Added gifdecod.cpp
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@3407 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
This commit is contained in:
Julian Smart
606
src/common/gifdecod.cpp
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606
src/common/gifdecod.cpp
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/////////////////////////////////////////////////////////////////////////////
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// Name: gifdecod.cpp
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// Purpose: wxGIFDecoder, GIF reader for wxImage and wxAnimation
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// Author: Guillermo Rodriguez Garcia <guille@iies.es>
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// Version: 3.01
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// Last rev: 1999/08/14
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// Copyright: (c) Guillermo Rodriguez Garcia
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// Licence: wxWindows licence
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/////////////////////////////////////////////////////////////////////////////
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#ifdef __GNUG__
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#pragma implementation "gifdecod.h"
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#endif
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// For compilers that support precompilation, includes "wx.h".
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#include "wx/wxprec.h"
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#ifdef __BORLANDC__
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# pragma hdrstop
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#endif
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#ifndef WX_PRECOMP
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# include "wx/setup.h"
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#endif
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#if wxUSE_STREAMS
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#include <stdlib.h>
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#include <string.h>
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#include "wx/defs.h"
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#include "wx/gifdecod.h"
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//---------------------------------------------------------------------------
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// wxGIFDecoder constructor and destructor
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//---------------------------------------------------------------------------
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wxGIFDecoder::wxGIFDecoder(wxInputStream *s, bool anim)
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{
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m_f = s;
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m_anim = anim;
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m_background = -1;
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m_screenw = 0;
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m_screenh = 0;
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m_pimage = NULL;
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m_pfirst = NULL;
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m_plast = NULL;
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m_image = 0;
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m_nimages = 0;
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}
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wxGIFDecoder::~wxGIFDecoder()
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{
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Destroy();
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}
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void wxGIFDecoder::Destroy()
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{
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IMAGEN *pimg, *paux;
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pimg = m_pfirst;
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while (pimg != NULL)
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{
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paux = pimg->next;
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free(pimg->p);
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free(pimg->pal);
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free(pimg);
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pimg = paux;
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}
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}
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//---------------------------------------------------------------------------
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// Convert this image to a wxImage object
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//---------------------------------------------------------------------------
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// This function was designed by Vaclav Slavik
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bool wxGIFDecoder::ConvertToImage(wxImage *image) const
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{
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unsigned char *src, *dst, *pal;
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unsigned long i;
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int transparent;
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/* create the image */
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image->Create(GetWidth(), GetHeight());
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if (!image->Ok())
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return FALSE;
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pal = GetPalette();
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src = GetData();
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dst = image->GetData();
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transparent = GetTransparentColour();
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/* set transparent colour mask */
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if (transparent != -1)
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{
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for (i = 0; i < 256; i++)
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{
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if ((pal[3 * i + 0] == 255) &&
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(pal[3 * i + 1] == 0) &&
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(pal[3 * i + 2] == 255))
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{
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pal[3 * i + 2] = 254;
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}
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}
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pal[3 * transparent + 0] = 255,
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pal[3 * transparent + 1] = 0,
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pal[3 * transparent + 2] = 255;
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image->SetMaskColour(255, 0, 255);
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}
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else
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image->SetMask(FALSE);
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/* copy image data */
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for (i = 0; i < (GetWidth() * GetHeight()); i++, src++)
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{
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*(dst++) = pal[3 * (*src) + 0];
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*(dst++) = pal[3 * (*src) + 1];
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*(dst++) = pal[3 * (*src) + 2];
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}
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return TRUE;
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}
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//---------------------------------------------------------------------------
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// Data accessors
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//---------------------------------------------------------------------------
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// Get data for current frame
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int wxGIFDecoder::GetFrameIndex() const { return m_image; }
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unsigned char* wxGIFDecoder::GetData() const { return (m_pimage->p); }
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unsigned char* wxGIFDecoder::GetPalette() const { return (m_pimage->pal); }
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unsigned int wxGIFDecoder::GetWidth() const { return (m_pimage->w); }
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unsigned int wxGIFDecoder::GetHeight() const { return (m_pimage->h); }
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unsigned int wxGIFDecoder::GetTop() const { return (m_pimage->top); }
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unsigned int wxGIFDecoder::GetLeft() const { return (m_pimage->left); }
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int wxGIFDecoder::GetTransparentColour() const { return (m_pimage->transparent); }
