当前位置: 首页>>代码示例>>C++>>正文

C++ FileObject::seek方法代码示例

本文整理汇总了C++中FileObject::seek方法的典型用法代码示例。如果您正苦于以下问题：C++ FileObject::seek方法的具体用法？C++ FileObject::seek怎么用？C++ FileObject::seek使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类FileObject的用法示例。


在下文中一共展示了FileObject::seek方法的4个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。

示例1: process

//-------------------------------------------------------------------------------------
bool FileDataDownload::process()
{
	ResourceObjectPtr fptr = Resmgr::getSingleton().openResource(path_.c_str(), "rb");
	if(fptr == NULL || !fptr->valid())
	{
		ERROR_MSG(fmt::format("FileDataDownload::process(): can't open {}.\n", 
			Resmgr::getSingleton().matchRes(path_).c_str()));
		
		error_ = true;
		return false;
	}

	FileObject* f = static_cast<FileObject*>(fptr.get());
	if(totalBytes_ == 0)
	{
		f->seek(0, SEEK_END);
		totalBytes_ = f->tell();
	}

	f->seek(totalSentBytes_, SEEK_SET);
	remainSent_ = f->read(stream_, 65535);
	currSent_ = 0;

	if(remainSent_ == 0)
		remainSent_ = totalBytes_ - totalSentBytes_;

	return false;
}
开发者ID:lmb0989，项目名称:kbengine，代码行数:29，代码来源:data_download.cpp

示例2: load

void ImageFilter_PNG::load(FileObject &file, Drawable &surface, IMAGE &img)
{
#ifdef HAVE_PNG
	file.seek(0);
	png_structp png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL ,NULL, NULL);
    if (!png_ptr) throw IllegalImageFormatException();

    png_infop info_ptr = png_create_info_struct(png_ptr);
    if (!info_ptr)  {
        png_destroy_read_struct(&png_ptr,(png_infopp)NULL, (png_infopp)NULL);
        throw IllegalImageFormatException();
    }

    png_infop end_info = png_create_info_struct(png_ptr);
    if (!end_info) {
        png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
        throw IllegalImageFormatException();
    }

	png_set_read_fn(png_ptr, &file, (png_rw_ptr) user_read_data);

    //png_set_write_fn(png_structp write_ptr, voidp write_io_ptr, png_rw_ptr write_data_fn,
    //    png_flush_ptr output_flush_fn);

	png_read_info(png_ptr, info_ptr);

	//png_read_png(png_ptr, info_ptr,0,NULL);



	png_bytep row_pointer=(png_bytep) png_malloc(png_ptr,img.pitch);

	RGBFormat zformat=surface.rgbformat();		// Zielformat holen

	if (row_pointer!=NULL) {
		int bpp;
		switch (png_get_color_type(png_ptr, info_ptr)) {

		case PNG_COLOR_TYPE_RGB_ALPHA:
			//bpp=png_get_bit_depth(png_ptr, info_ptr);
			bpp=4;	// TODO: Bittiefe kann auch 16 Bit pro Farbkanal sein
			//printf ("PNG RGBA, bpp=%i\n",bpp);
			for (int y=0;y<img.height;y++) {
				png_read_row(png_ptr, row_pointer, NULL);
				for (int x=0;x<img.width;x++) {
					int r=row_pointer[x*bpp+0];
					int g=row_pointer[x*bpp+1];
					int b=row_pointer[x*bpp+2];
					int a=row_pointer[x*bpp+3];
					surface.putPixel(x,y,Color(r,g,b,a));
				}
			}
			break;
		case PNG_COLOR_TYPE_RGB:
			//bpp=png_get_bit_depth(png_ptr, info_ptr)/8;
			bpp=3;
			for (int y=0;y<img.height;y++) {
				png_read_row(png_ptr, row_pointer, NULL);
				for (int x=0;x<img.width;x++) {
					int r=row_pointer[x*bpp+0];
					int g=row_pointer[x*bpp+1];
					int b=row_pointer[x*bpp+2];
					surface.putPixel(x,y,Color(r,g,b,255));
				}
			}
			break;
		case PNG_COLOR_TYPE_GRAY:
			//bpp=png_get_bit_depth(png_ptr, info_ptr)/8;
			bpp=1;
			// Ist das Zielformat auch Greyscale?
			if (zformat==RGBFormat::A8 || zformat==RGBFormat::GREY8) {
				for (int y=0;y<img.height;y++) {
					png_read_row(png_ptr, row_pointer, NULL);
					for (int x=0;x<img.width;x++) {
						int r=row_pointer[x*bpp+0];
						surface.putPixel(x,y,Color(r,r,r));
					}
				}
			} else {
				for (int y=0;y<img.height;y++) {
					png_read_row(png_ptr, row_pointer, NULL);
					for (int x=0;x<img.width;x++) {
						int r=row_pointer[x*bpp+0];
						surface.putPixel(x,y,Color(r,r,r));
					}
				}
			}
			break;
		case PNG_COLOR_TYPE_GRAY_ALPHA:
			bpp=2;
			//bpp=png_get_bit_depth(png_ptr, info_ptr)/8;
			for (int y=0;y<img.height;y++) {
				png_read_row(png_ptr, row_pointer, NULL);
				for (int x=0;x<img.width;x++) {
					int r=row_pointer[x*bpp+0];
					int a=row_pointer[x*bpp+1];
					surface.putPixel(x,y,Color(r,r,r,a));
				}
			}
			break;
//.........这里部分代码省略.........
开发者ID:pfedick，项目名称:pplib，代码行数:101，代码来源:ImageFilter_PNG.cpp

