Remove apparently erroneous -1 from DrawBitmap() in wxMSW wxGC code.

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

diff --git a/src/common/image.cpp b/src/common/image.cpp
index e82fa02082d78a84026d5a5a92ecd6f7a3b797ea..de87a34257f985fd3111ed2ca12d8c6f5bf2f6f1 100644 (file)
--- a/src/common/image.cpp
+++ b/src/common/image.cpp
@@ -29,7 +29,6 @@
     #include "wx/colour.h"
 #endif
 
     #include "wx/colour.h"
 #endif
 

-#include "wx/filefn.h"

 #include "wx/wfstream.h"
 #include "wx/xpmdecod.h"
 
 #include "wx/wfstream.h"
 #include "wx/xpmdecod.h"
 


@@ -253,6 +252,43 @@ wxObjectRefData* wxImage::CloneRefData(const wxObjectRefData* that) const
     return refData_new;
 }
 
     return refData_new;
 }
 

+// returns a new image with the same dimensions, alpha, and mask as *this
+// if on_its_side is true, width and height are swapped
+wxImage wxImage::MakeEmptyClone(int flags) const
+{
+    wxImage image;
+
+    wxCHECK_MSG( Ok(), image, wxS("invalid image") );
+
+    long height = M_IMGDATA->m_height;
+    long width  = M_IMGDATA->m_width;
+
+    if ( flags & Clone_SwapOrientation )
+        wxSwap( width, height );
+
+    if ( !image.Create( width, height, false ) )
+    {
+        wxFAIL_MSG( wxS("unable to create image") );
+        return image;
+    }
+
+    if ( M_IMGDATA->m_alpha )
+    {
+        image.SetAlpha();
+        wxCHECK2_MSG( image.GetAlpha(), return wxImage(),
+                      wxS("unable to create alpha channel") );
+    }
+
+    if ( M_IMGDATA->m_hasMask )
+    {
+        image.SetMaskColour( M_IMGDATA->m_maskRed,
+                             M_IMGDATA->m_maskGreen,
+                             M_IMGDATA->m_maskBlue );
+    }
+
+    return image;
+}
+

 wxImage wxImage::Copy() const
 {
     wxImage image;
 wxImage wxImage::Copy() const
 {
     wxImage image;


@@ -295,11 +331,11 @@ wxImage wxImage::ShrinkBy( int xFactor , int yFactor ) const
     bool hasMask = false ;
     unsigned char maskRed = 0;
     unsigned char maskGreen = 0;
     bool hasMask = false ;
     unsigned char maskRed = 0;
     unsigned char maskGreen = 0;

-    unsigned char maskBlue =0 ;
+    unsigned char maskBlue = 0 ;

 
 

-    unsigned char *source_data = M_IMGDATA->m_data;
+    const unsigned char *source_data = M_IMGDATA->m_data;

     unsigned char *target_data = data;
     unsigned char *target_data = data;

-    unsigned char *source_alpha = 0 ;
+    const unsigned char *source_alpha = 0 ;

     unsigned char *target_alpha = 0 ;
     if (M_IMGDATA->m_hasMask)
     {
     unsigned char *target_alpha = 0 ;
     if (M_IMGDATA->m_hasMask)
     {


@@ -337,7 +373,7 @@ wxImage wxImage::ShrinkBy( int xFactor , int yFactor ) const
                 long y_offset = (y * yFactor + y1) * old_width;
                 for ( int x1 = 0 ; x1 < xFactor ; ++x1 )
                 {
                 long y_offset = (y * yFactor + y1) * old_width;
                 for ( int x1 = 0 ; x1 < xFactor ; ++x1 )
                 {

-                    unsigned char *pixel = source_data + 3 * ( y_offset + x * xFactor + x1 ) ;
+                    const unsigned char *pixel = source_data + 3 * ( y_offset + x * xFactor + x1 ) ;

                     unsigned char red = pixel[0] ;
                     unsigned char green = pixel[1] ;
                     unsigned char blue = pixel[2] ;
                     unsigned char red = pixel[0] ;
                     unsigned char green = pixel[1] ;
                     unsigned char blue = pixel[2] ;


@@ -406,23 +442,16 @@ wxImage::Scale( int width, int height, wxImageResizeQuality quality ) const
     if ( old_width == width && old_height == height )
         return *this;
 
     if ( old_width == width && old_height == height )
         return *this;
 

-    // resample the image using either the nearest neighbourhood, bilinear or
-    // bicubic method as specified
-    switch ( quality )
+    if (quality == wxIMAGE_QUALITY_HIGH)

     {
     {

-        case wxIMAGE_QUALITY_BICUBIC:
-        case wxIMAGE_QUALITY_BILINEAR:
-            // both of these algorithms should be used for up-sampling the
-            // image only, when down-sampling always use box averaging for best
-            // results
-            if ( width < old_width && height < old_height )
-                image = ResampleBox(width, height);
-            else if ( quality == wxIMAGE_QUALITY_BILINEAR )
-                image = ResampleBilinear(width, height);
-            else if ( quality == wxIMAGE_QUALITY_BICUBIC )
-                image = ResampleBicubic(width, height);
-            break;
+        quality = (width < old_width && height < old_height)
+            ? wxIMAGE_QUALITY_BOX_AVERAGE
+            : wxIMAGE_QUALITY_BICUBIC;
+    }

