// Modified by:
// Created: 10.03.03
// RCS-ID: $Id$
-// Copyright: (c) 2002 Vadim Zeitlin <vadim@wxwindows.org>
+// Copyright: (c) 2002 Vadim Zeitlin <vadim@wxwidgets.org>
// Licence: wxWindows licence
///////////////////////////////////////////////////////////////////////////////
#ifndef _WX_RAWBMP_H_BASE_
#define _WX_RAWBMP_H_BASE_
+#include "wx/image.h"
+
// ----------------------------------------------------------------------------
// Abstract Pixel API
//
/*
Usage example:
+ typedef wxPixelData<wxBitmap, wxNativePixelFormat> PixelData;
+
wxBitmap bmp;
- wxRawBitmapData data(bitmap);
+ PixelData data(bmp);
if ( !data )
{
... raw access to bitmap data unavailable, do something else ...
return;
}
- if ( data.m_width < 20 || data.m_height < 20 )
+ if ( data.GetWidth() < 20 || data.GetHeight() < 20 )
{
... complain: the bitmap it too small ...
return;
}
- wxRawBitmapIterator p(data);
+ PixelData::Iterator p(data);
// we draw a (10, 10)-(20, 20) rect manually using the given r, g, b
- p.Offset(10, 10);
+ p.Offset(data, 10, 10);
for ( int y = 0; y < 10; ++y )
{
- wxRawBitmapIterator rowStart = p;
+ PixelData::Iterator rowStart = p;
for ( int x = 0; x < 10; ++x, ++p )
{
}
p = rowStart;
- p.OffsetY(1);
+ p.OffsetY(data, 1);
}
*/
-// this struct represents a pointer to raw bitmap data
-class wxRawBitmapData
+/*
+ Note: we do not use WXDLLEXPORT with classes in this file because VC++ has
+ problems with exporting inner class defined inside a specialization of a
+ template class from a DLL. Besides, as all the methods are inline it's not
+ really necessary to put them in DLL at all.
+ */
+
+// ----------------------------------------------------------------------------
+// wxPixelFormat
+// ----------------------------------------------------------------------------
+
+/*
+ wxPixelFormat is a template class describing the bitmap data format. It
+ contains the constants describing the format of pixel data, but does not
+ describe how the entire bitmap is stored (i.e. top-to-bottom,
+ bottom-to-top, ...). It is also a "traits"-like class, i.e. it only
+ contains some constants and maybe static methods but nothing more, so it
+ can be safely used without incurring any overhead as all accesses to it are
+ done at compile-time.
+
+ Current limitations: we don't support RAGABA and ARAGAB formats supported
+ by Mac OS X. If there is sufficient interest, these classes could be
+ extended to deal with them. Neither do we support alpha channel having
+ different representation from the RGB ones (happens under QNX/Photon I
+ think), but again this could be achieved with some small extra effort.
