编译frameworks\native\services\surfaceflinger\tests\resize

 mmm frameworks/native/services/surfaceflinger/tests/resize/遇到几个错误，这里面讲一下解决过程，有一部分参考网络。感谢。

一、问题：

frameworks/native/services/surfaceflinger/tests/resize/resize.cpp:50:26: error: aggregate 'ANativeWindow_Buffer outBuffer' has incomplete type and cannot be defined

解决：

在resize.cpp中，添加#include <android/native_window.h>

二、问题：

frameworks/native/services/surfaceflinger/tests/resize/resize.cpp:58:29: error: no matching function for call to 'android::Surface::lock(ANativeWindow_Buffer*)'

解决：

surface->lock(&outBuffer);  ---》surface->lock(&outBuffer, NULL);

三、问题：

frameworks/native/services/surfaceflinger/tests/resize/resize.cpp:70:1: error: expected '}' at end of input 。。。

解决：

最后加一个“｝”

四、问题：

out/target/product/msm8909/obj/lib/crtbegin_dynamic.o:crtbegin.c:function _start: error: undefined reference to 'main'
collect2: error: ld returned 1 exit status

解决：

屏蔽//namespace android { 

//｝

五、问题：

error: undefined reference to 'android::ProcessState::self()'

解决：

android.mk中加入：

LOCAL_SHARED_LIBRARIES := \
libcutils \
libutils \
    libui \
    libgui \
    libbinder

最终编译经过了！真够费劲的。

附上 修改后的代码：

/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * 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.
 */

#include <cutils/memory.h>

#include <utils/Log.h>

#include <android/native_window.h>

#include <binder/IPCThreadState.h>
#include <binder/ProcessState.h>
#include <binder/IServiceManager.h>

#include <gui/Surface.h>
#include <gui/SurfaceComposerClient.h>

using namespace android;

//namespace android {

int main(int argc, char** argv)
{
    // set up the thread-pool
    sp<ProcessState> proc(ProcessState::self());
    ProcessState::self()->startThreadPool();

    // create a client to surfaceflinger
    sp<SurfaceComposerClient> client = new SurfaceComposerClient();
    
    sp<SurfaceControl> surfaceControl = client->createSurface(String8("resize"),
            320, 240, PIXEL_FORMAT_RGB_565, 0);

    sp<Surface> surface = surfaceControl->getSurface();

    SurfaceComposerClient::openGlobalTransaction();
    surfaceControl->setLayer(100000);
    SurfaceComposerClient::closeGlobalTransaction();

    ANativeWindow_Buffer outBuffer;
    surface->lock(&outBuffer, NULL);
    ssize_t bpr = outBuffer.stride * bytesPerPixel(outBuffer.format);
    android_memset16((uint16_t*)outBuffer.bits, 0x07E0, bpr*outBuffer.height);
    surface->unlockAndPost();
/*
    surface->lock(&outBuffer, NULL);
    android_memset16((uint16_t*)outBuffer.bits, 0x07E0, bpr*outBuffer.height);
    surface->unlockAndPost();
*/
    SurfaceComposerClient::openGlobalTransaction();
    surfaceControl->setSize(320, 240);
    SurfaceComposerClient::closeGlobalTransaction();

    
    IPCThreadState::self()->joinThreadPool();
    
    return 0;
}
//}

附解释版本，对于理解surfaceflinger颇有帮助，一行一行敲的，纯属原创：

/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * 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.
 */

#include <cutils/memory.h>

#include <utils/Log.h>

#include <android/native_window.h>

#include <binder/IPCThreadState.h>
#include <binder/ProcessState.h>
#include <binder/IServiceManager.h>

#include <gui/Surface.h>
#include <gui/SurfaceComposerClient.h>

using namespace android;

//namespace android {

int main(int argc, char** argv)
{
    // set up the thread-pool need for binder,创建binder通信接口，SurfaceComposerClient 和 surfaceflinger之间的通讯
    sp<ProcessState> proc(ProcessState::self());
    ProcessState::self()->startThreadPool();

    // create a client to surfaceflinger
    sp<SurfaceComposerClient> client = new SurfaceComposerClient();
    
	//经过SurfaceComposerClient获取一个大小为300(w)x400(h)的surface画布，这块画布数据格式为PIXEL_FORMAT_RGB_565，
	//每一个像素字节数为(bytesPerPixel(outBuffer.format))=2
    sp<SurfaceControl> surfaceControl = client->createSurface(String8("resize"),
            300, 400, PIXEL_FORMAT_RGB_565, 0);
//surfaceControl是控制每一个surface的属性，包含大小，z-order,位置,透明度等
    sp<Surface> surface = surfaceControl->getSurface();

	//在设置每一个layer的属性的时候须要打开一个事务，告诉surfaceflinger监控程序，layer状态的改变，须要进行对相关layer进行重绘
    SurfaceComposerClient::openGlobalTransaction();
	//设置layer（surface）的相关属性
    surfaceControl->setLayer(100000);
	surfaceControl->setPosition(100,100);
    surfaceControl->setSize(100, 100);
	//关闭事务，表明设置完毕，这样surfaceflinger服务端就会按要求重绘，这里尚未发送到显示端，只是一个显示数据上的概念
    SurfaceComposerClient::closeGlobalTransaction();
//这个数据结构跟简单，包含显示窗口的大小，格式，还有数据
	/*
	typedef struct ANativeWindow_Buffer {
		// The number of pixels that are show horizontally.
		int32_t width;

		// The number of pixels that are shown vertically.
		int32_t height;

		// The number of *pixels* that a line in the buffer takes in
		// memory.  This may be >= width.
		int32_t stride;

		// The format of the buffer.  One of WINDOW_FORMAT_*
		int32_t format;

		// The actual bits.
		void* bits;
		
		// Do not touch.
		uint32_t reserved[6];
	} ANativeWindow_Buffer;
	*/
	ANativeWindow_Buffer outBuffer;
	//因此应用程序先调用 surface->lock锁定layer的swapstate，并得到画图的buffer而后就能够在上面进行画图了，完成之后就会调用surface->unlockAndPost()来通知SurfaceFlinger进行Flip。
    surface->lock(&outBuffer, NULL);
    ssize_t bpr = outBuffer.stride * bytesPerPixel(outBuffer.format);
	//下面的数据打印结果：outBuffer.stride = 128, bytesPerPixel(outBuffer.format)=2,outBuffer.height=100
	printf("outBuffer.stride = %d, bytesPerPixel(outBuffer.format)=%d,outBuffer.height=%d\n",outBuffer.stride, bytesPerPixel(outBuffer.format),outBuffer.height);
	//设置显示数据都为0x07E0，rgb565表明绿色。0000 0111 1110 0000
    android_memset16((uint16_t*)outBuffer.bits, 0x07E0, bpr*outBuffer.height);
	//调用surface->unlockAndPost()来通知SurfaceFlinger进行Flip(刷新到LCD上)
    surface->unlockAndPost();
    
    IPCThreadState::self()->joinThreadPool();
    
    return 0;
}
//}

Android.mk

LOCAL_PATH:= $(call my-dir)
include $(CLEAR_VARS)

LOCAL_SRC_FILES:= \
	resize.cpp

LOCAL_SHARED_LIBRARIES := \
	libcutils \
	libutils \
    libui \
    libgui \
	libbinder

LOCAL_MODULE:= test-resize

LOCAL_MODULE_TAGS := tests

include $(BUILD_EXECUTABLE)