 
 

+    // Resample the image using the method as specified.
+    switch ( quality )
+    {

         case wxIMAGE_QUALITY_NEAREST:
             if ( old_width % width == 0 && old_width >= width &&
                 old_height % height == 0 && old_height >= height )
         case wxIMAGE_QUALITY_NEAREST:
             if ( old_width % width == 0 && old_width >= width &&
                 old_height % height == 0 && old_height >= height )


@@ -432,6 +461,18 @@ wxImage::Scale( int width, int height, wxImageResizeQuality quality ) const
 
             image = ResampleNearest(width, height);
             break;
 
             image = ResampleNearest(width, height);
             break;

+
+        case wxIMAGE_QUALITY_BILINEAR:
+            image = ResampleBilinear(width, height);
+            break;
+
+        case wxIMAGE_QUALITY_BICUBIC:
+            image = ResampleBicubic(width, height);
+            break;
+
+        case wxIMAGE_QUALITY_BOX_AVERAGE:
+            image = ResampleBox(width, height);
+            break;

     }
 
     // If the original image has a mask, apply the mask to the new image
     }
 
     // If the original image has a mask, apply the mask to the new image


@@ -462,9 +503,9 @@ wxImage wxImage::ResampleNearest(int width, int height) const
 
     wxCHECK_MSG( data, image, wxT("unable to create image") );
 
 
     wxCHECK_MSG( data, image, wxT("unable to create image") );
 

-    unsigned char *source_data = M_IMGDATA->m_data;
+    const unsigned char *source_data = M_IMGDATA->m_data;

     unsigned char *target_data = data;
     unsigned char *target_data = data;

-    unsigned char *source_alpha = 0 ;
+    const unsigned char *source_alpha = 0 ;

     unsigned char *target_alpha = 0 ;
 
     if ( !M_IMGDATA->m_hasMask )
     unsigned char *target_alpha = 0 ;
 
     if ( !M_IMGDATA->m_hasMask )


@@ -487,14 +528,14 @@ wxImage wxImage::ResampleNearest(int width, int height) const
     long y = 0;
     for ( long j = 0; j < height; j++ )
     {
     long y = 0;
     for ( long j = 0; j < height; j++ )
     {

-        unsigned char* src_line = &source_data[(y>>16)*old_width*3];
-        unsigned char* src_alpha_line = source_alpha ? &source_alpha[(y>>16)*old_width] : 0 ;
+        const unsigned char* src_line = &source_data[(y>>16)*old_width*3];
+        const unsigned char* src_alpha_line = source_alpha ? &source_alpha[(y>>16)*old_width] : 0 ;

 
         long x = 0;
         for ( long i = 0; i < width; i++ )
         {
 
         long x = 0;
         for ( long i = 0; i < width; i++ )
         {

-            unsigned char* src_pixel = &src_line[(x>>16)*3];
-            unsigned char* src_alpha_pixel = source_alpha ? &src_alpha_line[(x>>16)] : 0 ;
+            const unsigned char* src_pixel = &src_line[(x>>16)*3];
+            const unsigned char* src_alpha_pixel = source_alpha ? &src_alpha_line[(x>>16)] : 0 ;

             dest_pixel[0] = src_pixel[0];
             dest_pixel[1] = src_pixel[1];
             dest_pixel[2] = src_pixel[2];
             dest_pixel[0] = src_pixel[0];
             dest_pixel[1] = src_pixel[1];
             dest_pixel[2] = src_pixel[2];


@@ -525,8 +566,8 @@ wxImage wxImage::ResampleBox(int width, int height) const
     const int scale_factor_x_2 = (int)(scale_factor_x / 2);
     const int scale_factor_y_2 = (int)(scale_factor_y / 2);
 
     const int scale_factor_x_2 = (int)(scale_factor_x / 2);
     const int scale_factor_y_2 = (int)(scale_factor_y / 2);
 

-    unsigned char* src_data = M_IMGDATA->m_data;
-    unsigned char* src_alpha = M_IMGDATA->m_alpha;
+    const unsigned char* src_data = M_IMGDATA->m_data;
+    const unsigned char* src_alpha = M_IMGDATA->m_alpha;

     unsigned char* dst_data = ret_image.GetData();
     unsigned char* dst_alpha = NULL;
 
     unsigned char* dst_data = ret_image.GetData();
     unsigned char* dst_alpha = NULL;
 


@@ -553,16 +594,16 @@ wxImage wxImage::ResampleBox(int width, int height) const
             averaged_pixels = 0;
             sum_r = sum_g = sum_b = sum_a = 0.0;
 
             averaged_pixels = 0;
             sum_r = sum_g = sum_b = sum_a = 0.0;
 

-            for ( int j = int(src_y - scale_factor_y/2.0 + 1);
-                  j <= int(src_y + scale_factor_y_2);
+            for ( int j = int(src_y - scale_factor_y/2.0 + 1), k = j;
+                  j <= int(src_y + scale_factor_y_2) || j < k + 2;

                   j++ )
             {
                 // We don't care to average pixels that don't exist (edges)
                 if ( j < 0 || j > M_IMGDATA->m_height - 1 )
                     continue;
 
                   j++ )
             {
                 // We don't care to average pixels that don't exist (edges)
                 if ( j < 0 || j > M_IMGDATA->m_height - 1 )
                     continue;
 

