X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/1acd7ba6f2ffc10369ed74a2ac4d8a28eadf1151..12a44087e448071f9f108208a0a88e908d543d44:/docs/latex/wx/image.tex diff --git a/docs/latex/wx/image.tex b/docs/latex/wx/image.tex index 91e691bafa..281fd8a7e1 100644 --- a/docs/latex/wx/image.tex +++ b/docs/latex/wx/image.tex @@ -7,7 +7,10 @@ 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. +wxBitmap object must be created from it, and that bitmap drawn on the wxDC, using +wxDC::DrawBitmap. + +This class is currently only available under GTK and Windows. \wxheading{Derived from} @@ -31,13 +34,15 @@ 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 = wxIMAGE\_TYPE\_PNG}} Loads an image from a file. @@ -53,16 +58,14 @@ Loads an image from a file. \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\_PNG}}}{Load a PNG bitmap file.} +\twocolitem{{\bf \indexit{wxIMAGE\_TYPE\_BMP}}}{Load a Windows bitmap file.} +\twocolitem{{\bf \indexit{wxIMAGE\_TYPE\_PNG}}}{Load a PNG bitmap file.} \end{twocollist} 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.} +If all possible wxWindows settings are used, the loading a BMP (Windows bitmap) file +and a PNG (portable network graphics) file is supported on all platforms that +implement wxImage.} \wxheading{See also} @@ -99,7 +102,13 @@ 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 (crude) colour reduction has to take place. Especially when converting +to 8-bit (or even less) bitmaps, the routine is slow and will reduce the +quality of the resulting bitmap. A proper set of colour reduction methods has +not yet been written. \membersection{wxImage::Create}\label{wximagecreate} @@ -141,7 +150,7 @@ Finds the handler associated with the given image type. \docparam{extension}{The file extension, such as ``bmp".} -\docparam{imageType}{The image type, such as wxBITMAP\_TYPE\_BMP.} +\docparam{imageType}{The image type, such as wxIMAGE\_TYPE\_BMP.} \wxheading{Return value} @@ -161,7 +170,9 @@ 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} @@ -230,7 +241,8 @@ 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. +configuration, can be handlers for Windows BMP (loading) and PNG +(loading and saving) file formats. This function is called by wxWindows on startup. @@ -266,11 +278,8 @@ The meaning of {\it name} is determined by the {\it type} parameter.} \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\_PNG}}{Load a PNG image file.} +\twocolitem{{\bf wxIMAGE\_TYPE\_BMP}}{Load a Windows image file.} +\twocolitem{{\bf wxIMAGE\_TYPE\_PNG}}{Load a PNG image file.} \end{twocollist} The validity of these flags depends on the platform and wxWindows configuration.} @@ -316,18 +325,15 @@ Saves a image in the named file. \docparam{name}{A filename. The meaning of {\it name} is determined by the {\it type} parameter.} -\docparam{type}{One of the following values: +\docparam{type}{Currently only one type can be used: \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\_PNG}}{Save a PNG image file.} +\twocolitem{{\bf wxIMAGE\_TYPE\_PNG}}{Save a PNG image file.} \end{twocollist} -The validity of these flags depends on the platform and wxWindows configuration.} +The validity of these flags depends on the platform and wxWindows configuration +as well as user-added handlers.} \wxheading{Return value} @@ -345,13 +351,19 @@ Depending on how wxWindows has been configured, not all formats may be available \func{wxImage}{Scale}{\param{int}{ width}, \param{int}{ height}} -Returns a scaled version of the image. +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 do blit a wxMemoryDC into another wxMemoryDC. Windows can such scaling +itself, but on GTK scaling bitmaps is done using this routine +internally. \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} @@ -369,7 +381,10 @@ Sets the mask colour for this image. \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 have to get that data by calling GetData(). \membersection{wxImage::operator $=$}