Merge pull request #83 from JetBrains/metal_integrated_gc

Using an integrated video card on Metal rendering

skiko/build.gradle.kts

@@ -381,6 +381,7 @@ tasks.withType(LinkSharedLibrary::class.java).configureEach {
                     "-framework", "CoreServices",
                     "-framework", "CoreText",
                     "-framework", "Foundation",
+                    "-framework", "IOKit",
                     "-framework", "Metal",
                     "-framework", "OpenGL",
                     "-framework", "QuartzCore" // for CoreAnimation

skiko/src/jvmMain/objectiveC/macos/MetalRedrawer.mm

@@ -13,6 +13,11 @@
 #import <mtl/GrMtlBackendContext.h>
 #import <mtl/GrMtlTypes.h>
 
+#define MuxGraphicsCard 7
+#define kOpen 0
+#define kGetMuxState 3
+#define kDriverClassName "AppleGraphicsControl"
+
 @interface AWTMetalLayer : CAMetalLayer
 
 @property jobject javaRef;
@@ -100,6 +105,55 @@ JNIEXPORT jlong JNICALL Java_org_jetbrains_skiko_redrawer_MetalRedrawer_makeMeta
     return (jlong) renderTarget;
 }
 
+BOOL isUsingIntegratedGPU() {
+    kern_return_t kernResult = 0;
+    io_iterator_t iterator = IO_OBJECT_NULL;
+    io_service_t service = IO_OBJECT_NULL;
+    
+    kernResult = IOServiceGetMatchingServices(kIOMasterPortDefault, IOServiceMatching(kDriverClassName), &iterator);
+    assert(kernResult == KERN_SUCCESS);
+
+    service = IOIteratorNext(iterator);
+    io_connect_t switcherConnect;
+    
+    kernResult = IOServiceOpen(service, mach_task_self(), 0, &switcherConnect);
+    assert(kernResult == KERN_SUCCESS);
+    
+    kernResult = IOConnectCallScalarMethod(switcherConnect, kOpen, NULL, 0, NULL, NULL);
+    assert(kernResult == KERN_SUCCESS);
+
+    uint64_t output;
+    uint32_t outputCount = 1;
+    uint64_t scalarI_64[2] = { 1, MuxGraphicsCard };
+    
+    kernResult = IOConnectCallScalarMethod(switcherConnect,
+                                           kGetMuxState,
+                                           scalarI_64,
+                                           2,
+                                           &output,
+                                           &outputCount);
+    return output != 0;
+}
+
+id<MTLDevice> MTLCreateIntegratedDevice() {
+    BOOL isIntegratedGPU = isUsingIntegratedGPU();
+    id<MTLDevice> gpu = nil;
+
+    if (isIntegratedGPU) {
+        NSArray<id<MTLDevice>> *devices = MTLCopyAllDevices();
+        for (id<MTLDevice> device in devices) {
+            if (device.isLowPower) {
+                gpu = device;
+                break;
+            }
+        }
+    }
+    if (gpu == nil) {
+        gpu = MTLCreateSystemDefaultDevice();
+    }
+    return gpu;
+}
+
 JNIEXPORT jlong JNICALL Java_org_jetbrains_skiko_redrawer_MetalRedrawer_createMetalDevice(
     JNIEnv *env, jobject redrawer, jlong platformInfoPtr)
 {
@@ -116,7 +170,7 @@ JNIEXPORT jlong JNICALL Java_org_jetbrains_skiko_redrawer_MetalRedrawer_createMe
     [container addSublayer: layer];
     layer.javaRef = env->NewGlobalRef(redrawer);
 
-    id<MTLDevice> fDevice = MTLCreateSystemDefaultDevice();
+    id<MTLDevice> fDevice = MTLCreateIntegratedDevice();
     id<MTLCommandQueue> fQueue = [fDevice newCommandQueue];
 
     device.container = container;