+
+ Template parameters are:
+ - type of a single pixel component
+ - size of the single pixel in bits
+ - indices of red, green and blue pixel components inside the pixel
+ - index of the alpha component or -1 if none
+ - type which can contain the full pixel value (all channels)
+ */
+
+template <class Channel,
+ size_t Bpp, int R, int G, int B, int A = -1,
+ class Pixel = wxUint32>
+
+struct wxPixelFormat
{
-public:
- // ctor associates this pointer with a bitmap and locks the bitmap for raw
- // access, it will be unlocked only by our dtor and so these objects should
- // normally be only created on the stack, i.e. have limited life-time
- wxRawBitmapData(wxBitmap bmp) : m_bmp(bmp)
- {
- if ( !bmp.GetRawData(this) )
- m_pixels = NULL;
- }
+ // iterator over pixels is usually of type "ChannelType *"
+ typedef Channel ChannelType;
+
+ // the type which may hold the entire pixel value
+ typedef Pixel PixelType;
+
+ // NB: using static ints initialized inside the class declaration is not
+ // portable as it doesn't work with VC++ 6, so we must use enums
+
+ // size of one pixel in bits
+ enum { BitsPerPixel = Bpp };
- // we evaluate to true only if we could get access to bitmap data
- // successfully
- operator bool() const { return m_pixels != NULL; }
+ // size of one pixel in ChannelType units (usually bytes)
+ enum { SizePixel = Bpp / (8 * sizeof(Channel)) };
- // dtor unlocks the bitmap
- ~wxRawBitmapData()
+ // the channels indices inside the pixel
+ enum
{
- m_bmp.UngetRawData(this);
- }
+ RED = R,
+ GREEN = G,
+ BLUE = B,
+ ALPHA = A
+ };
+
+ // true if we have an alpha channel (together with the other channels, this
+ // doesn't cover the case of wxImage which stores alpha separately)
+ enum { HasAlpha = A != -1 };
+};
+
+// some "predefined" pixel formats
+// -------------------------------
+
+// wxImage format is common to all platforms
+typedef wxPixelFormat<unsigned char, 24, 0, 1, 2> wxImagePixelFormat;
+
+// the (most common) native bitmap format without alpha support
+#if defined(__WXMSW__)
+ // under MSW the RGB components are reversed, they're in BGR order
+ typedef wxPixelFormat<unsigned char, 24, 2, 1, 0> wxNativePixelFormat;
+
+ #define wxPIXEL_FORMAT_ALPHA 3
+#elif defined(__WXMAC__)
+ // under Mac, first component is unused but still present, hence we use
+ // 32bpp, not 24
+ typedef wxPixelFormat<unsigned char, 32, 1, 2, 3> wxNativePixelFormat;
+
+ #define wxPIXEL_FORMAT_ALPHA 0
+#elif defined(__WXCOCOA__)
+ // Cocoa is standard RGB or RGBA (normally it is RGBA)
+ typedef wxPixelFormat<unsigned char, 24, 0, 1, 2> wxNativePixelFormat;
+
+ #define wxPIXEL_FORMAT_ALPHA 3
+#elif defined(__WXGTK__)
+ // Under GTK+ 2.X we use GdkPixbuf, which should be RGBA
+ typedef wxPixelFormat<unsigned char, 32, 0, 1, 2> wxNativePixelFormat;
+
+ #define wxPIXEL_FORMAT_ALPHA 3
+#endif
+
+// the (most common) native format for bitmaps with alpha channel
+#ifdef wxPIXEL_FORMAT_ALPHA
+ typedef wxPixelFormat<unsigned char, 32,
+ wxNativePixelFormat::RED,
+ wxNativePixelFormat::GREEN,
+ wxNativePixelFormat::BLUE,
+ wxPIXEL_FORMAT_ALPHA> wxAlphaPixelFormat;
+#endif // wxPIXEL_FORMAT_ALPHA
+
+// we also define the (default/best) pixel format for the given class: this is
+// used as default value for the pixel format in wxPixelIterator template
+template <class T> struct wxPixelFormatFor;
+
+#if wxUSE_IMAGE
+// wxPixelFormatFor is only defined for wxImage, attempt to use it with other
+// classes (wxBitmap...) will result in compile errors which is exactly what we
+// want
+template <>
+struct wxPixelFormatFor<wxImage>
+{
+ typedef wxImagePixelFormat Format;
+};
+#endif //wxUSE_IMAGE
+
+// ----------------------------------------------------------------------------
+// wxPixelData
+// ----------------------------------------------------------------------------
- // call this to indicate that we should use the alpha channel
- void UseAlpha() { m_bmp.UseAlpha(); }
+/*
+ wxPixelDataBase is just a helper for wxPixelData: it contains things common
+ to both wxImage and wxBitmap specializations.
