Files
wxWidgets/src/msw/dib.cpp
Vadim Zeitlin 20af6fd5d3 Remove wxDIB::m_hasAlpha from wxMSW.
This field can't be set reliably as we don't know if LoadImage() Windows
function loaded an 0RGB or an RGB bitmap so remove it completely to avoid the
risk of using it wrongly.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@65899 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
2010-10-24 22:40:27 +00:00

816 lines
24 KiB
C++

///////////////////////////////////////////////////////////////////////////////
// Name: src/msw/dib.cpp
// Purpose: implements wxDIB class
// Author: Vadim Zeitlin
// Modified by:
// Created: 03.03.03 (replaces the old file with the same name)
// RCS-ID: $Id$
// Copyright: (c) 2003 Vadim Zeitlin <vadim@wxwindows.org>
// Licence: wxWindows licence
///////////////////////////////////////////////////////////////////////////////
/*
TODO: support for palettes is very incomplete, several functions simply
ignore them (we should select and realize the palette, if any, before
caling GetDIBits() in the DC we use with it.
*/
// ============================================================================
// declarations
// ============================================================================
// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------
// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"
#ifdef __BORLANDC__
#pragma hdrstop
#endif
#if wxUSE_WXDIB
#ifndef WX_PRECOMP
#include "wx/string.h"
#include "wx/log.h"
#include "wx/intl.h"
#include "wx/bitmap.h"
#include "wx/image.h"
#endif //WX_PRECOMP
#include "wx/file.h"
#include <stdio.h>
#include <stdlib.h>
#if !defined(__MWERKS__)
#include <memory.h>
#endif
#include "wx/msw/dib.h"
#ifdef __WXWINCE__
#include <shellapi.h> // for SHLoadDIBitmap()
#endif
// ----------------------------------------------------------------------------
// private functions
// ----------------------------------------------------------------------------
// calculate the number of palette entries needed for the bitmap with this
// number of bits per pixel
static inline WORD GetNumberOfColours(WORD bitsPerPixel)
{
// only 1, 4 and 8bpp bitmaps use palettes (well, they could be used with
// 24bpp ones too but we don't support this as I think it's quite uncommon)
return (WORD)(bitsPerPixel <= 8 ? 1 << bitsPerPixel : 0);
}
// wrapper around ::GetObject() for DIB sections
static inline bool GetDIBSection(HBITMAP hbmp, DIBSECTION *ds)
{
// note that at least under Win9x (this doesn't seem to happen under Win2K
// but this doesn't mean anything, of course), GetObject() may return
// sizeof(DIBSECTION) for a bitmap which is *not* a DIB section and the way
// to check for it is by looking at the bits pointer
return ::GetObject(hbmp, sizeof(DIBSECTION), ds) == sizeof(DIBSECTION) &&
ds->dsBm.bmBits;
}
// ============================================================================
// implementation
// ============================================================================
// ----------------------------------------------------------------------------
// wxDIB creation
// ----------------------------------------------------------------------------
bool wxDIB::Create(int width, int height, int depth)
{
// we don't support formats using palettes right now so we only create
// either 24bpp (RGB) or 32bpp (RGBA) bitmaps
wxASSERT_MSG( depth, wxT("invalid image depth in wxDIB::Create()") );
if ( depth < 24 )
depth = 24;
// allocate memory for bitmap structures
BITMAPINFO info;
wxZeroMemory(info);
info.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
info.bmiHeader.biWidth = width;
// we use positive height here which corresponds to a DIB with normal, i.e.
