X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/8529b0b909e478f0cf43aaafb262d1913d87c824..87f0b1323b7ac77f02133b836c8dfee63b0fd387:/src/common/imagpng.cpp

diff --git a/src/common/imagpng.cpp b/src/common/imagpng.cpp
index 3472c5a1fc..7fee6adbdb 100644
--- a/src/common/imagpng.cpp
+++ b/src/common/imagpng.cpp
@@ -43,7 +43,7 @@
 // constants
 // ----------------------------------------------------------------------------
 
-// image can not have any transparent pixels at all, have only 100% opaque
+// image cannot have any transparent pixels at all, have only 100% opaque
 // and/or 100% transparent pixels in which case a simple mask is enough to
 // store this information in wxImage or have a real alpha channel in which case
 // we need to have it in wxImage as well
@@ -116,11 +116,9 @@ IMPLEMENT_DYNAMIC_CLASS(wxPNGHandler,wxImageHandler)
 //     First, let me describe what's the problem: libpng uses jmp_buf in
 //     its png_struct structure. Unfortunately, this structure is
 //     compiler-specific and may vary in size, so if you use libpng compiled
-//     as DLL with another compiler than the main executable, it may not work
-//     (this is for example the case with wxMGL port and SciTech MGL library
-//     that provides custom runtime-loadable libpng implementation with jmpbuf
-//     disabled altogether). Luckily, it is still possible to use setjmp() &
-//     longjmp() as long as the structure is not part of png_struct.
+//     as DLL with another compiler than the main executable, it may not work.
+//     Luckily, it is still possible to use setjmp() & longjmp() as long as the
+//     structure is not part of png_struct.
 //
 //     Sadly, there's no clean way to attach user-defined data to png_struct.
 //     There is only one customizable place, png_struct.io_ptr, which is meant
@@ -558,7 +556,7 @@ wxPNGHandler::LoadFile(wxImage *image,
 
     image->Create((int)width, (int)height, (bool) false /* no need to init pixels */);
 
-    if (!image->Ok())
+    if (!image->IsOk())
         goto error;
 
     // initialize all line pointers to NULL to ensure that they can be safely
@@ -602,6 +600,47 @@ wxPNGHandler::LoadFile(wxImage *image,
     }
 #endif // wxUSE_PALETTE
 
+
+    // set the image resolution if it's available
+    png_uint_32 resX, resY;
+    int unitType;
+    if (png_get_pHYs(png_ptr, info_ptr, &resX, &resY, &unitType)
+        == PNG_INFO_pHYs)
+    {
+        wxImageResolution res = wxIMAGE_RESOLUTION_CM;
+
+        switch (unitType)
+        {
+            default:
+                wxLogWarning(_("Unknown PNG resolution unit %d"), unitType);
+                // fall through
+
+            case PNG_RESOLUTION_UNKNOWN:
+                image->SetOption(wxIMAGE_OPTION_RESOLUTIONX, resX);
+                image->SetOption(wxIMAGE_OPTION_RESOLUTIONY, resY);
+
+                res = wxIMAGE_RESOLUTION_NONE;
+                break;
+
+            case PNG_RESOLUTION_METER:
+                /*
+                Convert meters to centimeters.
+                Use a string to not lose precision (converting to cm and then
+                to inch would result in integer rounding error).
+                If an app wants an int, GetOptionInt will convert and round
+                down for them.
+                */
+                image->SetOption(wxIMAGE_OPTION_RESOLUTIONX,
+                    wxString::FromCDouble((double) resX / 100.0, 2));
+                image->SetOption(wxIMAGE_OPTION_RESOLUTIONY,
+                    wxString::FromCDouble((double) resY / 100.0, 2));
+                break;
+        }
+
+        image->SetOption(wxIMAGE_OPTION_RESOLUTIONUNIT, res);
+    }
+
+
     png_destroy_read_struct( &png_ptr, &info_ptr, (png_infopp) NULL );
 
     // loaded successfully, now init wxImage with this data
@@ -619,7 +658,7 @@ error:
        wxLogError(_("Couldn't load a PNG image - file is corrupted or not enough memory."));
     }
 
-    if ( image->Ok() )
+    if ( image->IsOk() )
     {
         image->Destroy();
     }
@@ -754,15 +793,13 @@ bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbos
 #endif
     ;
 
-    png_color_8 mask;
+    png_color_8 mask = { 0, 0, 0, 0, 0 };
 
     if (bHasMask)
     {
         mask.red   = image->GetMaskRed();
         mask.green = image->GetMaskGreen();
         mask.blue  = image->GetMaskBlue();
-        mask.alpha = 0;
-        mask.gray  = 0;
     }
 
     PaletteMap palette;