+ */
+class wxPixelDataBase
+{
+public:
+ // origin of the rectangular region we represent
+ wxPoint GetOrigin() const { return m_ptOrigin; }
- // accessors
- unsigned char *GetPixels() const { return m_pixels; }
+ // width and height of the region we represent
int GetWidth() const { return m_width; }
int GetHeight() const { return m_height; }
- int GetByPP() const { return m_bypp; }
- int GetBPP() const { return 8*GetByPP(); }
- int GetRowStride() const { return m_stride; }
-// private: -- public because accessed by the macros below but still mustn't be
-// used directly
+ wxSize GetSize() const { return wxSize(m_width, m_height); }
+
+ // the distance between two rows
+ int GetRowStride() const { return m_stride; }
- // the bitmap we're associated with
- wxBitmap m_bmp;
+// private: -- see comment in the beginning of the file
- // pointer to the start of the data
- unsigned char *m_pixels;
+ // the origin of this image inside the bigger bitmap (usually (0, 0))
+ wxPoint m_ptOrigin;
// the size of the image we address, in pixels
int m_width,
m_height;
- // number of bytes (NOT bits) per pixel, including alpha channel if any
- int m_bypp;
-
// this parameter is the offset of the start of the (N+1)st row from the
// Nth one and can be different from m_bypp*width in some cases:
// a) the most usual one is to force 32/64 bit alignment of rows
// c) finally, it could conceivably be 0 for the images with all
// lines being identical
int m_stride;
+
+protected:
+ // ctor is protected because this class is only meant to be used as the
+ // base class by wxPixelData
+ wxPixelDataBase()
+ {
+ m_width =
+ m_height =
+ m_stride = 0;
+ }
};
-// this is the type for the iterator over raw bitmap data
-class wxRawBitmapIterator
+/*
+ wxPixelData represents the entire bitmap data, i.e. unlike
+ wxPixelFormat (which it uses) it also stores the global bitmap
+ characteristics such as its size, inter-row separation and so on.
+
+ Because of this it can be used to move the pixel iterators (which don't
+ have enough information about the bitmap themselves). This may seem a bit
+ unnatural but must be done in this way to keep the iterator objects as
+ small as possible for maximum efficiency as otherwise they wouldn't be put
+ into the CPU registers by the compiler any more.
+
+ Implementation note: we use the standard workaround for lack of partial
+ template specialization support in VC (both 6 and 7): instead of partly
+ specializing the class Foo<T, U> for some T we introduce FooOut<T> and
+ FooIn<U> nested in it, make Foo<T, U> equivalent to FooOut<T>::FooIn<U> and
+ fully specialize FooOut.
+
+ Also note that this class doesn't have any default definition because we
+ can't really do anything without knowing the exact image class. We do
+ provide wxPixelDataBase to make it simpler to write new wxPixelData
+ specializations.
+ */
+
+// we need to define this skeleton template to mollify VC++
+template <class Image>
+struct wxPixelDataOut
{
-public:
- // ctors and such
- // --------------
+ template <class PixelFormat>
+ class wxPixelDataIn
+ {
+ public:
+ class Iterator { };
+ };
+};
- // we must be associated/initialized with some bitmap data object
- wxRawBitmapIterator(const wxRawBitmapData& data) : m_data(&data)
+#if wxUSE_IMAGE
+// wxPixelData specialization for wxImage: this is the simplest case as we
+// don't have to care about different pixel formats here
+template <>
+struct wxPixelDataOut<wxImage>
+{
+ // NB: this is a template class even though it doesn't use its template