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int wxGIFDecoder::GetDisposalMethod() const { return (m_pimage->disposal); }
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long wxGIFDecoder::GetDelay() const { return (m_pimage->delay); }
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// Get global data
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unsigned int wxGIFDecoder::GetLogicalScreenWidth() const { return m_screenw; }
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unsigned int wxGIFDecoder::GetLogicalScreenHeight() const { return m_screenh; }
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int wxGIFDecoder::GetBackgroundColour() const { return m_background; }
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int wxGIFDecoder::GetNumberOfFrames() const { return m_nimages; }
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bool wxGIFDecoder::IsAnimation() const { return (m_nimages > 1); }
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//---------------------------------------------------------------------------
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// Functions to move through the animation
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//---------------------------------------------------------------------------
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bool wxGIFDecoder::GoFirstFrame()
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{
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if (!IsAnimation())
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return FALSE;
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m_image = 1;
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m_pimage = m_pfirst;
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return TRUE;
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}
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bool wxGIFDecoder::GoLastFrame()
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{
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if (!IsAnimation())
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return FALSE;
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m_image = m_nimages;
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m_pimage = m_plast;
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return TRUE;
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}
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bool wxGIFDecoder::GoNextFrame(bool cyclic)
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{
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if (!IsAnimation())
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return FALSE;
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if ((m_image < m_nimages) || (cyclic))
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{
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m_pimage = m_pimage->next;
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m_image++;
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if (!m_pimage)
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{
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m_image = 1;
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m_pimage = m_pfirst;
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}
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return TRUE;
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}
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else
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return FALSE;
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}
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bool wxGIFDecoder::GoPrevFrame(bool cyclic)
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{
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if (!IsAnimation())
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return FALSE;
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if ((m_image > 1) || (cyclic))
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{
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m_pimage = m_pimage->prev;
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m_image--;
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if (!m_pimage)
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{
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m_image = m_nimages;
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m_pimage = m_plast;
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}
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return TRUE;
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}
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else
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return FALSE;
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}
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bool wxGIFDecoder::GoFrame(int which)
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{
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int i;
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if (!IsAnimation())
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return FALSE;
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if ((which >= 1) && (which <= m_nimages))
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{
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m_pimage = m_pfirst;
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for (i = 1; i < which; i++)
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m_pimage = m_pimage->next;
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return TRUE;
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}
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else
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return FALSE;
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}
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//---------------------------------------------------------------------------
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// GIF reading and decoding
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//---------------------------------------------------------------------------
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// getcode:
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// Reads the next code from the file stream, with size 'bits'
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//
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int wxGIFDecoder::getcode(int bits, int ab_fin)
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{
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unsigned int mask; /* bit mask */
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unsigned int code; /* code (result) */
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/* get remaining bits from last byte read */
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mask = (1 << bits) - 1;
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code = (m_lastbyte >> (8 - m_restbits)) & mask;
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/* keep reading new bytes while needed */
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while (bits > m_restbits)
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{
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/* if no bytes left in this block, read the next block */
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if (m_restbyte == 0)
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{
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m_restbyte = (unsigned char)m_f->GetC();
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/* Some encoders are a bit broken: instead of issuing
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* an end-of-image symbol (ab_fin) they come up with
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* a zero-length subblock!! We catch this here so
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* that the decoder sees an ab_fin code.
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*/
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if (m_restbyte == 0)
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{
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code = ab_fin;
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break;
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}
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}
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/* read next byte and isolate the bits we need */
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m_lastbyte = (unsigned char)m_f->GetC();
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mask = (1 << (bits - m_restbits)) - 1;
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code = code + ((m_lastbyte & mask) << m_restbits);
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m_restbyte--;
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/* adjust total number of bits extracted from the buffer */
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m_restbits = m_restbits + 8;
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}
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/* find number of bits remaining for next code */
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m_restbits = (m_restbits - bits);
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return code;
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}
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// dgif:
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// GIF decoding function. The initial code size (aka root size)
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// is 'bits'. Supports interlaced images (interl == 1).
