f
+
+        assertCloseEnough(
+            singleLineMetrics("aa"), LineMetrics(
+                startIndex = 0,
+                endIndex = 2,
+                endExcludingWhitespaces = 2,
+                endIncludingNewline = 2,
+                isHardBreak = true,
+                ascent = 13.5625,
+                descent = 3.3806817531585693,
+                unscaledAscent = 13.5625,
+                height = 17.0,
+                width = 15.789999961853027,
+                left = 0.0,
+                baseline = 13.619318008422852,
+                lineNumber = 0
+            ), epsilon = lineMetricsEpsilon
+        )
+
+        assertCloseEnough(
+            singleLineMetrics("яя"), LineMetrics(
+                startIndex = 0,
+                endIndex = 2,
+                endExcludingWhitespaces = 2,
+                endIncludingNewline = 2,
+                isHardBreak = true,
+                ascent = 13.5625,
+                descent = 3.3806817531585693,
+                unscaledAscent = 13.5625,
+                height = 17.0,
+                width = 15.710000038146973,
+                left = 0.0,
+                baseline = 13.619318008422852,
+                lineNumber = 0
+            ), epsilon = lineMetricsEpsilon
+        )
     }
+
     @Test
     @SkipJsTarget // FIXME Emscripten's stringToUTF8 function does not correctly handle invalid unicode symbols.
     fun invalidUnicode() = runTest {

skiko/src/commonTest/kotlin/org/jetbrains/skia/util/assertCloseEnough.kt

@@ -5,6 +5,7 @@ import org.jetbrains.skia.FontMetrics
 import org.jetbrains.skia.Matrix33
 import org.jetbrains.skia.Point
 import org.jetbrains.skia.Rect
+import org.jetbrains.skia.paragraph.LineMetrics
 import org.jetbrains.skia.paragraph.Shadow
 import org.jetbrains.skia.paragraph.TextBox
 import org.jetbrains.skiko.KotlinBackend
@@ -17,6 +18,9 @@ private val EPSILON = if (kotlinBackend == KotlinBackend.JS) 0.00001f else 0.000
 private inline fun Float?.isCloseEnoughTo(b: Float?, epsilon: Float) =
     if (this == null) b == null else if (b == null) false else if (epsilon == 0f) this == b else abs(this - b) < epsilon
 
+private inline fun Double?.isCloseEnoughTo(b: Double?, epsilon: Float) =
+    if (this == null) b == null else if (b == null) false else if (epsilon == 0f) this == b else abs(this - b) < epsilon
+
 private inline fun Point.isCloseEnoughTo(b: Point, epsilon: Float) =
     x.isCloseEnoughTo(b.x, epsilon) && y.isCloseEnoughTo(b.y, epsilon)
 
@@ -48,6 +52,20 @@ private inline fun FontMetrics.isCloseEnoughTo(b: FontMetrics, epsilon: Float) =
         strikeoutThickness.isCloseEnoughTo(b.strikeoutThickness, epsilon) &&
         strikeoutPosition.isCloseEnoughTo(b.strikeoutPosition, epsilon)
 
+private inline fun LineMetrics.isCloseEnoughTo(b: LineMetrics, epsilon: Float): Boolean =
+    startIndex == b.startIndex &&
+    endIndex == b.endIndex &&
+    endExcludingWhitespaces == b.endExcludingWhitespaces &&
+    endIncludingNewline == b.endIncludingNewline &&
+    isHardBreak == b.isHardBreak &&
+    ascent.isCloseEnoughTo(b.ascent, epsilon) &&
+    descent.isCloseEnoughTo(b.descent, epsilon) &&
+    unscaledAscent.isCloseEnoughTo(b.unscaledAscent, epsilon) &&
+    height.isCloseEnoughTo(b.height, epsilon) &&
+    width.isCloseEnoughTo(b.width, epsilon) &&
+    baseline.isCloseEnoughTo(b.baseline, epsilon) &&
+    lineNumber == b.lineNumber
+
 private inline fun Rect.isCloseEnoughTo(rect: Rect, epsilon: Float): Boolean =
     left.isCloseEnoughTo(rect.left, epsilon) && right.isCloseEnoughTo(rect.right, epsilon)
             && top.isCloseEnoughTo(rect.top, epsilon) && bottom.isCloseEnoughTo(rect.bottom, epsilon)
@@ -87,6 +105,10 @@ internal fun assertCloseEnough(expected: Rect, actual: Rect, epsilon: Float = EP
     assertTrue(expected.isCloseEnoughTo(actual, epsilon), message = "expected=$expected, actual=$actual, eps=$epsilon")
 }
 
+internal fun assertCloseEnough(expected: LineMetrics, actual: LineMetrics, epsilon: Float = EPSILON) {
+    assertTrue(expected.isCloseEnoughTo(actual, epsilon), message = "expected=$expected, actual=$actual, eps=$epsilon")
+}
+
 private fun fail(message: String) {
     throw AssertionError(message)
 }

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

@@ -18,20 +18,20 @@ SKIKO_EXPORT void org_jetbrains_skia_paragraph_LineMetrics__1nDisposeArray
 }
 
 SKIKO_EXPORT void org_jetbrains_skia_paragraph_LineMetrics__1nGetArrayElement
-    (KNativePointer blob, KInt index, KNativePointer longArgs, KNativePointer doubleArgs) {
+    (KNativePointer blob, KInt index, KNativePointer intArgs, KNativePointer doubleArgs) {
 
     std::vector<LineMetrics>* vect = reinterpret_cast<std::vector<LineMetrics> *>(blob);
-    int* longs = reinterpret_cast<int *>(longArgs);
+    int* ints = reinterpret_cast<int *>(intArgs);
     double* doubles = reinterpret_cast<double *>(doubleArgs);
 
     LineMetrics lm = vect->at(index);
 
-    longs[0] = lm.fStartIndex;
-    longs[1] = lm.fEndIndex;
-    longs[2] = lm.fEndExcludingWhitespaces;
-    longs[3] = lm.fEndIncludingNewline;
-    longs[4] = lm.fHardBreak;
-    longs[5] = lm.fLineNumber;
+    ints[0] = lm.fStartIndex;
+    ints[1] = lm.fEndIndex;
+    ints[2] = lm.fEndExcludingWhitespaces;
+    ints[3] = lm.fEndIncludingNewline;
+    ints[4] = lm.fHardBreak;
+    ints[5] = lm.fLineNumber;
 
     doubles[0] = lm.fAscent;
     doubles[1] = lm.fDescent;