// bottom to top, order -- normally using negative height (which means
// reversed for MS and hence natural for all the normal people top to
// bottom line scan order) could be used to avoid the need for the image
// reversal in Create(image) but this doesn't work under NT, only Win9x!
info.bmiHeader.biHeight = height;
info.bmiHeader.biPlanes = 1;
info.bmiHeader.biBitCount = (WORD)depth;
info.bmiHeader.biSizeImage = GetLineSize(width, depth)*height;
m_handle = ::CreateDIBSection
(
0, // hdc (unused with DIB_RGB_COLORS)
&info, // bitmap description
DIB_RGB_COLORS, // use RGB, not palette
&m_data, // [out] DIB bits
NULL, // don't use file mapping
0 // file mapping offset (not used here)
);
if ( !m_handle )
{
wxLogLastError(wxT("CreateDIBSection"));
return false;
}
m_width = width;
m_height = height;
m_depth = depth;
return true;
}
bool wxDIB::Create(const wxBitmap& bmp)
{
wxCHECK_MSG( bmp.Ok(), false, wxT("wxDIB::Create(): invalid bitmap") );
if ( !Create(GetHbitmapOf(bmp)) )
return false;
return true;
}
bool wxDIB::Create(HBITMAP hbmp)
{
// this bitmap could already be a DIB section in which case we don't need
// to convert it to DIB
DIBSECTION ds;
if ( GetDIBSection(hbmp, &ds) )
{
m_handle = hbmp;
// wxBitmap will free it, not we
m_ownsHandle = false;
// copy all the bitmap parameters too as we have them now anyhow
m_width = ds.dsBm.bmWidth;
m_height = ds.dsBm.bmHeight;
m_depth = ds.dsBm.bmBitsPixel;
m_data = ds.dsBm.bmBits;
}
else // no, it's a DDB -- convert it to DIB
{
// prepare all the info we need
BITMAP bm;
if ( !::GetObject(hbmp, sizeof(bm), &bm) )
{
wxLogLastError(wxT("GetObject(bitmap)"));
return false;
}
int d = bm.bmBitsPixel;
if ( d <= 0 )
d = wxDisplayDepth();
if ( !Create(bm.bmWidth, bm.bmHeight, d) || !CopyFromDDB(hbmp) )
return false;
}
return true;
}
// Windows CE doesn't have GetDIBits() so use an alternative implementation
// for it
//
// in fact I'm not sure if GetDIBits() is really much better than using
// BitBlt() like this -- it should be faster but I didn't do any tests, if
// anybody has time to do them and by chance finds that GetDIBits() is not
// much faster than BitBlt(), we could always use the Win CE version here
#ifdef __WXWINCE__
bool wxDIB::CopyFromDDB(HBITMAP hbmp)
{
MemoryHDC hdcSrc;
if ( !hdcSrc )
return false;
SelectInHDC selectSrc(hdcSrc, hbmp);
if ( !selectSrc )
return false;
MemoryHDC hdcDst;
if ( !hdcDst )
return false;
SelectInHDC selectDst(hdcDst, m_handle);
if ( !selectDst )
return false;
if ( !::BitBlt(
hdcDst,
0, 0, m_width, m_height,
hdcSrc,
0, 0,
SRCCOPY
) )
{
wxLogLastError(wxT("BitBlt(DDB -> DIB)"));
return false;
}
return true;
}
#else // !__WXWINCE__
bool wxDIB::CopyFromDDB(HBITMAP hbmp)
{
DIBSECTION ds;
if ( !GetDIBSection(m_handle, &ds) )
{
// we're sure that our handle is a DIB section, so this should work
wxFAIL_MSG( wxT("GetObject(DIBSECTION) unexpectedly failed") );
return false;
}
if ( !::GetDIBits
(
ScreenHDC(), // the DC to use
hbmp, // the source DDB
0, // first scan line
m_height, // number of lines to copy
ds.dsBm.bmBits, // pointer to the buffer
(BITMAPINFO *)&ds.dsBmih, // bitmap header
DIB_RGB_COLORS // and not DIB_PAL_COLORS