示例3: save

void ImageFilter_PNG::save (const Drawable &surface, FileObject &file, const AssocArray &param)
{
#ifdef HAVE_PNG
	Color farbe;
	int pitch,colortype;
	//int r,g,b,a;
	int width,height;
	png_byte *buffer;
	png_color	pc[256];
	//RGBA	rgb;

	if (surface.isEmpty()) throw EmptyImageException();

	file.seek(0);
	width=surface.width();
	height=surface.height();

	pitch=colortype=0;
	int png_color_type=PNG_COLOR_TYPE_GRAY;
	int compression_level=Z_BEST_COMPRESSION;
	RGBFormat srgb=surface.rgbformat();
	if (srgb==RGBFormat::A8R8G8B8) png_color_type=PNG_COLOR_TYPE_RGB_ALPHA;

	if (param.exists("colortype")) png_color_type=param.getString("colortype").toInt();
	if (!png_color_type) png_color_type=PNG_COLOR_TYPE_RGB;

	switch (png_color_type) {
		case PNG_COLOR_TYPE_GRAY:
			colortype=PNG_COLOR_TYPE_GRAY;
			pitch=width*1;
			break;
		case PNG_COLOR_TYPE_PALETTE:
			colortype=PNG_COLOR_TYPE_PALETTE;
			pitch=width*1;
			break;
		case PNG_COLOR_TYPE_RGB:
			colortype=PNG_COLOR_TYPE_RGB;
			pitch=width*3;
			break;
		case PNG_COLOR_TYPE_RGB_ALPHA:
			colortype=PNG_COLOR_TYPE_RGB_ALPHA;
			pitch=width*4;
			break;
		case PNG_COLOR_TYPE_GRAY_ALPHA:
			colortype=PNG_COLOR_TYPE_GRAY_ALPHA;
			pitch=width*2;
			break;
		default:
			colortype=PNG_COLOR_TYPE_RGB;
			pitch=width*3;
			break;
	};


	png_structp png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL,NULL,NULL);
	if (!png_ptr) throw OperationFailedException("ImageFilter_PNG::save");
	png_infop info_ptr = png_create_info_struct(png_ptr);
	if (!info_ptr) {
		png_destroy_write_struct(&png_ptr,(png_infopp)NULL);
		throw OperationFailedException("ImageFilter_PNG::save");
	}

	if (setjmp(png_jmpbuf(png_ptr))) {
		png_destroy_write_struct(&png_ptr,&info_ptr);
		throw OperationFailedException("ImageFilter_PNG::save");
	}

	//png_set_read_fn(png_ptr,(voidp) file, (png_rw_ptr) user_read_data);
	png_set_write_fn(png_ptr, &file, (png_rw_ptr) user_write_data, (png_flush_ptr) user_flush_data);

