ebiten/internal/devicescale/impl_android.go
2021-03-28 23:39:06 +09:00

106 lines
3.6 KiB
Go

// Copyright 2016 Hajime Hoshi
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package devicescale
/*
#include <jni.h>
#include <stdlib.h>
// Basically same as:
//
// WindowService windowService = context.getSystemService(Context.WINDOW_SERVICE);
// Display display = windowManager.getDefaultDisplay();
// DisplayMetrics displayMetrics = new DisplayMetrics();
// display.getRealMetrics(displayMetrics);
// this.deviceScale = displayMetrics.density;
//
static float deviceScale(uintptr_t java_vm, uintptr_t jni_env, uintptr_t ctx) {
JavaVM* vm = (JavaVM*)java_vm;
JNIEnv* env = (JNIEnv*)jni_env;
jobject context = (jobject)ctx;
const char* kWindowService = "window";
const jclass android_content_Context =
(*env)->FindClass(env, "android/content/Context");
const jclass android_view_WindowManager =
(*env)->FindClass(env, "android/view/WindowManager");
const jclass android_view_Display =
(*env)->FindClass(env, "android/view/Display");
const jclass android_util_DisplayMetrics =
(*env)->FindClass(env, "android/util/DisplayMetrics");
const jobject android_context_Context_WINDOW_SERVICE =
(*env)->GetStaticObjectField(
env, android_content_Context,
(*env)->GetStaticFieldID(env, android_content_Context, "WINDOW_SERVICE", "Ljava/lang/String;"));
const jobject windowManager =
(*env)->CallObjectMethod(
env, context,
(*env)->GetMethodID(env, android_content_Context, "getSystemService", "(Ljava/lang/String;)Ljava/lang/Object;"),
android_context_Context_WINDOW_SERVICE);
const jobject display =
(*env)->CallObjectMethod(
env, windowManager,
(*env)->GetMethodID(env, android_view_WindowManager, "getDefaultDisplay", "()Landroid/view/Display;"));
const jobject displayMetrics =
(*env)->NewObject(
env, android_util_DisplayMetrics,
(*env)->GetMethodID(env, android_util_DisplayMetrics, "<init>", "()V"));
(*env)->CallVoidMethod(
env, display,
(*env)->GetMethodID(env, android_view_Display, "getRealMetrics", "(Landroid/util/DisplayMetrics;)V"),
displayMetrics);
const float density =
(*env)->GetFloatField(
env, displayMetrics,
(*env)->GetFieldID(env, android_util_DisplayMetrics, "density", "F"));
(*env)->DeleteLocalRef(env, android_content_Context);
(*env)->DeleteLocalRef(env, android_view_WindowManager);
(*env)->DeleteLocalRef(env, android_view_Display);
(*env)->DeleteLocalRef(env, android_util_DisplayMetrics);
(*env)->DeleteLocalRef(env, android_context_Context_WINDOW_SERVICE);
(*env)->DeleteLocalRef(env, windowManager);
(*env)->DeleteLocalRef(env, display);
(*env)->DeleteLocalRef(env, displayMetrics);
return density;
}
*/
import "C"
import (
"fmt"
"golang.org/x/mobile/app"
)
func impl(x, y int) float64 {
s := 0.0
if err := app.RunOnJVM(func(vm, env, ctx uintptr) error {
// TODO: This might be crash when this is called from init(). How can we detect this?
s = float64(C.deviceScale(C.uintptr_t(vm), C.uintptr_t(env), C.uintptr_t(ctx)))
return nil
}); err != nil {
panic(fmt.Sprintf("devicescale: error %v", err))
}
return s
}