+ // parameter because otherwise wxPixelData couldn't compile
+ template <class dummyPixelFormat>
+ class wxPixelDataIn : public wxPixelDataBase
{
- m_ptr = m_data->GetPixels();
- }
+ public:
+ // the type of the class we're working with
+ typedef wxImage ImageType;
- // default copy ctor, assignment operator and dtor are ok
+ // the iterator which should be used for working with data in this
+ // format
+ class Iterator
+ {
+ public:
+ // the pixel format we use
+ typedef wxImagePixelFormat PixelFormat;
+
+ // the type of the pixel components
+ typedef typename dummyPixelFormat::ChannelType ChannelType;
+
+ // the pixel data we're working with
+ typedef
+ wxPixelDataOut<wxImage>::wxPixelDataIn<PixelFormat> PixelData;
+
+ // go back to (0, 0)
+ void Reset(const PixelData& data)
+ {
+ *this = data.GetPixels();
+ }
+
+ // creates the iterator pointing to the beginning of data
+ Iterator(PixelData& data)
+ {
+ Reset(data);
+ }
+
+ // creates the iterator initially pointing to the image origin
+ Iterator(const wxImage& image)
+ {
+ m_pRGB = image.GetData();
+
+ if ( image.HasAlpha() )
+ {
+ m_pAlpha = image.GetAlpha();
+ }
+ else // alpha is not used at all
+ {
+ m_pAlpha = NULL;
+ }
+ }
+
+ // true if the iterator is valid
+ bool IsOk() const { return m_pRGB != NULL; }
+
+
+ // navigation
+ // ----------
+
+ // advance the iterator to the next pixel, prefix version
+ Iterator& operator++()
+ {
+ m_pRGB += PixelFormat::SizePixel;
+ if ( m_pAlpha )
+ ++m_pAlpha;
+
+ return *this;
+ }
+
+ // postfix (hence less efficient -- don't use it unless you
+ // absolutely must) version
+ Iterator operator++(int)
+ {
+ Iterator p(*this);
+ ++*this;
+ return p;
+ }
+
+ // move x pixels to the right and y down
+ //
+ // note that the rows don't wrap!
+ void Offset(const PixelData& data, int x, int y)
+ {
+ m_pRGB += data.GetRowStride()*y + PixelFormat::SizePixel*x;
+ if ( m_pAlpha )
+ m_pAlpha += data.GetWidth() + x;
+ }
+
+ // move x pixels to the right (again, no row wrapping)
+ void OffsetX(const PixelData& WXUNUSED(data), int x)
+ {
+ m_pRGB += PixelFormat::SizePixel*x;
+ if ( m_pAlpha )
+ m_pAlpha += x;
+ }
+
+ // move y rows to the bottom
+ void OffsetY(const PixelData& data, int y)
+ {
+ m_pRGB += data.GetRowStride()*y;
+ if ( m_pAlpha )
+ m_pAlpha += data.GetWidth();
+ }
+
+ // go to the given position
+ void MoveTo(const PixelData& data, int x, int y)
+ {
+ Reset(data);
+ Offset(data, x, y);
+ }
+
+
+ // data access
+ // -----------
+
+ // access to invidividual colour components
+ ChannelType& Red() { return m_pRGB[PixelFormat::RED]; }
+ ChannelType& Green() { return m_pRGB[PixelFormat::GREEN]; }
+ ChannelType& Blue() { return m_pRGB[PixelFormat::BLUE]; }
+ ChannelType& Alpha() { return *m_pAlpha; }
+
+ // private: -- see comment in the beginning of the file
+
+ // pointer into RGB buffer
+ unsigned char *m_pRGB;
+
+ // pointer into alpha buffer or NULL if alpha isn't used
+ unsigned char *m_pAlpha;
+ };
+
+ // initializes us with the data of the given image
+ wxPixelDataIn(ImageType& image) : m_image(image), m_pixels(image)
+ {
+ m_width = image.GetWidth();
+ m_height = image.GetHeight();
+ m_stride = Iterator::SizePixel * m_width;
+ }
-
- // navigation
- // ----------
+ // initializes us with the given region of the specified image
+ wxPixelDataIn(ImageType& image,
+ const wxPoint& pt,
+ const wxSize& sz) : m_image(image), m_pixels(image)
+ {
+ m_stride = Iterator::SizePixel * m_width;
- // move x pixels to the right and y down
- //
- // note that the rows don't wrap!