	// Compression-Level setzen

	png_set_compression_level (png_ptr, compression_level);




	png_set_IHDR(png_ptr, info_ptr, width,height,8,colortype,
		PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);




	buffer=(png_byte*)png_malloc(png_ptr,pitch);
	if (!buffer) {
		png_destroy_write_struct(&png_ptr,&info_ptr);
		throw OutOfMemoryException();
	}
	if (buffer!=NULL) {
		// png_write_row(png_ptr, row_pointer);
		int bpp;
		switch (colortype) {
			case PNG_COLOR_TYPE_PALETTE:
				bpp=1;
				if (surface.rgbformat()==RGBFormat::Palette) {	// Surface verwendet Palette
					for (int i=0;i<256;i++) {
						// TODO:
						//surface->GetColor(i,&rgb);
						//pc[i].red=rgb.red;
						//pc[i].green=rgb.green;
//.........这里部分代码省略.........
开发者ID:pfedick，项目名称:pplib，代码行数:101，代码来源:ImageFilter_PNG.cpp

示例4: ident

int ImageFilter_PNG::ident(FileObject &file, IMAGE &img)
{
#ifdef HAVE_PNG
	try {
		const char *address=file.map(0,256);
		file.seek(0);
		if (address==NULL) return 0;

		if (png_sig_cmp((png_byte*)address, 0, 8)!=0) { // Ist es ein PNG-File?
			return 0;
		}
		png_structp png_ptr = png_create_read_struct
				(PNG_LIBPNG_VER_STRING, NULL ,NULL, NULL);
		if (!png_ptr) return 0;

		png_infop info_ptr = png_create_info_struct(png_ptr);
		if (!info_ptr) {
			png_destroy_read_struct(&png_ptr,(png_infopp)NULL, (png_infopp)NULL);
			return 0;
		}
		png_infop end_info = png_create_info_struct(png_ptr);
		if (!end_info) {
			png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL);
			return 0;
		}
		png_set_read_fn(png_ptr,&file, (png_rw_ptr) user_read_data);
		//png_set_write_fn(png_structp write_ptr, voidp write_io_ptr, png_rw_ptr write_data_fn,
		//    png_flush_ptr output_flush_fn);
		png_read_info(png_ptr, info_ptr);
		img.width=png_get_image_width(png_ptr, info_ptr);
		img.height=png_get_image_height(png_ptr, info_ptr);
		img.bitdepth=png_get_bit_depth(png_ptr, info_ptr);
		img.colors=0;
		img.pitch=png_get_rowbytes(png_ptr, info_ptr);
		//img->pfp.header_version=0;
		bool supported=true;
		img.format=RGBFormat::unknown;
		if (img.bitdepth!=8) supported=false;		// Nur 8-Bit/Farbwert wird unterstützt

		switch (png_get_color_type(png_ptr, info_ptr)) {
			case PNG_COLOR_TYPE_GRAY:
				img.bitdepth=8;
				img.colors=256;
				img.format=RGBFormat::GREY8;
				break;
			case PNG_COLOR_TYPE_PALETTE:
				img.bitdepth=8;
				img.colors=256;
				img.format=RGBFormat::Palette;
				//supported=false;
				break;
			case PNG_COLOR_TYPE_RGB:
				img.colors=0xffffff;
				img.bitdepth=24;
				img.format=RGBFormat::X8R8G8B8;
				break;
			case PNG_COLOR_TYPE_RGB_ALPHA:
				img.colors=0xffffff;
				img.bitdepth=32;
				img.format=RGBFormat::A8R8G8B8;
				break;
			case PNG_COLOR_TYPE_GRAY_ALPHA:
				img.colors=256;
				img.bitdepth=32;
				img.format=RGBFormat::GREYALPHA32;
				break;
		};

		if (png_get_interlace_type(png_ptr,info_ptr)!=PNG_INTERLACE_NONE) {	// Interlaced wird nicht unterstützt
			supported=false;
		}

		png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
		if (!supported) {
			return 0;
		}
		return 1;
	} catch (...) {
		return 0;
	}
	return 0;
#else
	return 0;
#endif
}
开发者ID:pfedick，项目名称:pplib，代码行数:85，代码来源:ImageFilter_PNG.cpp


注：本文中的FileObject::seek方法示例由纯净天空整理自Github/MSDocs等开源代码及文档管理平台，相关代码片段筛选自各路编程大神贡献的开源项目，源码版权归原作者所有，传播和使用请参考对应项目的License；未经允许，请勿转载。