pal.c

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/* The idea of this test app is inspired from tutorial       *
 * found at http://www.theparticle.com/pgraph.html           *
 *                                                           *
 * Developed by: Aleksey Bragin <aleksey@studiocerebral.com> *
 * Version: 1.0                                              */

#include <windows.h>
#include <stdlib.h>

#define W_WIDTH 320
#define W_HEIGHT 240

// special version of BITMAPINFO and LOGPALETTE for max of 256 palette entries
typedef struct
{
    BITMAPINFOHEADER bmiHeader;
    RGBQUAD bmiColors[256];
} BITMAPINFO256;

typedef struct {
    WORD    palVersion;
    WORD    palNumEntries;
    PALETTEENTRY palPalEntry[256];
} LOGPALETTE256;

// The only global variable --- contents of the DIBitmap
BYTE* dibits;

void GeneratePalette(RGBQUAD* p)
{
    int i;
    for(i=0;i<256;i++)
    {
        p[i].rgbRed = i;
        p[i].rgbGreen = i;
        p[i].rgbBlue = i;
        p[i].rgbReserved = 0;
    }
}

void DoBlt(HBITMAP hBM)
{
    HDC hDC,Context;
    HWND ActiveWindow;
    RECT dest;
    HBITMAP dflBmp;

    if((ActiveWindow = GetActiveWindow()) == NULL)
        return;

    hDC = GetDC(ActiveWindow);
    GetClientRect(ActiveWindow,&dest);

    Context = CreateCompatibleDC(0);
    dflBmp = SelectObject(Context, hBM);
    BitBlt(hDC, 0, 0, dest.right, dest.bottom, Context, 0, 0, SRCCOPY);
    SelectObject(Context, dflBmp);
    DeleteDC(Context);
    DeleteObject(dflBmp);
    ReleaseDC(ActiveWindow, hDC);
}

void UpdatePalette(HBITMAP hBM){
    int i,y;
    static unsigned int c=0;

    for(i=0;i<W_WIDTH;i++){
        for(y=0;y<=W_HEIGHT-1;y++)
            dibits[y*320+i] = c % 256;

        if (c > 512)
            c = 0;
        else
            c++; // It's operation of incrementing of c variable, not reference of a cool OO language :-)
    }

    DoBlt(hBM);
}

void InitBitmap(HBITMAP *hBM){
    HPALETTE PalHan;
    HWND ActiveWindow;
    HDC hDC;
    RGBQUAD palette[256];
    int i;
    BITMAPINFO256 bmInf;
    LOGPALETTE256 palInf;

    ActiveWindow = GetActiveWindow();
    hDC = GetDC(ActiveWindow);

    bmInf.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
    bmInf.bmiHeader.biWidth = W_WIDTH;
    bmInf.bmiHeader.biHeight = -abs(W_HEIGHT);
    bmInf.bmiHeader.biPlanes = 1;
    bmInf.bmiHeader.biBitCount = 8;
    bmInf.bmiHeader.biCompression = BI_RGB;
    bmInf.bmiHeader.biSizeImage = 0;
    bmInf.bmiHeader.biXPelsPerMeter = 0;
    bmInf.bmiHeader.biYPelsPerMeter = 0;
    bmInf.bmiHeader.biClrUsed = 256;
    bmInf.bmiHeader.biClrImportant = 256;

    GeneratePalette(palette);

    for(i=0;i<256;i++)
        bmInf.bmiColors[i] = palette[i];

    palInf.palVersion = 0x300;
    palInf.palNumEntries = 256;
    for(i=0;i<256;i++){
        palInf.palPalEntry[i].peRed = palette[i].rgbRed;
        palInf.palPalEntry[i].peGreen = palette[i].rgbGreen;
        palInf.palPalEntry[i].peBlue = palette[i].rgbBlue;
        palInf.palPalEntry[i].peFlags = PC_NOCOLLAPSE;
    }

    // Create palette
    PalHan = CreatePalette((LOGPALETTE*)&palInf);

    // Select it into hDC
    SelectPalette(hDC,PalHan,FALSE);

    // Realize palette in hDC
    RealizePalette(hDC);

    // Delete handle to palette
    DeleteObject(PalHan);

    // Create dib section
    *hBM = CreateDIBSection(hDC,(BITMAPINFO*)&bmInf,
        DIB_RGB_COLORS,(void**)&dibits,0,0);

    // Release dc
    ReleaseDC(ActiveWindow,hDC);
}

LRESULT CALLBACK WndProc(HWND hWnd,UINT msg, WPARAM wParam,LPARAM lParam)
{
    switch(msg){
        case WM_DESTROY:
            PostQuitMessage(0);
            return 0;
        default:
            return DefWindowProc(hWnd,msg,wParam,lParam);
    }
}



int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance, LPSTR lpszCmdParam,int nCmdShow)
{
    WNDCLASS WndClass;
    HWND hWnd;
    MSG msg;
    char szName[] = "Palette BitBlt test";
    BOOL exit = FALSE;
    HBITMAP hBM;

    // Create and register window class (not modified!!!!!!!!!!!1)
    WndClass.style = CS_HREDRAW|CS_VREDRAW|CS_OWNDC;
    WndClass.lpfnWndProc = WndProc;
    WndClass.cbClsExtra = 0;
    WndClass.cbWndExtra = 0;
    WndClass.hbrBackground = NULL;//GetStockObject(BLACK_BRUSH);
    WndClass.hIcon = NULL;//LoadIcon(hInstance,NULL);
    WndClass.hCursor = NULL;//LoadCursor(NULL,IDC_ARROW);
    WndClass.hInstance = hInstance;
    WndClass.lpszClassName = szName;
    WndClass.lpszMenuName = 0;

    RegisterClass(&WndClass);

    // Create and show window (change styles !!!!!!!!)
    hWnd = CreateWindow(szName, "ReactOS palette bitblt test",
        WS_CAPTION|WS_MINIMIZEBOX|WS_SYSMENU,
        CW_USEDEFAULT,CW_USEDEFAULT,W_WIDTH,W_HEIGHT,
        0,0,hInstance,0);
    ShowWindow(hWnd,nCmdShow);

    // Prepare bitmap to be bitblt
    InitBitmap(&hBM);

    // Main message loop
    while (!exit)
    {
        UpdatePalette(hBM);
        Sleep(200);

        if(PeekMessage(&msg,0,0,0,PM_NOREMOVE) == TRUE)
        {
            if (!GetMessage(&msg,0,0,0))
                exit = TRUE;

            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    return msg.wParam;
}