ebiten/internal/devicescale/impl_android.go

106 lines
3.6 KiB
Go
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

// 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
}