) )
{
wxLogLastError(wxT("GetDIBits()"));
return false;
}
return true;
}
#endif // __WXWINCE__/!__WXWINCE__
// ----------------------------------------------------------------------------
// Loading/saving the DIBs
// ----------------------------------------------------------------------------
bool wxDIB::Load(const wxString& filename)
{
#ifdef __WXWINCE__
m_handle = SHLoadDIBitmap(filename);
#else // !__WXWINCE__
m_handle = (HBITMAP)::LoadImage
(
wxGetInstance(),
filename.t_str(),
IMAGE_BITMAP,
0, 0, // don't specify the size
LR_CREATEDIBSECTION | LR_LOADFROMFILE
);
#endif // __WXWINCE__
if ( !m_handle )
{
wxLogLastError(wxT("Loading DIB from file"));
return false;
}
return true;
}
bool wxDIB::Save(const wxString& filename)
{
wxCHECK_MSG( m_handle, false, wxT("wxDIB::Save(): invalid object") );
#if wxUSE_FILE
wxFile file(filename, wxFile::write);
bool ok = file.IsOpened();
if ( ok )
{
DIBSECTION ds;
if ( !GetDIBSection(m_handle, &ds) )
{
wxLogLastError(wxT("GetObject(hDIB)"));
}
else
{
BITMAPFILEHEADER bmpHdr;
wxZeroMemory(bmpHdr);
const size_t sizeHdr = ds.dsBmih.biSize;
const size_t sizeImage = ds.dsBmih.biSizeImage;
bmpHdr.bfType = 0x4d42; // 'BM' in little endian
bmpHdr.bfOffBits = sizeof(BITMAPFILEHEADER) + ds.dsBmih.biSize;
bmpHdr.bfSize = bmpHdr.bfOffBits + sizeImage;
// first write the file header, then the bitmap header and finally the
// bitmap data itself
ok = file.Write(&bmpHdr, sizeof(bmpHdr)) == sizeof(bmpHdr) &&
file.Write(&ds.dsBmih, sizeHdr) == sizeHdr &&
file.Write(ds.dsBm.bmBits, sizeImage) == sizeImage;
}
}
#else // !wxUSE_FILE
bool ok = false;
#endif // wxUSE_FILE/!wxUSE_FILE
if ( !ok )
{
wxLogError(_("Failed to save the bitmap image to file \"%s\"."),
filename.c_str());
}
return ok;
}
// ----------------------------------------------------------------------------
// wxDIB accessors
// ----------------------------------------------------------------------------
void wxDIB::DoGetObject() const
{
// only do something if we have a valid DIB but we don't [yet] have valid
// data
if ( m_handle && !m_data )
{
// although all the info we need is in BITMAP and so we don't really
// need DIBSECTION we still ask for it as modifying the bit values only
// works for the real DIBs and not for the bitmaps and it's better to
// check for this now rather than trying to find out why it doesn't
// work later
DIBSECTION ds;
if ( !GetDIBSection(m_handle, &ds) )
{
wxLogLastError(wxT("GetObject(hDIB)"));
return;
}
wxDIB *self = wxConstCast(this, wxDIB);
self->m_width = ds.dsBm.bmWidth;
self->m_height = ds.dsBm.bmHeight;
self->m_depth = ds.dsBm.bmBitsPixel;
self->m_data = ds.dsBm.bmBits;
}
}
// ----------------------------------------------------------------------------
// DDB <-> DIB conversions
// ----------------------------------------------------------------------------
#ifndef __WXWINCE__
HBITMAP wxDIB::CreateDDB(HDC hdc) const
{
wxCHECK_MSG( m_handle, 0, wxT("wxDIB::CreateDDB(): invalid object") );
DIBSECTION ds;
if ( !GetDIBSection(m_handle, &ds) )
{
wxLogLastError(wxT("GetObject(hDIB)"));
return 0;
}
// how many colours are we going to have in the palette?
