CPNGFile Class Reference

#include <StdPNG.h>

Public Member Functions
	CPNGFile ()
	~CPNGFile ()
void	ClearPngStructs ()
void	Default ()
void	Clear ()
bool	Load (BYTE *pFile, int iSize)
DWORD	GetPix (int iX, int iY)
uint32_t *	GetRow (int iY)
bool	Create (int iWdt, int iHgt, bool fAlpha)
bool	SetPix (int iX, int iY, DWORD dwValue)
bool	Save (const char *szFilename)
BYTE *	GetImageData ()
int	GetBitsPerPixel ()

Static Public Member Functions
static void	ScheduleSaving (CPNGFile *png, const char *filename)
static void	WaitForSaves ()

Public Attributes
unsigned long	iWdt
unsigned long	iHgt
int	iBPC
int	iClrType
int	iIntrlcType
int	iCmprType
int	iFltrType

Detailed Description

Definition at line 23 of file StdPNG.h.

Constructor & Destructor Documentation

CPNGFile()

CPNGFile::CPNGFile

(

)

Definition at line 96 of file StdPNG.cpp.

{
    Default();
}

References Default().

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~CPNGFile()

CPNGFile::~CPNGFile

(

)

Definition at line 115 of file StdPNG.cpp.

{
    // clear
    Clear();
}

References Clear().

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Member Function Documentation

Clear()

void CPNGFile::Clear

(

)

Definition at line 136 of file StdPNG.cpp.

{
    // free image data
    if (pImageData) { delete [] pImageData; pImageData=nullptr; }
    // clear internal png ptrs
    ClearPngStructs();
    // free file ptr if owned
    if (fpFileOwned)
        delete [] pFile;
    pFile=nullptr;
    // reset fields
    fpFileOwned=false;
    pFilePtr=nullptr;
    iRowSize=0;
    iPixSize=0;
    // close file if open
    if (fp) { fclose(fp); fp=nullptr; }
}

References ClearPngStructs().

Referenced by Create(), Load(), Save(), and ~CPNGFile().

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ClearPngStructs()

void CPNGFile::ClearPngStructs

(

)

Definition at line 121 of file StdPNG.cpp.

{
    // clear internal png ptrs
    if (png_ptr || info_ptr || end_info)
    {
        if (fWriteMode)
            png_destroy_write_struct(&png_ptr, &info_ptr);
        else
            png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
    }
    png_ptr=nullptr;
    info_ptr=end_info=nullptr;
    fWriteMode=false;
}

Referenced by Clear(), and Save().

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Create()

bool CPNGFile::Create	(	int	iWdt,
		int	iHgt,
		bool	fAlpha
	)

Definition at line 191 of file StdPNG.cpp.

{
    // catch invalid size
    if (iWdt<=0 || iHgt<=0) return false;
    // clear current image in mem
    Clear();
    // set dimensions
    this->iWdt=iWdt; this->iHgt=iHgt;
    // set color type
    iBPC = 8;
    iClrType = fAlpha ? PNG_COLOR_TYPE_RGB_ALPHA : PNG_COLOR_TYPE_RGB;
    iPixSize = fAlpha ? 4 : 3;
    // set interlacing, filters and stuff
    iIntrlcType = PNG_INTERLACE_NONE;
    iCmprType = PNG_COMPRESSION_TYPE_DEFAULT;
    iFltrType = PNG_FILTER_TYPE_DEFAULT;
    // calculate rowbytes
    int iBPP = (fAlpha ? 4 : 3) * iBPC;
    iRowSize = (iBPP*iWdt+7)>>3;
    // create image data
    pImageData = new unsigned char[iHgt * iRowSize];
    // success
    return true;
}

References Clear(), iBPC, iClrType, iCmprType, iFltrType, iHgt, iIntrlcType, and iWdt.

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Default()

void CPNGFile::Default

(

)

Definition at line 101 of file StdPNG.cpp.

{
    // zero fields
    pFile=nullptr;
    fpFileOwned=false;
    pFilePtr=nullptr;
    png_ptr=nullptr;
    info_ptr=end_info=nullptr;
    pImageData=nullptr;
    iRowSize=0;
    iPixSize=0;
    fp=nullptr;
}

Referenced by CPNGFile().

