Bitmap.cpp

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/* Bitmap.cpp
 
   Copyright (C)  David C. J. Matthews 2004, 2008  dm at prolingua.co.uk
 
   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   as published by the Free Software Foundation; either version 2
   of the License, or (at your option) any later version.
 
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
 
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
   Or, point your browser to http://www.gnu.org/copyleft/gpl.html
 
*/
 
#include "Bitmap.h"
#include "Visible.h"
#include "Presentable.h"
#include "Ingredients.h"
#include "Root.h"
#include "BaseClasses.h"
#include "ParseNode.h"
#include "ASN1Codes.h"
#include "Engine.h"
#include "Logging.h"
#include "freemheg.h"
 
#include <algorithm>
#include <cinttypes>
 
/*
UK MHEG content hook values: 2 => MPEG I-frame, 4 => PNG bitmap
*/
 
MHBitmap::~MHBitmap()
{
    delete(m_pContent);
}
 
void MHBitmap::Initialise(MHParseNode *p, MHEngine *engine)
{
    MHVisible::Initialise(p, engine);
    // Tiling - optional
    MHParseNode *pTiling = p->GetNamedArg(C_TILING);
 
    if (pTiling)
    {
        m_fTiling = pTiling->GetArgN(0)->GetBoolValue();
    }
 
    // Transparency - optional
    MHParseNode *pTransparency = p->GetNamedArg(C_ORIGINAL_TRANSPARENCY);
 
    if (pTransparency)
    {
        m_nOrigTransparency = pTransparency->GetArgN(0)->GetIntValue();
    }
 
    m_pContent = engine->GetContext()->CreateBitmap(m_fTiling);
}
 
void MHBitmap::PrintMe(FILE *fd, int nTabs) const
{
    PrintTabs(fd, nTabs);
    fprintf(fd, "{:Bitmap ");
    MHVisible::PrintMe(fd, nTabs + 1);
 
    if (m_fTiling)
    {
        PrintTabs(fd, nTabs + 1);
        fprintf(fd, ":Tiling true\n");
    }
 
    if (m_nOrigTransparency != 0)
    {
        PrintTabs(fd, nTabs + 1);
        fprintf(fd, ":OrigTransparency %d\n", m_nOrigTransparency);
    }
 
    PrintTabs(fd, nTabs);
    fprintf(fd, "}\n");
}
 
void MHBitmap::Preparation(MHEngine *engine)
{
    if (m_fAvailable)
    {
        return;
    }
 
    m_nTransparency = m_nOrigTransparency; // Transparency isn't used in UK MHEG
    MHVisible::Preparation(engine);
}
 
//
void MHBitmap::ContentPreparation(MHEngine *engine)
{
    MHVisible::ContentPreparation(engine);
 
    if (m_contentType == IN_NoContent)
    {
        MHERROR("Bitmap must contain a content");
    }
 
    if (m_contentType == IN_IncludedContent)
        CreateContent(m_includedContent.Bytes(), m_includedContent.Size(), engine);
}
 
// Decode the content.
void MHBitmap::ContentArrived(const unsigned char *data, int length, MHEngine *engine)
{
    if (! m_pContent)
    {
        return;    // Shouldn't happen.
    }
 
    CreateContent(data, length, engine);
    // Now signal that the content is available.
    engine->EventTriggered(this, EventContentAvailable);
}
 
void MHBitmap::CreateContent(const unsigned char *data, int length, MHEngine *engine)
{
    QRegion updateArea = GetVisibleArea(); // If there's any content already we have to redraw it.
 
