reverted rev 1.26, workarounds for memchecking code no longer needed

[wxWidgets.git] / src / common / imagpng.cpp

diff --git a/src/common/imagpng.cpp b/src/common/imagpng.cpp
index f0801e3dcb2bce3cb2794d8146df1ef40001a1f0..250fac506acf6d28c269c35c0d0d6689b403ef6b 100644 (file)
--- a/src/common/imagpng.cpp
+++ b/src/common/imagpng.cpp
@@ -11,7 +11,7 @@
 // declarations
 // ============================================================================
 
 // declarations
 // ============================================================================
 

-#ifdef __GNUG__
+#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)

 #pragma implementation "imagpng.h"
 #endif
 
 #pragma implementation "imagpng.h"
 #endif
 


@@ -74,7 +74,7 @@ enum Transparency
 // return the kind of transparency needed for this image assuming that it does
 // have transparent pixels, i.e. either Transparency_Alpha or Transparency_Mask
 static Transparency
 // return the kind of transparency needed for this image assuming that it does
 // have transparent pixels, i.e. either Transparency_Alpha or Transparency_Mask
 static Transparency

-CheckTransparency(const unsigned char *ptr,
+CheckTransparency(unsigned char **lines,

                   png_uint_32 x, png_uint_32 y, png_uint_32 w, png_uint_32 h,
                   size_t numColBytes);
 
                   png_uint_32 x, png_uint_32 y, png_uint_32 w, png_uint_32 h,
                   size_t numColBytes);
 


@@ -86,6 +86,20 @@ static void
 FindMaskColour(unsigned char **lines, png_uint_32 width, png_uint_32 height,
                unsigned char& rMask, unsigned char& gMask, unsigned char& bMask);
 
 FindMaskColour(unsigned char **lines, png_uint_32 width, png_uint_32 height,
                unsigned char& rMask, unsigned char& gMask, unsigned char& bMask);
 

+// is the pixel with this value of alpha a fully opaque one?
+static inline
+bool IsOpaque(unsigned char a)
+{
+    return a == 0xff;
+}
+
+// is the pixel with this value of alpha a fully transparent one?
+static inline
+bool IsTransparent(unsigned char a)
+{
+    return !a;
+}
+

 // ============================================================================
 // wxPNGHandler implementation
 // ============================================================================
 // ============================================================================
 // wxPNGHandler implementation
 // ============================================================================


@@ -146,12 +160,14 @@ struct wxPNGInfoStruct
 extern "C"
 {
 
 extern "C"
 {
 

-void PNGLINKAGEMODE _PNG_stream_reader( png_structp png_ptr, png_bytep data, png_size_t length )
+void PNGLINKAGEMODE wx_PNG_stream_reader( png_structp png_ptr, png_bytep data,
+                                          png_size_t length )

 {
     WX_PNG_INFO(png_ptr)->stream.in->Read(data, length);
 }
 
 {
     WX_PNG_INFO(png_ptr)->stream.in->Read(data, length);
 }
 

-void PNGLINKAGEMODE _PNG_stream_writer( png_structp png_ptr, png_bytep data, png_size_t length )
+void PNGLINKAGEMODE wx_PNG_stream_writer( png_structp png_ptr, png_bytep data,
+                                          png_size_t length )

 {
     WX_PNG_INFO(png_ptr)->stream.out->Write(data, length);
 }
 {
     WX_PNG_INFO(png_ptr)->stream.out->Write(data, length);
 }


@@ -191,39 +207,45 @@ PNGLINKAGEMODE wx_png_warning(png_structp png_ptr, png_const_charp message)
 // ----------------------------------------------------------------------------
 
 // determine the kind of transparency we need for this image: if the only alpha
 // ----------------------------------------------------------------------------
 
 // determine the kind of transparency we need for this image: if the only alpha

-// values it has are 0 and 0xff then we can simply create a mask for it, we
-// should be ok with a simple mask but otherwise we need a full blown alpha
-// channel in wxImage
+// values it has are 0 (transparent) and 0xff (opaque) then we can simply
+// create a mask for it, we should be ok with a simple mask but otherwise we
+// need a full blown alpha channel in wxImage

 //
 // parameters:
 //
 // parameters:

-//      ptr             the start of the data to examine
+//      lines           raw PNG data

 //      x, y            starting position
 //      w, h            size of the image
 //      numColBytes     number of colour bytes (1 for grey scale, 3 for RGB)
 //                      (NB: alpha always follows the colour bytes)
 Transparency
 //      x, y            starting position
 //      w, h            size of the image
 //      numColBytes     number of colour bytes (1 for grey scale, 3 for RGB)
 //                      (NB: alpha always follows the colour bytes)
 Transparency