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//
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int wxGIFDecoder::dgif(IMAGEN *img, int interl, int bits)
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{
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int ab_prefix[4096]; /* alphabet (prefixes) */
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int ab_tail[4096]; /* alphabet (tails) */
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int stack[4096]; /* decompression stack */
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int ab_clr; /* clear code */
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int ab_fin; /* end of info code */
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int ab_bits; /* actual symbol width, in bits */
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int ab_free; /* first free position in alphabet */
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int ab_max; /* last possible character in alphabet */
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int pass; /* pass number in interlaced images */
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int pos; /* index into decompresion stack */
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unsigned int x, y; /* position in image buffer */
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int code, readcode, lastcode, abcabca;
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/* these won't change */
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ab_clr = (1 << bits);
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ab_fin = (1 << bits) + 1;
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/* these will change through the decompression proccess */
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ab_bits = bits + 1;
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ab_free = (1 << bits) + 2;
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ab_max = (1 << ab_bits) - 1;
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lastcode = -1;
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abcabca = -1;
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pass = 1;
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pos = x = y = 0;
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/* reset static globals */
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m_restbits = 0;
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m_restbyte = 0;
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m_lastbyte = 0;
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do
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{
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/* get next code */
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readcode = code = getcode(ab_bits, ab_fin);
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/* end of image? */
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if (code == ab_fin) break;
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/* reset alphabet? */
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if (code == ab_clr)
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{
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/* reset main variables */
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ab_bits = bits + 1;
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ab_free = (1 << bits) + 2;
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ab_max = (1 << ab_bits) - 1;
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lastcode = -1;
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abcabca = -1;
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/* skip to next code */
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continue;
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}
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/* unknown code: special case (like in ABCABCA) */
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if (code >= ab_free)
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{
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code = lastcode; /* take last string */
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stack[pos++] = abcabca; /* add first character */
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}
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/* build the string for this code in the stack */
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while (code > ab_clr)
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{
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stack[pos++] = ab_tail[code];
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code = ab_prefix[code];
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}
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stack[pos] = code; /* push last code into the stack */
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abcabca = code; /* save for special case */
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/* make new entry in alphabet (only if NOT just cleared) */
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if (lastcode != -1)
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{
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ab_prefix[ab_free] = lastcode;
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ab_tail[ab_free] = code;
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ab_free++;
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if ((ab_free > ab_max) && (ab_bits < 12))
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{
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ab_bits++;
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ab_max = (1 << ab_bits) - 1;
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}
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}
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/* dump stack data to the buffer */
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while (pos >= 0)
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{
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(img->p)[x + (y * (img->w))] = (char)stack[pos--];
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if (++x >= (img->w))
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{
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x = 0;
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if (interl)
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{
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/* support for interlaced images */
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switch (pass)
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{
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case 1: y += 8; break;
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case 2: y += 8; break;
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case 3: y += 4; break;
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case 4: y += 2; break;
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}
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if (y >= (img->h))
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{
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switch (++pass)
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{
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case 2: y = 4; break;
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case 3: y = 2; break;
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case 4: y = 1; break;
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}
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}
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}
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else
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{
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/* non-interlaced */
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y++;
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}
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}
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}
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pos = 0;
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lastcode = readcode;
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}
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while (code != ab_fin);
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return 0;
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}
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// ReadGIF:
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// Reads and decodes one or more GIF images, depending on whether
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// animated GIF support is enabled. Can read GIFs with any bit
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// size (color depth), but the output images are always expanded
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// to 8 bits per pixel. Also, the image palettes always contain
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// 256 colors, although some of them may be unused. Returns E_OK
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// (== 0) on success, or an error code if something fails. Error
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// codes are E_ARCHIVO, E_FORMATO, E_MEMORIA (see header file).
