X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/2432b92dd7a837db13d3938a56c1959decd03203..b14391d1c8fde767eabedd2243dd6583f685f53f:/docs/latex/wx/image.tex diff --git a/docs/latex/wx/image.tex b/docs/latex/wx/image.tex index 91e691bafa..f913b2b6ba 100644 --- a/docs/latex/wx/image.tex +++ b/docs/latex/wx/image.tex @@ -6,16 +6,51 @@ can be loaded from a file in a variety of formats, and is extensible to new form via image format handlers. Functions are available to set and get image bits, so it can be used for basic image manipulation. -A wxImage cannot (currently) be drawn directly to a wxDC. Instead, a platform-specific -wxBitmap object must be created from it, and that bitmap drawn on the wxDC. +A wxImage cannot (currently) be drawn directly to a \helpref{wxDC}{wxdc}. Instead, +a platform-specific \helpref{wxBitmap}{wxbitmap} object must be created from it using +the \helpref{ConvertToBitmap}{wximageconverttobitmap} function. This bitmap can then +be drawn in a device context, using \helpref{wxDC::DrawBitmap}{wxdcdrawbitmap}. + +One colour value of the image may be used as a mask colour which will lead to the automatic +creation of a \helpref{wxMask}{wxmask} object associated to the bitmap object. + +\wxheading{Available image handlers} + +The following image handlers are available. {\bf wxBMPHandler} is always +installed by default. To use other image formats, install the appropiate +handler with \helpref{wxImage::AddHandler}{wximageaddhandler} or +\helpref{wxInitAllImageHandlers}{wxinitallimagehandlers}. + +\twocolwidtha{5cm}% +\begin{twocollist} +\twocolitem{{\bf \indexit{wxBMPHandler}}}{Only for loading, always installed.} +\twocolitem{{\bf \indexit{wxPNGHandler}}}{For loading and saving.} +\twocolitem{{\bf \indexit{wxJPEGHandler}}}{For loading and saving.} +\twocolitem{{\bf \indexit{wxGIFHandler}}}{Only for loading, due to legal issues.} +\twocolitem{{\bf \indexit{wxPCXHandler}}}{For loading and saving (see below).} +\twocolitem{{\bf \indexit{wxPNMHandler}}}{For loading and saving (see below).} +\twocolitem{{\bf \indexit{wxTIFFHandler}}}{For loading and saving.} +\end{twocollist} + +When saving in PCX format, {\bf wxPCXHandler} will count the number of +different colours in the image; if there are 256 or less colours, it will +save as 8 bit, else it will save as 24 bit. + +Loading PNMs only works for ASCII or raw RGB images. When saving in +PNM format, {\bf wxPNMHandler} will always save as raw RGB. \wxheading{Derived from} \helpref{wxObject}{wxobject} +\wxheading{Include files} + + + \wxheading{See also} -\helpref{wxBitmap}{wxbitmap} +\helpref{wxBitmap}{wxbitmap}, +\helpref{wxInitAllImageHandlers}{wxinitallimagehandlers} \latexignore{\rtfignore{\wxheading{Members}}} @@ -31,43 +66,78 @@ Copy constructor. \func{}{wxImage}{\param{const wxBitmap\&}{ bitmap}} -Constructs an image from a platform-dependent bitmap. +Constructs an image from a platform-dependent bitmap. This preserves +mask information so that bitmaps and images can be converted back +and forth without loss in that respect. \func{}{wxImage}{\param{int}{ width}, \param{int}{ height}} Creates an image with the given width and height. -\func{}{wxImage}{\param{const wxString\& }{name}, \param{long}{ type = wxBITMAP\_TYPE\_PNG}} +\func{}{wxImage}{\param{const wxString\& }{name}, \param{long}{ type = wxBITMAP\_TYPE\_ANY}} + +\func{}{wxImage}{\param{const wxString\& }{name}, \param{const wxString\&}{ mimetype}} Loads an image from a file. +\func{}{wxImage}{\param{wxInputStream\& }{stream}, \param{long}{ type = wxBITMAP\_TYPE\_ANY}} + +\func{}{wxImage}{\param{wxInputStream\& }{stream}, \param{const wxString\&}{ mimetype}} + +Loads an image from an input stream. + \wxheading{Parameters} \docparam{width}{Specifies the width of the image.