-CheckTransparency(const unsigned char *ptr,
+CheckTransparency(unsigned char **lines,

                   png_uint_32 x, png_uint_32 y, png_uint_32 w, png_uint_32 h,
                   size_t numColBytes)
 {
     // suppose that a mask will suffice and check all the remaining alpha
     // values to see if it does
                   png_uint_32 x, png_uint_32 y, png_uint_32 w, png_uint_32 h,
                   size_t numColBytes)
 {
     // suppose that a mask will suffice and check all the remaining alpha
     // values to see if it does

-    unsigned char a2;
-    unsigned const char *ptr2 = ptr;
-    for ( png_uint_32 y2 = y; y2 < h; y2++ )
+    for ( ; y < h; y++ )

     {
     {

-        for ( png_uint_32 x2 = x + 1; x2 < w; x2++ )
+        // each pixel is numColBytes+1 bytes, offset into the current line by
+        // the current x position
+        unsigned const char *ptr = lines[y] + (x * (numColBytes + 1));
+
+        for ( png_uint_32 x2 = x; x2 < w; x2++ )

         {
         {

-            // skip the grey byte
-            ptr2 += numColBytes;
-            a2 = *ptr2++;
+            // skip the grey or colour byte(s)
+            ptr += numColBytes;

 
 

-            if ( a2 && a2 != 0xff )
+            unsigned char a2 = *ptr++;
+
+            if ( !IsTransparent(a2) && !IsOpaque(a2) )

             {
                 // not fully opaque nor fully transparent, hence need alpha
                 return Transparency_Alpha;
             }
         }
             {
                 // not fully opaque nor fully transparent, hence need alpha
                 return Transparency_Alpha;
             }
         }

+
+        // during the next loop iteration check all the pixels in the row
+        x = 0;

     }
 
     // mask will be enough
     }
 
     // mask will be enough


@@ -238,13 +260,11 @@ unsigned char *InitAlpha(wxImage *image, png_uint_32 x, png_uint_32 y)
     unsigned char *alpha = image->GetAlpha();
 
     // set alpha for the pixels we had so far
     unsigned char *alpha = image->GetAlpha();
 
     // set alpha for the pixels we had so far

-    for ( png_uint_32 y2 = 0; y2 <= y; y2++ )
+    png_uint_32 end = y * image->GetWidth() + x;
+    for ( png_uint_32 i = 0; i < end; i++ )

     {
     {

-        for ( png_uint_32 x2 = 0; x2 < x; x2++ )
-        {
-            // all the previous pixels were opaque
-            *alpha++ = 0xff;
-        }
+        // all the previous pixels were opaque
+        *alpha++ = 0xff;

     }
 
     return alpha;
     }
 
     return alpha;


@@ -339,7 +359,7 @@ void CopyDataFromPNG(wxImage *image,
 
                 // the first time we encounter a transparent pixel we must
                 // decide about what to do about them
 
                 // the first time we encounter a transparent pixel we must
                 // decide about what to do about them

-                if ( a != 0xff && transparency == Transparency_None )
+                if ( !IsOpaque(a) && transparency == Transparency_None )

                 {
                     // we'll need at least the mask for this image and
                     // maybe even full alpha channel info: the former is
                 {
                     // we'll need at least the mask for this image and
                     // maybe even full alpha channel info: the former is


@@ -347,7 +367,7 @@ void CopyDataFromPNG(wxImage *image,
                     // only, otherwisewe need the latter
                     transparency = CheckTransparency
                                    (
                     // only, otherwisewe need the latter
                     transparency = CheckTransparency
                                    (

-                                        ptrSrc,
+                                        lines,

                                         x, y,
                                         width, height,
                                         1
                                         x, y,
                                         width, height,
                                         1


@@ -371,8 +391,25 @@ void CopyDataFromPNG(wxImage *image,
 
                 switch ( transparency )
                 {
 
                 switch ( transparency )
                 {

+                    case Transparency_Mask:
+                        if ( IsTransparent(a) )
+                        {
+                            *ptrDst++ = rMask;
+                            *ptrDst++ = bMask;
+                            *ptrDst++ = gMask;
+                            break;
+                        }
+                        // else: !transparent
+
+                        // must be opaque then as otherwise we shouldn't be
+                        // using the mask at all
+                        wxASSERT_MSG( IsOpaque(a), _T("logic error") );
+
+                        // fall through
+

                     case Transparency_Alpha:
                     case Transparency_Alpha:

-                        *alpha++ = a;
+                        if ( alpha )
+                            *alpha++ = a;