-                for ( int i = int(src_x - scale_factor_x/2.0 + 1);
-                      i <= src_x + scale_factor_x_2;
+                for ( int i = int(src_x - scale_factor_x/2.0 + 1), e = i;
+                      i <= src_x + scale_factor_x_2 || i < e + 2;

                       i++ )
                 {
                     // Don't average edge pixels
                       i++ )
                 {
                     // Don't average edge pixels


@@ -599,8 +640,8 @@ wxImage wxImage::ResampleBilinear(int width, int height) const
 {
     // This function implements a Bilinear algorithm for resampling.
     wxImage ret_image(width, height, false);
 {
     // This function implements a Bilinear algorithm for resampling.
     wxImage ret_image(width, height, false);

-    unsigned char* src_data = M_IMGDATA->m_data;
-    unsigned char* src_alpha = M_IMGDATA->m_alpha;
+    const unsigned char* src_data = M_IMGDATA->m_data;
+    const unsigned char* src_alpha = M_IMGDATA->m_alpha;

     unsigned char* dst_data = ret_image.GetData();
     unsigned char* dst_alpha = NULL;
 
     unsigned char* dst_data = ret_image.GetData();
     unsigned char* dst_alpha = NULL;
 


@@ -652,21 +693,21 @@ wxImage wxImage::ResampleBilinear(int width, int height) const
             int src_pixel_index10 = y_offset2 * M_IMGDATA->m_width + x_offset1;
             int src_pixel_index11 = y_offset2 * M_IMGDATA->m_width + x_offset2;
 
             int src_pixel_index10 = y_offset2 * M_IMGDATA->m_width + x_offset1;
             int src_pixel_index11 = y_offset2 * M_IMGDATA->m_width + x_offset2;
 

-            //first line
+            // first line

             r1 = src_data[src_pixel_index00 * 3 + 0] * dx1 + src_data[src_pixel_index01 * 3 + 0] * dx;
             g1 = src_data[src_pixel_index00 * 3 + 1] * dx1 + src_data[src_pixel_index01 * 3 + 1] * dx;
             b1 = src_data[src_pixel_index00 * 3 + 2] * dx1 + src_data[src_pixel_index01 * 3 + 2] * dx;
             if ( src_alpha )
                 a1 = src_alpha[src_pixel_index00] * dx1 + src_alpha[src_pixel_index01] * dx;
 
             r1 = src_data[src_pixel_index00 * 3 + 0] * dx1 + src_data[src_pixel_index01 * 3 + 0] * dx;
             g1 = src_data[src_pixel_index00 * 3 + 1] * dx1 + src_data[src_pixel_index01 * 3 + 1] * dx;
             b1 = src_data[src_pixel_index00 * 3 + 2] * dx1 + src_data[src_pixel_index01 * 3 + 2] * dx;
             if ( src_alpha )
                 a1 = src_alpha[src_pixel_index00] * dx1 + src_alpha[src_pixel_index01] * dx;
 

-            //second line
+            // second line

             r2 = src_data[src_pixel_index10 * 3 + 0] * dx1 + src_data[src_pixel_index11 * 3 + 0] * dx;
             g2 = src_data[src_pixel_index10 * 3 + 1] * dx1 + src_data[src_pixel_index11 * 3 + 1] * dx;
             b2 = src_data[src_pixel_index10 * 3 + 2] * dx1 + src_data[src_pixel_index11 * 3 + 2] * dx;
             if ( src_alpha )
                 a2 = src_alpha[src_pixel_index10] * dx1 + src_alpha[src_pixel_index11] * dx;
 
             r2 = src_data[src_pixel_index10 * 3 + 0] * dx1 + src_data[src_pixel_index11 * 3 + 0] * dx;
             g2 = src_data[src_pixel_index10 * 3 + 1] * dx1 + src_data[src_pixel_index11 * 3 + 1] * dx;
             b2 = src_data[src_pixel_index10 * 3 + 2] * dx1 + src_data[src_pixel_index11 * 3 + 2] * dx;
             if ( src_alpha )
                 a2 = src_alpha[src_pixel_index10] * dx1 + src_alpha[src_pixel_index11] * dx;
 

-            //result lines
+            // result lines

 
             dst_data[0] = static_cast<unsigned char>(r1 * dy1 + r2 * dy);
             dst_data[1] = static_cast<unsigned char>(g1 * dy1 + g2 * dy);
 
             dst_data[0] = static_cast<unsigned char>(r1 * dy1 + r2 * dy);
             dst_data[1] = static_cast<unsigned char>(g1 * dy1 + g2 * dy);


@@ -729,8 +770,8 @@ wxImage wxImage::ResampleBicubic(int width, int height) const
 
     ret_image.Create(width, height, false);
 
 
     ret_image.Create(width, height, false);
 

-    unsigned char* src_data = M_IMGDATA->m_data;
-    unsigned char* src_alpha = M_IMGDATA->m_alpha;
+    const unsigned char* src_data = M_IMGDATA->m_data;
+    const unsigned char* src_alpha = M_IMGDATA->m_alpha;

     unsigned char* dst_data = ret_image.GetData();
     unsigned char* dst_alpha = NULL;
 
     unsigned char* dst_data = ret_image.GetData();
     unsigned char* dst_alpha = NULL;
 