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GetBitsPerPixel()

int CPNGFile::GetBitsPerPixel

(

)

Definition at line 292 of file StdPNG.cpp.

{
    switch (iClrType)
    {
    case PNG_COLOR_TYPE_RGB: return 24;
    case PNG_COLOR_TYPE_RGB_ALPHA: return 32;
    }
    return 0;
}

References iClrType.

GetImageData()

BYTE* CPNGFile::GetImageData ( )

inline

Definition at line 64 of file StdPNG.h.

{ return pImageData; }   // return raw image data

GetPix()

DWORD CPNGFile::GetPix	(	int	iX,
		int	iY
	)

Definition at line 175 of file StdPNG.cpp.

{
    // image loaded?
    if (!pImageData) return 0;
    // return pixel value
    unsigned char *pPix=pImageData+iY*iRowSize+iX*iPixSize;
    switch (iClrType)
    {
    case PNG_COLOR_TYPE_RGB:
        return C4RGB(pPix[2], pPix[1], pPix[0]);
    case PNG_COLOR_TYPE_RGB_ALPHA:
        return RGBA(pPix[2], pPix[1], pPix[0], pPix[3]);
    }
    return 0;
}

References C4RGB, iClrType, and RGBA().

Referenced by C4TextureShape::Load(), C4SolidMask::LoadMaskFromFile(), and C4Surface::ReadPNG().

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GetRow()

uint32_t* CPNGFile::GetRow ( int  iY )

inline

Definition at line 56 of file StdPNG.h.

    {
        return reinterpret_cast<uint32_t *>(pImageData+iY*iRowSize);
    }

Referenced by C4Surface::ReadPNG().

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Load()

bool CPNGFile::Load	(	BYTE *	pFile,
		int	iSize
	)

Definition at line 155 of file StdPNG.cpp.

{
    // clear any previously loaded file
    Clear();
    // store file ptr as not owned
    this->pFile = pFile;
    iFileSize=iSize;
    fpFileOwned=false;
    // perform the loading
    if (!DoLoad())
    {
        Clear();
        return false;
    }
    // reset file-field
    this->pFile = nullptr; iFileSize=0;
    // success
    return true;
}

References Clear(), and iSize.

Referenced by C4TextureShape::Load(), C4SolidMask::LoadMaskFromFile(), and C4Surface::ReadPNG().

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Save()

bool CPNGFile::Save

(

const char *

szFilename

)

Definition at line 236 of file StdPNG.cpp.

{
    // regular file saving - first, there has to be a buffer
    if (!pImageData) return false;
    // open the file
    fp = fopen(szFilename, "wb"); if (!fp) return false;
    // clear any previously initialized png-structs (e.g. by reading)
    ClearPngStructs();
    // reinit them for writing
    fWriteMode=true;
    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
    if (!png_ptr) { Clear(); return false; }
    info_ptr = png_create_info_struct(png_ptr);
    if (!info_ptr) { Clear(); return false; }
    // error handling
    if (setjmp(png_jmpbuf(png_ptr))) { Clear(); return false; }
    // io initialization
    png_init_io(png_ptr, fp);
    // compression stuff
    png_set_filter(png_ptr, 0, PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_PAETH);
    png_set_compression_level(png_ptr, Z_BEST_COMPRESSION);
    png_set_compression_mem_level(png_ptr, 8);
    png_set_compression_strategy(png_ptr, Z_DEFAULT_STRATEGY);
    png_set_compression_window_bits(png_ptr, 15);
    png_set_compression_method(png_ptr, 8);
    // set header
    png_set_IHDR(png_ptr, info_ptr, iWdt, iHgt, iBPC, iClrType, iIntrlcType, iCmprType, iFltrType);
    // double-check our calculated row size
    int iRealRowSize=png_get_rowbytes(png_ptr, info_ptr);
    if (iRealRowSize != iRowSize)
    {
        // this won't go well, so better abort
        Clear(); return false;
    }
    // write png header
    png_write_info(png_ptr, info_ptr);
    // image data is given as bgr...
    png_set_bgr(png_ptr);
    // create row array
    unsigned char **ppRowBuf = new unsigned char *[iHgt];
    unsigned char **ppRows=ppRowBuf; unsigned char *pRow=pImageData;
    for (unsigned int i=0; i<iHgt; ++i,pRow+=iRowSize) *ppRows++=pRow;
    // write image
    png_write_image(png_ptr, ppRowBuf);
    // free row buffer
    delete [] ppRowBuf;
    // write end struct
    png_write_end(png_ptr, info_ptr);
    // finally, close the file
    fclose(fp); fp = nullptr;
    // clear png structs
    ClearPngStructs();
    // success!
    return true;
}

