Simple wrapper for one function.

skiko/build.gradle.kts

@@ -556,7 +556,6 @@ val skikoJvmRuntimeJar by project.tasks.registering(Jar::class) {
 
 project.tasks.register<Jar>("skikoJsJar") {
     // We produce jar that contains .js of wrapper/bindings and .wasm with Skia + bindings.
-    from(kotlin.js().compilations["main"].output.allOutputs)
     from(project.tasks.named("wasmCompile").get().outputs)
     from(project.tasks.named("jsJar").get().outputs)
     archiveBaseName.set("skiko-wasm")

skiko/src/jsMain/cpp/BackendRenderTarget.cc

+#include "GrBackendSurface.h"
+#include <emscripten.h>
+
+typedef int32_t jint;
+typedef int64_t jlong;
+
+static void deleteBackendRenderTarget(GrBackendRenderTarget* rt) {
+    delete rt;
+}
+
+EMSCRIPTEN_KEEPALIVE
+extern "C" long BackendRenderTarget_nGetFinalizer() {
+    return static_cast<jlong>(reinterpret_cast<uintptr_t>(&deleteBackendRenderTarget));
+}
+
+EMSCRIPTEN_KEEPALIVE
+extern "C" long BackendRenderTarget_nMakeGL
+  (jint width, jint height, jint sampleCnt, jint stencilBits, jint fbId, jint fbFormat) {
+    GrGLFramebufferInfo glInfo = { static_cast<unsigned int>(fbId), static_cast<unsigned int>(fbFormat) };
+    GrBackendRenderTarget* instance = new GrBackendRenderTarget(width, height, sampleCnt, stencilBits, glInfo);
+    return reinterpret_cast<jlong>(instance);
+}
+
+EMSCRIPTEN_KEEPALIVE
+extern "C" long BackendRenderTarget_nMakeMetal
+  (jint width, jint height, jlong texturePtr) {
+#ifdef SK_METAL
+    GrMTLHandle texture = reinterpret_cast<GrMTLHandle>(static_cast<uintptr_t>(texturePtr));
+    GrMtlTextureInfo fbInfo;
+    fbInfo.fTexture.retain(texture);
+    GrBackendRenderTarget* instance = new GrBackendRenderTarget(width, height, fbInfo);
+    return reinterpret_cast<jlong>(instance);
+#else
+    return 0;
+#endif
+}
+
+#ifdef SK_DIRECT3D
+#include "d3d/GrD3DTypes.h"
+#endif
+
+EMSCRIPTEN_KEEPALIVE
+extern "C" jlong BackendRenderTarget_MakeDirect3D
+  (jint width, jint height, jlong texturePtr, jint format, jint sampleCnt, jint levelCnt) {
+#ifdef SK_DIRECT3D
+    GrD3DTextureResourceInfo texResInfo = {};
+    ID3D12Resource* resource = reinterpret_cast<ID3D12Resource*>(static_cast<uintptr_t>(texturePtr));
+    texResInfo.fResource.retain(resource);
+    texResInfo.fResourceState = D3D12_RESOURCE_STATE_COMMON;
+    texResInfo.fFormat = static_cast<DXGI_FORMAT>(format);
+    texResInfo.fSampleCount = static_cast<uint32_t>(sampleCnt);
+    texResInfo.fLevelCount = static_cast<uint32_t>(levelCnt);
+    GrBackendRenderTarget* instance = new GrBackendRenderTarget(width, height, texResInfo);
+    return reinterpret_cast<jlong>(instance);
+#else
+    return 0;
+#endif
+}
\ No newline at end of file

skiko/src/jsMain/cpp/wrapper.cc

 #include "GrBackendSurface.h"
 #include "GrDirectContext.h"
+#include <emscripten.h>
 
-void* init_surface() {
+EMSCRIPTEN_KEEPALIVE
+extern "C" void* init_surface() {
    return nullptr;
 }
 

skiko/src/macosX64Main/cpp/common/BackendRenderTarget.cc

 #include <iostream>
-#include <jni.h>
+#include <stdint.h>
 #include "GrBackendSurface.h"
 
+typedef jint int32_t;
+typedef jlong int64_t;
+
 static void deleteBackendRenderTarget(GrBackendRenderTarget* rt) {
     delete rt;
 }
@@ -29,14 +32,13 @@ extern "C" jlong BackendRenderTarget_nMakeMetal
     return 0;
 #endif
 }
-#endif
 
 #ifdef SK_DIRECT3D
 #include "d3d/GrD3DTypes.h"
 #endif
 
 extern "C" jlong BackendRenderTarget_MakeDirect3D
-  (jint width, jint height, jlong texturePtr, jint format, jint sampleCnt, jint levelCnt) {#ifdef SK_DIRECT3D
+  (jint width, jint height, jlong texturePtr, jint format, jint sampleCnt, jint levelCnt) {
 #ifdef SK_DIRECT3D
     GrD3DTextureResourceInfo texResInfo = {};
     ID3D12Resource* resource = reinterpret_cast<ID3D12Resource*>(static_cast<uintptr_t>(texturePtr));