@@ -813,26 +854,14 @@ wxImage wxImage::ResampleBicubic(int width, int height) const
 // Blur in the horizontal direction
 wxImage wxImage::BlurHorizontal(int blurRadius) const
 {
 // Blur in the horizontal direction
 wxImage wxImage::BlurHorizontal(int blurRadius) const
 {

-    wxImage ret_image;
-    ret_image.Create(M_IMGDATA->m_width, M_IMGDATA->m_height, false);
+    wxImage ret_image(MakeEmptyClone());

 
 

-    unsigned char* src_data = M_IMGDATA->m_data;
-    unsigned char* dst_data = ret_image.GetData();
-    unsigned char* src_alpha = M_IMGDATA->m_alpha;
-    unsigned char* dst_alpha = NULL;
+    wxCHECK( ret_image.Ok(), ret_image );

 
 

-    // Check for a mask or alpha
-    if ( src_alpha )
-    {
-        ret_image.SetAlpha();
-        dst_alpha = ret_image.GetAlpha();
-    }
-    else if ( M_IMGDATA->m_hasMask )
-    {
-        ret_image.SetMaskColour(M_IMGDATA->m_maskRed,
-                                M_IMGDATA->m_maskGreen,
-                                M_IMGDATA->m_maskBlue);
-    }
+    const unsigned char* src_data = M_IMGDATA->m_data;
+    unsigned char* dst_data = ret_image.GetData();
+    const unsigned char* src_alpha = M_IMGDATA->m_alpha;
+    unsigned char* dst_alpha = ret_image.GetAlpha();

 
     // number of pixels we average over
     const int blurArea = blurRadius*2 + 1;
 
     // number of pixels we average over
     const int blurArea = blurRadius*2 + 1;


@@ -928,26 +957,14 @@ wxImage wxImage::BlurHorizontal(int blurRadius) const
 // Blur in the vertical direction
 wxImage wxImage::BlurVertical(int blurRadius) const
 {
 // Blur in the vertical direction
 wxImage wxImage::BlurVertical(int blurRadius) const
 {

-    wxImage ret_image;
-    ret_image.Create(M_IMGDATA->m_width, M_IMGDATA->m_height, false);
+    wxImage ret_image(MakeEmptyClone());

 
 

-    unsigned char* src_data = M_IMGDATA->m_data;
-    unsigned char* dst_data = ret_image.GetData();
-    unsigned char* src_alpha = M_IMGDATA->m_alpha;
-    unsigned char* dst_alpha = NULL;
+    wxCHECK( ret_image.Ok(), ret_image );

 
 

-    // Check for a mask or alpha
-    if ( src_alpha )
-    {
-        ret_image.SetAlpha();
-        dst_alpha = ret_image.GetAlpha();
-    }
-    else if ( M_IMGDATA->m_hasMask )
-    {
-        ret_image.SetMaskColour(M_IMGDATA->m_maskRed,
-                                M_IMGDATA->m_maskGreen,
-                                M_IMGDATA->m_maskBlue);
-    }
+    const unsigned char* src_data = M_IMGDATA->m_data;
+    unsigned char* dst_data = ret_image.GetData();
+    const unsigned char* src_alpha = M_IMGDATA->m_alpha;
+    unsigned char* dst_alpha = ret_image.GetAlpha();

 
     // number of pixels we average over
     const int blurArea = blurRadius*2 + 1;
 
     // number of pixels we average over
     const int blurArea = blurRadius*2 + 1;


@@ -1055,31 +1072,9 @@ wxImage wxImage::Blur(int blurRadius) const
 
 wxImage wxImage::Rotate90( bool clockwise ) const
 {
 
 wxImage wxImage::Rotate90( bool clockwise ) const
 {

-    wxImage image;
-
-    wxCHECK_MSG( Ok(), image, wxT("invalid image") );
-
-    image.Create( M_IMGDATA->m_height, M_IMGDATA->m_width, false );
+    wxImage image(MakeEmptyClone(Clone_SwapOrientation));

 
 

-    unsigned char *data = image.GetData();
-
-    wxCHECK_MSG( data, image, wxT("unable to create image") );
-
-    unsigned char *source_data = M_IMGDATA->m_data;
-    unsigned char *target_data;
-    unsigned char *alpha_data = 0 ;
-    unsigned char *source_alpha = M_IMGDATA->m_alpha;
-    unsigned char *target_alpha = 0 ;
-
-    if ( source_alpha )
-    {
-        image.SetAlpha();
-        alpha_data = image.GetAlpha();
-        wxCHECK_MSG( alpha_data, image, wxS("unable to create alpha channel") );
-    }
-
-    if ( M_IMGDATA->m_hasMask )
-        image.SetMaskColour( M_IMGDATA->m_maskRed, M_IMGDATA->m_maskGreen, M_IMGDATA->m_maskBlue );
+    wxCHECK( image.Ok(), image );

 
     long height = M_IMGDATA->m_height;
     long width  = M_IMGDATA->m_width;
 
     long height = M_IMGDATA->m_height;
     long width  = M_IMGDATA->m_width;


@@ -1098,62 +1093,142 @@ wxImage wxImage::Rotate90( bool clockwise ) const
                         clockwise ? height - 1 - hot_y : hot_y);
     }
 
