win32bitmap.cpp

swain-0.5.2.zip的源代码,比较好用,希望大家喜欢.

/*
This file is part of SWAIN (http://sourceforge.net/projects/swain).
Copyright (C) 2006  Daniel Lindstr鰉 and Daniel Nilsson

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA  02110-1301, USA.
*/
#include "StdAfx.h"
#include "Win32Bitmap.h"
#include "win32_drawing.h"	// needed for g_hWndDrawingWindow
//#include <imaging.h>
#include <initguid.h>
#include <olectl.h>
#include <ole2.h>
//#include <imgguids.h>

HBITMAP LoadAnImage(WCHAR* FileName);

Win32Bitmap::Win32Bitmap(WCHAR *filename, bool rotate) {

	HBITMAP temp = LoadAnImage(filename);
	if(temp == NULL)
		throw "Could not load image.";
	BITMAP bm;
	GetObject(temp, sizeof(bm), (void *)&bm);
	this->height = rotate ? bm.bmWidth : bm.bmHeight;
	this->width = rotate ? bm.bmHeight : bm.bmWidth;
	
	HDC winhdc = GetDC(g_hWndDrawingWindow);
	hdc = CreateCompatibleDC(winhdc);
	HDC hdc2 = CreateCompatibleDC(winhdc);
	this->bitmap = CreateCompatibleBitmap(winhdc, this->width, this->height);
	SelectObject(hdc2, temp);
	SelectObject(hdc, bitmap);

	POINT p[3];
	p[0].x = this->width;
	p[0].y = 0;
	p[1].x = this->width;
	p[1].y = this->height;
	p[2].x = 0;
	p[2].y = 0;

	if(rotate)
		PlgBlt(hdc, p, hdc2, 0, 0, this->height, this->width, 0, 0, 0);
	else
		BitBlt(hdc, 0, 0, this->width, this->height, hdc2, 0, 0, SRCCOPY);
}

Win32Bitmap::~Win32Bitmap(void) {
	DeleteDC(hdc);
	DeleteObject(bitmap);
}

HDC Win32Bitmap::getHDC() {
	return hdc;
}

int Win32Bitmap::getWidth() {
	return width;
}

int Win32Bitmap::getHeight() {
	return height;
}



// Function LoadAnImage: accepts a file name and returns a HBITMAP.
// On error, it returns 0.
HBITMAP LoadAnImage(WCHAR* FileName)
   {
   // Use IPicture stuff to use JPG / GIF files
   IPicture* p;
   IStream* s;
//   IPersistStream* ps;
   HGLOBAL hG;
   void* pp;
   FILE* fp;


   // Read file in memory
   fp = _wfopen(FileName,L"rb");
   if (!fp)
	return NULL;

   fseek(fp,0,SEEK_END);
   int fs = ftell(fp);
   fseek(fp,0,SEEK_SET);
   hG = GlobalAlloc(GPTR,fs);
   if (!hG)
      {
      fclose(fp);
      return NULL;
      }
   pp = (void*)hG;
   fread(pp,1,fs,fp);
   fclose(fp);

   // Create an IStream so IPicture can
   CreateStreamOnHGlobal(hG,false,&s);
   if (!s)
      {
      GlobalFree(hG);
      return NULL;
      }

   OleLoadPicture(s,0,false,IID_IPicture,(void**)&p);

   if (!p)
      {
      s->Release();
      GlobalFree(hG);
      return NULL;
      }
   s->Release();
   GlobalFree(hG);


   HBITMAP hB = 0;
   p->get_Handle((unsigned int*)&hB);

   // Copy the image. Necessary, because upon p's release,
   // the handle is destroyed.
   HBITMAP hBB = (HBITMAP)CopyImage(hB,IMAGE_BITMAP,0,0,
                                    LR_COPYRETURNORG);

   p->Release();
   return hBB;
}