user-0 提问: 萌新求问生成BMP图像的程序问题。

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user: user-1
content: 代码功能归根结底不是别人帮自己看或讲解或注释出来的；而是被自己静下心来花足够长的时间和精力亲自动手单步或设断点或对执行到某步获得的中间结果显示或写到日志文件中一步一步分析出来的。 提醒：再牛×的老师也无法代替学生自己领悟和上厕所！ 单步调试和设断点调试（VS IDE中编译连接通过以后，按F10或F11键单步执行，按Shift+F11退出当前函数；在某行按F9设断点后按F5执行停在该断点处。）是程序员必须掌握的技能之一。  仅供参考：#include <math.h> #include <string.h> #include <stdio.h> #include <windows.h> #include <gdiplus.h> #pragma comment(lib, "gdiplus.lib") using namespace Gdiplus; wchar_t formats[5][11]={     L"image/bmp",     L"image/jpeg",     L"image/gif",     L"image/tiff",     L"image/png", }; wchar_t exts[5][5]={     L".bmp",     L".jpg",     L".gif",     L".tif",     L".png", }; int GetEncoderClsid(const WCHAR* format, CLSID* pClsid) {    UINT  num = 0;          // number of image encoders    UINT  size = 0;         // size of the image encoder array in bytes    ImageCodecInfo* pImageCodecInfo = NULL;    GetImageEncodersSize(&num, &size);    if(size == 0) return -1;  // Failure    pImageCodecInfo = (ImageCodecInfo*)(malloc(size));    if(pImageCodecInfo == NULL) return -1;  // Failure    GetImageEncoders(num, size, pImageCodecInfo);    for (UINT j = 0; j < num; ++j) {       if ( wcscmp(pImageCodecInfo[j].MimeType, format) == 0 ) {          *pClsid = pImageCodecInfo[j].Clsid;          free(pImageCodecInfo);          return j;  // Success       }    }    free(pImageCodecInfo);    return -1;  // Failure } int wmain(int argc,wchar_t *argv[]) {     int r=1;     if (argc<4) {     USAGE:         wprintf(L"%s srcimg.{bmp|jpg|gif|tif|png|wmf|emf|ico}  desimg.{bmp|jpg|gif|tif|png}  angle\n",argv[0]);         return r;     }     int i;     for (i=0;i<5;i++) {         if (0==_wcsicmp(argv[1]+wcslen(argv[1])-4,exts[i])) break;     }     if (i>=5) goto USAGE;     for (i=0;i<5;i++) {         if (0==_wcsicmp(argv[2]+wcslen(argv[2])-4,exts[i])) break;     }     if (i>=5) goto USAGE;     GdiplusStartupInput gdiplusstartupinput;     ULONG_PTR gdiplustoken;     GdiplusStartup(&gdiplustoken, &gdiplusstartupinput, NULL);     {         Image img(argv[1]);         if (Ok==img.GetLastStatus()) {             UINT height = img.GetHeight();             UINT width  = img.GetWidth();             REAL angle;             if (1==swscanf_s(argv[3],L"%f",&angle)) {                 REAL size;                 size=(REAL)sqrt(1.0*width*width+1.0*height*height);                 Matrix mat;                 mat.Translate(size / -2.0f, size / -2.0f);                 mat.Rotate(-angle, MatrixOrderAppend);                 mat.Translate(size / 2.0f, size / 2.0f, MatrixOrderAppend);                 PointF pfTL((size-width)/2.0f      ,(size-height)/2.0f       );                 PointF pfTR((size-width)/2.0f+width,(size-height)/2.0f       );                 PointF pfBL((size-width)/2.0f      ,(size-height)/2.0f+height);                 PointF pfBR((size-width)/2.0f+width,(size-height)/2.0f+height);                 Graphics tgp(&img);                 Bitmap bmp((UINT)size,(UINT)size,&tgp);//Let bmp Resolution equal to img Resolution                 Graphics gp(&bmp);                 gp.SetTransform(&mat);                 gp.DrawImage(&img,pfTL);                 REAL xmin,ymin,xmax,ymax,x,y,rw,rh;                 mat.TransformPoints(&pfTL);                 xmin=xmax=pfTL.X;                 ymin=ymax=pfTL.Y;                 mat.TransformPoints(&pfTR);                 if (xmin>pfTR.X) xmin=pfTR.X;                 if (xmax<pfTR.X) xmax=pfTR.X;                 if (ymin>pfTR.Y) ymin=pfTR.Y;                 if (ymax<pfTR.Y) ymax=pfTR.Y;                 mat.TransformPoints(&pfBL);                 if (xmin>pfBL.X) xmin=pfBL.X;                 if (xmax<pfBL.X) xmax=pfBL.X;                 if (ymin>pfBL.Y) ymin=pfBL.Y;                 if (ymax<pfBL.Y) ymax=pfBL.Y;                 mat.TransformPoints(&pfBR);                 if (xmin>pfBR.X) xmin=pfBR.X;                 if (xmax<pfBR.X) xmax=pfBR.X;                 if (ymin>pfBR.Y) ymin=pfBR.Y;                 if (ymax<pfBR.Y) ymax=pfBR.Y;                 x=xmin;                 y=ymin;                 rw=xmax-x;                 rh=ymax-y;                 Bitmap* clone;                 clone = bmp.Clone(x,y,rw,rh,PixelFormat24bppRGB);//bmp.GetPixelFormat()                 CLSID encoderClsid;                 if (0<=GetEncoderClsid(formats[i],&encoderClsid)) {                     if (Ok==clone->Save(argv[2],&encoderClsid)) {                         wprintf(L"OK to %s  %s  %s  %s\n",argv[0],argv[1],argv[2],argv[3]);                         r=0;                     } else {                         wprintf(L"Error to save %s\n",argv[2]);                         r=4;                     }                 } else {                     wprintf(L"Error to GetEncoderClsid(%s,...)\n",formats[i]);                     r=3;                 }                 delete clone;             } else {                 wprintf(L"Error to get angle %s\n",argv[3]);                 r=2;             }         } else {             wprintf(L"Error to load %s\n",argv[1]);             r=5;         }     }     GdiplusShutdown(gdiplustoken);     return r; }

user: user-0