android native code 显示图片

最新推荐文章于 2024-07-28 23:31:48 发布

转载最新推荐文章于 2024-07-28 23:31:48 发布 · 1k 阅读

文章标签：

#android #module #layer #include #build #path

本文介绍如何使用 Android NDK 和 nativecode 在 Android 设备上显示图片。通过创建 SurfaceComposerClient 和 SurfaceControl 对象，设置图层并绘制位图到屏幕上。

些日子一直在纠结于android的东西，各种配环境、编译，终于告一小段落了。

用native code开发ndk提供的资源是远远不够的，要使用android源码这个超级sdk。具体方法就是下载好源码然后把自己写的代码和它的Android.mk文件放在源码根目录的一子目录里，然后在根目录make LOCAL_MODULE。

用native code显示图片由于网上很少有相关资料，所有费了一些劲。

Android.mk:

LOCAL_PATH:= $(call my-dir)

include $(CLEAR_VARS)

LOCAL_SRC_FILES:= test.cpp

LOCAL_MODULE:= testbmp

LOCAL_MODULE_TAGS := tests

LOCAL_SHARED_LIBRARIES :=
                libskia
                libutils
                libsurfaceflinger_client
                libui 

$(info $(LOCAL_SHARED_LIBRARIES))

include $(BUILD_EXECUTABLE)

test.cpp:

#include <core/SkCanvas.h>
#include <core/SkDevice.h>
#include <surfaceflinger/SurfaceComposerClient.h>

using namespace android;

#define SCREEN_WIDTH 480
#define SCREEN_HEIGHT 640
#define SCREEN_NUMBER 5
#define ORIGIN_X 0
#define ORIGIN_Y 0
#define BACKGROUND_LAYER 100000
#define FRONT_LAYER 120000

sp<SurfaceComposerClient> g_uiClient;
sp<SurfaceControl> g_bkSurfacecontrol;
sp<SurfaceControl> g_ftSurfacecontrol[SCREEN_NUMBER];
sp<Surface> g_bkSurface;
sp<Surface> g_ftSurface[SCREEN_NUMBER];

int p[10000] = {
        0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff,
        0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff,
        0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff,
        0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000,
        0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000,
        0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000, 0xff000000,
        0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000,
        0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000,
        0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000,
        0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000, 0xffff0000,
};

int testInit()
{
    g_uiClient = new SurfaceComposerClient();
    int i = 0;
    g_ftSurfacecontrol[i] = g_uiClient->createSurface(getpid(), 0, SCREEN_WIDTH, SCREEN_HEIGHT, PIXEL_FORMAT_RGBA_8888);
    g_ftSurface[i] = g_ftSurfacecontrol[i]->getSurface();
    g_uiClient->openTransaction();
    g_ftSurfacecontrol[i]->setLayer(FRONT_LAYER);
    g_ftSurfacecontrol[i]->setSize(SCREEN_WIDTH, SCREEN_HEIGHT);
    g_ftSurfacecontrol[i]->setPosition(ORIGIN_X + i * SCREEN_WIDTH, ORIGIN_Y);
    g_uiClient->closeTransaction();

    g_bkSurfacecontrol = g_uiClient->createSurface(getpid(), 0, SCREEN_WIDTH * 1, SCREEN_HEIGHT, PIXEL_FORMAT_RGBA_8888);
    g_uiClient->openTransaction();
    g_bkSurfacecontrol->setLayer(BACKGROUND_LAYER);
    g_bkSurfacecontrol->setSize(SCREEN_WIDTH * SCREEN_NUMBER, SCREEN_HEIGHT);
    g_bkSurfacecontrol->setPosition(ORIGIN_X, ORIGIN_Y);
    g_uiClient->closeTransaction();
    g_bkSurface = g_bkSurfacecontrol->getSurface();

    return 0;
}

void BkFlushBufferDraw(int *p)
{
    Surface::SurfaceInfo info;
    g_bkSurface->lock(&info);

    SkBitmap bitmap;
    ssize_t bpr = info.s * bytesPerPixel(info.format);
    bitmap.setConfig(SkBitmap::kARGB_8888_Config, info.w, info.h, (int)bpr);
    bitmap.setPixels(info.bits);

    SkCanvas* canvas = new SkCanvas(new SkDevice(bitmap));
    canvas->setViewport(bitmap.width(), bitmap.height());

    SkBitmap bitmap2;
    bitmap2.setConfig(SkBitmap::kARGB_8888_Config, 10, 10);

    bitmap2.setPixels(p);
    canvas->drawBitmap(bitmap2, (SkScalar)30.0,(SkScalar)30.0);

    g_bkSurface->unlockAndPost();
    sleep(100000000);
}
int main()
{
    testInit();
    BkFlushBufferDraw(p);

    return 0;
}

然后make testbmp就可以了。

其中int p[]是图像的数组，每像素一字节，从低到高分别是RGBA。