DWORD biClrUsed = ds.dsBmih.biClrUsed;
if ( !biClrUsed )
{
// biClrUsed field might not be set
biClrUsed = GetNumberOfColours(ds.dsBmih.biBitCount);
}
if ( !biClrUsed )
{
return ConvertToBitmap((BITMAPINFO *)&ds.dsBmih, hdc, ds.dsBm.bmBits);
}
else
{
// fake a BITMAPINFO w/o bits, just the palette info
wxCharBuffer bmi(sizeof(BITMAPINFO) + (biClrUsed - 1)*sizeof(RGBQUAD));
BITMAPINFO *pBmi = (BITMAPINFO *)bmi.data();
MemoryHDC hDC;
// get the colour table
SelectInHDC sDC(hDC, m_handle);
::GetDIBColorTable(hDC, 0, biClrUsed, pBmi->bmiColors);
memcpy(&pBmi->bmiHeader, &ds.dsBmih, ds.dsBmih.biSize);
return ConvertToBitmap(pBmi, hdc, ds.dsBm.bmBits);
}
}
/* static */
HBITMAP wxDIB::ConvertToBitmap(const BITMAPINFO *pbmi, HDC hdc, void *bits)
{
wxCHECK_MSG( pbmi, 0, wxT("invalid DIB in ConvertToBitmap") );
// here we get BITMAPINFO struct followed by the actual bitmap bits and
// BITMAPINFO starts with BITMAPINFOHEADER followed by colour info
const BITMAPINFOHEADER *pbmih = &pbmi->bmiHeader;
// get the pointer to the start of the real image data if we have a plain
// DIB and not a DIB section (in the latter case the pointer must be passed
// to us by the caller)
if ( !bits )
{
// we must skip over the colour table to get to the image data
//
// colour table either has the real colour data in which case its
// number of entries is given by biClrUsed or is used for masks to be
// used for extracting colour information from true colour bitmaps in
// which case it always have exactly 3 DWORDs
int numColors;
switch ( pbmih->biCompression )
{
case BI_BITFIELDS:
numColors = 3;
break;
case BI_RGB:
// biClrUsed has the number of colors but it may be not initialized at
// all
numColors = pbmih->biClrUsed;
if ( !numColors )
{
numColors = GetNumberOfColours(pbmih->biBitCount);
}
break;
default:
// no idea how it should be calculated for the other cases
numColors = 0;
}
bits = (char *)pbmih + sizeof(*pbmih) + numColors*sizeof(RGBQUAD);
}
HBITMAP hbmp = ::CreateDIBitmap
(
hdc ? hdc // create bitmap compatible
: (HDC) ScreenHDC(), // with this DC
pbmih, // used to get size &c
CBM_INIT, // initialize bitmap bits too
bits, // ... using this data
pbmi, // this is used for palette only
DIB_RGB_COLORS // direct or indexed palette?
);
if ( !hbmp )
{
wxLogLastError(wxT("CreateDIBitmap"));
}
return hbmp;
}
/* static */
size_t wxDIB::ConvertFromBitmap(BITMAPINFO *pbi, HBITMAP hbmp)
{
wxASSERT_MSG( hbmp, wxT("invalid bmp can't be converted to DIB") );
// prepare all the info we need
BITMAP bm;
if ( !::GetObject(hbmp, sizeof(bm), &bm) )
{
wxLogLastError(wxT("GetObject(bitmap)"));
return 0;
}
// we need a BITMAPINFO anyhow and if we're not given a pointer to it we
// use this one
BITMAPINFO bi2;
const bool wantSizeOnly = pbi == NULL;
if ( wantSizeOnly )
pbi = &bi2;
// just for convenience
const int h = bm.bmHeight;
// init the header
BITMAPINFOHEADER& bi = pbi->bmiHeader;
wxZeroMemory(bi);
bi.biSize = sizeof(BITMAPINFOHEADER);
bi.biWidth = bm.bmWidth;
bi.biHeight = h;
bi.biPlanes = 1;
bi.biBitCount = bm.bmBitsPixel;
// memory we need for BITMAPINFO only
DWORD dwLen = bi.biSize + GetNumberOfColours(bm.bmBitsPixel) * sizeof(RGBQUAD);
// get either just the image size or the image bits
if ( !::GetDIBits
(
ScreenHDC(), // the DC to use
hbmp, // the source DDB
0, // first scan line
h, // number of lines to copy
wantSizeOnly ? NULL // pointer to the buffer or
: (char *)pbi + dwLen, // NULL if we don't have it
pbi, // bitmap header
DIB_RGB_COLORS // or DIB_PAL_COLORS
) )
{
wxLogLastError(wxT("GetDIBits()"));
return 0;
}
// return the total size
return dwLen + bi.biSizeImage;
}
/* static */
HGLOBAL wxDIB::ConvertFromBitmap(HBITMAP hbmp)
{
// first calculate the size needed
const size_t size = ConvertFromBitmap(NULL, hbmp);
if ( !size )
{
// conversion to DDB failed?