                         clockwise ? height - 1 - hot_y : hot_y);
     }
 

-    for (long j = 0; j < height; j++)
+    unsigned char *data = image.GetData();
+    unsigned char *target_data;
+
+    // we rotate the image in 21-pixel (63-byte) wide strips
+    // to make better use of cpu cache - memory transfers
+    // (note: while much better than single-pixel "strips",
+    //  our vertical strips will still generally straddle 64-byte cachelines)
+    for (long ii = 0; ii < width; )

     {
     {

-        for (long i = 0; i < width; i++)
+        long next_ii = wxMin(ii + 21, width);
+
+        for (long j = 0; j < height; j++)

         {
         {

-            if (clockwise)
-            {
-                target_data = data + (((i+1)*height) - j - 1)*3;
-                if(source_alpha)
-                    target_alpha = alpha_data + (((i+1)*height) - j - 1);
-            }
-            else
+            const unsigned char *source_data
+                                     = M_IMGDATA->m_data + (j*width + ii)*3;
+
+            for (long i = ii; i < next_ii; i++)

             {
             {

-                target_data = data + ((height*(width-1)) + j - (i*height))*3;
-                if(source_alpha)
-                    target_alpha = alpha_data + ((height*(width-1)) + j - (i*height));
+                if ( clockwise )
+                {
+                    target_data = data + ((i + 1)*height - j - 1)*3;
+                }
+                else
+                {
+                    target_data = data + (height*(width - 1 - i) + j)*3;
+                }
+                memcpy( target_data, source_data, 3 );
+                source_data += 3;

             }
             }

-            memcpy( target_data, source_data, 3 );
-            source_data += 3;
+        }
+
+        ii = next_ii;
+    }
+
+    const unsigned char *source_alpha = M_IMGDATA->m_alpha;
+
+    if ( source_alpha )
+    {
+        unsigned char *alpha_data = image.GetAlpha();
+        unsigned char *target_alpha = 0 ;

 
 

-            if(source_alpha)
+        for (long ii = 0; ii < width; )
+        {
+            long next_ii = wxMin(ii + 64, width);
+
+            for (long j = 0; j < height; j++)

             {
             {

-                memcpy( target_alpha, source_alpha, 1 );
-                source_alpha += 1;
+                source_alpha = M_IMGDATA->m_alpha + j*width + ii;
+
+                for (long i = ii; i < next_ii; i++)
+                {
+                    if ( clockwise )
+                    {
+                        target_alpha = alpha_data + (i+1)*height - j - 1;
+                    }
+                    else
+                    {
+                        target_alpha = alpha_data + height*(width - i - 1) + j;
+                    }
+
+                    *target_alpha = *source_alpha++;
+                }

             }
             }

+
+            ii = next_ii;

         }
     }
 
     return image;
 }
 
         }
     }
 
     return image;
 }
 

-wxImage wxImage::Mirror( bool horizontally ) const
+wxImage wxImage::Rotate180() const

 {
 {

-    wxImage image;
+    wxImage image(MakeEmptyClone());

 
 

-    wxCHECK_MSG( Ok(), image, wxT("invalid image") );
+    wxCHECK( image.Ok(), image );

 
 

-    image.Create( M_IMGDATA->m_width, M_IMGDATA->m_height, false );
+    long height = M_IMGDATA->m_height;
+    long width  = M_IMGDATA->m_width;
+
+    if ( HasOption(wxIMAGE_OPTION_CUR_HOTSPOT_X) )
+    {
+        image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_X,
+                        width - 1 - GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_X));
+    }
+
+    if ( HasOption(wxIMAGE_OPTION_CUR_HOTSPOT_Y) )
+    {
+        image.SetOption(wxIMAGE_OPTION_CUR_HOTSPOT_Y,
+                        height - 1 - GetOptionInt(wxIMAGE_OPTION_CUR_HOTSPOT_Y));
+    }

 
     unsigned char *data = image.GetData();
 
     unsigned char *data = image.GetData();

-    unsigned char *alpha = NULL;
+    unsigned char *alpha = image.GetAlpha();
+    const unsigned char *source_data = M_IMGDATA->m_data;
+    unsigned char *target_data = data + width * height * 3;

 
 

-    wxCHECK_MSG( data, image, wxT("unable to create image") );
+    for (long j = 0; j < height; j++)
+    {
+        for (long i = 0; i < width; i++)
+        {
+            target_data -= 3;
+            memcpy( target_data, source_data, 3 );
+            source_data += 3;
+        }
+    }

 
 

-    if (M_IMGDATA->m_alpha != NULL) {
-        image.SetAlpha();
-        alpha = image.GetAlpha();
-        wxCHECK_MSG( alpha, image, wxT("unable to create alpha channel") );
+    if ( alpha )
+    {
+        const unsigned char *src_alpha = M_IMGDATA->m_alpha;
+        unsigned char *dest_alpha = alpha + width * height;
+
+        for (long j = 0; j < height; ++j)
+        {
+            for (long i = 0; i < width; ++i)
+            {
+                *(--dest_alpha) = *(src_alpha++);
+            }
+        }