} \docparam{height}{Specifies the height of the image.} -\docparam{name}{This refers to an image filename. Its meaning is determined by the {\it type} parameter.} +\docparam{name}{Name of the file from which to load the image.} + +\docparam{stream}{Opened input stream from which to load the image. Currently, the stream must support seeking.} \docparam{type}{May be one of the following: -\twocolwidtha{5cm} +\twocolwidtha{5cm}% \begin{twocollist} \twocolitem{{\bf \indexit{wxBITMAP\_TYPE\_BMP}}}{Load a Windows bitmap file.} \twocolitem{{\bf \indexit{wxBITMAP\_TYPE\_GIF}}}{Load a GIF bitmap file.} -\twocolitem{{\bf \indexit{wxBITMAP\_TYPE\_XBM}}}{Load an X bitmap file.} -\twocolitem{{\bf \indexit{wxBITMAP\_TYPE\_XPM}}}{Load an XPM bitmap file.} +\twocolitem{{\bf \indexit{wxBITMAP\_TYPE\_JPEG}}}{Load a JPEG bitmap file.} \twocolitem{{\bf \indexit{wxBITMAP\_TYPE\_PNG}}}{Load a PNG bitmap file.} -\end{twocollist} +\twocolitem{{\bf \indexit{wxBITMAP\_TYPE\_PCX}}}{Load a PCX bitmap file.} +\twocolitem{{\bf \indexit{wxBITMAP\_TYPE\_PNM}}}{Load a PNM bitmap file.} +\twocolitem{{\bf \indexit{wxBITMAP\_TYPE\_TIF}}}{Load a TIFF bitmap file.} +\twocolitem{{\bf \indexit{wxBITMAP\_TYPE\_ANY}}}{Will try to autodetect the format.} +\end{twocollist}} + +\docparam{mimetype}{MIME type string (for example 'image/jpeg')} + +\wxheading{Remarks} -The validity of these flags depends on the platform and wxWindows configuration. -If all possible wxWindows settings are used, the Windows platform supports BMP, BMP\_RESOURCE, -XPM\_DATA, and XPM. Under X, the available formats are BMP, GIF, XBM, and XPM.} +Depending on how wxWindows has been configured, not all formats may be available. + +Note : any handler other than BMP must be previously +initialized with \helpref{wxImage::AddHandler}{wximageaddhandler} or +\helpref{wxInitAllImageHandlers}{wxinitallimagehandlers}. \wxheading{See also} \helpref{wxImage::LoadFile}{wximageloadfile} +\pythonnote{Constructors supported by wxPython are:\par +\indented{2cm}{\begin{twocollist} +\twocolitem{{\bf wxImage(name, flag)}}{Loads an image from a file} +\twocolitem{{\bf wxNullImage()}}{Create a null image (has no size or +image data)} +\twocolitem{{\bf wxEmptyImage(width, height)}}{Creates an empty image +of the given size} +\twocolitem{{\bf wxImageFromMime(name, mimetype}}{Creates an image from +the given file of the given mimetype} +\twocolitem{{\bf wxImageFromBitmap(bitmap)}}{Creates an image from a +platform-dependent bitmap} +\end{twocollist}} +} + \membersection{wxImage::\destruct{wxImage}} \func{}{\destruct{wxImage}}{\void} @@ -87,6 +157,7 @@ of a given handler class in an application session.} \helpref{wxImageHandler}{wximagehandler} +\pythonnote{In wxPython this static method is named {\tt wxImage_AddHandler}.} \membersection{wxImage::CleanUpHandlers} \func{static void}{CleanUpHandlers}{\void} @@ -99,7 +170,15 @@ This function is called by wxWindows on exit. \constfunc{wxBitmap}{ConvertToBitmap}{\void} -Converts the image to a platform-specific bitmap object. +Converts the image to a platform-specific bitmap object. This has to be done +to actually display an image as you cannot draw an image directly on a window. +The resulting bitmap will use the colour depth of the current system which entails +that a colour reduction has to take place. + +When in 8-bit mode (PseudoColour mode), the GTK port will use a color cube created +on program