return NULL;
}
HGLOBAL hDIB = ::GlobalAlloc(GMEM_MOVEABLE, size);
if ( !hDIB )
{
// this is an error which does risk to happen especially under Win9x
// and which the user may understand so let him know about it
wxLogError(_("Failed to allocate %luKb of memory for bitmap data."),
(unsigned long)(size / 1024));
return NULL;
}
if ( !ConvertFromBitmap((BITMAPINFO *)(void *)GlobalPtrLock(hDIB), hbmp) )
{
// this really shouldn't happen... it worked the first time, why not
// now?
wxFAIL_MSG( wxT("wxDIB::ConvertFromBitmap() unexpectedly failed") );
return NULL;
}
return hDIB;
}
#endif // __WXWINCE__
// ----------------------------------------------------------------------------
// palette support
// ----------------------------------------------------------------------------
#if wxUSE_PALETTE
wxPalette *wxDIB::CreatePalette() const
{
// GetDIBColorTable not available in eVC3
#if defined(_WIN32_WCE) && _WIN32_WCE < 400
return NULL;
#else
wxCHECK_MSG( m_handle, NULL, wxT("wxDIB::CreatePalette(): invalid object") );
DIBSECTION ds;
if ( !GetDIBSection(m_handle, &ds) )
{
wxLogLastError(wxT("GetObject(hDIB)"));
return 0;
}
// how many colours are we going to have in the palette?
DWORD biClrUsed = ds.dsBmih.biClrUsed;
if ( !biClrUsed )
{
// biClrUsed field might not be set
biClrUsed = GetNumberOfColours(ds.dsBmih.biBitCount);
}
if ( !biClrUsed )
{
// bitmaps of this depth don't have palettes at all
//
// NB: another possibility would be to return
// GetStockObject(DEFAULT_PALETTE) or even CreateHalftonePalette()?
return NULL;
}
MemoryHDC hDC;
// LOGPALETTE struct has only 1 element in palPalEntry array, we're
// going to have biClrUsed of them so add necessary space
LOGPALETTE *pPalette = (LOGPALETTE *)
malloc(sizeof(LOGPALETTE) + (biClrUsed - 1)*sizeof(PALETTEENTRY));
wxCHECK_MSG( pPalette, NULL, wxT("out of memory") );
// initialize the palette header
pPalette->palVersion = 0x300; // magic number, not in docs but works
pPalette->palNumEntries = (WORD)biClrUsed;
// and the colour table
wxCharBuffer rgb(sizeof(RGBQUAD) * biClrUsed);
RGBQUAD *pRGB = (RGBQUAD*)rgb.data();
SelectInHDC selectHandle(hDC, m_handle);
::GetDIBColorTable(hDC, 0, biClrUsed, pRGB);
for ( DWORD i = 0; i < biClrUsed; i++, pRGB++ )
{
pPalette->palPalEntry[i].peRed = pRGB->rgbRed;
pPalette->palPalEntry[i].peGreen = pRGB->rgbGreen;
pPalette->palPalEntry[i].peBlue = pRGB->rgbBlue;
pPalette->palPalEntry[i].peFlags = 0;
}
HPALETTE hPalette = ::CreatePalette(pPalette);
free(pPalette);
if ( !hPalette )
{
wxLogLastError(wxT("CreatePalette"));
return NULL;
}
wxPalette *palette = new wxPalette;
palette->SetHPALETTE((WXHPALETTE)hPalette);
return palette;
#endif
}
#endif // wxUSE_PALETTE
// ----------------------------------------------------------------------------
// wxImage support
// ----------------------------------------------------------------------------
#if wxUSE_IMAGE
bool wxDIB::Create(const wxImage& image)
{
wxCHECK_MSG( image.Ok(), false, wxT("invalid wxImage in wxDIB ctor") );
const int h = image.GetHeight();
const int w = image.GetWidth();
// if we have alpha channel, we need to create a 32bpp RGBA DIB, otherwise
// a 24bpp RGB is sufficient
const bool hasAlpha = image.HasAlpha();
const int bpp = hasAlpha ? 32 : 24;
if ( !Create(w, h, bpp) )
return false;
// DIBs are stored in bottom to top order (see also the comment above in
// Create()) so we need to copy bits line by line and starting from the end
const int srcBytesPerLine = w * 3;
const int dstBytesPerLine = GetLineSize(w, bpp);
const unsigned char *src = image.GetData() + ((h - 1) * srcBytesPerLine);
const unsigned char *alpha = hasAlpha ? image.GetAlpha() + (h - 1)*w
: NULL;
unsigned char *dstLineStart = (unsigned char *)m_data;
for ( int y = 0; y < h; y++ )
{
// copy one DIB line
unsigned char *dst = dstLineStart;
if ( alpha )
{
for ( int x = 0; x < w; x++ )
{
// RGB order is reversed, and we need to premultiply
// all channels by alpha value for use with ::AlphaBlend.
