To find resources such as sound and image files.

• §1. Resource finder

§1. Resource finder. This simple function is shared by the code for figures, sound effects and internal data files. When Inform reads a sentence such as:

    Sound of Organ is the file "Passacaglia.aiff".

it needs to find this file, which will either be in the materials for the project, or in materials for the extension in which this sentence occurs (if it occurs in an extension). In either case, it'll be in the Sounds subdirectory. Here "Sounds" is what we will call the department name for sound effects.

This code was introduced as part of the implementation of IE-0001, and for the first time throws problem messages if named resources do not exist.

int check_resources_are_present = TRUE;

void ResourceFinder::set_mode(int val) {
    check_resources_are_present = val;  set by -resource-checking at command line
}

filename *ResourceFinder::find_resource?Usage of ResourceFinder::find_resource:
Figures - §5
Sound Effects - §5
Internal Files - §5(text_stream *department, text_stream *leaf, wording W) {
    inform_extension *E = NULL;
    if (Wordings::nonempty(W))
        E = Extensions::corresponding_to(Lexer::file_of_origin(Wordings::first_wn(W)));

    pathname *materials_dept = Pathnames::down(Task::resources_path(), department);
    pathname *extension_dept = E?(Pathnames::down(Extensions::materials_path(E), department)):NULL;
    if (extension_dept) Look for an extension resource1.1;
    if (materials_dept) Look for a regular materials resource1.2;

    Problems::quote_source(1, current_sentence);
    Problems::quote_wording(2, W);
    Problems::quote_stream(3, department);
    StandardProblems::handmade_problem(Task::syntax_tree(), _p_(Untestable));
    Problems::issue_problem_segment(
        "You wrote %1, which means I am looking for a file called %2, but I'm "
        "unable to find it. ");
    if (extension_dept)
        Problems::issue_problem_segment(
            "The file should either be in the '%3' subfolder of the materials folder, "
            "or in the 'Materials/%3' subfolder of this extension.");
    else
        Problems::issue_problem_segment(
            "The file should be in the '%3' subfolder of the materials folder.");
    Problems::issue_problem_end();
    return NULL;
}

§1.1. So here we're reading the line from an extension, say Leipzig Organ Recitals. We first look for an audio file called something like Leipzig Organ Recitals-v1/Materials/Sounds/Passacaglia.aiff. If that exists, then we know this is a resource which the extension provides; but we still give the project a chance to override that with a file Project.materials/Sounds/Leipzig Organ Recitals/Passacaglia.aiff, which would be used in preference.

Look for an extension resource1.1 =

    filename *F = ResourceFinder::if_present(Filenames::in(extension_dept, leaf));
    if (F) {
        pathname *materials_override =
            Pathnames::down(materials_dept, E->as_copy->edition->work->title);
        filename *OF = ResourceFinder::if_present(Filenames::in(materials_override, leaf));
        if (OF) return OF;
        return F;
    }

• This code is used in §1.

§1.2. Otherwise the resource is not provided by the extension in which the sentence occurs, or else, the sentence does not occur in an extension. (Of course, this is by far the most likely thing.) Here we just look in the project's materials folder, so for example Project.materials/Sounds/Passacaglia.aiff.

Look for a regular materials resource1.2 =

    filename *F = Filenames::in(materials_dept, leaf);
    if (check_resources_are_present == FALSE) return F;
    F = ResourceFinder::if_present(F);
    if (F) return F;

• This code is used in §1.

§2. This checks the existence of such a file on disc. We're not going to fret over the possibility of accidentally opening a directory here.

filename *ResourceFinder::if_present?Usage of ResourceFinder::if_present:
§1.1, §1.2(filename *F) {
    FILE *handle = Filenames::fopen(F, "rb");
    if (handle == NULL) return NULL;
    fclose(handle);
    return F;
}