// ========================================================== // Loader/Saver Plugin Cradle // // Design and implementation by // - Floris van den Berg (flvdberg@wxs.nl) // - Hervé Drolon (drolon@infonie.fr) // // This file is part of FreeImage 3 // // COVERED CODE IS PROVIDED UNDER THIS LICENSE ON AN "AS IS" BASIS, WITHOUT WARRANTY // OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION, WARRANTIES // THAT THE COVERED CODE IS FREE OF DEFECTS, MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE // OR NON-INFRINGING. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE COVERED // CODE IS WITH YOU. SHOULD ANY COVERED CODE PROVE DEFECTIVE IN ANY RESPECT, YOU (NOT // THE INITIAL DEVELOPER OR ANY OTHER CONTRIBUTOR) ASSUME THE COST OF ANY NECESSARY // SERVICING, REPAIR OR CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL // PART OF THIS LICENSE. NO USE OF ANY COVERED CODE IS AUTHORIZED HEREUNDER EXCEPT UNDER // THIS DISCLAIMER. // // Use at your own risk! // ========================================================== #include #include #include "FreeImage.h" #include "Utilities.h" // ========================================================== BOOL APIENTRY DllMain(HANDLE hModule, DWORD ul_reason_for_call, LPVOID lpReserved) { switch (ul_reason_for_call) { case DLL_PROCESS_ATTACH : case DLL_PROCESS_DETACH : case DLL_THREAD_ATTACH : case DLL_THREAD_DETACH : break; } return TRUE; } // ========================================================== // Plugin Interface // ========================================================== static int s_format_id; // ========================================================== // Plugin Implementation // ========================================================== /** Returns the format string for the plugin. Each plugin, both internal in the DLL and external in a .fip file, must have a unique format string to be addressable. */ static const char * DLL_CALLCONV Format() { return "CRADLE"; } /** Returns a description string for the plugin. Though a description is not necessary per-se, it is advised to return an unique string in order to tell the user what type of bitmaps this plugin will read and/or write. */ static const char * DLL_CALLCONV Description() { return "Here comes the description for your image loader/saver"; } /** Returns a comma separated list of file extensions indicating what files this plugin can open. no spaces or whatsoever are allowed. The list, being used by FreeImage_GetFIFFromFilename, is usually used as a last resort in finding the type of the bitmap we are dealing with. Best is to check the first few bytes on the low-level bits level first and compare them with a known signature . If this fails, FreeImage_GetFIFFromFilename can be used. */ static const char * DLL_CALLCONV Extension() { return "ext1,ext2"; } /** RegExpr is only needed for the Qt wrapper It allows the Qt mechanism for loading bitmaps to identify the bitmap */ static const char * DLL_CALLCONV RegExpr() { return NULL; } /** Returns a MIME content type string for that format (MIME stands for Multipurpose Internet Mail Extension). */ static const char * DLL_CALLCONV MimeType() { return "image/myformat"; } /** FreeImage's internal way of seeing if a bitmap is of the desired type. When the type of a bitmap is to be retrieved, FreeImage runs Validate for each registered plugin until one returns true. If a plugin doesn't have a validate function, a return value of false is assumed. You can always force to use a particular plugin by directly specifying it on the command line, but this can result in a dead DLL if the plugin was not made for the bitmap. */ static BOOL DLL_CALLCONV Validate(FreeImageIO &io, fi_handle handle) { return FALSE; } /** SupportsExportDepth is the first in a possible range of new plugin functions to ask specific information to that plugin. This function returns TRUE if it can save a bitmap in the required bitdepth. If it can't the bitmap has to be converted by the user or another plugin has to be chosen. */ static BOOL DLL_CALLCONV SupportsExportDepth(int depth) { return FALSE; } /** Returns TRUE if the plugin belonging to the given FREE_IMAGE_FORMAT can save a bitmap in the desired data type, returns FALSE otherwise. Currently, TIFF is the only plugin able to save all non-standard images. The PNG plugin is able to save unsigned 16-bit images. */ static BOOL DLL_CALLCONV SupportsExportType(FREE_IMAGE_TYPE type) { return (type == FIT_BITMAP) ? TRUE : FALSE; } /** SupportsICCProfiles