NDK使用ANativeWindow渲染surface，
大致代码如下：
ANativeWindow *nativeWindow = ANativeWindow_fromSurface(env, surface);
if (nativeWindow == 0) {
LOGE("ANativeWindow_window_from_surface error;env[0x%x] surface[0x%x]", env, surface);
return NULL;
}
int err = ANativeWindow_setBuffersGeometry(nativeWindow, width, height, WINDOW_FORMAT_RGB_565);
if ( err < 0 ) {
LOGE("ANativeWindow_setBuffersGeometry error");
return NULL;
}
LOGI("AnativeSurface_Draw param invalid. %d | %d | %d | %d | %d | %d", env, NativeSurface, ImgData, dataLen, width, height);
if (env == NULL || NativeSurface == NULL || ImgData == NULL
|| dataLen == 0 || width == 0 || height == 0) {
LOGE("AnativeSurface_Draw param invalid. %d | %d | %d | %d | %d | %d", env, NativeSurface, ImgData, dataLen, width, height);
return ;
}
ANativeWindow_Buffer windowBuffer;
int nlocked = ANativeWindow_lock((ANativeWindow*)NativeSurface, &windowBuffer, 0);
if (nlocked < 0) {
LOGW("AnativeSurface lock error:%d", nlocked);
return;
}
if (windowBuffer.bits != NULL) {
memcpy(windowBuffer.bits, ImgData, dataLen);
}
ANativeWindow_unlockAndPost((ANativeWindow*)NativeSurface);
ANativeWindow_release((ANativeWindow*)NativeSurface);
在测试的过程中，发现有些机型上出现花屏的现象，经内存拷贝测试，发现这些机型上，windowbuffer.bits的大小不等于 width * height * RGBSIZE，因此会导致数据错位而无法正常显示。
翻了下native_window.h(development/ndk/platforms/android-x/include/android目录下)，对于windowBuffer的定义如下：
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;
其中一个叫stride的项，表示在内存中每一行包含的像素数量，这个值可能会大于width。
再次测试，发现所有有问题的机型，果然stride大于width。因此在拷贝的时候需要注意内存对齐。。
最后解决方案如下：
if (windowBuffer.bits != NULL) {
//memcpy(windowBuffer.bits, ImgData, dataLen);
if (windowBuffer.width == windowBuffer.stride) {
memcpy(windowBuffer.bits, ImgData, dataLen);
} else {
for (int ii=0; ii < windowBuffer.height; ii++) {
char *srcPointer = ImgData + windowBuffer.width * ii * 2;
char *dstPointer = ((char *)windowBuffer.bits) + windowBuffer.stride * ii * 2;
memcpy(dstPointer, srcPointer, windowBuffer.width * 2);
}
}
}
