freerdp获取cursor的方法

rdp协议中会把图像和鼠标样式分开发送，这样做的好处是，避免鼠标与图像一起绘制时会导致鼠标严重延迟，freerdp中可以很容易的获取鼠标样式的bitmap，但是在windows中，需要绘制ico就需要重建icoinfo文件，相对复杂，不是本文关心的内容，因此本文只介绍如何获取rbga内容。

入口函数

创建一个保存鼠标样式的数据类型，node_register_pointer函数需要在freerdp_connect函数中首先调用，

typedef struct _NodePointer
{
	rdpPointer pointer;
	byte * buffer;
  int width;
  int height;
}NodePointer;
BOOL node_register_pointer(rdpGraphics* graphics)
{
	rdpPointer pointer;
	if (!graphics)
		return FALSE;
	ZeroMemory(&pointer, sizeof(rdpPointer));
	pointer.size = sizeof(NodePointer);
	pointer.New = reinterpret_cast<pPointer_New>(node_Pointer_New);
	pointer.Free = reinterpret_cast<pPointer_Free>(node_Pointer_Free);
	pointer.Set = reinterpret_cast<pPointer_Set>(node_Pointer_Set);
	graphics_register_pointer(graphics, &pointer);
	return TRUE;
}

Pointer回调

核心代码在于freerdp_image_copy_from_pointer_data函数，可以通过xorMaskData和andMaskData数据得到rgba数据，当然也可以修改PIXEL_FORMAT_RGBA32为PIXEL_FORMAT_GBRA32来调整rgba的顺序。

BOOL node_Pointer_New(rdpContext* context, const rdpPointer* pointer)
{
	int size = pointer->height * pointer->width * GetBytesPerPixel(PIXEL_FORMAT_RGBA32);
	BYTE* pdata = (BYTE*)_aligned_malloc( size, 16 );
	rdpGdi* gdi = context->gdi;
	freerdp_image_copy_from_pointer_data(pdata, PIXEL_FORMAT_RGBA32, 0, 0, 0,
	pointer->width, pointer->height,
	pointer->xorMaskData, pointer->lengthXorMask,
	pointer->andMaskData, pointer->lengthAndMask, pointer->xorBpp, &gdi->palette);
    ((NodePointer *)pointer)->buffer = pdata;
	return TRUE;
}
BOOL node_Pointer_Free(rdpContext* context, rdpPointer* pointer)
{
	if (!pointer)
		return FALSE;
	byte * buffer= ((NodePointer*)pointer)->buffer;
	if (hCur != 0)
		_aligned_free(buffer);
	return TRUE;
}
BOOL node_Pointer_Set(rdpContext* context, const rdpPointer* pointer)
{
	if (!pointer)
		return FALSE;
	//客户端直接修改cursor,或者通过网络发送到别的地方
	return TRUE;
}