void run_grammar(tx_grammar_literal *lit) {
size_t i;
int row, col;
pixel px;
tx_grammar_literal *chosen = NULL;
tx_grammar_expansion_site *ges = NULL;
// Create a list of expansion sites:
list *expansion_sites = create_list();
// Start by loading our source file into our result texture and calling our
// pre-processing filter if we have one:
if (lit->filename == NULL) {
if (lit->anchor_x == 0 || lit->anchor_y == 0) {
fprintf(
stderr,
"Error: grammar with NULL filename must have nonzero anchor values.\n"
);
fprintf(stderr, "(found: %zu, %zu)\n", lit->anchor_x, lit->anchor_y);
exit(EXIT_FAILURE);
}
lit->result = create_texture(lit->anchor_x, lit->anchor_y);
} else {
lit->result = load_texture_from_png(lit->filename);
}
if (lit->preprocess != NULL) {
(*(lit->preprocess))(lit->result, lit->preargs);
}
// Now expand each child reference at random. Note that due to the low
// resolution of the pseudo-random process, any item with a weight of less
// than 1/65536th of the total weight of all items in a disjunction will
// never be picked.
for (col = 0; col < lit->result->width; ++col) {
for (row = 0; row < lit->result->height; ++row) {
px = tx_get_px(lit->result, col, row);
for (i = 0; i < N_GRAMMAR_KEYS; ++i) {
if (px == GRAMMAR_KEYS[i] && lit->children[i] != NULL) {
chosen = choose_child(
lit->children[i],
hash_3d(hash_2d(hash_1d((ptrdiff_t) lit), i), col, row)
);
if (chosen->result == NULL) {
run_grammar(chosen);
}
ges = create_expansion_site();
ges->col = col;
ges->row = row;
ges->literal = chosen;
l_append_element(expansion_sites, ges);
ges = NULL; // destroy_list later on takes care of the memory used.
}
}
}
}
l_witheach(expansion_sites, (void *) lit, expand_literal_into);
// Clean up our list of expansion sites:
destroy_list(expansion_sites);
// Before wrapping up call our post-processing function if it exists:
if (lit->postprocess != NULL) {
(*(lit->postprocess))(lit->result, lit->postargs);
}
}
static VALUE run_gazelle_parse(VALUE self, VALUE input, bool run_callbacks) {
VALUE compiled_file_stream = rb_iv_get(self, "@filename");
char *filename = RSTRING_TO_PTR(compiled_file_stream);
char *input_string = RSTRING_TO_PTR(input);
if (run_grammar(self, filename, input, input_string, run_callbacks))
return Qfalse;
return(terminal_error ? Qfalse : Qtrue);
}
