til: make builtins first-class modules w/new flag

Also move builtins to a separate listing while at it

For now this results in the builtins showing up in the modules
list alongside the actual rendering modules.  Future work must
refine this UX, maybe by adding some metadata to the spec.values
for categorizing/prioritizing what's shown always vs. what's
present but hidden without asking to be shown hidden stuff or
whatever.

Just consolidating some junk and working towards every nested
module setup going through the same machinery, and always being
able to access the builtins.

1 files changed, 167 insertions, 0 deletions

diff --git a/src/til_builtins.c b/src/til_builtins.c
new file mode 100644
index 0000000..7a36d23
--- /dev/null
+++ b/src/til_builtins.c
@@ -0,0 +1,167 @@
+#include "til.h"
+#include "til_fb.h"
+#include "til_module_context.h"
+#include "til_settings.h"
+#include "til_stream.h"
+
+#include "libs/txt/txt.h" /* for rendering some diagnostics (ref built-in)) */
+
+
+/* "blank" built-in module */
+static void _blank_prepare_frame(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan)
+{
+	*res_frame_plan = (til_frame_plan_t){ .fragmenter = til_fragmenter_slice_per_cpu };
+}
+
+
+static void _blank_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+{
+	til_fb_fragment_clear(*fragment_ptr);
+}
+
+
+til_module_t	_blank_module = {
+	.prepare_frame = _blank_prepare_frame,
+	.render_fragment = _blank_render_fragment,
+	.name = "blank",
+	.description = "Blanker (built-in)",
+	.author = "built-in",
+};
+
+
+/* "noop" built-in module */
+til_module_t	_noop_module = {
+	.name = "noop",
+	.description = "Nothing-doer (built-in)",
+	.author = "built-in",
+	.flags = TIL_MODULE_BUILTIN,
+};
+
+
+/* "ref" built-in module */
+typedef struct _ref_setup_t {
+	til_setup_t		til_setup;
+
+	char			*path;
+} _ref_setup_t;
+
+
+typedef struct _ref_context_t {
+	til_module_context_t	til_module_context;
+
+	til_module_context_t	*ref;
+} _ref_context_t;
+
+
+static til_module_context_t * _ref_create_context(const til_module_t *module, til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, til_setup_t *setup)
+{
+	_ref_context_t	*ctxt;
+
+	ctxt = til_module_context_new(module, sizeof(*ctxt), stream, seed, ticks, n_cpus, setup);
+	if (!ctxt)
+		return NULL;
+
+	return &ctxt->til_module_context;
+}
+
+
+static void _ref_destroy_context(til_module_context_t *context)
+{
+	_ref_context_t	*ctxt = (_ref_context_t *)context;
+
+	ctxt->ref = til_module_context_free(ctxt->ref);
+	free(context);
+}
+
+
+static void _ref_render_fragment(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr)
+{
+	_ref_context_t	*ctxt = (_ref_context_t *)context;
+	_ref_setup_t	*s = (_ref_setup_t *)context->setup;
+
+	if (!ctxt->ref) {
+		int	r;
+
+		/* TODO: switch to til_stream_find_module_context(), this clones concept is DOA. */
+		r = til_stream_find_module_contexts(stream, s->path, 1, &ctxt->ref);
+		if (r < 0) {
+			txt_t	*msg = txt_newf("%s: BAD PATH \"%s\"", context->setup->path, s->path);
+
+			til_fb_fragment_clear(*fragment_ptr);
+			txt_render_fragment(msg, *fragment_ptr, 0xffffffff,
+					    0, 0,
+					    (txt_align_t){
+						.horiz = TXT_HALIGN_LEFT,
+						.vert = TXT_VALIGN_TOP,
+					    });
+			txt_free(msg);
+			/* TODO: maybe print all available contexts into the fragment? */
+			return;
+		}
+	}
+
+	til_module_render_limited(ctxt->ref, stream, ticks, context->n_cpus, fragment_ptr);
+}
+
+
+static void _ref_setup_free(til_setup_t *setup)
+{
+	_ref_setup_t	*s = (_ref_setup_t *)setup;
+
+	free(s->path);
+	free(s);
+}
+
+
+static int _ref_setup(const til_settings_t *settings, til_setting_t **res_setting, const til_setting_desc_t **res_desc, til_setup_t **res_setup);
+
+
+til_module_t	_ref_module = {
+	.create_context = _ref_create_context,
+	.destroy_context = _ref_destroy_context,
+	.render_fragment = _ref_render_fragment,
+	.setup = _ref_setup,
+	.name = "ref",
+	.description = "Context referencer (built-in)",
+	.author = "built-in",
+	.flags = TIL_MODULE_BUILTIN,
+};
+
+
+static int _ref_setup(const til_settings_t *settings, til_setting_t **res_setting, const til_setting_desc_t **res_desc, til_setup_t **res_setup)
+{
+	const char	*path;
+	int		r;
+
+	r = til_settings_get_and_describe_value(settings,
+						&(til_setting_spec_t){
+							.name = "Context path to reference",
+							.key = "path",
+							.regex = "[a-zA-Z0-9/_]+",
+							.preferred = "",
+						},
+						&path,
+						res_setting,
+						res_desc);
+	if (r)
+		return r;
+
+	if (res_setup) {
+		_ref_setup_t    *setup;
+
+		setup = til_setup_new(settings, sizeof(*setup), _ref_setup_free, &_ref_module);
+		if (!setup)
+			return -ENOMEM;
+
+		setup->path = strdup(path);
+		if (!setup->path) {
+			til_setup_free(&setup->til_setup);
+
+			return -ENOMEM;
+	       }
+
+		*res_setup = &setup->til_setup;
+	}
+
+	return 0;
+}