informs FreeImage that a plugin supports ICC profiles. This function returns TRUE if the plugin can load and save a profile. ICC profile information is accessed via freeimage->get_icc_profile_proc(dib) */ static BOOL DLL_CALLCONV SupportsICCProfiles() { return FALSE; } // ---------------------------------------------------------- /** Loads a bitmap into memory. On entry it is assumed that the bitmap to be loaded is of the correct type. If the bitmap is of an incorrect type, the plugin might not gracefully fail but crash or enter an endless loop. It is also assumed that all the bitmap data is available at one time. If the bitmap is not complete, for example because it is being downloaded while loaded, the plugin might also not gracefully fail. The Load function has the following parameters: The first parameter (FreeImageIO *io) is a structure providing function pointers in order to make use of FreeImage's IO redirection. Using FreeImage's file i/o functions instead of standard ones it is garantueed that all bitmap types, both current and future ones, can be loaded from memory, file cabinets, the internet and more. The second parameter (fi_handle handle) is a companion of FreeImageIO and can be best compared with the standard FILE* type, in a generalized form. The third parameter (int page) indicates wether we will be loading a certain page in the bitmap or if we will load the default one. This parameter is only used if the plugin supports multi-paged bitmaps, e.g. cabinet bitmaps that contain a series of images or pages. If the plugin does support multi-paging, the page parameter can contain either a number higher or equal to 0 to load a certain page, or -1 to load the default page. If the plugin does not support multi-paging, the page parameter is always -1. The fourth parameter (int flags) manipulates the load function to load a bitmap in a certain way. Every plugin has a different flag parameter with different meanings. The last parameter (void *data) can contain a special data block used when the file is read multi-paged. Because not every plugin supports multi-paging not every plugin will use the data parameter and it will be set to NULL.However, when the plugin does support multi-paging the parameter contains a pointer to a block of data allocated by the Open function. */ static FIBITMAP * DLL_CALLCONV Load(FreeImageIO *io, fi_handle handle, int page, int flags, void *data) { return NULL; } static BOOL DLL_CALLCONV Save(FreeImageIO *io, FIBITMAP *dib, fi_handle handle, int page, int flags, void *data) { return FALSE; } // ========================================================== // Init // ========================================================== /** Initialises the plugin. The first parameter (Plugin *plugin) contains a pointer to a pre-allocated Plugin structure wherein pointers to the available plugin functions has to be stored. The second parameter (int format_id) is an identification number that the plugin may use to show plugin specific warning messages or other information to the user. The plugin number is generated by FreeImage and can differ everytime the plugin is initialised. If you want to create your own plugin you have to take some rules into account. Plugin functions have to be compiled __stdcall using the multithreaded c runtime libraries. Throwing exceptions in plugin functions is allowed, as long as those exceptions are being caught inside the same plugin. It is forbidden for a plugin function to directly call FreeImage functions or to allocate memory and pass it to the main DLL. Exception to this rule is the special file data block that may be allocated the Open function. Allocating a FIBITMAP inside a plugin can be using the function allocate_proc in the FreeImage structure, which will allocate the memory using the DLL's c runtime library. */ void DLL_CALLCONV Init(Plugin *plugin, int format_id) { s_format_id = format_id; plugin->format_proc = Format; plugin->description_proc = Description; plugin->extension_proc = Extension; plugin->regexpr_proc = RegExpr; plugin->open_proc = NULL; plugin->close_proc = NULL; plugin->pagecount_proc = NULL; plugin->pagecapability_proc = NULL; plugin->load_proc = Load; plugin->save_proc = Save; plugin->validate_proc = Validate; plugin->mime_proc = MimeType; plugin->supports_export_bpp_proc = SupportsExportDepth; plugin->supports_export_type_proc = SupportsExportType; plugin->supports_icc_profiles_proc = SupportsICCProfiles; }