start-up to look up colors. This ensures a very fast conversion, but +the image quality won't be perfect (and could be better for photo images using more +sophisticated dithering algorithms). \membersection{wxImage::Create}\label{wximagecreate} @@ -137,12 +216,18 @@ Finds the handler associated with the given extension and type. Finds the handler associated with the given image type. +\func{static wxImageHandler*}{FindHandlerMime}{\param{const wxString\& }{mimetype}} + +Finds the handler associated with the given MIME type. + \docparam{name}{The handler name.} \docparam{extension}{The file extension, such as ``bmp".} \docparam{imageType}{The image type, such as wxBITMAP\_TYPE\_BMP.} +\docparam{mimetype}{MIME type.} + \wxheading{Return value} A pointer to the handler if found, NULL otherwise. @@ -161,7 +246,9 @@ Returns the blue intensity at the given coordinate. \constfunc{unsigned char*}{GetData}{\void} -Returns the image data as an array. +Returns the image data as an array. This is most often used when doing +direct image manipulation. The return value points to an array of +chararcters in RGBGBRGB... format. \membersection{wxImage::GetGreen}\label{wximagegetgreen} @@ -209,6 +296,13 @@ Gets the green value of the mask colour. Gets the red value of the mask colour. +\membersection{wxImage::GetSubImage}\label{wximagegetsubimage} + +\constfunc{wxImage}{GetSubImage}{\param{const wxRect\&}{ rect}} + +Returns a sub image of the current one as long as the rect belongs entirely to +the image. + \membersection{wxImage::GetWidth}\label{wximagegetwidth} \constfunc{int}{GetWidth}{\void} @@ -229,14 +323,16 @@ Returns TRUE if there is a mask active, FALSE otherwise. \func{static void}{InitStandardHandlers}{\void} -Adds the standard image format handlers, which, depending on wxWindows -configuration, can be handlers for Windows image, Windows image resource, and XPM. +Internal use only. Adds standard image format handlers. It only install BMP +for the time being, which is used by wxBitmap. -This function is called by wxWindows on startup. +This function is called by wxWindows on startup, and shouldn't be called by +the user. \wxheading{See also} \helpref{wxImageHandler}{wximagehandler} +\helpref{wxInitAllImageHandlers}{wxinitallimagehandlers} \membersection{wxImage::InsertHandler} @@ -253,27 +349,44 @@ of a given handler class in an application session.} \membersection{wxImage::LoadFile}\label{wximageloadfile} -\func{bool}{LoadFile}{\param{const wxString\&}{ name}, \param{long}{ type}} +\func{bool}{LoadFile}{\param{const wxString\&}{ name}, \param{long}{ type = wxBITMAP\_TYPE\_ANY}} -Loads an image from a file. +\func{bool}{LoadFile}{\param{const wxString\&}{ name}, \param{const wxString\&}{ mimetype}} + +Loads an image from a file. If no handler type is provided, the library will +try to autodetect the format. + +\func{bool}{LoadFile}{\param{wxInputStream\&}{ stream}, \param{long}{ type}} + +\func{bool}{LoadFile}{\param{wxInputStream\&}{ stream}, \param{const wxString\&}{ mimetype}} + +Loads an image from an input stream. \wxheading{Parameters} -\docparam{name}{A filename. -The meaning of {\it name} is determined by the {\it type} parameter.} +\docparam{name}{Name of the file from which to load the image.} + +\docparam{stream}{Opened input stream from which to load the image. Currently, the stream must support seeking.} \docparam{type}{One of the following values: -\twocolwidtha{5cm} +\twocolwidtha{5cm}% \begin{twocollist} \twocolitem{{\bf wxBITMAP\_TYPE\_BMP}}{Load a Windows image file.} \twocolitem{{\bf wxBITMAP\_TYPE\_GIF}}{Load a GIF image file.