     }
 
     }
 

-    if (M_IMGDATA->m_hasMask)
-        image.SetMaskColour( M_IMGDATA->m_maskRed, M_IMGDATA->m_maskGreen, M_IMGDATA->m_maskBlue );
+    return image;
+}
+
+wxImage wxImage::Mirror( bool horizontally ) const
+{
+    wxImage image(MakeEmptyClone());
+
+    wxCHECK( image.Ok(), image );

 
     long height = M_IMGDATA->m_height;
     long width  = M_IMGDATA->m_width;
 
 
     long height = M_IMGDATA->m_height;
     long width  = M_IMGDATA->m_width;
 

-    unsigned char *source_data = M_IMGDATA->m_data;
+    unsigned char *data = image.GetData();
+    unsigned char *alpha = image.GetAlpha();
+    const unsigned char *source_data = M_IMGDATA->m_data;

     unsigned char *target_data;
 
     if (horizontally)
     unsigned char *target_data;
 
     if (horizontally)


@@ -1198,7 +1273,7 @@ wxImage wxImage::Mirror( bool horizontally ) const
             source_data += 3*width;
         }
 
             source_data += 3*width;
         }
 

-        if (alpha != NULL)
+        if ( alpha )

         {
             // src_alpha starts at the first pixel and increases by 1 width after each step
             // (a step here is the copy of the alpha channel of an entire line)
         {
             // src_alpha starts at the first pixel and increases by 1 width after each step
             // (a step here is the copy of the alpha channel of an entire line)


@@ -1241,7 +1316,7 @@ wxImage wxImage::GetSubImage( const wxRect &rect ) const
 
     wxCHECK_MSG( subdata, image, wxT("unable to create image") );
 
 
     wxCHECK_MSG( subdata, image, wxT("unable to create image") );
 

-    if (src_alpha != NULL) {
+    if ( src_alpha ) {

         image.SetAlpha();
         subalpha = image.GetAlpha();
         wxCHECK_MSG( subalpha, image, wxT("unable to create alpha channel"));
         image.SetAlpha();
         subalpha = image.GetAlpha();
         wxCHECK_MSG( subalpha, image, wxT("unable to create alpha channel"));


@@ -1353,17 +1428,20 @@ void wxImage::Paste( const wxImage &image, int x, int y )
     if (width < 1) return;
     if (height < 1) return;
 
     if (width < 1) return;
     if (height < 1) return;
 

-    if ((!HasMask() && !image.HasMask()) ||
-        (HasMask() && !image.HasMask()) ||
-       ((HasMask() && image.HasMask() &&
+    // If we can, copy the data using memcpy() as this is the fastest way. But
+    // for this  the image being pasted must have "compatible" mask with this
+    // one meaning that either it must not have one at all or it must use the
+    // same masked colour.
+    if ( !image.HasMask() ||
+        ((HasMask() &&

          (GetMaskRed()==image.GetMaskRed()) &&
          (GetMaskGreen()==image.GetMaskGreen()) &&
          (GetMaskRed()==image.GetMaskRed()) &&
          (GetMaskGreen()==image.GetMaskGreen()) &&

-         (GetMaskBlue()==image.GetMaskBlue()))))
+         (GetMaskBlue()==image.GetMaskBlue()))) )

     {
     {

-        unsigned char* source_data = image.GetData() + xx*3 + yy*3*image.GetWidth();
+        const unsigned char* source_data = image.GetData() + 3*(xx + yy*image.GetWidth());

         int source_step = image.GetWidth()*3;
 
         int source_step = image.GetWidth()*3;
 

-        unsigned char* target_data = GetData() + (x+xx)*3 + (y+yy)*3*M_IMGDATA->m_width;
+        unsigned char* target_data = GetData() + 3*((x+xx) + (y+yy)*M_IMGDATA->m_width);

         int target_step = M_IMGDATA->m_width*3;
         for (int j = 0; j < height; j++)
         {
         int target_step = M_IMGDATA->m_width*3;
         for (int j = 0; j < height; j++)
         {


@@ -1379,7 +1457,7 @@ void wxImage::Paste( const wxImage &image, int x, int y )
         if ( !HasAlpha() )
             InitAlpha();
 
         if ( !HasAlpha() )
             InitAlpha();
 

-        unsigned char* source_data = image.GetAlpha() + xx + yy*image.GetWidth();
+        const unsigned char* source_data = image.GetAlpha() + xx + yy*image.GetWidth();

         int source_step = image.GetWidth();
 
         unsigned char* target_data = GetAlpha() + (x+xx) + (y+yy)*M_IMGDATA->m_width;
         int source_step = image.GetWidth();
 
         unsigned char* target_data = GetAlpha() + (x+xx) + (y+yy)*M_IMGDATA->m_width;


@@ -1399,10 +1477,10 @@ void wxImage::Paste( const wxImage &image, int x, int y )
         unsigned char g = image.GetMaskGreen();
         unsigned char b = image.GetMaskBlue();
 
         unsigned char g = image.GetMaskGreen();
         unsigned char b = image.GetMaskBlue();
 

-        unsigned char* source_data = image.GetData() + xx*3 + yy*3*image.GetWidth();
+        const unsigned char* source_data = image.GetData() + 3*(xx + yy*image.GetWidth());

         int source_step = image.GetWidth()*3;
 
         int source_step = image.GetWidth()*3;
 

