如何从给定的偏移量开始复制内存。例如
int main()
{
int a1[100], a2[100], i;
errno_t err;
// Populate a2 with squares of integers
for (i = 0; i < 100; i++)
{
a2[i] = i*i;
}
// Tell memcpy_s to copy 10 ints (40 bytes), giving
// the size of the a1 array (also 40 bytes).
err = memcpy
由于某些原因,我不能确定我是否受到了访问冲突。
memcpy_s (buffer, bytes_per_line * height, image, bytes_per_line * height);
这是整个函数:
int Flip_Bitmap(UCHAR *image, int bytes_per_line, int height)
{
// this function is used to flip bottom-up .BMP images
UCHAR *buffer; // used to perform the image processing
背景
考虑以下代码:
template <typename T>
void WriteData(const size_t &offset, const T &data)
{
if(sizeof(data) <= 8) //if size is 64bits or less, memcpy is not as efficient as a direct write
*reinterpret_cast<T*>(reinterpret_cast<char*>(_memView)
我必须做一件可怕的事情,即在预编译时用不同的函数调用自动替换函数调用,使用不同的参数数。示例:
#include <iostream>
int FuncToChange(void* a, int b, void* c, int d) {
return 0;
}
int NewFunc(void* a, void* c, int d) {
return 1;
}
#define FuncToChange($1, $2, $3, $4) NewFunc($1, $3, $4)
int main()
{
int a = 1, b = 2, c = 256;
我有一个基类,它包含一个未分配的指针_vertices,我想从派生类构造函数中填充它:
class GameRenderable {
bool _indexed;
int _vertSize;
int _idxSize;
unsigned int VAO, VBO, EBO;
unsigned int _texture0;
protected:
float *_vertices;
unsigned int *_indices;
public:
GameRenderable(GameRenderableMode grm);
我正在尝试使用外部布尔信号通过x264 C应用程序接口强制下一个编码帧成为IDR帧。我使用的是带有“超快”和“零度”预设的“基线”配置文件。我试着在编码之前使用输入图片设置,就像在这个代码片段中一样,但这不起作用。我的类Open()和Encode()方法如下所示。任何帮助都将不胜感激。 int X264Encoder::Open(void)
{
if (_x264VideoEncoder != NULL)
Close();
// Set up default parameters.
if (x264_param_default_preset(&_param, _
请举个小例子。我试着在文档中使用它,但我不能理解如何使用。
消息:
main.cpp|97|error: no matching function for call to
'CryptoPP::SecBlock<unsigned char>::operator+=(CryptoPP::SecBlock<unsigned char>*)'
secblock.h|568|note: candidate:
CryptoPP::SecBlock<T, A>& CryptoPP::SecBlock<T, A>:
这是程序的代码,它应该发送一个简单的'ping‘。我知道我可以使用IcmpSendEcho2()函数,但我决定这样做:
struct ICMPh
{
unsigned char typ;
unsigned char kod;
unsigned short suma_spr;
unsigned short id;
unsigned short seq;
};
unsigned short CalcChecksum (char *pBuffer, int nLen)
{
////Checksum for ICMP is calculated in the same way as f