const unsigned char a = *alpha++;
*dst++ = (unsigned char)((src[2] * a + 127) / 255);
*dst++ = (unsigned char)((src[1] * a + 127) / 255);
*dst++ = (unsigned char)((src[0] * a + 127) / 255);
*dst++ = a;
src += 3;
}
}
else // no alpha channel
{
for ( int x = 0; x < w; x++ )
{
// RGB order is reversed.
*dst++ = src[2];
*dst++ = src[1];
*dst++ = src[0];
src += 3;
}
}
// pass to the previous line in the image
src -= 2*srcBytesPerLine;
if ( alpha )
alpha -= 2*w;
// and to the next one in the DIB
dstLineStart += dstBytesPerLine;
}
return true;
}
wxImage wxDIB::ConvertToImage() const
{
wxCHECK_MSG( IsOk(), wxNullImage,
wxT("can't convert invalid DIB to wxImage") );
// create the wxImage object
const int w = GetWidth();
const int h = GetHeight();
wxImage image(w, h, false /* don't bother clearing memory */);
if ( !image.Ok() )
{
wxFAIL_MSG( wxT("could not allocate data for image") );
return wxNullImage;
}
const int bpp = GetDepth();
bool hasAlpha = false;
if ( bpp == 32 )
{
// 32 bit bitmaps may be either 0RGB or ARGB and we don't know in
// advance which one do we have so suppose we have alpha of them and
// get rid of it later if it turns out we didn't.
image.SetAlpha();
}
// this is the same loop as in Create() just above but with copy direction
// reversed
const int dstBytesPerLine = w * 3;
const int srcBytesPerLine = GetLineSize(w, bpp);
unsigned char *dst = image.GetData() + ((h - 1) * dstBytesPerLine);
unsigned char *alpha = image.HasAlpha() ? image.GetAlpha() + (h - 1)*w
: NULL;
const unsigned char *srcLineStart = (unsigned char *)GetData();
for ( int y = 0; y < h; y++ )
{
// copy one DIB line
const unsigned char *src = srcLineStart;
for ( int x = 0; x < w; x++ )
{
dst[2] = *src++;
dst[1] = *src++;
dst[0] = *src++;
if ( bpp == 32 )
{
// wxImage uses non premultiplied alpha so undo
// premultiplication done in Create() above
const unsigned char a = *src;
*alpha++ = a;
if ( a > 0 )
{
dst[0] = (dst[0] * 255) / a;
dst[1] = (dst[1] * 255) / a;
dst[2] = (dst[2] * 255) / a;
hasAlpha = true;
}
src++;
}
dst += 3;
}
// pass to the previous line in the image
dst -= 2*dstBytesPerLine;
if ( alpha )
alpha -= 2*w;
// and to the next one in the DIB
srcLineStart += srcBytesPerLine;
}
if ( !hasAlpha && image.HasAlpha() )
image.ClearAlpha();
return image;
}
#endif // wxUSE_IMAGE
#endif // wxUSE_WXDIB