- void Offset(int x, int y)
- {
- m_ptr += m_data->GetRowStride()*y + m_data->GetByPP()*x;
- }
+ InitRect(pt, sz);
+ }
- // move x pixels to the right (again, no row wrapping)
- void OffsetX(int x)
- {
- m_ptr += m_data->GetByPP()*x;
- }
+ // initializes us with the given region of the specified image
+ wxPixelDataIn(ImageType& image,
+ const wxRect& rect) : m_image(image), m_pixels(image)
+ {
+ m_stride = Iterator::SizePixel * m_width;
- // move y rows to the bottom
- void OffsetY(int y)
- {
- m_ptr += m_data->GetRowStride()*y;
- }
+ InitRect(rect.GetPosition(), rect.GetSize());
+ }
- // go back to (0, 0)
- void Reset()
- {
- m_ptr = m_data->GetPixels();
- }
+ // we evaluate to true only if we could get access to bitmap data
+ // successfully
+ operator bool() const { return m_pixels.IsOk(); }
- // go to the given position
- void MoveTo(int x, int y)
- {
- Reset();
- Offset(x, y);
- }
+ // get the iterator pointing to the origin
+ Iterator GetPixels() const { return m_pixels; }
- // same as OffsetX(1) for convenience
- wxRawBitmapIterator& operator++()
- {
- OffsetX(1);
- return *this;
- }
+ private:
+ void InitRect(const wxPoint& pt, const wxSize& sz)
+ {
+ m_width = sz.x;
+ m_height = sz.y;
- // postfix (hence less efficient) version
- wxRawBitmapIterator operator++(int)
- {
- wxRawBitmapIterator p(*this);
- OffsetX(1);
- return p;
- }
+ m_ptOrigin = pt;
+ m_pixels.Offset(*this, pt.x, pt.y);
+ }
- // data access
- // -----------
+ // the image we're working with
+ ImageType& m_image;
- // DIBs store data in BGR format, i.e. "little endian" RGB
- enum
- {
-#ifdef __WXMSW__
- BLUE, GREEN, RED,
-#else // !__WXMSW__
- RED, GREEN, BLUE,
-#endif // __WXMSW__/!__WXMSW__
- ALPHA
+ // the iterator pointing to the image origin
+ Iterator m_pixels;
};
+};
+#endif //wxUSE_IMAGE
- // access to invidividual colour components
- unsigned char& Red() { return m_ptr[RED]; }
- unsigned char& Green() { return m_ptr[GREEN]; }
- unsigned char& Blue() { return m_ptr[BLUE]; }
- unsigned char& Alpha() { return m_ptr[ALPHA]; }
+#if wxUSE_GUI
+// wxPixelData specialization for wxBitmap: here things are more interesting as
+// we also have to support different pixel formats
+template <>
+struct wxPixelDataOut<wxBitmap>
+{
+ template <class Format>
+ class wxPixelDataIn : public wxPixelDataBase
+ {
+ public:
+ // the type of the class we're working with
+ typedef wxBitmap ImageType;
- // address the pixel contents directly
- //
- // warning: the format is platform dependent
- wxUint32& Data() { return *(wxUint32 *)m_ptr; }
+ class Iterator
+ {
+ public:
+ // the pixel format we use
+ typedef Format PixelFormat;
+
+ // the type of the pixel components
+ typedef typename PixelFormat::ChannelType ChannelType;
+
+ // the pixel data we're working with
+ typedef wxPixelDataOut<wxBitmap>::wxPixelDataIn<Format> PixelData;
+
+
+ // go back to (0, 0)
+ void Reset(const PixelData& data)
+ {
+ *this = data.GetPixels();
+ }
+
+ // initializes the iterator to point to the origin of the given
+ // pixel data
+ Iterator(PixelData& data)
+ {
+ Reset(data);
+ }
+
+ // initializes the iterator to point to the origin of the given
+ // bitmap
+ Iterator(wxBitmap& bmp, PixelData& data)
+ {
+ // using cast here is ugly but it should be safe as
+ // GetRawData() real return type should be consistent with
+ // BitsPerPixel (which is in turn defined by ChannelType) and
+ // this is the only thing we can do without making GetRawData()
+ // a template function which is undesirable
+ m_ptr = (ChannelType *)
+ bmp.GetRawData(data, PixelFormat::BitsPerPixel);
+ }
+
+ // return true if this iterator is valid
+ bool IsOk() const { return m_ptr != NULL; }
+
+
+ // navigation
+ // ----------
+
+ // advance the iterator to the next pixel, prefix version
+ Iterator& operator++()
+ {
+ m_ptr += PixelFormat::SizePixel;
+
+ return *this;
+ }
+
+ // postfix (hence less efficient -- don't use it unless you
+ // absolutely must) version
+ Iterator operator++(int)
+ {
+ Iterator p(*this);
+ ++*this;
+ return p;
+ }
+
+ // move x pixels to the right and y down
+ //
+ // note that the rows don't wrap!
