ebiten/internal/devicescale/impl_android.go
2018-10-06 19:43:23 +09:00

77 lines
2.5 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 `getResources().getDisplayMetrics().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 jclass android_content_ContextWrapper =
(*env)->FindClass(env, "android/content/ContextWrapper");
const jclass android_content_res_Resources =
(*env)->FindClass(env, "android/content/res/Resources");
const jclass android_util_DisplayMetrics =
(*env)->FindClass(env, "android/util/DisplayMetrics");
const jobject resources =
(*env)->CallObjectMethod(
env, context,
(*env)->GetMethodID(env, android_content_ContextWrapper, "getResources", "()Landroid/content/res/Resources;"));
const jobject displayMetrics =
(*env)->CallObjectMethod(
env, resources,
(*env)->GetMethodID(env, android_content_res_Resources, "getDisplayMetrics", "()Landroid/util/DisplayMetrics;"));
const float density =
(*env)->GetFloatField(
env, displayMetrics,
(*env)->GetFieldID(env, android_util_DisplayMetrics, "density", "F"));
(*env)->DeleteLocalRef(env, android_content_ContextWrapper);
(*env)->DeleteLocalRef(env, android_content_res_Resources);
(*env)->DeleteLocalRef(env, android_util_DisplayMetrics);
(*env)->DeleteLocalRef(env, resources);
(*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
}