} -\twocolitem{{\bf wxBITMAP\_TYPE\_XBM}}{Load an X image file.} -\twocolitem{{\bf wxBITMAP\_TYPE\_XPM}}{Load an XPM image file.} +\twocolitem{{\bf wxBITMAP\_TYPE\_JPEG}}{Load a JPEG image file.} +\twocolitem{{\bf wxBITMAP\_TYPE\_PCX}}{Load a PCX image file.} \twocolitem{{\bf wxBITMAP\_TYPE\_PNG}}{Load a PNG image file.} -\end{twocollist} +\twocolitem{{\bf wxBITMAP\_TYPE\_PNM}}{Load a PNM image file.} +\twocolitem{{\bf wxBITMAP\_TYPE\_TIF}}{Load a TIFF image file.} +\twocolitem{{\bf wxBITMAP\_TYPE\_ANY}}{Will try to autodetect the format.} +\end{twocollist}} + +\docparam{mimetype}{MIME type string (for example 'image/jpeg')} -The validity of these flags depends on the platform and wxWindows configuration.} +\wxheading{Remarks} + +Depending on how wxWindows has been configured, not all formats may be available. \wxheading{Return value} @@ -283,6 +396,17 @@ TRUE if the operation succeeded, FALSE otherwise. \helpref{wxImage::SaveFile}{wximagesavefile} +\pythonnote{In place of a single overloaded method name, wxPython +implements the following methods:\par +\indented{2cm}{\begin{twocollist} +\twocolitem{{\bf LoadFile(filename, type)}}{Loads an image of the given +type from a file} +\twocolitem{{\bf LoadMimeFile(filename, mimetype)}}{Loads an image of the given +mimetype from a file} +\end{twocollist}} +} + + \membersection{wxImage::Ok}\label{wximageok} \constfunc{bool}{Ok}{\void} @@ -310,24 +434,34 @@ TRUE if the handler was found and removed, FALSE otherwise. \func{bool}{SaveFile}{\param{const wxString\& }{name}, \param{int}{ type}} +\func{bool}{SaveFile}{\param{const wxString\& }{name}, \param{const wxString\&}{ mimetype}} + Saves a image in the named file. +\func{bool}{SaveFile}{\param{wxOutputStream\& }{stream}, \param{int}{ type}} + +\func{bool}{SaveFile}{\param{wxOutputStream\& }{stream}, \param{const wxString\&}{ mimetype}} + +Saves a image in the given stream. + \wxheading{Parameters} -\docparam{name}{A filename. The meaning of {\it name} is determined by the {\it type} parameter.} +\docparam{name}{Name of the file to save the image to.} -\docparam{type}{One of the following values: +\docparam{stream}{Opened output stream to save the image to.} + +\docparam{type}{Currently three types can be used: -\twocolwidtha{5cm} +\twocolwidtha{5cm}% \begin{twocollist} -\twocolitem{{\bf wxBITMAP\_TYPE\_BMP}}{Save a Windows image file.} -\twocolitem{{\bf wxBITMAP\_TYPE\_GIF}}{Save a GIF image file.} -\twocolitem{{\bf wxBITMAP\_TYPE\_XBM}}{Save an X image file.} -\twocolitem{{\bf wxBITMAP\_TYPE\_XPM}}{Save an XPM image file.} +\twocolitem{{\bf wxBITMAP\_TYPE\_JPEG}}{Save a JPEG image file.} \twocolitem{{\bf wxBITMAP\_TYPE\_PNG}}{Save a PNG image file.} -\end{twocollist} +\twocolitem{{\bf wxBITMAP\_TYPE\_PCX}}{Save a PCX image file (tries to save as 8-bit if possible, falls back to 24-bit otherwise).} +\twocolitem{{\bf wxBITMAP\_TYPE\_PNM}}{Save a PNM image file (as raw RGB always).} +\twocolitem{{\bf wxBITMAP\_TYPE\_TIF}}{Save a TIFF image file.} +\end{twocollist}} -The validity of these flags depends on the platform and wxWindows configuration.} +\docparam{mimetype}{MIME type.