+ void Offset(const PixelData& data, int x, int y)
+ {
+ m_ptr += data.GetRowStride()*y + PixelFormat::SizePixel*x;
+ }
+
+ // move x pixels to the right (again, no row wrapping)
+ void OffsetX(const PixelData& WXUNUSED(data), int x)
+ {
+ m_ptr += PixelFormat::SizePixel*x;
+ }
+
+ // move y rows to the bottom
+ void OffsetY(const PixelData& data, int y)
+ {
+ m_ptr += data.GetRowStride()*y;
+ }
+
+ // go to the given position
+ void MoveTo(const PixelData& data, int x, int y)
+ {
+ Reset(data);
+ Offset(data, x, y);
+ }
+
+
+ // data access
+ // -----------
+
+ // access to invidividual colour components
+ ChannelType& Red() { return m_ptr[PixelFormat::RED]; }
+ ChannelType& Green() { return m_ptr[PixelFormat::GREEN]; }
+ ChannelType& Blue() { return m_ptr[PixelFormat::BLUE]; }
+ ChannelType& Alpha() { return m_ptr[PixelFormat::ALPHA]; }
+
+ // address the pixel contents directly
+ //
+ // warning: the format is platform dependent
+ typename PixelFormat::PixelType& Data()
+ { return *(typename PixelFormat::PixelType *)m_ptr; }
+
+ // private: -- see comment in the beginning of the file
+
+ // for efficiency reasons this class should not have any other
+ // fields, otherwise it won't be put into a CPU register (as it
+ // should inside the inner loops) by some compilers, notably gcc
+ ChannelType *m_ptr;
+ };
+
+ // ctor associates this pointer with a bitmap and locks the bitmap for
+ // raw access, it will be unlocked only by our dtor and so these
+ // objects should normally be only created on the stack, i.e. have
+ // limited life-time
+ wxPixelDataIn(wxBitmap& bmp) : m_bmp(bmp), m_pixels(bmp, *this)
+ {
+ }
-// private: -- don't access these fields directly, same as as above
- unsigned char *m_ptr;
+ wxPixelDataIn(wxBitmap& bmp, const wxRect& rect)
+ : m_bmp(bmp), m_pixels(bmp, *this)
+ {
+ InitRect(rect.GetPosition(), rect.GetSize());
+ }
- const wxRawBitmapData *m_data;
-};
+ wxPixelDataIn(wxBitmap& bmp, const wxPoint& pt, const wxSize& sz)
+ : m_bmp(bmp), m_pixels(bmp, *this)
+ {
+ InitRect(pt, sz);
+ }
+ // we evaluate to true only if we could get access to bitmap data
+ // successfully
+ operator bool() const { return m_pixels.IsOk(); }
-// these macros are used to change the current location in the bitmap
-// ------------------------------------------------------------------
+ // get the iterator pointing to the origin
+ Iterator GetPixels() const { return m_pixels; }
-// move x pixels to the right and y down
-//
-// note that the rows don't wrap!
