internal static extern int GetDIBits([In] IntPtr hdc, [In] IntPtr hbmp, uint uStartScan, uint cScanLines, ref IntPtr lpvBits, ref BITMAPINFO lpbi, uint uUsage);
internal static extern IntPtr CreateDIBSection(IntPtr hdc, [In] ref BITMAPINFO pbmi,
uint pila, out IntPtr ppvBits, IntPtr hSection, uint dwOffset);
/// <summary>
/// Converts raw image data into PARGB32.
/// </summary>
/// <param name="hdc">The handle to the device context..</param>
/// <param name="pargb">The pixel data.</param>
/// <param name="hbmp">The bitmap handle.</param>
/// <param name="imageSize">The image size.</param>
/// <param name="rowLength">The row length.</param>
private unsafe static void ConvertToPARGB32(IntPtr hdc, UInt32* pargb, IntPtr hbmp, Size imageSize, int rowLength)
{
var bmi = new BITMAPINFO
{
bmiHeader = new BITMAPINFOHEADER
{
biSize = (uint) Marshal.SizeOf(typeof (BITMAPINFOHEADER)),
biPlanes = 1,
biCompression = (uint) BI.BI_RGB,
biWidth = imageSize.Width,
biHeight = imageSize.Height,
biBitCount = 32
}
};
// Allocate data sufficient for the pixel data.
IntPtr hHeap = Kernel32.GetProcessHeap();
void* pvBits = Kernel32.HeapAlloc(hHeap, 0, new UIntPtr((uint)(bmi.bmiHeader.biWidth * 4 * bmi.bmiHeader.biHeight))).ToPointer();
if (pvBits == (void*) 0)
return;
// Get the bitmap bits.
var ptr = new IntPtr(pvBits);
if (Gdi32.GetDIBits(hdc, hbmp, 0, (uint) bmi.bmiHeader.biHeight, ref ptr,ref bmi, (uint)DIB.DIB_RGB_COLORS) ==
bmi.bmiHeader.biHeight)
{
// Now handle each pixel.
UInt32 cxDelta = (uint)(rowLength - bmi.bmiHeader.biWidth);
UInt32* pargbMask = (uint*)pvBits;
for (UInt32 y = (UInt32) bmi.bmiHeader.biHeight; y != 0; --y)
{
for (UInt32 x = (UInt32) bmi.bmiHeader.biWidth; x != 0; --x)
{
if ((*pargbMask++) != 0)
{
// transparent pixel
*pargb++ = 0;
}
else
{
// opaque pixel
*pargb++ |= 0xFF000000;
}
}
pargb += cxDelta;
}
}
Kernel32.HeapFree(hHeap, 0, new IntPtr(pvBits));
}
/// <summary>
/// Creates a 32 bit HBITMAP of the specified size.
/// </summary>
/// <param name="hdc">The HDC.</param>
/// <param name="size">The size.</param>
/// <param name="bits">The bits.</param>
/// <param name="hBitmap">The bitmap handle.</param>
/// <returns>True if the bitmap was created successfully.</returns>
private static bool Create32BitHBITMAP(IntPtr hdc, Size size, out IntPtr bits, out IntPtr hBitmap)
{
// Create a bitmap info setup for a 32 bit bitmap.
var bi = new BITMAPINFO
{
bmiHeader = new BITMAPINFOHEADER
{
biSize = (uint) Marshal.SizeOf(typeof (BITMAPINFOHEADER)),
biPlanes = 1,
biCompression = (uint) BI.BI_RGB,
biWidth = size.Width,
biHeight = size.Height,
biBitCount = 32
}
};
// Create the DIB section.
hBitmap = Gdi32.CreateDIBSection(hdc, ref bi, (uint)DIB.DIB_RGB_COLORS, out bits, IntPtr.Zero, 0);
// Return success only if we have a handle and bitmap bits.
return hBitmap != IntPtr.Zero && bits != IntPtr.Zero;
}
public static extern int GetDIBits([In] IntPtr hdc, [In] IntPtr hbmp, uint uStartScan, uint cScanLines, ref IntPtr lpvBits, ref BITMAPINFO lpbi, uint uUsage);
public static extern int GetDIBits([In] IntPtr hdc, [In] IntPtr hbmp, uint uStartScan, uint cScanLines, [Out] byte[] lpvBits, ref BITMAPINFO lpbi, uint uUsage);
