png.cpp

   1 /////////////////////////////////////////////////////////////////////////////////
   2 //
   3 // $Id: png.cpp,v 1.4 2003/08/03 16:56:29 nedko Exp $
   4 //
   5 // DESCRIPTION:
   6 //
   7 // NOTES:
   8 //
   9 /////////////////////////////////////////////////////////////////////////////////
  10
  11 #include "ph.h"
  12 #include "png.h"
  13
  14 #define NOT_LOADED_BITMAP_HEIGHT  30
  15 #define NOT_LOADED_BITMAP_WIDTH  400
  16 #define NOT_LOADED_BITMAP_RED   0x80
  17 #define NOT_LOADED_BITMAP_GREEN 0xE0
  18 #define NOT_LOADED_BITMAP_BLUE  0xFF
  19 #define NOT_LOADED_BITMAP_ALPHA 0xE0
  20
  21 CPNGImage::CPNGImage()
  22 {
  23   m_nWidth = NOT_LOADED_BITMAP_WIDTH;
  24   m_nHeight = NOT_LOADED_BITMAP_HEIGHT;
  25   m_pData = NULL;
  26 }
  27
  28 CPNGImage::~CPNGImage()
  29 {
  30   if (m_pData)
  31     delete m_pData;
  32 }
  33
  34 void PNGAPI
  35 CPNGImage::PNG_ErrorHandler PNGARG((png_structp s, png_const_charp str))
  36 {
  37   ::MessageBox(NULL,str,"PNG Error",MB_OK);
  38 }
  39
  40 bool
  41 CPNGImage::LoadPNGImage(const char *pszPath)
  42 {
  43   png_structp png_ptr;
  44   png_infop info_ptr;
  45   unsigned int sig_read = 0;
  46
  47   FILE *fp = fopen(pszPath, "rb");
  48   if (!fp)
  49   {
  50     return false;
  51   }
  52
  53   png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,
  54                                    NULL,
  55                                    PNG_ErrorHandler,
  56                                    PNG_ErrorHandler);
  57
  58   if (png_ptr == NULL)
  59   {
  60     fclose(fp);
  61     return false;
  62   }
  63
  64   info_ptr = png_create_info_struct(png_ptr);
  65   if (info_ptr == NULL)
  66   {
  67     fclose(fp);
  68     png_destroy_read_struct(&png_ptr, png_infopp_NULL, png_infopp_NULL);
  69     return false;
  70   }
  71
  72   if (setjmp(png_jmpbuf(png_ptr)))
  73   {
  74     /* Free all of the memory associated with the png_ptr and info_ptr */
  75     png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL);
  76     fclose(fp);
  77     /* If we get here, we had a problem reading the file */
  78     return false;
  79   }
  80
  81   png_init_io(png_ptr, fp);
  82
  83   /* If we have already read some of the signature */
  84   png_set_sig_bytes(png_ptr, sig_read);
  85
  86   png_read_png(png_ptr,
  87                info_ptr,
  88                PNG_TRANSFORM_IDENTITY,
  89                png_voidp_NULL);
  90
  91   m_nHeight = png_get_image_height(png_ptr, info_ptr);
  92   m_nWidth = png_get_image_width(png_ptr, info_ptr);
  93
  94   m_pData = new unsigned char[m_nWidth*m_nHeight*4];
  95   png_bytep *row_pointers = png_get_rows(png_ptr, info_ptr);
  96   for (unsigned int y = 0 ; y < m_nHeight; y++)
  97   {
  98     memcpy(m_pData + m_nWidth * 4 * y,row_pointers[y],m_nWidth*4);
  99   }
 100
 101   PremultiplyAlpha(m_nWidth, m_nHeight, m_pData);
 102
 103   /* clean up after the read, and free any memory allocated - REQUIRED */
 104   png_destroy_read_struct(&png_ptr, &info_ptr, png_infopp_NULL);
 105
 106   /* close the file */
 107   fclose(fp);
 108
 109   return true;
 110 }
