Function pj_expand_init_internal

ThirdParty/libproj/vtklibproj/src/init.cpp:358–397

/

/*****************************************************************************/
static paralist *pj_expand_init_internal(PJ_CONTEXT *ctx, paralist *init, int allow_init_epsg) {
/******************************************************************************
Append expansion of <key> to the paralist <init>. The expansion is appended,
rather than inserted at <init>'s place, since <init> may contain
overrides to the expansion. These must take precedence, and hence come first
in the expanded list.

Consider e.g. the key 'foo:bar' which (hypothetically) expands to 'proj=utm
zone=32 ellps=GRS80', i.e. a UTM projection on the GRS80 ellipsoid.

The expression 'init=foo:bar ellps=intl' will then expand to:

           'init=foo:bar ellps=intl proj=utm zone=32 ellps=GRS80',

where 'ellps=intl' precedes 'ellps=GRS80', and hence takes precedence,
turning the expansion into an UTM projection on the Hayford ellipsoid.

Note that 'init=foo:bar' stays in the list. It is ignored after expansion.

******************************************************************************/
    paralist *last;
    paralist *expn;

    /* Nowhere to start? */
    if (nullptr==init)
        return nullptr;

    expn = get_init(ctx, init->param, allow_init_epsg);

    /* Nothing in expansion? */
    if (nullptr==expn)
        return nullptr;

    /* Locate  the end of the list */
    for (last = init;  last && last->next;  last = last->next);

    /* Then append and return */
    last->next = expn;
    return init;
}

paralist *pj_expand_init(PJ_CONTEXT *ctx, paralist *init) {
    return pj_expand_init_internal(ctx, init, TRUE);