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//
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int wxGIFDecoder::ReadGIF()
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{
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int ncolors, bits, interl, transparent, disposal, i;
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long size;
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long delay;
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unsigned char type;
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unsigned char pal[768];
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unsigned char buf[16];
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IMAGEN **ppimg, *pimg, *pprev;
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/* check GIF signature and animated GIF support (ver. >= 89a) */
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m_f->Read(buf, 6);
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if (memcmp(buf, "GIF", 3) != 0)
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return E_FORMATO;
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if (memcmp(buf + 3, "89a", 3) < 0)
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m_anim = FALSE;
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/* read logical screen descriptor block (LSDB) */
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m_f->Read(buf, 7);
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m_screenw = buf[0] + 256 * buf[1];
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m_screenh = buf[2] + 256 * buf[3];
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/* load global color map if available */
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if ((buf[4] & 0x80) == 0x80)
|
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{
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m_background = buf[5];
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ncolors = 2 << (buf[4] & 0x07);
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m_f->Read(pal, 3 * ncolors);
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}
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/* transparent colour, disposal method and delay default to unused */
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transparent = -1;
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disposal = -1;
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delay = -1;
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/* read images */
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ppimg = &m_pfirst;
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pprev = NULL;
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pimg = NULL;
|
||||
|
||||
while (1)
|
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{
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type = (unsigned char)m_f->GetC();
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/* end of data? */
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if (type == 0x3B)
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break;
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|
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/* extension block? */
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||||
if (type == 0x21)
|
||||
{
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if (((unsigned char)m_f->GetC()) == 0xF9)
|
||||
/* graphics control extension, parse it */
|
||||
{
|
||||
m_f->Read(buf, 6);
|
||||
|
||||
/* read delay and convert from 1/100 of a second to ms */
|
||||
delay = 10 * (buf[2] + 256 * buf[3]);
|
||||
|
||||
/* read transparent colour index, if used */
|
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if (buf[1] & 0x01)