                         // fall through
 
                     case Transparency_None:
                         // fall through
 
                     case Transparency_None:


@@ -380,11 +417,6 @@ void CopyDataFromPNG(wxImage *image,
                         *ptrDst++ = g;
                         *ptrDst++ = g;
                         break;
                         *ptrDst++ = g;
                         *ptrDst++ = g;
                         break;

-
-                    case Transparency_Mask:
-                        *ptrDst++ = rMask;
-                        *ptrDst++ = bMask;
-                        *ptrDst++ = gMask;

                 }
             }
         }
                 }
             }
         }


@@ -403,11 +435,11 @@ void CopyDataFromPNG(wxImage *image,
 
                 // the logic here is the same as for the grey case except
                 // where noted
 
                 // the logic here is the same as for the grey case except
                 // where noted

-                if ( a != 0xff && transparency == Transparency_None )
+                if ( !IsOpaque(a) && transparency == Transparency_None )

                 {
                     transparency = CheckTransparency
                                    (
                 {
                     transparency = CheckTransparency
                                    (

-                                        ptrSrc,
+                                        lines,

                                         x, y,
                                         width, height,
                                         3
                                         x, y,
                                         width, height,
                                         3


@@ -427,8 +459,36 @@ void CopyDataFromPNG(wxImage *image,
 
                 switch ( transparency )
                 {
 
                 switch ( transparency )
                 {

+                    case Transparency_Mask:
+                        if ( IsTransparent(a) )
+                        {
+                            *ptrDst++ = rMask;
+                            *ptrDst++ = bMask;
+                            *ptrDst++ = gMask;
+                            break;
+                        }
+                        else // !transparent
+                        {
+                            // must be opaque then as otherwise we shouldn't be
+                            // using the mask at all
+                            wxASSERT_MSG( IsOpaque(a), _T("logic error") );
+
+                            // if we couldn't find a unique colour for the
+                            // mask, we can have real pixels with the same
+                            // value as the mask and it's better to slightly
+                            // change their colour than to make them
+                            // transparent
+                            if ( r == rMask && g == gMask && b == bMask )
+                            {
+                                r++;
+                            }
+                        }
+
+                        // fall through
+

                     case Transparency_Alpha:
                     case Transparency_Alpha:

-                        *alpha++ = a;
+                        if ( alpha )
+                            *alpha++ = a;

                         // fall through
 
                     case Transparency_None:
                         // fall through
 
                     case Transparency_None:


@@ -436,20 +496,6 @@ void CopyDataFromPNG(wxImage *image,
                         *ptrDst++ = g;
                         *ptrDst++ = b;
                         break;
                         *ptrDst++ = g;
                         *ptrDst++ = b;
                         break;

-
-                    case Transparency_Mask:
-                        // if we couldn't find a unique colour for the mask, we
-                        // can have real pixels with the same value as the mask
-                        // and it's better to slightly change their colour than
-                        // to make them transparent
-                        if ( r == rMask && g == gMask && b == bMask )
-                        {
-                            r++;
-                        }
-
-                        *ptrDst++ = rMask;
-                        *ptrDst++ = bMask;
-                        *ptrDst++ = gMask;

                 }
             }
         }
                 }
             }
         }


@@ -496,7 +542,7 @@ wxPNGHandler::LoadFile(wxImage *image,
 
     // NB: please see the comment near wxPNGInfoStruct declaration for
     //     explanation why this line is mandatory
 
     // NB: please see the comment near wxPNGInfoStruct declaration for
     //     explanation why this line is mandatory

-    png_set_read_fn( png_ptr, &wxinfo, _PNG_stream_reader);
+    png_set_read_fn( png_ptr, &wxinfo, wx_PNG_stream_reader);

 
     info_ptr = png_create_info_struct( png_ptr );
     if (!info_ptr)
 
     info_ptr = png_create_info_struct( png_ptr );
     if (!info_ptr)


@@ -623,7 +669,7 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbos
 
     // NB: please see the comment near wxPNGInfoStruct declaration for
     //     explanation why this line is mandatory
 
     // NB: please see the comment near wxPNGInfoStruct declaration for
     //     explanation why this line is mandatory

-    png_set_write_fn( png_ptr, &wxinfo, _PNG_stream_writer, NULL);
+    png_set_write_fn( png_ptr, &wxinfo, wx_PNG_stream_writer, NULL);

 
     png_set_IHDR( png_ptr, info_ptr, image->GetWidth(), image->GetHeight(), 8,
         PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,
 
     png_set_IHDR( png_ptr, info_ptr, image->GetWidth(), image->GetHeight(), 8,
         PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,