`Blender` fixes (#1162 followup) (#1175)

Fixes from #1168 extracted as a followup patch for #1162

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

@@ -3,14 +3,23 @@ package org.jetbrains.skia
 import org.jetbrains.skia.impl.NativePointer
 import org.jetbrains.skia.impl.RefCnt
 import org.jetbrains.skia.impl.Stats
+import org.jetbrains.skia.impl.Library.Companion.staticLoad
 import org.jetbrains.skia.impl.interopScope
 
 /**
  * Blender represents a custom blend function in the Skia pipeline.  A blender combines a source
  * color (the result of our paint) and destination color (from the canvas) into a final color.
-*/
+ */
 class Blender internal constructor(ptr: NativePointer) : RefCnt(ptr) {
     companion object {
+        init {
+            staticLoad()
+        }
+
+        fun makeMode(mode: BlendMode): Blender {
+            Stats.onNativeCall()
+            return Blender(_nMakeMode(mode.ordinal))
+        }
 
         fun makeArithmetic(
             k1: Float,
@@ -19,20 +28,18 @@ class Blender internal constructor(ptr: NativePointer) : RefCnt(ptr) {
             k4: Float,
             enforcePMColor: Boolean,
         ): Blender {
-            return try {
             Stats.onNativeCall()
-                interopScope {
+            return interopScope {
                 Blender(
                     _nMakeArithmetic(
                         k1,
                         k2,
                         k3,
                         k4,
-                            enforcePMColor)
+                        enforcePMColor,
+                    ),
                 )
             }
-            } finally {
-            }
         }
     }
 }
@@ -45,3 +52,6 @@ private external fun _nMakeArithmetic(
     k4: Float,
     enforcePMColor: Boolean
 ): NativePointer
+
+@ExternalSymbolName("org_jetbrains_skia_Blender__1nMakeMode")
+private external fun _nMakeMode(mode: Int): NativePointer

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

@@ -448,14 +448,17 @@ class Paint : Managed {
         }
 
     /**
-     * @param blender  how geometry is filled with color; if null, color is used instead
+     * Returns the user-supplied blend function, if one has been set.
      *
-     * @see [https://fiddle.skia.org/c/@Color_Filter_Methods](https://fiddle.skia.org/c/@Color_Filter_Methods)
+     * A null blender signifies the default SrcOver behavior.
      *
-     * @see [https://fiddle.skia.org/c/@Paint_setShader](https://fiddle.skia.org/c/@Paint_setShader)
+     * For convenience, you can call [blendMode] if the blend effect can be expressed
+     * as one of those values.
      *
-     * @return  [Shader] or null
-     * @see [https://fiddle.skia.org/c/@Paint_refShader](https://fiddle.skia.org/c/@Paint_refShader)
+     * @see [https://fiddle.skia.org/c/@Paint_setBlender](https://fiddle.skia.org/c/@Paint_setBlender)
+     * @see [https://fiddle.skia.org/c/@Paint_refBlender](https://fiddle.skia.org/c/@Paint_refBlender)
+     *
+     * @return  the [Blender] assigned to this paint, otherwise null
      */
     var blender: Blender?
         get() = try {
@@ -695,7 +698,7 @@ private external fun _nSetImageFilter(ptr: NativePointer, filterPtr: NativePoint
 private external fun _nGetBlender(ptr: NativePointer): NativePointer
 
 @ExternalSymbolName("org_jetbrains_skia_Paint__1nSetBlender")
-private external fun _nSetBlender(ptr: NativePointer, shaderPtr: NativePointer)
+private external fun _nSetBlender(ptr: NativePointer, blenderPtr: NativePointer)
 
 @ExternalSymbolName("org_jetbrains_skia_Paint__1nHasNothingToDraw")
 private external fun _nHasNothingToDraw(ptr: NativePointer): Boolean

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

@@ -58,6 +58,7 @@ class RuntimeEffect internal constructor(ptr: NativePointer) : RefCnt(ptr) {
             }
         } finally {
             reachabilityBarrier(this)
+            reachabilityBarrier(uniforms)
         }
     }
 }

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

@@ -51,10 +51,15 @@ class BlenderTest {
         runtimeEffect.makeBlender(null)
     }
 
-//    @Test
-//    fun arithmetic() = blenderTest {
-//        Blender.makeArithmetic(
-//            k1 = 0.5f, k2 = 0.5f, k3 = 0.5f, k4 = 0.5f, enforcePMColor = true
-//        )
-//    }
+    @Test
+    fun arithmetic() = blenderTest {
+        Blender.makeArithmetic(
+            k1 = 0.5f, k2 = 0.5f, k3 = 0.5f, k4 = 0.5f, enforcePMColor = true
+        )
+    }
+
+    @Test
+    fun mode() = blenderTest {
+        Blender.makeMode(BlendMode.CLEAR)
+    }
 }