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transparent = buf[4];
|
||||
|
||||
/* read disposal method */
|
||||
disposal = (buf[1] & 0x1C) - 1;
|
||||
}
|
||||
else
|
||||
/* other extension, skip */
|
||||
{
|
||||
while ((i = (unsigned char)m_f->GetC()) != 0)
|
||||
{
|
||||
/* This line should not be neccessary!
|
||||
* Some images are not loaded correctly
|
||||
* without it. A bug in wxStream?
|
||||
*/
|
||||
// m_f->SeekI(m_f->TellI(), wxFromStart);
|
||||
m_f->SeekI(i, wxFromCurrent);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/* image descriptor block? */
|
||||
if (type == 0x2C)
|
||||
{
|
||||
/* allocate memory for IMAGEN struct */
|
||||
pimg = (*ppimg) = (IMAGEN *) malloc(sizeof(IMAGEN));
|
||||
|
||||
if (pimg == NULL)
|
||||
{
|
||||
Destroy();
|
||||
return E_MEMORIA;
|
||||
}
|
||||
|
||||
/* fill in the data */
|
||||
m_f->Read(buf, 9);
|
||||
pimg->left = buf[4] + 256 * buf[5];
|
||||
pimg->top = buf[4] + 256 * buf[5];
|
||||
pimg->w = buf[4] + 256 * buf[5];
|
||||
pimg->h = buf[6] + 256 * buf[7];
|
||||
interl = ((buf[8] & 0x40)? 1 : 0);
|
||||
size = pimg->w * pimg->h;
|
||||
|
||||
pimg->transparent = transparent;
|
||||
pimg->disposal = disposal;
|
||||
pimg->delay = delay;
|
||||
pimg->next = NULL;
|
||||
pimg->prev = pprev;
|
||||
pprev = pimg;
|
||||
ppimg = &pimg->next;
|
||||
|
||||
/* allocate memory for image and palette */
|
||||
pimg->p = (unsigned char *) malloc(size);
|
||||
pimg->pal = (unsigned char *) malloc(768);
|
||||
|
||||
if ((!pimg->p) || (!pimg->pal))
|
||||
{
|
||||
Destroy();
|
||||
return E_MEMORIA;
|
||||
}
|
||||
|
||||
/* load local color map if available, else use global map */
|
||||
if ((buf[8] & 0x80) == 0x80)
|
||||
{
|
||||
ncolors = 2 << (buf[8] & 0x07);
|
||||
m_f->Read(pimg->pal, 3 * ncolors);
|
||||
}
|
||||
else
|
||||
memcpy(pimg->pal, pal, 768);
|
||||
|
||||
/* get initial code size from first byte in raster data */
|
||||
bits = (unsigned char)m_f->GetC();
|
||||
|
||||
/* decode image */
|
||||
dgif(pimg, interl, bits);
|
||||
|
||||
m_nimages++;
|
||||
}
|
||||
|
||||
/* if we have one image and no animated GIF support, exit */
|
||||
if (m_nimages == 1 && !m_anim)
|
||||
break;
|
||||
}
|
||||
|
||||
/* finish successfully :-) */
|
||||
if (m_nimages != 0)
|
||||
{
|
||||
m_image = 1;
|
||||
m_plast = pimg;
|
||||
m_pimage = m_pfirst;
|
||||
}
|
||||
|
||||
return E_OK;
|
||||
}
|
||||
|
||||
#endif // wxUSE_STREAM
|
||||
@@ -1,28 +1,31 @@
|
||||
/////////////////////////////////////////////////////////////////////////////
|
||||
// Name: imaggif.cpp
|
||||
// Purpose: wxGIFHandler
|
||||
// Author: Guillermo Rodriguez Garcia
|
||||
// wxWindows adaptation by Vaclav Slavik
|
||||
// Author: Vaclav Slavik
|
||||
// Based on wxGIFDecoder by Guillermo Rodriguez Garcia
|
||||
// RCS-ID: $Id$
|
||||
// Licence: wxWindows licence
|
||||
/////////////////////////////////////////////////////////////////////////////
|
||||
|
||||
/*
|
||||
We don't put pragma implement in this file because it is already present in
|
||||
src/common/image.cpp
|
||||
We don't put pragma implement in this file because it is already present in
|
||||
src/common/image.cpp
|
||||
*/
|
||||
|
||||
// For compilers that support precompilation, includes "wx.h".
|
||||
#include <wx/wxprec.h>
|
||||
|
||||
#ifdef __BORLANDC__
|
||||
#pragma hdrstop
|
||||
# pragma hdrstop
|
||||
#endif
|
||||
|
||||
#ifndef WX_PRECOMP
|
||||
#include "wx/defs.h"
|
||||
# include "wx/defs.h"
|
||||
#endif
|
||||
|
||||
#include "wx/image.h"
|
||||
// #include "wx/imaggif.h"
|
||||
#include "wx/gifdecod.h"
|
||||
#include "wx/wfstream.h"
|
||||
#include "wx/module.h"
|
||||
#include "wx/log.h"
|
||||
@@ -31,390 +34,29 @@ IMPLEMENT_DYNAMIC_CLASS(wxGIFHandler,wxImageHandler)
