Hi I am looking to capture screenshot of the window on top or the desktop that is presently running application on top using GetBackBuffer() method in DirectX. And instead of saving I want to display the screenshot in a window.
However I am new to DirectX programming and and am unclear in the order of functions to be called. I referred to a few blogs and threads and have compiled this code:
#include <windows.h>
#include <windowsx.h>
#include <d3d9.h>
#include <stdio.h>
#pragma comment (lib, "d3d9.lib")
LPDIRECT3D9 d3d; LPDIRECT3DDEVICE9 d3ddev;
void initD3D(HWND hWnd); void render_frame(void); void cleanD3D(void);
LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam);
int WINAPI WinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int nCmdShow)
{
HWND hWnd;
WNDCLASSEX wc;
ZeroMemory(&wc, sizeof(WNDCLASSEX));
wc.cbSize = sizeof(WNDCLASSEX);
wc.style = CS_HREDRAW | CS_VREDRAW;
wc.lpfnWndProc = WindowProc;
wc.hInstance = hInstance;
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)COLOR_WINDOW;
wc.lpszClassName = L"WindowClass";
RegisterClassEx(&wc);
hWnd = CreateWindowEx(NULL,
L"WindowClass",
L"Our First Direct3D Program",
WS_OVERLAPPEDWINDOW,
300, 300,
800, 600,
NULL,
NULL,
hInstance,
NULL);
ShowWindow(hWnd, nCmdShow);
initD3D(hWnd);
MSG msg;
while (TRUE)
{
while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
if (msg.message == WM_QUIT)
break;
render_frame();
}
cleanD3D();
return msg.wParam;
}
LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message)
{
case WM_DESTROY:
{
PostQuitMessage(0);
return 0;
} break;
}
return DefWindowProc(hWnd, message, wParam, lParam);
}
void initD3D(HWND hWnd)
{
d3d = Direct3DCreate9(D3D_SDK_VERSION);
D3DPRESENT_PARAMETERS d3dpp;
ZeroMemory(&d3dpp, sizeof(d3dpp)); d3dpp.Windowed = TRUE; d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD; d3dpp.hDeviceWindow = hWnd;
d3d->CreateDevice(D3DADAPTER_DEFAULT,
D3DDEVTYPE_HAL,
hWnd,
D3DCREATE_SOFTWARE_VERTEXPROCESSING,
&d3dpp,
&d3ddev);
}
void render_frame(void)
{
IDirect3DSurface9 *offscreenSurface = 0;
IDirect3DSurface9 *destSurface = 0;
d3ddev->CreateOffscreenPlainSurface(800, 600, D3DFMT_A8B8G8R8, D3DPOOL_SYSTEMMEM, &offscreenSurface, NULL);
HRESULT hr = d3ddev->GetBackBuffer(0, 0, D3DBACKBUFFER_TYPE_MONO, &offscreenSurface);
d3ddev->GetRenderTargetData(offscreenSurface, destSurface);
HRESULT hr1 = d3ddev->CreateRenderTarget(800, 600, D3DFMT_A8R8G8B8, D3DMULTISAMPLE_NONE, 0, TRUE, &offscreenSurface, NULL);
d3ddev->BeginScene();
d3ddev->EndScene();
d3ddev->Present(NULL, NULL, NULL, NULL); }
void cleanD3D(void)
{
d3ddev->Release(); d3d->Release(); }
I understand that I am doing something wrong and been trying to figure that out for the past days but I could not fix my code to make it capture screenshot of the desktop.
So please suggest me what changes I need to make in the code so that it does what it is supposed to.