From c3289b5f5cccad9365b6c917f3cda2dd98efa1b5 Mon Sep 17 00:00:00 2001 From: David Robillard Date: Sun, 17 Oct 2010 07:16:09 +0000 Subject: Add atom-helpers.h. --- ext/atom.lv2/atom-helpers.h | 109 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 109 insertions(+) create mode 100644 ext/atom.lv2/atom-helpers.h (limited to 'ext/atom.lv2') diff --git a/ext/atom.lv2/atom-helpers.h b/ext/atom.lv2/atom-helpers.h new file mode 100644 index 0000000..801bd32 --- /dev/null +++ b/ext/atom.lv2/atom-helpers.h @@ -0,0 +1,109 @@ +/* lv2_atom_helpers.h - Helper functions for the LV2 atoms extension. + * Copyright (C) 2008-2010 David Robillard + * + * 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 + */ + +#ifndef LV2_ATOM_HELPERS_H +#define LV2_ATOM_HELPERS_H + +#include +#include +#include +#include "lv2/http/lv2plug.in/ns/ext/atom/atom.h" + +/** @file + * Helper functions for the LV2 Atom extension + * . + * + * These functions are provided for convenience only, use of them is not + * required for supporting atoms (i.e. the definition of atoms in memory + * is described in atom.h and NOT by this API). + * + * Note that these functions are all static inline which basically means: + * do not take the address of these functions. + */ + + +/** Pad a size to 64 bits (for atom sizes) */ +static inline uint16_t +lv2_atom_pad_size(uint16_t size) +{ + return (size + 7) & (~7); +} + +typedef LV2_Atom_Property* LV2_Atom_Dict_Iter; + +static inline LV2_Atom_Dict_Iter +lv2_atom_dict_get_iter(LV2_Atom_Property* prop) +{ + return (LV2_Atom_Dict_Iter)prop; +} + +static inline bool +lv2_atom_dict_iter_is_end(LV2_Atom* dict, LV2_Atom_Dict_Iter iter) +{ + return (uint8_t*)iter >= (dict->body + dict->size); +} + +static inline bool +lv2_atom_dict_iter_equals(const LV2_Atom_Dict_Iter l, const LV2_Atom_Dict_Iter r) +{ + return l == r; +} + +static inline LV2_Atom_Dict_Iter +lv2_atom_dict_iter_next(const LV2_Atom_Dict_Iter iter) +{ + return (LV2_Atom_Dict_Iter)( + (uint8_t*)iter + sizeof(LV2_Atom_Property) + lv2_atom_pad_size(iter->object.size)); +} + +static inline LV2_Atom_Property* +lv2_atom_dict_iter_get(LV2_Atom_Dict_Iter iter) +{ + return (LV2_Atom_Property*)iter; +} + +/** Append a Property body to an Atom that contains properties (e.g. atom:Dict). + * This function will write the property body (not including an LV2_Object + * header) at lv2_atom_pad_size(body + size). Thus, it can be used with any + * Atom type that contains headerless 64-bit aligned properties. + * @param dict Pointer to the atom that contains the property to add. dict.size + * must be valid, but dict.type is ignored. + * @param size Must point to the size field of the container atom, and will be + * padded up to 64 bits then increased by @a value_size. + * @param body Must point to the body of the container atom. + * @return a pointer to the new LV2_Atom_Property in @a body. + */ +static inline LV2_Atom_Property* +lv2_atom_append_property(LV2_Atom* dict, + uint32_t key, + uint16_t value_type, + uint16_t value_size, + const char* value_body) +{ + dict->size = lv2_atom_pad_size(dict->size); + LV2_Atom_Property* prop = (LV2_Atom_Property*)(dict->body + dict->size); + prop->predicate = key; + prop->object.type = value_type; + prop->object.size = value_size; + memcpy(prop->object.body, value_body, value_size); + dict->size += sizeof(uint32_t) + sizeof(LV2_Atom_Property) + value_size; + return prop; +} + +#endif /* LV2_ATOM_HELPERS_H */ + -- cgit v1.2.1