 111
 112 unsigned int
 113 CPNGImage::GetWidth()
 114 {
 115   return m_nWidth;
 116 }
 117
 118 unsigned int
 119 CPNGImage::GetHeight()
 120 {
 121   return m_nHeight;
 122 }
 123
 124 HBITMAP
 125 CPNGImage::CreateBitmap(HDC hMemoryDC)
 126 {
 127   HBITMAP hBitmap;
 128   BITMAPINFO bi;
 129   ZeroMemory(&bi,sizeof(bi));
 130   bi.bmiHeader.biSize = sizeof(bi.bmiHeader);
 131   bi.bmiHeader.biWidth = m_nWidth;
 132   bi.bmiHeader.biHeight = m_nHeight;
 133   bi.bmiHeader.biPlanes = 1;
 134   bi.bmiHeader.biBitCount = 32;
 135   bi.bmiHeader.biCompression = BI_RGB;
 136
 137   void *pDIBBits;
 138
 139   hBitmap = ::CreateDIBSection(hMemoryDC,&bi,DIB_RGB_COLORS,&pDIBBits,NULL,0);
 140
 141   if (m_pData)
 142   {
 143     memcpy(pDIBBits, m_pData, m_nWidth * m_nHeight * 4);
 144   }
 145   else
 146   {
 147     unsigned char *pData = GenerateNotLoadedBitmapData(m_nWidth, m_nHeight);
 148
 149     memcpy(pDIBBits, pData, m_nWidth * m_nHeight * 4);
 150
 151     delete pData;
 152   }
 153
 154   return hBitmap;
 155 }
 156
 157 unsigned char *
 158 CPNGImage::GenerateNotLoadedBitmapData(unsigned int nWidth, unsigned int nHeight)
 159 {
 160   unsigned int x,y;
 161   unsigned char *pPixel;
 162
 163   unsigned char *pData = new unsigned char[nWidth*nHeight*4];
 164   for (y = 0 ; y < nHeight; y++)
 165   {
 166     pPixel= pData + nWidth * 4 * y;
 167
 168     for (x = 0 ; x < nWidth ; x++)
 169     {
 170       pPixel[0]= NOT_LOADED_BITMAP_BLUE;
 171       pPixel[1]= NOT_LOADED_BITMAP_GREEN;
 172       pPixel[2]= NOT_LOADED_BITMAP_RED;
 173       pPixel[3]= NOT_LOADED_BITMAP_ALPHA;
 174
 175       pPixel+= 4;
 176     }
 177   }
 178
 179   PremultiplyAlpha(nWidth, nHeight, pData);
 180
 181   return pData;
 182 }
 183
 184 void
 185 CPNGImage::PremultiplyAlpha(unsigned int nWidth,
 186                             unsigned int nHeight,
 187                             unsigned char *pData)
 188 {
 189   unsigned int x,y;
 190   unsigned char *pPixel;
 191
 192   for (y = 0 ; y < nHeight; y++)
 193   {
 194     pPixel = pData + nWidth * 4 * y;
 195
 196     for (x = 0 ; x < nWidth ; x++)
 197     {
 198       pPixel[0]= (unsigned __int8)(((unsigned int)pPixel[0])*pPixel[3]/255);
 199       pPixel[1]= (unsigned __int8)(((unsigned int)pPixel[1])*pPixel[3]/255);
 200       pPixel[2]= (unsigned __int8)(((unsigned int)pPixel[2])*pPixel[3]/255);
 201       pPixel+= 4;
 202     }
 203   }
 204 }
 205
 206 /////////////////////////////////////////////////////////////////////////////////
 207 //
 208 // Modifications log:
 209 //
 210 // !!! WARNING !!! Following lines are automatically updated by the CVS system.
 211 //
 212 //   $Log: png.cpp,v $
 213 //   Revision 1.4  2003/08/03 16:56:29  nedko
 214 //   Flush current work
 215 //
 216 //   Revision 1.3  2002/06/29 16:00:28  nedko
 217 //   *** empty log message ***
 218 //
 219 //   Revision 1.2  2002/06/29 15:20:10  nedko
 220 //   *** empty log message ***
 221 //
 222 //   Revision 1.1  2002/06/29 15:03:33  nedko
 223 //   *** empty log message ***
 224 //
 225 /////////////////////////////////////////////////////////////////////////////////