|
||||
|
||||
#if wxUSE_STREAMS
|
||||
|
||||
/*
|
||||
|
||||
FOLLOWING CODE IS BY G.R.G. :
|
||||
(except wxInputStream stuff)
|
||||
|
||||
*/
|
||||
|
||||
/************************************************************************
|
||||
READGIF.H - Reads a GIF file
|
||||
------------------------------------------------------------------------
|
||||
Guillermo Rodriguez Garcia
|
||||
<guille@iies.es>
|
||||
|
||||
Version: 2.1
|
||||
*************************************************************************/
|
||||
|
||||
|
||||
typedef struct
|
||||
{
|
||||
int w; /* width */
|
||||
int h; /* height */
|
||||
int transparent; /* transparent color (-1 = none) */
|
||||
unsigned char *p; /* bitmap */
|
||||
unsigned char *pal; /* palette */
|
||||
} IMAGEN;
|
||||
|
||||
|
||||
|
||||
/************************************************************************
|
||||
READGIF.C - Reads a GIF file
|
||||
------------------------------------------------------------------------
|
||||
Guillermo Rodriguez Garcia
|
||||
<guille@iies.es>
|
||||
|
||||
Version: 2.1
|
||||
*************************************************************************/
|
||||
|
||||
|
||||
#include <stdlib.h>
|
||||
#include <string.h>
|
||||
|
||||
|
||||
/* error codes */
|
||||
#define E_OK 0 /* everything was OK */
|
||||
#define E_ARCHIVO -1 /* error opening file */
|
||||
#define E_FORMATO -2 /* error in gif header */
|
||||
#define E_MEMORIA -3 /* error allocating memory */
|
||||
|
||||
|
||||
/* This class binding is by VS, so all bugs in it are mine ;-) */
|
||||
|
||||
class gifDecoder
|
||||
{
|
||||
private:
|
||||
/* globals */
|
||||
int restbits; /* remaining valid bits */
|
||||
unsigned int restbyte; /* remaining bytes in this block */
|
||||
unsigned int lastbyte; /* last byte read */
|
||||
|
||||
wxInputStream *f; /* input file */
|
||||
|
||||
public:
|
||||
gifDecoder(wxInputStream *s) { f = s; }
|
||||
int getcode(int bits);
|
||||
int dgif(IMAGEN *img, int interl, int bits);
|
||||
int readgif(IMAGEN *img);
|
||||
};
|
||||
|
||||
|
||||
|
||||
/* getcode:
|
||||
* Reads the next code from the file, with size 'bits'
|
||||
*/
|
||||
int gifDecoder::getcode(int bits)
|
||||
{
|
||||
unsigned int mask; /* bit mask */
|
||||
unsigned int code; /* code (result) */
|
||||
|
||||
|
||||
/* get remaining bits from last byte read */
|
||||
mask = (1 << bits) - 1;
|
||||
code = (lastbyte >> (8 - restbits)) & mask;
|
||||
|
||||
/* keep reading new bytes while needed */
|
||||
while (bits > restbits)
|
||||
{
|
||||
/* if no bytes left in this block, read the next block */
|
||||
if (restbyte == 0)
|
||||
restbyte = (unsigned char)f->GetC();
|
||||
|
||||
/* read next byte and isolate the bits we need */
|
||||
lastbyte = (unsigned char)f->GetC();
|
||||
mask = (1 << (bits - restbits)) - 1;
|
||||
code = code + ((lastbyte & mask) << restbits);
|
||||
restbyte--;
|
||||
|
||||
/* adjust total number of bits extracted from the buffer */
|
||||
restbits = restbits + 8;
|
||||
}
|
||||
|
||||
/* find number of bits reamining for next code */
|
||||
restbits = (restbits - bits);
|
||||
|
||||
return code;
|
||||
}
|
||||
|
||||
|
||||
|
||||
/* dgif:
|
||||
* GIF decoding function. The initial code size (aka root size)
|
||||
* is 'bits'. Supports interlaced images (interl == 1).
|
||||
*/
|
||||
int gifDecoder::dgif(IMAGEN *img, int interl, int bits)
|
||||
{
|
||||
int ab_prefix[4096]; /* alphabet (prefixes) */
|
||||
int ab_tail[4096]; /* alphabet (tails) */
|
||||
int stack[4096]; /* decompression stack */
|
||||
|
||||
int ab_clr; /* clear code */
|
||||
int ab_fin; /* end of info code */
|
||||
int ab_bits; /* actual symbol width, in bits */
|
||||
int ab_free; /* first free position in alphabet */
|