} \wxheading{Return value} @@ -341,17 +475,87 @@ Depending on how wxWindows has been configured, not all formats may be available \helpref{wxImage::LoadFile}{wximageloadfile} +\pythonnote{In place of a single overloaded method name, wxPython +implements the following methods:\par +\indented{2cm}{\begin{twocollist} +\twocolitem{{\bf SaveFile(filename, type)}}{Saves the image using the given +type to the named file} +\twocolitem{{\bf SaveMimeFile(filename, mimetype)}}{Saves the image using the given +mimetype to the named file} +\end{twocollist}} +} + +\membersection{wxImage::Replace}\label{wximagereplace} + +\func{void}{Replace}{\param{unsigned char}{ r1}, \param{unsigned char}{ g1}, \param{unsigned char}{ b1}, +\param{unsigned char}{ r2}, \param{unsigned char}{ g2}, \param{unsigned char}{ b2}} + +Replaces the colour specified by {\it r1,g1,b1} by the colour {\it r2,g2,b2}. + +\membersection{wxImage::Rescale}\label{wximagerescale} + +\func{wxImage \&}{Rescale}{\param{int}{ width}, \param{int}{ height}} + +Changes the size of the image in-place: after a call to this function, the +image will have the given width and height. + +Returns the (modified) image itself. + +\wxheading{See also} + +\helpref{Scale}{wximagescale} + +\membersection{wxImage::Rotate}\label{wximagererotate} + +\func{wxImage}{Rotate}{\param{double}{ angle}, \param{const wxPoint\& }{rotationCentre}, + \param{bool}{ interpolating = TRUE}, \param{wxPoint*}{ offsetAfterRotation = NULL}} + +Rotates the image about the given point, by {\it angle} radians. Passing TRUE +to {\it interpolating} results in better image quality, but is slower. + +Returns the rotated image, leaving this image intact. + \membersection{wxImage::Scale}\label{wximagescale} -\func{wxImage}{Scale}{\param{int}{ width}, \param{int}{ height}} +\constfunc{wxImage}{Scale}{\param{int}{ width}, \param{int}{ height}} + +Returns a scaled version of the image. This is also useful for +scaling bitmaps in general as the only other way to scale bitmaps +is to blit a wxMemoryDC into another wxMemoryDC. + +It may be mentioned that the GTK port uses this function internally +to scale bitmaps when using mapping mode in wxDC. + +Example: + +\begin{verbatim} + // get the bitmap from somewhere + wxBitmap bmp = ...; + + // rescale it to have size of 32*32 + if ( bmp.GetWidth() != 32 || bmp.GetHeight() != 32 ) + { + wxImage image(bmp); + bmp = image.Scale(32, 32).ConvertToBitmap(); + + // another possibility: + image.Rescale(32, 32); + bmp = image; + } + +\end{verbatim} + +\wxheading{See also} -Returns a scaled version of the image. +\helpref{Rescale}{wximagerescale} \membersection{wxImage::SetData}\label{wximagesetdata} \func{void}{SetData}{\param{unsigned char*}{data}} -Sets the image data. +Sets the image data without performing checks. The data given must have +the size (width*height*3) or results will be unexpected. Don't use this +method if you aren't sure you know what you are doing. \membersection{wxImage::SetMask}\label{wximagesetmask} @@ -363,13 +567,17 @@ Specifies whether there is a mask or not. The area of the mask is determined by \func{void}{SetMaskColour}{\param{unsigned char }{red}, \param{unsigned char }{blue}, \param{unsigned char }{green}} -Sets the mask colour for this image. +Sets the mask colour for this image (and tells the image to use the mask). \membersection{wxImage::SetRGB}\label{wximagesetrgb} \func{void}{SetRGB}{\param{int }{x}, \param{int }{y}, \param{unsigned char }{red}, \param{unsigned char }{blue}, \param{unsigned char }{green}} -Sets the pixel at the given coordinate. +Sets the pixel at the given coordinate. This routine performs bounds-checks +for the coordinate so it can be considered a safe way to manipulate the +data, but in some cases this might be too slow so that the data will have to +be set directly. In that case you will have to get access to the image data +using the \helpref{GetData}{wximagegetdata} method. \membersection{wxImage::operator $=$} @@ -426,13 +634,25 @@ If you wish to extend the capabilities of