ddutil.cpp

国产的RPG源码

/*==========================================================================
 *
 *  Copyright (C) 1995-1996 Microsoft Corporation. All Rights Reserved.
 *
 *  File:       ddutil.cpp
 *  Content:    Routines for loading bitmap and palettes from resources
 *
 ***************************************************************************/
#undef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <stdio.h>
#include <windowsx.h>
#include <ddraw.h>
#include "ddutil.h"

//创建一个页面，并加载一个bmp图片
extern "C" IDirectDrawSurface * DDLoadBitmap(IDirectDraw *pdd, LPCSTR szBitmap, int dx, int dy)
{
    HBITMAP             hbm;
    BITMAP              bm;
    DDSURFACEDESC       ddsd;
    IDirectDrawSurface *pdds;
    //当一个资源
    hbm = (HBITMAP)LoadImage(GetModuleHandle(NULL), szBitmap, IMAGE_BITMAP, dx, dy, 
		LR_CREATEDIBSECTION);
	//失败，当一个文件
    if (hbm == NULL)
        hbm = (HBITMAP)LoadImage(NULL, szBitmap, IMAGE_BITMAP, dx, dy,
			LR_LOADFROMFILE|LR_CREATEDIBSECTION);

    if (hbm == NULL)
        return NULL;

    //得到图片大小
    GetObject(hbm, sizeof(bm), &bm);      

    //创建页面
    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;
	//加载图片
    DDCopyBitmap(pdds, hbm, 0, 0, 0, 0);

    DeleteObject(hbm);

    return pdds;
}

//显示一个bmp到一个页面
HRESULT DDReLoadBitmap(IDirectDrawSurface *pdds, LPCSTR szBitmap)
{
    HBITMAP             hbm;
    HRESULT             hr;
	//当一个资源来加载
    hbm = (HBITMAP)LoadImage(GetModuleHandle(NULL), szBitmap, IMAGE_BITMAP, 0, 0, 
					LR_CREATEDIBSECTION);
	//失败，当一个文件加载
    if (hbm == NULL)
        hbm = (HBITMAP)LoadImage(NULL, szBitmap, IMAGE_BITMAP, 0, 0, 
				LR_LOADFROMFILE|LR_CREATEDIBSECTION);
	//仍然失败
    if (hbm == NULL)
    {
		char str[128];
		sprintf(str, "handle is null [%s]\n", szBitmap);
        OutputDebugString(str);
        return E_FAIL;
    }
	//把图片显示到页面
    hr = DDCopyBitmap(pdds, hbm, 0, 0, 0, 0);
    if (hr != DD_OK)
    {
        OutputDebugString("ddcopybitmap failed\n");
    }


    DeleteObject(hbm);
    return hr;
}

//在一个页面上显示一个bmp图片
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;

    pdds->Restore();
	//创建一个和当前屏幕相关的 memory device context 
    hdcImage = CreateCompatibleDC(NULL);
    if (!hdcImage)
        OutputDebugString("createcompatible dc failed\n");
    SelectObject(hdcImage, hbm);
	//得到bmp的大小
    GetObject(hbm, sizeof(bm), &bm);    
    dx = dx == 0 ? bm.bmWidth  : dx;    // 只要传进来的参数不是0，就使用传进来的参数
    dy = dy == 0 ? bm.bmHeight : dy;
	//得到页面的大小
    ddsd.dwSize = sizeof(ddsd);
    ddsd.dwFlags = DDSD_HEIGHT | DDSD_WIDTH;
    pdds->GetSurfaceDesc(&ddsd);
	
    if ((hr = pdds->GetDC(&hdc)) == DD_OK)
    {
		//缩放blt
        StretchBlt(hdc, 0, 0, ddsd.dwWidth, ddsd.dwHeight, hdcImage, x, y, dx, dy, SRCCOPY);
        pdds->ReleaseDC(hdc);
    }

    DeleteDC(hdcImage);

    return hr;
}

//从一个bmp图片创建一个调色板，要是没有的话就创建一个缺省的调色板
extern "C" IDirectDrawPalette * DDLoadPalette(IDirectDraw *pdd, LPCSTR szBitmap)
{
    IDirectDrawPalette* ddpal;
    int                 i;
    int                 n;
    int                 fh;
    HRSRC               h;
    LPBITMAPINFOHEADER  lpbi;
    PALETTEENTRY        ape[256];
    RGBQUAD *           prgb;
	//创建一个缺省的调色板
    for (i=0; i<256; i++)
    {
		//0x07 = 00000111b   0x03 = 00000011b
		//3 bit 描述红色, 3 bit 描述绿色, 2 bit 描述蓝色
		//为什么呢？简单，让调色板的序号和颜色直接挂上钩
        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;
    }
	//从bmp图片加载
    if (szBitmap && (h = FindResource(NULL, szBitmap, RT_BITMAP)))
    {
        lpbi = (LPBITMAPINFOHEADER)LockResource(LoadResource(NULL, h));
        if (!lpbi)
            OutputDebugString("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;

        //BGR转化成RGB
        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 (szBitmap && (fh = _lopen(szBitmap, OF_READ)) != -1)
    {
        BITMAPFILEHEADER bf;
        BITMAPINFOHEADER bi;

        _lread(fh, &bf, sizeof(bf));
        _lread(fh, &bi, sizeof(bi));
        _lread(fh, ape, sizeof(ape));
        _lclose(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;

        //同样的方法
        for(i=0; i<n; i++ )
        {
            BYTE r = ape[i].peRed;
            ape[i].peRed  = ape[i].peBlue;
            ape[i].peBlue = r;
        }
    }
	//创建调色板
    pdd->CreatePalette(DDPCAPS_8BIT, ape, &ddpal, NULL);

    return ddpal;
}

//获得指定颜色所对应的调色板索引
extern "C" DWORD DDColorMatch(IDirectDrawSurface *pdds, COLORREF rgb)
{
    COLORREF rgbT;
    HDC hdc;
    DWORD dw = CLR_INVALID;
    DDSURFACEDESC ddsd;
    HRESULT hres;

    if (rgb != CLR_INVALID && pdds->GetDC(&hdc) == DD_OK)
    {
        rgbT = GetPixel(hdc, 0, 0);             // 保存当前值
        SetPixel(hdc, 0, 0, rgb);               // 设置成我们的值
        pdds->ReleaseDC(hdc);
    }
	//读回我们的值
    ddsd.dwSize = sizeof(ddsd);
    while ((hres = pdds->Lock(NULL, &ddsd, 0, NULL)) == DDERR_WASSTILLDRAWING)
        ;

    if (hres == DD_OK)
    {
        dw  = *(DWORD *)ddsd.lpSurface;                     // 转化成DWORD
        dw &= (1 << ddsd.ddpfPixelFormat.dwRGBBitCount)-1;  // mask it to bpp
												
        pdds->Unlock(NULL);
    }

    if (rgb != CLR_INVALID && pdds->GetDC(&hdc) == DD_OK)
    {
        SetPixel(hdc, 0, 0, rgbT);		//恢复原来的值
        pdds->ReleaseDC(hdc);
    }

    return dw;
}

//设置透明色
extern "C" HRESULT DDSetColorKey(IDirectDrawSurface *pdds, COLORREF rgb)
{
    DDCOLORKEY          ddck;
	//颜色转化，要是有调色板的话，转化成索引值
    ddck.dwColorSpaceLowValue  = DDColorMatch(pdds, rgb);
    ddck.dwColorSpaceHighValue = ddck.dwColorSpaceLowValue;
    return pdds->SetColorKey(DDCKEY_SRCBLT, &ddck);
}