References Clear(), ClearPngStructs(), iBPC, iClrType, iCmprType, iFltrType, iHgt, iIntrlcType, and iWdt.

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ScheduleSaving()

void CPNGFile::ScheduleSaving ( CPNGFile *  png, const char *  filename  )

static

Definition at line 354 of file StdPNG.cpp.

{
    // start a background thread to save the png file
    // thread is responsible for cleaning up
    CPNGSaveThread *saver = new CPNGSaveThread(png, filename);
    if (!saver->Start()) delete saver;
}

References StdThread::Start().

Referenced by C4GraphicsSystem::DoSaveScreenshot(), and C4Surface::SavePNG().

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SetPix()

bool CPNGFile::SetPix	(	int	iX,
		int	iY,
		DWORD	dwValue
	)

Definition at line 216 of file StdPNG.cpp.

{
    // image created?
    if (!pImageData) return false;
    // set pixel value
    unsigned char *pPix=pImageData+iY*iRowSize+iX*iPixSize;
    switch (iClrType)
    {
    case PNG_COLOR_TYPE_RGB: // RGB: set r, g and b values
        pPix[0] = GetBlueValue(dwValue);
        pPix[1] = GetGreenValue(dwValue);
        pPix[2] = GetRedValue(dwValue);
        return true;
    case PNG_COLOR_TYPE_RGB_ALPHA: // RGBA: simply set in mem
        *(DWORD *) pPix = dwValue;
        return true;
    }
    return false;
}

References GetBlueValue, GetGreenValue, GetRedValue, and iClrType.

WaitForSaves()

void CPNGFile::WaitForSaves ( )

static

Definition at line 362 of file StdPNG.cpp.

{
    // Yield main thread until all pending saves have finished.Wait for
    bool first = true;
    while (CPNGSaveThread::HasPendingThreads())
    {
        // English message because localization data is no longer loaded
        if (first) LogSilent("Waiting for pending image files to be written to disc...");
        first = false;
#ifdef HAVE_WINTHREAD
        Sleep(100);
#else
        sched_yield();
#endif
    }
}

References CPNGSaveThread::HasPendingThreads(), and LogSilent().

Referenced by C4Application::Clear().

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Member Data Documentation

iBPC

int CPNGFile::iBPC

Definition at line 45 of file StdPNG.h.

Referenced by Create(), and Save().

iClrType

int CPNGFile::iClrType

Definition at line 45 of file StdPNG.h.

Referenced by Create(), GetBitsPerPixel(), GetPix(), C4Surface::ReadPNG(), Save(), and SetPix().

iCmprType

int CPNGFile::iCmprType

Definition at line 45 of file StdPNG.h.

Referenced by Create(), and Save().

iFltrType

int CPNGFile::iFltrType

Definition at line 45 of file StdPNG.h.

Referenced by Create(), and Save().

iHgt

unsigned long CPNGFile::iHgt

Definition at line 44 of file StdPNG.h.

Referenced by Create(), C4TextureShape::Load(), C4SolidMask::LoadMaskFromFile(), C4Surface::ReadPNG(), and Save().

iIntrlcType

int CPNGFile::iIntrlcType

Definition at line 45 of file StdPNG.h.

Referenced by Create(), and Save().

iWdt

unsigned long CPNGFile::iWdt

Definition at line 44 of file StdPNG.h.

Referenced by Create(), C4TextureShape::Load(), C4SolidMask::LoadMaskFromFile(), C4Surface::ReadPNG(), and Save().

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The documentation for this class was generated from the following files:

• StdPNG.h
• StdPNG.cpp