Once you have an HBITMAP
, call HBITMAPToPixels
. Send the width
, the height
, and the bitsperpixel
. Next send the pixels..
On the other end of the socket, read width
, read height
, read bitsperpixel
.
Then create a buffer of size: ((width * Bmp.bmBitsPixel + 31) / 32) * 4 * height
Read that many bytes into the buffer and call HBITMAPFromPixels
The functions discussed are defined below..
#include <iostream>
#include <stdexcept>
#include <vector>
#include <cstring>
#include <memory>
#include <windows.h>
std::unique_ptr<std::remove_pointer<HBITMAP>::type, std::function<void(HBITMAP)>> HBITMAPFromPixels(const std::vector<std::uint8_t> &Pixels, std::uint32_t width, std::uint32_t height, std::uint16_t BitsPerPixel)
{
BITMAPINFO Info = {0};
std::memset(&Info, 0, sizeof(BITMAPINFO));
Info.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
Info.bmiHeader.biWidth = width;
Info.bmiHeader.biHeight = -height;
Info.bmiHeader.biPlanes = 1;
Info.bmiHeader.biBitCount = BitsPerPixel;
Info.bmiHeader.biCompression = BI_RGB;
Info.bmiHeader.biSizeImage = ((width * BitsPerPixel + 31) / 32) * 4 * height;
HBITMAP Result = CreateDIBitmap(GetDC(nullptr), &Info.bmiHeader, CBM_INIT, &Pixels[0], &Info, DIB_RGB_COLORS);
return std::unique_ptr<std::remove_pointer<HBITMAP>::type, std::function<void(HBITMAP)>>(Result, [&](HBITMAP hBmp){DeleteObject(hBmp);});
}
void HBITMAPToPixels(HBITMAP BitmapHandle, std::vector<std::uint8_t> &Pixels, std::uint32_t &width, std::uint32_t &height, std::uint16_t &BitsPerPixel)
{
if (BitmapHandle == nullptr)
{
throw std::logic_error("Null Pointer Exception. BitmapHandle is Null.");
}
Pixels.clear();
BITMAP Bmp = {0};
BITMAPINFO Info = {0};
HDC DC = CreateCompatibleDC(nullptr);
std::memset(&Info, 0, sizeof(BITMAPINFO));
HBITMAP OldBitmap = (HBITMAP)SelectObject(DC, BitmapHandle);
GetObject(BitmapHandle, sizeof(Bmp), &Bmp);
Info.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
Info.bmiHeader.biWidth = width = Bmp.bmWidth;
Info.bmiHeader.biHeight = height = Bmp.bmHeight;
Info.bmiHeader.biPlanes = 1;
Info.bmiHeader.biBitCount = BitsPerPixel = Bmp.bmBitsPixel;
Info.bmiHeader.biCompression = BI_RGB;
Info.bmiHeader.biSizeImage = ((width * Bmp.bmBitsPixel + 31) / 32) * 4 * height;
Pixels.resize(Info.bmiHeader.biSizeImage);
GetDIBits(DC, BitmapHandle, 0, height, &Pixels[0], &Info, DIB_RGB_COLORS);
SelectObject(DC, OldBitmap);
height = height < 0 ? -height : height;
DeleteDC(DC);
}