    int nCHook = m_nContentHook;
 
    if (nCHook == 0)
    {
        nCHook = engine->GetDefaultBitmapCHook();
    }
 
    switch (nCHook)
    {
    case 4: // PNG.
        m_pContent->CreateFromPNG(data, length);
        break;
    case 2: // MPEG I-frame.
    case 5: // BBC/Freesat MPEG I-frame background
        m_pContent->CreateFromMPEG(data, length);
        break;
    case 6: // JPEG ISO/IEC 10918-1, JFIF file
        m_pContent->CreateFromJPEG(data, length);
        break;
    default: // 1,3,5,8 are reserved. 7= H.264 Intra Frame
        MHERROR(QString("Unknown bitmap content hook %1").arg(nCHook));
    }
 
    updateArea += GetVisibleArea(); // Redraw this bitmap.
    engine->Redraw(updateArea); // Mark for redrawing
}
 
 
// Set the transparency.
void MHBitmap::SetTransparency(int nTransPerCent, MHEngine * /*engine*/)
{
    // The object transparency isn't actually used in UK MHEG.
    // We want a value between 0 and 255
    nTransPerCent = std::clamp(nTransPerCent, 0, 100);
 
    m_nTransparency = ((nTransPerCent * 255) + 50) / 100;
}
 
// Scale a bitmap.  In UK MHEG this is only used for MPEG I-frames, not PNG.
void MHBitmap::ScaleBitmap(int xScale, int yScale, MHEngine *engine)
{
    QRegion updateArea = GetVisibleArea(); // If there's any content already we have to redraw it.
    m_pContent->ScaleImage(xScale, yScale);
    updateArea += GetVisibleArea(); // Redraw this bitmap.
    engine->Redraw(updateArea); // Mark for redrawing
}
 
// Added action in UK MHEG.
void MHBitmap::SetBitmapDecodeOffset(int newXOffset, int newYOffset, MHEngine *engine)
{
    QRegion updateArea = GetVisibleArea(); // Redraw the area before the offset
    m_nXDecodeOffset = newXOffset;
    m_nYDecodeOffset = newYOffset;
    updateArea += GetVisibleArea(); // Redraw this bitmap.
    engine->Redraw(updateArea); // Mark for redrawing
}
 
// Added action in UK MHEG.
void MHBitmap::GetBitmapDecodeOffset(MHRoot *pXOffset, MHRoot *pYOffset)
{
    pXOffset->SetVariableValue(m_nXDecodeOffset);
    pYOffset->SetVariableValue(m_nYDecodeOffset);
}
 
void MHBitmap::Display(MHEngine * /*engine*/)
{
    if (! m_fRunning || ! m_pContent || m_nBoxWidth == 0 || m_nBoxHeight == 0)
    {
        return;    // Can't draw zero sized boxes.
    }
 
    m_pContent->Draw(m_nPosX + m_nXDecodeOffset, m_nPosY + m_nYDecodeOffset,
            QRect(m_nPosX, m_nPosY, m_nBoxWidth, m_nBoxHeight), m_fTiling,
            m_nContentHook == 5); // 'under video' if BBC MPEG I-frame background
}
 
// Return the region drawn by the bitmap.
QRegion MHBitmap::GetVisibleArea()
{
    if (! m_fRunning || m_pContent == nullptr)
    {
        return {};
    }
 
    // The visible area is the intersection of the containing box with the, possibly offset,
    // bitmap.
    QSize imageSize = m_pContent->GetSize();
    QRegion boxRegion = QRegion(m_nPosX, m_nPosY, m_nBoxWidth, m_nBoxHeight);
    QRegion bitmapRegion = QRegion(m_nPosX + m_nXDecodeOffset, m_nPosY + m_nYDecodeOffset,
                                   imageSize.width(), imageSize.height());
    return boxRegion & bitmapRegion;
}
 
// Return the area actually obscured by the bitmap.
QRegion MHBitmap::GetOpaqueArea()
{
    // The area is empty unless the bitmap is opaque.
    // and it's not a BBC MPEG I-frame background
    if (! m_fRunning || m_nContentHook == 5 || m_pContent == nullptr || ! m_pContent->IsOpaque())
    {
        return {};
    }
    return GetVisibleArea();
}