Implement native Paint::getColor4f, add test (#305)

skiko/src/commonMain/kotlin/org/jetbrains/skia/Paint.kt

 package org.jetbrains.skia
 
+import org.jetbrains.skia.impl.*
 import org.jetbrains.skia.impl.Library.Companion.staticLoad
-import org.jetbrains.skia.impl.Managed
-import org.jetbrains.skia.impl.Native
-import org.jetbrains.skia.impl.Stats
-import org.jetbrains.skia.impl.reachabilityBarrier
-import org.jetbrains.skia.impl.NativePointer
-import org.jetbrains.skia.impl.getPtr
 import kotlin.math.round
 
 class Paint : Managed {
@@ -187,7 +182,9 @@ class Paint : Managed {
     var color4f: Color4f
         get() = try {
             Stats.onNativeCall()
-            _nGetColor4f(_ptr)
+            Color4f(withResult(FloatArray(4)) {
+                _nGetColor4f(_ptr, it)
+            })
         } finally {
             reachabilityBarrier(this)
         }
@@ -644,7 +641,7 @@ private external fun _nSetMode(ptr: NativePointer, value: Int)
 private external fun Paint_nGetColor(ptr: NativePointer): Int
 
 @ExternalSymbolName("org_jetbrains_skia_Paint__1nGetColor4f")
-private external fun _nGetColor4f(ptr: NativePointer): Color4f
+private external fun _nGetColor4f(ptr: NativePointer, arr: InteropPointer)
 
 @ExternalSymbolName("org_jetbrains_skia_Paint__1nSetColor")
 private external fun _nSetColor(ptr: NativePointer, argb: Int)

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

+package org.jetbrains.skia
+
+import org.jetbrains.skia.tests.assertCloseEnough
+import kotlin.test.Test
+
+class PaintTest {
+    @Test
+    fun color4f() {
+        val paint = Paint()
+        val expected = Color4f(0.2f, 0.4f, 0.8f, 1.0f)
+        paint.setColor4f(expected, colorSpace = ColorSpace.sRGB)
+        assertCloseEnough(expected, paint.color4f)
+    }
+}
\ No newline at end of file

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

 package org.jetbrains.skia.tests
 
+import org.jetbrains.skia.Color4f
 import org.jetbrains.skia.Matrix33
 import org.jetbrains.skia.Point
 import kotlin.math.abs
@@ -19,3 +20,11 @@ internal fun assertCloseEnough(expected: Point, actual: Point?, epsilon: Float =
 internal fun assertCloseEnough(expected: Matrix33, actual: Matrix33?, epsilon: Float = EPSILON) {
     expected.mat.zip(actual!!.mat).forEach { (a, b) -> assertCloseEnough(a, b, epsilon) }
 }
+
+
+internal fun assertCloseEnough(expected: Color4f, actual: Color4f?, epsilon: Float = EPSILON) {
+    assertCloseEnough(expected.r, actual!!.r, epsilon)
+    assertCloseEnough(expected.g, actual.g, epsilon)
+    assertCloseEnough(expected.b, actual.b, epsilon)
+    assertCloseEnough(expected.a, actual.a, epsilon)
+}
\ No newline at end of file

skiko/src/jvmMain/cpp/common/Paint.cc

@@ -80,11 +80,12 @@ extern "C" JNIEXPORT void JNICALL Java_org_jetbrains_skia_PaintKt__1nSetColor
     instance->setColor(color);
 }
 
-extern "C" JNIEXPORT jobject JNICALL Java_org_jetbrains_skia_PaintKt__1nGetColor4f
-  (JNIEnv* env, jclass jclass, jlong ptr) {
+extern "C" JNIEXPORT void JNICALL Java_org_jetbrains_skia_PaintKt__1nGetColor4f
+  (JNIEnv* env, jclass jclass, jlong ptr, jfloatArray result) {
     SkPaint* instance = reinterpret_cast<SkPaint*>(static_cast<uintptr_t>(ptr));
     SkColor4f color = instance->getColor4f();
-    return env->NewObject(skija::Color4f::cls, skija::Color4f::ctor, color.fR, color.fG, color.fB, color.fA);
+    float data[4] { color.fR, color.fG, color.fB, color.fA };
+    env->SetFloatArrayRegion(result, 0, 4, data);
 }
 
 extern "C" JNIEXPORT void JNICALL Java_org_jetbrains_skia_PaintKt__1nSetColor4f

skiko/src/nativeJsMain/cpp/Paint.cc

@@ -81,19 +81,17 @@ SKIKO_EXPORT void org_jetbrains_skia_Paint__1nSetColor
 }
 
 
-SKIKO_EXPORT KInteropPointer org_jetbrains_skia_Paint__1nGetColor4f
-  (KNativePointer ptr) {
-    TODO("implement org_jetbrains_skia_Paint__1nGetColor4f");
-}
-
-#if 0
-SKIKO_EXPORT KInteropPointer org_jetbrains_skia_Paint__1nGetColor4f
-  (KNativePointer ptr) {
+SKIKO_EXPORT void org_jetbrains_skia_Paint__1nGetColor4f
+  (KNativePointer ptr, KInteropPointer result) {
     SkPaint* instance = reinterpret_cast<SkPaint*>((ptr));
+    float* res = reinterpret_cast<float*>(result);
     SkColor4f color = instance->getColor4f();
-    return env->NewObject(skija::Color4f::cls, skija::Color4f::ctor, color.fR, color.fG, color.fB, color.fA);
+
+    res[0] = color.fR;
+    res[1] = color.fG;
+    res[2] = color.fB;
+    res[3] = color.fA;
 }
-#endif
 
 
 SKIKO_EXPORT void org_jetbrains_skia_Paint__1nSetColor4f