Android Studio 3.2.1上vuh库使用的例子

Android Studio 3.2.1 上 vuh 库使用的例子，首先使用 基于Vulkan的GPGPU计算框架Vuh 编译出 Android 版本的动态库，然后依照如下步骤建立工程。

如下图所示，拷贝头文件跟动态库到指定的目录：

工程中几处关键的代码如下：

# For more information about using CMake with Android Studio, read the
# documentation: https://d.android.com/studio/projects/add-native-code.html
 
# Sets the minimum version of CMake required to build the native library.
 
cmake_minimum_required(VERSION 3.4.1)
 
 
# for Vulkan
add_definitions(-DVK_USE_PLATFORM_ANDROID_KHR=1 -DVULKAN_HPP_TYPESAFE_CONVERSION=1)
 
include_directories(src/main/cpp/include)
include_directories(${ANDROID_NDK}/sources/third_party/vulkan/src/include/)
 
add_library(vuh SHARED IMPORTED)
set_target_properties(vuh PROPERTIES IMPORTED_LOCATION  ${CMAKE_SOURCE_DIR}/src/main/jniLibs/${ANDROID_ABI}/libvuh.so)
 
add_library(vulkan SHARED IMPORTED)
set_target_properties(vulkan PROPERTIES IMPORTED_LOCATION  ${ANDROID_NDK}/platforms/${ANDROID_PLATFORM}/arch-arm/usr/lib/libvulkan.so)
 
 
# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds them for you.
# Gradle automatically packages shared libraries with your APK.
 
add_library( # Sets the name of the library.
        native-lib
 
        # Sets the library as a shared library.
        SHARED
 
        # Provides a relative path to your source file(s).
        src/main/cpp/native-lib.cpp)
 
# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.
 
find_library( # Sets the name of the path variable.
        log-lib
 
        # Specifies the name of the NDK library that
        # you want CMake to locate.
        log
        android)
 
# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, prebuilt third-party libraries, or system libraries.
 
target_link_libraries( # Specifies the target library.
        native-lib
 
        vulkan
        vuh
        # Links the target library to the log library
        # included in the NDK.
 
        ${log-lib})

apply plugin: 'com.android.application'
 
android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.mobibrw.vuhandroid"
        minSdkVersion 24
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        externalNativeBuild {
            cmake {
                cppFlags "-std=c++14 -v -g"
                abiFilters "armeabi-v7a"
            }
        }
    }
 
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    externalNativeBuild {
        cmake {
            path "CMakeLists.txt"
        }
    }
}
 
dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}

package com.mobibrw.vuhandroid;
 
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
 
public class MainActivity extends AppCompatActivity {
 
    // Used to load the 'native-lib' library on application startup.
    static {
        System.loadLibrary("vuh");
        System.loadLibrary("native-lib");
    }
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        // Example of a call to a native method
        TextView tv = (TextView) findViewById(R.id.sample_text);
        tv.setText(stringFromJNI());
    }
 
    /**
     * A native method that is implemented by the 'native-lib' native library,
     * which is packaged with this application.
     */
    public native String stringFromJNI();
}

#include <jni.h>
#include <string>
 
#include <vuh/array.hpp>
#include <vuh/vuh.h>
#include <vector>
 
auto saxpy()-> int {
    auto y = std::vector<float>(128, 1.0f);
    auto x = std::vector<float>(128, 2.0f);
    const auto a = 0.1f; // saxpy scaling constant
 
    auto instance = vuh::Instance();
    auto device = instance.devices().at(0);  // just get the first compute-capable device
 
    auto d_y = vuh::Array<float>(device, y); // allocate memory on device and copy data from host
    auto d_x = vuh::Array<float>(device, x); // same for x
 
    using Specs = vuh::typelist<uint32_t>;
    struct Params{uint32_t size; float a;};
    auto program = vuh::Program<Specs, Params>(device, "saxpy.spv"); // define the kernel by linking interface and spir-v implementation
    program.grid(128/64).spec(64)({128, a}, d_y, d_x); // run once, wait for completion
    d_y.toHost(begin(y));                              // copy data back to host
 
    return 0;
}
 
 
extern "C" JNIEXPORT jstring JNICALL
Java_com_mobibrw_vuhandroid_MainActivity_stringFromJNI(
        JNIEnv *env,
        jobject /* this */) {
    std::string hello = "Hello from C++";
    saxpy();
    return env->NewStringUTF(hello.c_str());
}

点击此处下载完整的工程vuhAndroid

参考链接

• Android app crashes after switching from .lib to .so
• Is it possible to use vulkan.hpp header with dynamically dispatched functions ONLY?
• 深入理解使用CMake编译 NDK 程序
• 向您的项目添加 C 和 C++ 代码