||||
int ab_max; /* last possible character in alphabet */
|
||||
int pass; /* pass number in interlaced images */
|
||||
int pos; /* index into decompresion stack */
|
||||
int x, y; /* position in image buffer */
|
||||
|
||||
int code, readcode, lastcode, abcabca;
|
||||
|
||||
/* these won't change */
|
||||
ab_clr = (1 << bits);
|
||||
ab_fin = (1 << bits) + 1;
|
||||
|
||||
/* these will change through the decompression proccess */
|
||||
ab_bits = bits + 1;
|
||||
ab_free = (1 << bits) + 2;
|
||||
ab_max = (1 << ab_bits) - 1;
|
||||
lastcode = -1;
|
||||
abcabca = -1;
|
||||
pass = 1;
|
||||
pos = x = y = 0;
|
||||
|
||||
/* reset static globals */
|
||||
restbits = 0;
|
||||
restbyte = 0;
|
||||
lastbyte = 0;
|
||||
|
||||
do
|
||||
{
|
||||
/* get next code */
|
||||
readcode = code = getcode(ab_bits);
|
||||
|
||||
/* end of image? */
|
||||
if (code == ab_fin) break;
|
||||
|
||||
/* reset alphabet? */
|
||||
if (code == ab_clr)
|
||||
{
|
||||
/* reset main variables */
|
||||
ab_bits = bits + 1;
|
||||
ab_free = (1 << bits) + 2;
|
||||
ab_max = (1 << ab_bits) - 1;
|
||||
lastcode = -1;
|
||||
abcabca = -1;
|
||||
|
||||
/* skip to next code */
|
||||
continue;
|
||||
}
|
||||
|
||||
/* unknown code: special case (like in ABCABCA) */
|
||||
if (code >= ab_free)
|
||||
{
|
||||
code = lastcode; /* take last string */
|
||||
stack[pos++] = abcabca; /* add first character */
|
||||
}
|
||||
|
||||
/* build the string for this code in the stack */
|
||||
while (code > ab_clr)
|
||||
{
|
||||
stack[pos++] = ab_tail[code];
|
||||
code = ab_prefix[code];
|
||||
}
|
||||
stack[pos] = code; /* push last code into the stack */
|
||||
abcabca = code; /* save for special case */
|
||||
|
||||
/* make new entry in alphabet (only if NOT just cleared) */
|
||||
if (lastcode != -1)
|
||||
{
|
||||
ab_prefix[ab_free] = lastcode;
|
||||
ab_tail[ab_free] = code;
|
||||
ab_free++;
|
||||
|
||||
if ((ab_free > ab_max) && (ab_bits < 12))
|
||||
{
|
||||
ab_bits++;
|
||||
ab_max = (1 << ab_bits) - 1;
|
||||
}
|
||||
}
|
||||
|
||||
/* dump stack data to the buffer */
|
||||
while (pos >= 0)
|
||||
{
|
||||
(img->p)[x + (y * (img->w))] = (char)stack[pos--];
|
||||
|
||||
if (++x >= (img->w))
|
||||
{
|
||||
x = 0;
|
||||
|
||||
if (interl)
|
||||
{
|
||||
/* support for interlaced images */
|
||||
switch (pass)
|
||||
{
|
||||
case 1: y += 8; break;
|
||||
case 2: y += 8; break;
|
||||
case 3: y += 4; break;
|
||||
case 4: y += 2; break;
|
||||
}
|
||||
if (y >= (img->h))
|
||||
{
|
||||
switch (++pass)
|
||||
{
|
||||
case 2: y = 4; break;
|
||||
case 3: y = 2; break;
|
||||
case 4: y = 1; break;
|
||||
}
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
/* non-interlaced */
|
||||
y++;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
pos = 0;
|
||||
lastcode = readcode;
|
||||
}
|
||||
while (code != ab_fin);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
|
||||
/* readgif:
|
||||
* Reads a GIF image from the file with filename 'nombre' in the
|
||||
* IMAGEN structure pointed by 'img'. Can read GIFs with any bit
|
||||
* size (color depth), but the output image is always expanded
|
||||
* to 8 bits per pixel. Also, the image palette always contains
|
||||
* 256 colors, although some of them may be unused. Returns E_OK
|
||||
* (== 0) on success, or an error code if something fails. Error
|
||||
* codes are E_ARCHIVO, E_FORMATO, E_MEMORIA (see above).
|
||||
*/
|
||||
int gifDecoder::readgif(IMAGEN *img)
|
||||
{
|
||||
int size, ncolors, bits, interl, i;
|
||||
unsigned char pal[768];
|
||||
unsigned char buf[16];
|
||||
|
||||
|
||||
/* read header and logical screen descriptor block (LSDB) */
|
||||
f->Read(buf, 13);
|
||||
|
||||
/* check GIF signature */
|
||||
