diff options
author | David Robillard <d@drobilla.net> | 2010-10-04 18:21:08 +0000 |
---|---|---|
committer | David Robillard <d@drobilla.net> | 2010-10-04 18:21:08 +0000 |
commit | cef9811dac46a9d54dab0f0d82ce5c3ae032fc7c (patch) | |
tree | 632b911da25fc24b6b3d331d7ceffc22606b8e5b /ext/uri-map.lv2/uri-map.h | |
parent | 61842745ab15454ee66be54a6f3bcc148a75406f (diff) | |
download | lv2-cef9811dac46a9d54dab0f0d82ce5c3ae032fc7c.tar.xz |
Initial import of lv2plug.in universe.
Diffstat (limited to 'ext/uri-map.lv2/uri-map.h')
-rw-r--r-- | ext/uri-map.lv2/uri-map.h | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/ext/uri-map.lv2/uri-map.h b/ext/uri-map.lv2/uri-map.h new file mode 100644 index 0000000..d0d04e4 --- /dev/null +++ b/ext/uri-map.lv2/uri-map.h @@ -0,0 +1,87 @@ +/* lv2_uri_map.h - C header file for the LV2 URI Map extension. + * + * Copyright (C) 2008-2009 David Robillard <http://drobilla.net> + * + * This header is free software; you can redistribute it and/or modify it + * under the terms of the GNU Lesser General Public License as published + * by the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This header is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public + * License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this header; if not, write to the Free Software Foundation, + * Inc., 59 Temple Place, Suite 330, Boston, MA 01222-1307 USA + */ + +/** @file + * C header for the LV2 URI Map extension <http://lv2plug.in/ns/ext/uri-map>. + * + * This extension defines a simple mechanism for plugins to map URIs to + * integers, usually for performance reasons (e.g. processing events + * typed by URIs in real time). The expected use case is for plugins to + * map URIs to integers for things they 'understand' at instantiation time, + * and store those values for use in the audio thread without doing any string + * comparison. This allows the extensibility of RDF with the performance of + * integers (or centrally defined enumerations). + */ + +#ifndef LV2_URI_MAP_H +#define LV2_URI_MAP_H + +#define LV2_URI_MAP_URI "http://lv2plug.in/ns/ext/uri-map" + +#include <stdint.h> + + +/** Opaque pointer to host data. */ +typedef void* LV2_URI_Map_Callback_Data; + + +/** The data field of the LV2_Feature for this extension. + * + * To support this feature the host must pass an LV2_Feature struct to the + * plugin's instantiate method with URI "http://lv2plug.in/ns/ext/uri-map" + * and data pointed to an instance of this struct. + */ +typedef struct { + + /** Opaque pointer to host data. + * + * The plugin MUST pass this to any call to functions in this struct. + * Otherwise, it must not be interpreted in any way. + */ + LV2_URI_Map_Callback_Data callback_data; + + /** Get the numeric ID of a URI from the host. + * + * @param callback_data Must be the callback_data member of this struct. + * @param map The 'context' of this URI. Certain extensions may define a + * URI that must be passed here with certain restrictions on the + * return value (e.g. limited range). This value may be NULL if + * the plugin needs an ID for a URI in general. + * @param uri The URI to be mapped to an integer ID. + * + * This function is referentially transparent - any number of calls with + * the same arguments is guaranteed to return the same value over the life + * of a plugin instance (though the same URI may return different values + * with a different map parameter). However, this function is not + * necessarily very fast: plugins should cache any IDs they might need in + * performance critical situations. + * The return value 0 is reserved and means an ID for that URI could not + * be created for whatever reason. Extensions may define more precisely + * what this means, but in general plugins should gracefully handle 0 + * and consider whatever they wanted the URI for "unsupported". + */ + uint32_t (*uri_to_id)(LV2_URI_Map_Callback_Data callback_data, + const char* map, + const char* uri); + +} LV2_URI_Map_Feature; + + +#endif /* LV2_URI_MAP_H */ + |