wxImage, derive a class from wxImageHa and add the handler using \helpref{wxImage::AddHandler}{wximageaddhandler} in your application initialisation. +\wxheading{Note (Legal Issue)} + +This software is based in part on the work of the Independent JPEG Group. + +(Applies when wxWindows is linked with JPEG support. wxJPEGHandler uses libjpeg +created by IJG.) + \wxheading{Derived from} \helpref{wxObject}{wxobject} +\wxheading{Include files} + + + \wxheading{See also} \helpref{wxImage}{wximage} +\helpref{wxInitAllImageHandlers}{wxinitallimagehandlers} \latexignore{\rtfignore{\wxheading{Members}}} @@ -461,24 +681,49 @@ Gets the name of this handler. Gets the file extension associated with this handler. +\membersection{wxImageHandler::GetImageCount}\label{wximagehandlergetimagecount} + +\func{int}{GetImageCount}{\param{wxInputStream\&}{ stream}} + +If the image file contains more than one image and the image handler is capable +of retrieving these individually, this function will return the number of +available images. + +\docparam{stream}{Opened input stream for reading image data. Currently, the stream must support seeking.} + +\wxheading{Return value} + +Number of available images. For most image handles, this defaults to 1. + \membersection{wxImageHandler::GetType} \constfunc{long}{GetType}{\void} Gets the image type associated with this handler. +\membersection{wxImageHandler::GetMimeType} + +\constfunc{wxString}{GetMimeType}{\void} + +Gets the MIME type associated with this handler. + \membersection{wxImageHandler::LoadFile}\label{wximagehandlerloadfile} -\func{bool}{LoadFile}{\param{wxImage* }{image}, \param{const wxString\&}{ name}} +\func{bool}{LoadFile}{\param{wxImage* }{image}, \param{wxInputStream\&}{ stream}, \param{bool}{ verbose=TRUE}, \param{int}{ index=0}} -Loads a image from a file or resource, putting the resulting data into {\it image}. +Loads a image from a stream, putting the resulting data into {\it image}. If the image file contains +more than one image and the image handler is capable of retrieving these individually, {\it index} +indicates which image to read from the stream. \wxheading{Parameters} \docparam{image}{The image object which is to be affected by this operation.} -\docparam{name}{Either a filename or a Windows resource name. -The meaning of {\it name} is determined by the {\it type} parameter.} +\docparam{stream}{Opened input stream for reading image data.} + +\docparam{verbose}{If set to TRUE, errors reported by the image handler will produce wxLogMessages.} + +\docparam{index}{The index of the image in the file (starting from zero).} \wxheading{Return value} @@ -492,15 +737,15 @@ TRUE if the operation succeeded, FALSE otherwise. \membersection{wxImageHandler::SaveFile}\label{wximagehandlersavefile} -\func{bool}{SaveFile}{\param{wxImage* }{image}, \param{const wxString\& }{name}} +\func{bool}{SaveFile}{\param{wxImage* }{image}, \param{wxOutputStream\& }{stream}} -Saves a image in the named file. +Saves a image in the output stream. \wxheading{Parameters} \docparam{image}{The image object which is to be affected by this operation.} -\docparam{name}{A filename. The meaning of {\it name} is determined by the {\it type} parameter.} +\docparam{stream}{Opened output stream for writing the data.} \wxheading{Return value} @@ -543,3 +788,13 @@ Sets the handler type. \docparam{name}{Handler type.} +\membersection{wxImageHandler::SetMimeType} + +\func{void}{SetMimeType}{\param{const wxString\& }{mimetype}} + +Sets the handler MIME type. + +\wxheading{Parameters} + +\docparam{mimename}{Handler MIME type.} +