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

-#include <iostream>
 #include <jni.h>
 #include "interop.hh"
 #include "SkBlender.h"
@@ -10,3 +9,8 @@ extern "C" JNIEXPORT jlong JNICALL Java_org_jetbrains_skia_BlenderKt__1nMakeArit
     return reinterpret_cast<jlong>(ptr);
 }
 
+extern "C" JNIEXPORT jlong JNICALL Java_org_jetbrains_skia_BlenderKt__1nMakeMode
+  (JNIEnv* env, jclass jclass, jint mode) {
+    SkBlender* ptr = SkBlender::Mode(static_cast<SkBlendMode>(mode)).release();
+    return reinterpret_cast<jlong>(ptr);
+}

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

@@ -185,15 +185,15 @@ extern "C" JNIEXPORT void JNICALL Java_org_jetbrains_skia_PaintKt__1nSetImageFil
 
 extern "C" JNIEXPORT jlong JNICALL Java_org_jetbrains_skia_PaintKt__1nGetBlender
   (JNIEnv* env, jclass jclass, jlong ptr) {
-SkPaint* instance = reinterpret_cast<SkPaint*>(static_cast<uintptr_t>(ptr));
-return reinterpret_cast<jlong>(instance->refBlender().release());
+    SkPaint* instance = reinterpret_cast<SkPaint*>(static_cast<uintptr_t>(ptr));
+    return reinterpret_cast<jlong>(instance->refBlender().release());
 }
 
 extern "C" JNIEXPORT void JNICALL Java_org_jetbrains_skia_PaintKt__1nSetBlender
-(JNIEnv* env, jclass jclass, jlong ptr, jlong filterPtr) {
-SkPaint* instance = reinterpret_cast<SkPaint*>(static_cast<uintptr_t>(ptr));
-SkBlender* filter = reinterpret_cast<SkBlender*>(static_cast<uintptr_t>(filterPtr));
-instance->setBlender(sk_ref_sp<SkBlender>(filter));
+  (JNIEnv* env, jclass jclass, jlong ptr, jlong blenderPtr) {
+    SkPaint* instance = reinterpret_cast<SkPaint*>(static_cast<uintptr_t>(ptr));
+    SkBlender* blender = reinterpret_cast<SkBlender*>(static_cast<uintptr_t>(blenderPtr));
+    instance->setBlender(sk_ref_sp<SkBlender>(blender));
 }
 
 extern "C" JNIEXPORT jint JNICALL Java_org_jetbrains_skia_PaintKt__1nGetBlendMode

skiko/src/nativeJsMain/cpp/Blender.cc

-#include <iostream>
 #include "SkBlender.h"
 #include "SkBlenders.h"
 #include "common.h"
@@ -8,3 +7,9 @@ SKIKO_EXPORT KNativePointer org_jetbrains_skia_Blender__1nMakeArithmetic
     SkBlender* ptr = SkBlenders::Arithmetic(k1, k2, k3, k4, enforcePMColor).release();
     return reinterpret_cast<KNativePointer>(ptr);
 }
+
+SKIKO_EXPORT KNativePointer org_jetbrains_skia_Blender__1nMakeMode
+  (KInt mode) {
+    SkBlender* ptr = SkBlender::Mode(static_cast<SkBlendMode>(mode)).release();
+    return reinterpret_cast<KNativePointer>(ptr);
+}

skiko/src/nativeJsMain/cpp/Paint.cc

@@ -187,16 +187,16 @@ SKIKO_EXPORT void org_jetbrains_skia_Paint__1nSetImageFilter
 }
 
 SKIKO_EXPORT KNativePointer org_jetbrains_skia_Paint__1nGetBlender
-(KNativePointer ptr) {
-SkPaint* instance = reinterpret_cast<SkPaint*>((ptr));
-return reinterpret_cast<KNativePointer>(instance->refBlender().release());
+  (KNativePointer ptr) {
+    SkPaint* instance = reinterpret_cast<SkPaint*>((ptr));
+    return reinterpret_cast<KNativePointer>(instance->refBlender().release());
 }
 
 SKIKO_EXPORT void org_jetbrains_skia_Paint__1nSetBlender
-        (KNativePointer ptr, KNativePointer filterPtr) {
-SkPaint* instance = reinterpret_cast<SkPaint*>((ptr));
-SkBlender* filter = reinterpret_cast<SkBlender*>((filterPtr));
-instance->setBlender(sk_ref_sp<SkBlender>(filter));
+  (KNativePointer ptr, KNativePointer blenderPtr) {
+    SkPaint* instance = reinterpret_cast<SkPaint*>((ptr));
+    SkBlender* blender = reinterpret_cast<SkBlender*>((blenderPtr));
+    instance->setBlender(sk_ref_sp<SkBlender>(blender));
 }
 
 SKIKO_EXPORT KInt org_jetbrains_skia_Paint__1nGetBlendMode