-        unsigned char* target_data = GetData() + (x+xx)*3 + (y+yy)*3*M_IMGDATA->m_width;
+        unsigned char* target_data = GetData() + 3*((x+xx) + (y+yy)*M_IMGDATA->m_width);

         int target_step = M_IMGDATA->m_width*3;
 
         for (int j = 0; j < height; j++)
         int target_step = M_IMGDATA->m_width*3;
 
         for (int j = 0; j < height; j++)


@@ -1454,47 +1532,33 @@ wxImage wxImage::ConvertToGreyscale(void) const
 
 wxImage wxImage::ConvertToGreyscale(double weight_r, double weight_g, double weight_b) const
 {
 
 wxImage wxImage::ConvertToGreyscale(double weight_r, double weight_g, double weight_b) const
 {

-    wxImage image;
-
-    wxCHECK_MSG( Ok(), image, wxT("invalid image") );
+    wxImage image(MakeEmptyClone());

 
 

-    image.Create(M_IMGDATA->m_width, M_IMGDATA->m_height, false);
+    wxCHECK( image.Ok(), image );

 
 

+    const unsigned char *src = M_IMGDATA->m_data;

     unsigned char *dest = image.GetData();
 
     unsigned char *dest = image.GetData();
 

-    wxCHECK_MSG( dest, image, wxT("unable to create image") );
-
-    unsigned char *src = M_IMGDATA->m_data;
-    bool hasMask = M_IMGDATA->m_hasMask;
-    unsigned char maskRed = M_IMGDATA->m_maskRed;
-    unsigned char maskGreen = M_IMGDATA->m_maskGreen;
-    unsigned char maskBlue = M_IMGDATA->m_maskBlue;
-
-    if ( hasMask )
-        image.SetMaskColour(maskRed, maskGreen, maskBlue);
+    const bool hasMask = M_IMGDATA->m_hasMask;
+    const unsigned char maskRed = M_IMGDATA->m_maskRed;
+    const unsigned char maskGreen = M_IMGDATA->m_maskGreen;
+    const unsigned char maskBlue = M_IMGDATA->m_maskBlue;

 
     const long size = M_IMGDATA->m_width * M_IMGDATA->m_height;
     for ( long i = 0; i < size; i++, src += 3, dest += 3 )
     {
         memcpy(dest, src, 3);
 
     const long size = M_IMGDATA->m_width * M_IMGDATA->m_height;
     for ( long i = 0; i < size; i++, src += 3, dest += 3 )
     {
         memcpy(dest, src, 3);

-        // don't modify the mask
-        if ( hasMask && src[0] == maskRed && src[1] == maskGreen && src[2] == maskBlue )
-        {
-        }
-        else
+        // only modify non-masked pixels
+        if ( !hasMask || src[0] != maskRed || src[1] != maskGreen || src[2] != maskBlue )

         {
             wxColour::MakeGrey(dest + 0, dest + 1, dest + 2, weight_r, weight_g, weight_b);
         }
     }
 
     // copy the alpha channel, if any
         {
             wxColour::MakeGrey(dest + 0, dest + 1, dest + 2, weight_r, weight_g, weight_b);
         }
     }
 
     // copy the alpha channel, if any

-    if (HasAlpha())
+    if ( image.HasAlpha() )

     {
     {

-        const size_t alphaSize = GetWidth() * GetHeight();
-        unsigned char *alpha = (unsigned char*)malloc(alphaSize);
-        memcpy(alpha, GetAlpha(), alphaSize);
-        image.InitAlpha();
-        image.SetAlpha(alpha);
+        memcpy( image.GetAlpha(), GetAlpha(), GetWidth() * GetHeight() );

     }
 
     return image;
     }
 
     return image;


@@ -2175,21 +2239,18 @@ bool wxImage::LoadFile( const wxString& WXUNUSED_UNLESS_STREAMS(filename),
                         int WXUNUSED_UNLESS_STREAMS(index) )
 {
 #if HAS_FILE_STREAMS
                         int WXUNUSED_UNLESS_STREAMS(index) )
 {
 #if HAS_FILE_STREAMS

-    if (wxFileExists(filename))
+    wxImageFileInputStream stream(filename);
+    if ( stream.IsOk() )

     {
     {

-        wxImageFileInputStream stream(filename);

         wxBufferedInputStream bstream( stream );
         wxBufferedInputStream bstream( stream );

-        return LoadFile(bstream, type, index);
+        if ( LoadFile(bstream, type, index) )
+            return true;

     }
     }

-    else
-    {
-        wxLogError( _("Can't load image from file '%s': file does not exist."), filename.c_str() );

 
 

-        return false;
-    }
-#else // !HAS_FILE_STREAMS
-    return false;
+    wxLogError(_("Failed to load image from file \"%s\"."), filename);

 #endif // HAS_FILE_STREAMS
 #endif // HAS_FILE_STREAMS

+
+    return false;

 }
 
 bool wxImage::LoadFile( const wxString& WXUNUSED_UNLESS_STREAMS(filename),
 }
 
 bool wxImage::LoadFile( const wxString& WXUNUSED_UNLESS_STREAMS(filename),


@@ -2197,21 +2258,18 @@ bool wxImage::LoadFile( const wxString& WXUNUSED_UNLESS_STREAMS(filename),
                         int WXUNUSED_UNLESS_STREAMS(index) )
 {
 #if HAS_FILE_STREAMS
                         int WXUNUSED_UNLESS_STREAMS(index) )
 {
 #if HAS_FILE_STREAMS