-#define wxBMP_OFFSET(p, x, y) \
- p.m_ptr += p.m_data->m_stride * (y) + p.m_data->m_bypp * (x)
+ // dtor unlocks the bitmap
+ ~wxPixelDataIn()
+ {
+ m_bmp.UngetRawData(*this);
+ }
-// move x pixels to the right (again, no row wrapping)
-#define wxBMP_OFFSET_X(p, x) p.m_ptr += p.m_data->m_bypp * (x)
+ // call this to indicate that we should use the alpha channel
+ void UseAlpha() { m_bmp.UseAlpha(); }
-// move y rows to the bottom
-#define wxBMP_OFFSET_Y(p, y) p.m_ptr += p.m_data->m_stride * (y)
+ // private: -- see comment in the beginning of the file
+ // the bitmap we're associated with
+ wxBitmap m_bmp;
+ // the iterator pointing to the image origin
+ Iterator m_pixels;
-// these macros are used to work with the pixel values
-//
-// all of them can be used as either lvalues or rvalues.
-// ----------------------------------------------------
+ private:
+ void InitRect(const wxPoint& pt, const wxSize& sz)
+ {
+ m_pixels.Offset(*this, pt.x, pt.y);
+
+ m_ptOrigin = pt;
+ m_width = sz.x;
+ m_height = sz.y;
+ }
+ };
+};
+#endif //wxUSE_GUI
-#define wxBMP_RED(p) (p.m_ptr[wxRawBitmapIterator::RED])
-#define wxBMP_GREEN(p) (p.m_ptr[wxRawBitmapIterator::GREEN])
-#define wxBMP_BLUE(p) (p.m_ptr[wxRawBitmapIterator::BLUE])
+template <class Image, class PixelFormat = wxPixelFormatFor<Image> >
+class wxPixelData :
+ public wxPixelDataOut<Image>::template wxPixelDataIn<PixelFormat>
+{
+public:
+ typedef
+ typename wxPixelDataOut<Image>::template wxPixelDataIn<PixelFormat>
+ Base;
+
+ wxPixelData(Image& image) : Base(image) { }
-#define wxBMP_ALPHA(p) (p.m_ptr[wxRawBitmapIterator::ALPHA])
+ wxPixelData(Image& i, const wxRect& rect) : Base(i, rect) { }
-// these macros are most efficient but return the buffer contents in
-// platform-specific format, e.g. RGB on all sane platforms and BGR under Win32
-#define wxBMP_RGB(p) *(wxUint32 *)(p.m_ptr)
-#define wxBMP_RGBA(p) *(wxUint32 *)(p.m_ptr)
+ wxPixelData(Image& i, const wxPoint& pt, const wxSize& sz)
+ : Base(i, pt, sz)
+ {
+ }
+};
+
+
+// some "predefined" pixel data classes
+#if wxUSE_IMAGE
+typedef wxPixelData<wxImage> wxImagePixelData;
+#endif //wxUSE_IMAGE
+#if wxUSE_GUI
+typedef wxPixelData<wxBitmap, wxNativePixelFormat> wxNativePixelData;
+typedef wxPixelData<wxBitmap, wxAlphaPixelFormat> wxAlphaPixelData;
+
+#endif //wxUSE_GUI
+
+// ----------------------------------------------------------------------------
+// wxPixelIterator
+// ----------------------------------------------------------------------------
+
+/*
+ wxPixel::Iterator represents something which points to the pixel data and
+ allows us to iterate over it. In the simplest case of wxBitmap it is,
+ indeed, just a pointer, but it can be something more complicated and,
+ moreover, you are free to specialize it for other image classes and bitmap
+ formats.
+
+ Note that although it would have been much more intuitive to have a real
+ class here instead of what we have now, this class would need two template
+ parameters, and this can't be done because we'd need compiler support for
+ partial template specialization then and neither VC6 nor VC7 provide it.
+ */
+template < class Image, class PixelFormat = wxPixelFormatFor<Image> >
+struct wxPixelIterator : public wxPixelData<Image, PixelFormat>::Iterator
+{
+};
#endif // _WX_RAWBMP_H_BASE_