Android Tango depth camera capture support.

media/capture/video/android/tango_api.cc

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "tango_api.h"
+
+#include <dlfcn.h>
+
+#include "base/logging.h"
+
+namespace media {
+
+// static
+std::unique_ptr<TangoApi> TangoApi::loadAndCreate() {

[aleksandar.stojiljkovic, 2017/07/24 08:16:58]

Note that WebAR code (I copied the native Tango initialization approach from)
uses multiple fallback locations [1] for locating libtango_client_api.so, and
here I use only one.
I'll extend it later - this one works fine with tango development kit tablet and
Lenovo Phab 2 Pro. 

https://github.com/googlevr/chromium-webar/blob/9e2420ffb2870a7cc8095ad444082...

+  void* lib_ = dlopen(
+      "/data/data/com.google.tango/libfiles/armeabi-v7a/"
+      "libtango_client_api.so",
+      RTLD_NOW);
+  if (!lib_) {
+    LOG(ERROR) << "Could not dlopen(\"libtango_client_api\"):" << dlerror();
+    return nullptr;
+  }
+  return std::unique_ptr<TangoApi>(new TangoApi(lib_));
+}
+
+TangoApi::TangoApi(void* lib_client_api) : lib_(lib_client_api) {}
+
+// An example of expanded code for TANGO_METHOD:
+// TANGO_METHOD(TangoErrorType, TangoService_setBinder, TANGO_ERROR,
+//                       void* jni_env, void* iBinder)
+// expands to:
+// TangoErrorType TangoService_setBinder(void* jni_env, void* iBinder) {
+//   using TangoService_setBinderPtr = TangoErrorType(*)(void* jni_env,
+//                                                       void* iBinder);
+//   static TangoService_setBinderPtr func =
+//       reinterpret_cast<TangoService_setBinderPtr>(dlsym(lib_, __func__));
+//   if (!func) {
+//     LOG(ERROR) << "dlsym failed on"<<  __PRETTY_FUNCTION__ << dlerror();
+//     return TANGO_ERROR;
+//   }
+#define TANGO_METHOD(ret, name, return_on_error, params, ...)   \
+  ret TangoApi::name(__VA_ARGS__) {                             \
+    using name##Ptr = ret (*)(__VA_ARGS__);                     \
+    static name##Ptr func =                                     \
+        reinterpret_cast<name##Ptr>(dlsym(lib_, __func__));     \
+    if (!func) {                                                \
+      LOG(ERROR) << "dlsym failed on" << __func__ << dlerror(); \
+      return return_on_error;                                   \
+    }                                                           \
+    return params;                                              \
+  }
+
+TANGO_METHOD(TangoApi::TangoErrorType,
+             TangoService_setBinder,
+             TANGO_METHOD_NOT_FOUND,
+             func(jni_env, iBinder),
+             void* jni_env,
+             void* iBinder)
+
+TANGO_METHOD(TangoApi::TangoConfig,
+             TangoService_getConfig,
+             nullptr,
+             func(config_type),
+             TangoConfigType config_type)
+
+TANGO_METHOD(TangoApi::TangoErrorType,
+             TangoConfig_setBool,
+             TANGO_METHOD_NOT_FOUND,
+             func(config, key, value),
+             TangoConfig config,
+             const char* key,
+             bool value)
+
+TANGO_METHOD(TangoApi::TangoErrorType,
+             TangoConfig_setInt32,
+             TANGO_METHOD_NOT_FOUND,
+             func(config, key, value),
+             TangoConfig config,
+             const char* key,
+             int32_t value)
+
+TANGO_METHOD(TangoApi::TangoErrorType,
+             TangoService_connect,
+             TANGO_METHOD_NOT_FOUND,
+             func(context, config),
+             void* context,
+             TangoConfig config)
+
+TANGO_METHOD(TangoApi::TangoErrorType,
+             TangoService_getCameraIntrinsics,
+             TANGO_METHOD_NOT_FOUND,
+             func(camera_id, intrinsics),
+             TangoCameraId camera_id,
+             TangoCameraIntrinsics* intrinsics)
+
+TANGO_METHOD(void, TangoService_disconnect, void(), func())
+
+TangoApi::TangoErrorType TangoApi::TangoService_connectOnPointCloudAvailable(
+    void (*TangoService_onPointCloudAvailable)(void* context,
+                                               const TangoPointCloud* cloud),
+    ...) {
+  using TangoService_connectOnPointCloudAvailablePtr =
+      TangoApi::TangoErrorType (*)(
+          void (*TangoService_onPointCloudAvailable)(
+              void* context, const TangoPointCloud* cloud),
+          ...);
+  static TangoService_connectOnPointCloudAvailablePtr func =
+      reinterpret_cast<TangoService_connectOnPointCloudAvailablePtr>(
+          dlsym(lib_, __func__));
+  if (!func) {
+    LOG(ERROR) << "dlsym failed on" << __PRETTY_FUNCTION__ << dlerror();
+    return TANGO_METHOD_NOT_FOUND;
+  }
+  va_list args;
+  va_start(args, TangoService_onPointCloudAvailable);
+  TangoApi::TangoErrorType result =
+      func(TangoService_onPointCloudAvailable, args);
+  va_end(args);
+  return result;
+}
+
+}  // namespace media