if (memcmp(buf, "GIF", 3) != 0) return E_FORMATO;
|
||||
|
||||
/* load global color map if available */
|
||||
if ((buf[10] & 0x80) == 0x80)
|
||||
{
|
||||
ncolors = 2 << (buf[10] & 0x07);
|
||||
f->Read(pal, 3 * ncolors);
|
||||
}
|
||||
|
||||
/* assume no transparent color */
|
||||
img->transparent = -1;
|
||||
|
||||
/* skip most extensions */
|
||||
while (((unsigned char)f->GetC()) == 0x21) /* separator */
|
||||
{
|
||||
if (((unsigned char)f->GetC()) == 0xF9) /* graphic control ext. */
|
||||
{
|
||||
f->Read(buf, 6);
|
||||
if (buf[1] & 0x01)
|
||||
img->transparent = buf[4];
|
||||
}
|
||||
else
|
||||
while ((i = (unsigned char)f->GetC()) != 0) /* byte count */
|
||||
f->SeekI(i, wxFromCurrent);
|
||||
}
|
||||
|
||||
/* read image descriptor block (IDB) */
|
||||
f->Read(buf, 9);
|
||||
img->w = buf[4] + 256 * buf[5];
|
||||
img->h = buf[6] + 256 * buf[7];
|
||||
size = img->w * img->h;
|
||||
interl = ((buf[8] & 0x40)? 1 : 0);
|
||||
|
||||
/* load local color map if available */
|
||||
if ((buf[8] & 0x80) == 0x80)
|
||||
{
|
||||
ncolors = 2 << (buf[8] & 0x07);
|
||||
f->Read(pal, 3 * ncolors);
|
||||
}
|
||||
|
||||
/* get initial code size from first byte in raster data */
|
||||
bits = (unsigned char)f->GetC();
|
||||
|
||||
/* allocate memory for image and palette */
|
||||
if ((img->p = (unsigned char*) malloc(size)) == NULL) return E_MEMORIA;
|
||||
if ((img->pal = (unsigned char*) malloc(768)) == NULL) return E_MEMORIA;
|
||||
|
||||
/* shift palette to fit VGA 6-bit format */
|
||||
for (i = 0; i < 768; i++)
|
||||
(img->pal)[i] = (unsigned char)pal[i]; /* >> 2 not in wxWin */
|
||||
|
||||
/* decode GIF */
|
||||
dgif(img, interl, bits);
|
||||
|
||||
/* finish successfully :-) */
|
||||
return E_OK;
|
||||
}
|
||||
|
||||
|
||||
|
||||
/*
|
||||
|
||||
FOLLOWING CODE IS BY V.S. :
|
||||
|
||||
*/
|
||||
|
||||
//-----------------------------------------------------------------------------
|
||||
// wxGIFHandler
|
||||
//-----------------------------------------------------------------------------
|
||||
|
||||
bool wxGIFHandler::LoadFile( wxImage *image, wxInputStream& stream, bool WXUNUSED(verbose) )
|
||||
{
|
||||
unsigned char *ptr, *src, *pal;
|
||||
IMAGEN igif;
|
||||
int i;
|
||||
gifDecoder *decod;
|
||||
wxGIFDecoder *decod;
|
||||
bool ok;
|
||||
|
||||
image->Destroy();
|
||||
decod = new wxGIFDecoder(&stream, TRUE);
|
||||
|
||||
decod = new gifDecoder(&stream);
|
||||
|
||||
if (decod->readgif(&igif) != E_OK) {
|
||||
if (decod->ReadGIF() != E_OK)
|
||||
{
|
||||
wxLogDebug(_T("Error reading GIF"));
|
||||
delete decod;
|
||||
return FALSE;
|
||||
}
|
||||
|
||||
image->Destroy();
|
||||
ok = decod->ConvertToImage(image);
|
||||
|
||||
delete decod;
|
||||
|
||||
image->Create(igif.w, igif.h);
|
||||
if (!image->Ok()) {
|
||||
free(igif.pal);
|
||||
free(igif.p);
|
||||
return FALSE;
|
||||
}
|
||||
|
||||
ptr = image->GetData();
|
||||
src = igif.p;
|
||||
pal = igif.pal;
|
||||
|
||||
if (igif.transparent != -1) {
|
||||
for (i = 0; i < 256; i++)
|
||||
if ((pal[3 * i + 0] == 255) && (pal[3 * i + 1] == 0) && (pal[3 * i + 2] == 255)) pal[3 * i + 2] = 254;
|
||||
pal[3 * (igif.transparent) + 0] = 255,
|
||||
pal[3 * (igif.transparent) + 1] = 0,
|
||||
pal[3 * (igif.transparent) + 2] = 255;
|
||||
image->SetMaskColour(255, 0, 255);
|
||||
}
|
||||
else image->SetMask(FALSE);
|
||||
|
||||
for (i = 0; i < igif.w * igif.h; i++, src++) {
|
||||
*(ptr++) = pal[3 * (*src) + 0];
|
||||
*(ptr++) = pal[3 * (*src) + 1];
|
||||
*(ptr++) = pal[3 * (*src) + 2];
|
||||
}
|
||||
|
||||
free(igif.pal);
|
||||
free(igif.p);
|
||||
return TRUE;
|
||||
return ok;
|
||||
}
|
||||
|
||||
bool wxGIFHandler::SaveFile( wxImage * WXUNUSED(image),
|
||||
|
||||
Reference in New Issue
Block a user