-    if (wxFileExists(filename))
+    wxImageFileInputStream stream(filename);
+    if ( stream.IsOk() )

     {
     {

-        wxImageFileInputStream stream(filename);

         wxBufferedInputStream bstream( stream );
         wxBufferedInputStream bstream( stream );

-        return LoadFile(bstream, mimetype, index);
+        if ( LoadFile(bstream, mimetype, index) )
+            return true;

     }
     }

-    else
-    {
-        wxLogError( _("Can't load image from file '%s': file does not exist."), filename.c_str() );

 
 

-        return false;
-    }
-#else // !HAS_FILE_STREAMS
-    return false;
+    wxLogError(_("Failed to load image from file \"%s\"."), filename);

 #endif // HAS_FILE_STREAMS
 #endif // HAS_FILE_STREAMS

+
+    return false;

 }
 
 
 }
 
 


@@ -2360,8 +2418,20 @@ bool wxImage::DoLoad(wxImageHandler& handler, wxInputStream& stream, int index)
     const unsigned maxWidth = GetOptionInt(wxIMAGE_OPTION_MAX_WIDTH),
                    maxHeight = GetOptionInt(wxIMAGE_OPTION_MAX_HEIGHT);
 
     const unsigned maxWidth = GetOptionInt(wxIMAGE_OPTION_MAX_WIDTH),
                    maxHeight = GetOptionInt(wxIMAGE_OPTION_MAX_HEIGHT);
 

+    // Preserve the original stream position if possible to rewind back to it
+    // if we failed to load the file -- maybe the next handler that we try can
+    // succeed after us then.
+    wxFileOffset posOld = wxInvalidOffset;
+    if ( stream.IsSeekable() )
+        posOld = stream.TellI();
+

     if ( !handler.LoadFile(this, stream, true/*verbose*/, index) )
     if ( !handler.LoadFile(this, stream, true/*verbose*/, index) )

+    {
+        if ( posOld != wxInvalidOffset )
+            stream.SeekI(posOld);
+

         return false;
         return false;

+    }

 
     // rescale the image to the specified size if needed
     if ( maxWidth || maxHeight )
 
     // rescale the image to the specified size if needed
     if ( maxWidth || maxHeight )


@@ -2397,6 +2467,17 @@ bool wxImage::LoadFile( wxInputStream& stream, wxBitmapType type, int index )
 
     if ( type == wxBITMAP_TYPE_ANY )
     {
 
     if ( type == wxBITMAP_TYPE_ANY )
     {

+        if ( !stream.IsSeekable() )
+        {
+            // The error message about image data format being unknown below
+            // would be misleading in this case as we are not even going to try
+            // any handlers because CanRead() never does anything for not
+            // seekable stream, so try to be more precise here.
+            wxLogError(_("Can't automatically determine the image format "
+                         "for non-seekable input."));
+            return false;
+        }
+

         const wxList& list = GetHandlers();
         for ( wxList::compatibility_iterator node = list.GetFirst();
               node;
         const wxList& list = GetHandlers();
         for ( wxList::compatibility_iterator node = list.GetFirst();
               node;


@@ -2407,7 +2488,7 @@ bool wxImage::LoadFile( wxInputStream& stream, wxBitmapType type, int index )
                  return true;
         }
 
                  return true;
         }
 

-        wxLogWarning( _("No handler found for image type.") );
+        wxLogWarning( _("Unknown image data format.") );

 
         return false;
     }
 
         return false;
     }


@@ -2422,7 +2503,7 @@ bool wxImage::LoadFile( wxInputStream& stream, wxBitmapType type, int index )
 
     if ( stream.IsSeekable() && !handler->CanRead(stream) )
     {
 
     if ( stream.IsSeekable() && !handler->CanRead(stream) )
     {

-        wxLogError(_("Image file is not of type %d."), type);
+        wxLogError(_("This is not a %s."), handler->GetName());

         return false;
     }
 
         return false;
     }
 


@@ -2445,7 +2526,7 @@ bool wxImage::LoadFile( wxInputStream& stream, const wxString& mimetype, int ind
 
     if ( stream.IsSeekable() && !handler->CanRead(stream) )
     {
 
     if ( stream.IsSeekable() && !handler->CanRead(stream) )
     {

-        wxLogError(_("Image file is not of type %s."), mimetype);
+        wxLogError(_("Image is not of type %s."), mimetype);

         return false;
     }
 
         return false;
     }
 


@@ -2845,15 +2926,15 @@ int wxImageHandler::GetImageCount( wxInputStream& stream )
 
 bool wxImageHandler::CanRead( const wxString& name )
 {
 
 bool wxImageHandler::CanRead( const wxString& name )
 {

-    if (wxFileExists(name))
+    wxImageFileInputStream stream(name);
+    if ( !stream.IsOk() )

     {
     {

-        wxImageFileInputStream stream(name);
-        return CanRead(stream);
-    }
+        wxLogError(_("Failed to check format of image file \"%s\"."), name);

 
 

-    wxLogError( _("Can't check image format of file '%s': file does not exist."), name.c_str() );
+        return false;
+    }

 
 

-    return false;
+    return CanRead(stream);

 }
 
 bool wxImageHandler::CallDoCanRead(wxInputStream& stream)
 }
 
 bool wxImageHandler::CallDoCanRead(wxInputStream& stream)