bitmap.cpp

#include <iostream>
#include <fstream>
#include <windows.h>
#include <string>
#include <iomanip>
#include <sstream>

int width = 2;
int height = 2;
int32_t bitmap2x2[4] = { 0xffff0000, 0xff00ff00, 0xff0000ff, 0x00000000 };

void WriteBitmapFromHandle(HBITMAP source_hbitmap, UINT uFormat, int width, int height) {

	// We would like to just call ::SetClipboardData on the source_hbitmap,
	// but that bitmap might not be of a sort we can write to the clipboard.
	// For this reason, we create a new bitmap, copy the bits over, and then
	// write that to the clipboard.
	HDC dc = ::GetDC(nullptr);
	HDC compatible_dc = ::CreateCompatibleDC(nullptr);
	HDC source_dc = ::CreateCompatibleDC(nullptr);
	// This is the HBITMAP we will eventually write to the clipboard
	HBITMAP hbitmap = ::CreateCompatibleBitmap(dc, width, height);
	if (!hbitmap) {
		// Failed to create the bitmap
		::DeleteDC(compatible_dc);
		::DeleteDC(source_dc);
		::ReleaseDC(nullptr, dc);
		return;
	}
	HBITMAP old_hbitmap = (HBITMAP)SelectObject(compatible_dc, hbitmap);
	HBITMAP old_source = (HBITMAP)SelectObject(source_dc, source_hbitmap);
	// Now we need to blend it into an HBITMAP we can place on the clipboard
	BLENDFUNCTION bf = { AC_SRC_OVER, 0, 255, AC_SRC_ALPHA };

	::GdiAlphaBlend(compatible_dc,
		0,
		0,
		width,
		height,
		source_dc,
		0,
		0,
		width,
		height,
		bf);

	// Clean up all the handles we just opened

	::SelectObject(compatible_dc, old_hbitmap);
	::SelectObject(source_dc, old_source);
	::DeleteObject(old_hbitmap);
	::DeleteObject(old_source);
	::DeleteDC(compatible_dc);
	::DeleteDC(source_dc);
	::ReleaseDC(nullptr, dc);

	EmptyClipboard();

	HANDLE data = SetClipboardData(uFormat, hbitmap);

	if (data) {
		std::cout << "data put on the clipboard" << std::endl;
	}

	::DeleteObject(source_hbitmap);
}

int main()
{
	if (OpenClipboard(NULL))
	{
		HDC hdc = CreateCompatibleDC(NULL);

		if (!hdc) {
			return -1;
		}

		BITMAPINFO info;
		info.bmiHeader.biSize = sizeof(BITMAPV5HEADER);
		info.bmiHeader.biWidth = width;
		info.bmiHeader.biHeight = -height;
		info.bmiHeader.biPlanes = 1;
		info.bmiHeader.biBitCount = 32;
		info.bmiHeader.biCompression = BI_RGB;
		info.bmiHeader.biSizeImage = 4 * width * height;
		info.bmiHeader.biClrUsed = 0;
		info.bmiHeader.biClrImportant = 0;

		void* bits = NULL;

		HBITMAP dib = ::CreateDIBSection(hdc, &info, DIB_RGB_COLORS, &bits, NULL, 0);

		if (!dib) {
			return -2;
		}

		memcpy(bits, &bitmap2x2[0], 4 * sizeof(int32_t));
		WriteBitmapFromHandle(dib, CF_BITMAP, width, height);

		if (!CloseClipboard()) {
			return -3;
		}

		::DeleteObject(dib);
	}

	return 0;
}