ddutil.cpp

来自「打飞机的游戏」· C++ 代码 · 共 282 行

/*==========================================================================
 *
 *  Copyright (C) 1995-1997 Microsoft Corporation. All Rights Reserved.
 *
 *  File:       ddutil.cpp
 *  Content:    Routines for loading bitmap and palettes from resources
 * 翻译引用:    jzZ 2000,05
 ***************************************************************************/

#undef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <windowsx.h>
#include <ddraw.h>
#include "ddutil.h"

/*
 *调入位图
 *从一个文件或资源中将一个位图文件载入到一个已经存在的DirectDraw表面(Surface)之中
 */
extern "C" IDirectDrawSurface * DDLoadBitmap(IDirectDraw *pdd, LPCTSTR tszBitmap, int dx, int dy)
{
    HBITMAP             hbm;
    BITMAP              bm;
    DDSURFACEDESC       ddsd;
    IDirectDrawSurface *pdds;

    //从一个资源中将一个位图载入,如果失败则试着从一个文件调入位图
    hbm = (HBITMAP)LoadImage(GetModuleHandle(NULL), tszBitmap, IMAGE_BITMAP, dx, dy, LR_CREATEDIBSECTION);

    if (hbm == NULL)
	hbm = (HBITMAP)LoadImage(NULL, tszBitmap, IMAGE_BITMAP, dx, dy, LR_LOADFROMFILE|LR_CREATEDIBSECTION);

    if (hbm == NULL)
	return NULL;

    //得到位图尺寸
    GetObject(hbm, sizeof(bm), &bm);      //得到位图尺寸

    //为位图建立DirectDraw表面
    ZeroMemory(&ddsd, sizeof(ddsd));
    ddsd.dwSize = sizeof(ddsd);
    ddsd.dwFlags = DDSD_CAPS | DDSD_HEIGHT |DDSD_WIDTH;
    ddsd.ddsCaps.dwCaps = DDSCAPS_OFFSCREENPLAIN;
    ddsd.dwWidth = bm.bmWidth;
    ddsd.dwHeight = bm.bmHeight;

    if (pdd->CreateSurface(&ddsd, &pdds, NULL) != DD_OK)
	return NULL;

    DDCopyBitmap(pdds, hbm, 0, 0, 0, 0);

    DeleteObject(hbm);

    return pdds;
}

/*
 *重新提取位图
 *一般在表面重建后用来重新提取位图(资源或者文件中的)到DirectDraw表面
 */

HRESULT DDReLoadBitmap(IDirectDrawSurface *pdds, LPCTSTR tszBitmap)
{
    HBITMAP             hbm;
    HRESULT             hr;

    //从一个资源中将一个位图载入,如果失败则试着从一个文件调入位图
    hbm = (HBITMAP)LoadImage(GetModuleHandle(NULL), tszBitmap, IMAGE_BITMAP, 0, 0, LR_CREATEDIBSECTION);

    if (hbm == NULL)
	hbm = (HBITMAP)LoadImage(NULL, tszBitmap, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE|LR_CREATEDIBSECTION);

    if (hbm == NULL)
    {
	OutputDebugString(TEXT("handle is null\n"));
	return E_FAIL;
    }

    hr = DDCopyBitmap(pdds, hbm, 0, 0, 0, 0);
    if (hr != DD_OK)
    {
	OutputDebugString(TEXT("ddcopybitmap failed\n"));
    }


    DeleteObject(hbm);
    return hr;
}

/*
 *  DDCopyBitmap
 *	拷贝位图
 *  draw a bitmap into a DirectDrawSurface
 *	在DirectDraw表面中画位图
 */
extern "C" HRESULT DDCopyBitmap(IDirectDrawSurface *pdds, HBITMAP hbm, int x, int y, int dx, int dy)
{
    HDC                 hdcImage;
    HDC                 hdc;
    BITMAP              bm;
    DDSURFACEDESC       ddsd;
    HRESULT             hr;

    if (hbm == NULL || pdds == NULL)
	return E_FAIL;

    //	确保表面已经重建
    pdds->Restore();

    //	选择一个位图到储存的DC中,我们才能使用它
    hdcImage = CreateCompatibleDC(NULL);
    if (!hdcImage)
	OutputDebugString(TEXT("createcompatible dc failed\n"));
    SelectObject(hdcImage, hbm);

    //得到位图尺寸
    GetObject(hbm, sizeof(bm), &bm);    // 得到位图尺寸
    dx = dx == 0 ? bm.bmWidth  : dx;    // 使用这个得到的尺寸,除非为0
    dy = dy == 0 ? bm.bmHeight : dy;

    //得到表面尺寸
    ddsd.dwSize = sizeof(ddsd);
    ddsd.dwFlags = DDSD_HEIGHT | DDSD_WIDTH;
    pdds->GetSurfaceDesc(&ddsd);

    if ((hr = pdds->GetDC(&hdc)) == DD_OK)
    {
	StretchBlt(hdc, 0, 0, ddsd.dwWidth, ddsd.dwHeight, hdcImage, x, y, dx, dy, SRCCOPY);
	pdds->ReleaseDC(hdc);
    }

