Creating an Empty Vector Handle and Attaching it to a Window
To create a new empty vector handle and attach it to a window:
1. |
Start Visual C++, version 2005. |
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2. |
Select the File->New->Project menu option. |
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3. |
In the New Project dialog box, make sure to select “Visual C++” ŕ “Win32” from the tree on the left of the dialog, and select “Win32 Project” as the project template. Give the project the name "Tutorial " and make sure to allocate your project under the following folder LEAD Technologies\LEADTOOLS EVAL 15\Examples\API folder click OK. |
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4. |
When the “Win32 Application Wizard” initializes, click Finish. | |
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5. |
Change the “WndProc” function to look like this: |
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
int wmId, wmEvent;
PAINTSTRUCT ps;
HDC hdc;
static VECTORHANDLE Vector; // our vector handle
RECT Rect;
switch (message)
{
case WM_COMMAND:
wmId = LOWORD(wParam);
wmEvent = HIWORD(wParam);
// Parse the menu selections:
switch (wmId)
{
case IDM_ABOUT:
DialogBox(hInst, MAKEINTRESOURCE(IDD_ABOUTBOX), hWnd, About);
break;
case IDM_EXIT:
DestroyWindow(hWnd);
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
break;
case WM_PAINT:
hdc = BeginPaint(hWnd, &ps);
// draw the vector
L_VecPaint( hdc, &Vector, TRUE );
EndPaint(hWnd, &ps);
break;
case WM_DESTROY:
// free the vector handle
L_VecFree( &Vector );
PostQuitMessage(0);
break;
case WM_CREATE:
// initiates the vector handle
L_VecInit ( &Vector );
// set wireframe mode
L_VecSetPolygonMode ( &Vector, VECTOR_POLYGON_LINE );
// attach it to the main window
L_VecAttachToWindow ( hWnd, &Vector, VECTOR_ENGINE_DOUBLEBUFFER );
// set default view
ResetView( hWnd, &Vector );
break;
case WM_SIZE:
// set the vector viewport to all client area
GetClientRect( hWnd, &Rect );
L_VecSetViewport( &Vector, &Rect );
break;
default:
return DefWindowProc(hWnd, message, wParam, lParam);
}
return 0;
}
6. |
Change the “_tWinMain” function to look like this: |
int APIENTRY _tWinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPTSTR lpCmdLine,
int nCmdShow)
{
const L_TCHAR szClassName[] = TEXT("lead_vector_tutorial");
WNDCLASSEX WndClass;
HWND hWnd;
MSG Msg;
UNREFERENCED_PARAMETER( hPrevInstance );
UNREFERENCED_PARAMETER( lpCmdLine );
// unlock vector support
L_UnlockSupport ( L_SUPPORT_VECTOR, L_KEY_VECTOR );
WndClass.cbSize = sizeof( WNDCLASSEX );
WndClass.style = CS_HREDRAW | CS_VREDRAW;
WndClass.lpfnWndProc = WndProc;
WndClass.cbClsExtra = 0;
WndClass.cbWndExtra = 0;
WndClass.hInstance = hInst;
WndClass.hIcon = LoadIcon( NULL, IDI_APPLICATION );
WndClass.hCursor = LoadCursor( NULL, IDC_ARROW );
WndClass.hbrBackground = NULL;
WndClass.lpszMenuName = NULL;
WndClass.lpszClassName = szClassName;
WndClass.hIconSm = NULL;
RegisterClassEx( &WndClass );
hWnd = CreateWindowEx( 0L, szClassName,
TEXT("VectorTutorial"),
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, 0, CW_USEDEFAULT, 0,
NULL, NULL, hInst, NULL );
ShowWindow( hWnd, nCmdShow );
UpdateWindow( hWnd );
while( GetMessage( &Msg, NULL, 0, 0 ) != 0 )
{
TranslateMessage( &Msg );
DispatchMessage( &Msg );
}
UnregisterClass( szClassName, hInst );
return (int)Msg.wParam;
}
7. |
Add the following includes to the top of your CPP file (Note that the include statements will have to be modified to match the location of the LEADTOOLS toolkit on your system): |
#include "C:\Program Files\LEAD Technologies\LEADTOOLS 15\Include\L_Bitmap.h"
#include "C:\Program Files\LEAD Technologies\LEADTOOLS 15\Include\Lvkrn.h"
8. |
In the “Solution Explorer”, right-click your project “tutorial” and select “Add” ŕ “New Item”, and add a new CPP file and name it “Imports.cpp”. |
9. |
Add the following code to “Imports.cpp” you just created
(Note that the pragma statements will have to be modified to match the
location of the LEADTOOLS toolkit on your system):
#if defined(WIN64) #pragma comment( lib, "..\\..\\..\\..\\Lib\\API\\x64\\Lvkrn_x.lib") #pragma comment( lib, "..\\..\\..\\..\\Lib\\API\\x64\\Ltkrn_x.lib") #else #pragma comment( lib, "..\\..\\..\\..\\Lib\\API\\Win32\\Lvkrn_u.lib") #pragma comment( lib, "..\\..\\..\\..\\Lib\\API\\Win32\\Ltkrn_u.lib") #endif
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10. |
Add the following code to “Tutorial.cpp” above the
WndProc function: { // let the vector toolkit calculates the extent of the current drawing. L_VecSetParallelogram ( pVector, NULL, NULL );
// let the vector toolkits calculates the origin of current drawing. L_VecSetOrigin ( pVector, NULL );
// let the vector toolkits calculates the default camera position (top-view) L_VecSetCamera ( pVector, NULL );
// cause a redraw of our main window InvalidateRect( hWnd, NULL, FALSE ); }
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11. |
Compile and run the project by selecting Build ŕ Rebuild Solution and Debug ŕ Start Without Debugging from the menu. |
12. |
The program should display a white background drawn by the vector handle. |