    DeleteDC(hdcImage);

    return hr;
}

/*提取调色板
 *从位图资源中建立DirectDraw的调色板
 *如果资源不存在或者为空,就建立默认得332调色板
 */
extern "C" IDirectDrawPalette * DDLoadPalette(IDirectDraw *pdd, LPCTSTR tszBitmap)
{
    IDirectDrawPalette* ddpal;
    int                 i;
    int                 n;
	HANDLE              fh;
    HRSRC               h;
    LPBITMAPINFOHEADER  lpbi;
    PALETTEENTRY        ape[256];
    RGBQUAD *           prgb;
	DWORD				dwRead;

    //建立默认的332调色板
    for (i=0; i<256; i++)
    {
	ape[i].peRed   = (BYTE)(((i >> 5) & 0x07) * 255 / 7);
	ape[i].peGreen = (BYTE)(((i >> 2) & 0x07) * 255 / 7);
	ape[i].peBlue  = (BYTE)(((i >> 0) & 0x03) * 255 / 3);
	ape[i].peFlags = (BYTE)0;
    }

    //得到指向位图资源的指针
    if (tszBitmap && (h = FindResource(NULL, tszBitmap, RT_BITMAP)))
    {
	lpbi = (LPBITMAPINFOHEADER)LockResource(LoadResource(NULL, h));
	if (!lpbi)
	    OutputDebugString(TEXT("lock resource failed\n"));
	prgb = (RGBQUAD*)((BYTE*)lpbi + lpbi->biSize);

	if (lpbi == NULL || lpbi->biSize < sizeof(BITMAPINFOHEADER))
	    n = 0;
	else if (lpbi->biBitCount > 8)
	    n = 0;
	else if (lpbi->biClrUsed == 0)
	    n = 1 << lpbi->biBitCount;
	else
	    n = lpbi->biClrUsed;

	//一个DIB色表就是自身BGR色的储存
	//建立自己得色表
	for(i=0; i<n; i++ )
	{
	    ape[i].peRed   = prgb[i].rgbRed;
	    ape[i].peGreen = prgb[i].rgbGreen;
	    ape[i].peBlue  = prgb[i].rgbBlue;
	    ape[i].peFlags = 0;
	}
    }
    else if (tszBitmap && (fh = CreateFile(tszBitmap, GENERIC_READ, FILE_SHARE_READ, 
											NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 
											NULL)) != INVALID_HANDLE_VALUE)
    {
	BITMAPFILEHEADER bf;
	BITMAPINFOHEADER bi;

	ReadFile(fh, &bf, sizeof(bf), &dwRead, NULL);
	ReadFile(fh, &bi, sizeof(bi), &dwRead, NULL);
	ReadFile(fh, ape, sizeof(ape), &dwRead, NULL);
	CloseHandle(fh);

	if (bi.biSize != sizeof(BITMAPINFOHEADER))
	    n = 0;
	else if (bi.biBitCount > 8)
	    n = 0;
	else if (bi.biClrUsed == 0)
	    n = 1 << bi.biBitCount;
	else
	    n = bi.biClrUsed;

	//建立自己得色表
	for(i=0; i<n; i++ )
	{
	    BYTE r = ape[i].peRed;
	    ape[i].peRed  = ape[i].peBlue;
	    ape[i].peBlue = r;
	}
    }

    pdd->CreatePalette(DDPCAPS_8BIT, ape, &ddpal, NULL);

    return ddpal;
}

/*
 *匹配颜色
 *将RGB色混合为物理色彩
 *通过GDI的SetPixel()完成配色工作,然后锁定要绘图的内存
 */
extern "C" DWORD DDColorMatch(IDirectDrawSurface *pdds, COLORREF rgb)
{
    COLORREF rgbT;
    HDC hdc;
    DWORD dw = CLR_INVALID;
    DDSURFACEDESC ddsd;
    HRESULT hres;

    //用GDI的SetPixel进行颜色匹配
    if (rgb != CLR_INVALID && pdds->GetDC(&hdc) == DD_OK)
    {
	rgbT = GetPixel(hdc, 0, 0);  //保存目前点值
	SetPixel(hdc, 0, 0, rgb);    //填写新的点值
	pdds->ReleaseDC(hdc);
    }

    //锁定表面我们就可以读回改变的颜色
    ddsd.dwSize = sizeof(ddsd);
    while ((hres = pdds->Lock(NULL, &ddsd, 0, NULL)) == DDERR_WASSTILLDRAWING)
	;

    if (hres == DD_OK)
    {
	dw  = *(DWORD *)ddsd.lpSurface;                     // 得到DWORD
	dw &= (1 << ddsd.ddpfPixelFormat.dwRGBBitCount)-1;  // 遮盖BPP
	pdds->Unlock(NULL);
    }

    //从后备中输出颜色
    if (rgb != CLR_INVALID && pdds->GetDC(&hdc) == DD_OK)
    {
	SetPixel(hdc, 0, 0, rgbT);
	pdds->ReleaseDC(hdc);
    }

    return dw;
}

/*
 *设置透明色
 *为表面设置一个RGB透明色
 *如果通过CLR_INVALID设置透明色,那么位图左上角的点值即为透明色
 */
extern "C" HRESULT DDSetColorKey(IDirectDrawSurface *pdds, COLORREF rgb)
{
    DDCOLORKEY          ddck;

    ddck.dwColorSpaceLowValue  = DDColorMatch(pdds, rgb);
    ddck.dwColorSpaceHighValue = ddck.dwColorSpaceLowValue;
    return pdds->SetColorKey(DDCKEY_SRCBLT, &ddck);
}