modules/shapes: add spin setting for star+pinwheel

Introduces spin={-1,0,1} with a few intermediate fractions on
both sides of 0.  Controls rate and direction.

As-is these multiple choice style options don't let you
explicitly set a value in rototiller on the commandline that
isn't in the set.

There should probably be a flag in the desc we can set when
bypassing the available options is tolerable, probably when
regex's start getting enforced.

That way rototiller's commandline setting parsing can just lean
on the regex, and if the desc says anything can come in that
passes the regex even if it's not in the values set, this can all
still work and have something resembling input validation.

At the end of the day, the multiple choice value sets are
supposed to be a convenience/guide to a sane variety of values
and of particular utility to randomizers like used by
rtv/montage/compose, but also GUI setting selectors like in
glimmer.

They're not intended to get in the way preventing development
from accessing explicit values of arbitrary precision which can
be really necessary especially when trying to determine what's
best for going in the values set.

1 files changed, 40 insertions, 3 deletions

diff --git a/src/modules/shapes/shapes.c b/src/modules/shapes/shapes.c
index f084a01..68d194e 100644
--- a/src/modules/shapes/shapes.c
+++ b/src/modules/shapes/shapes.c
@@ -66,6 +66,7 @@
 
 #define SHAPES_DEFAULT_TYPE	SHAPES_TYPE_PINWHEEL
 #define SHAPES_DEFAULT_POINTS	5
+#define SHAPES_DEFAULT_SPIN	.1
 
 typedef enum shapes_type_t {
 	SHAPES_TYPE_CIRCLE,
@@ -78,6 +79,7 @@ typedef struct shapes_setup_t {
 	til_setup_t	til_setup;
 	shapes_type_t	type;
 	unsigned	n_points;
+	float		spin;
 } shapes_setup_t;
 
 typedef struct shapes_context_t {
@@ -173,7 +175,7 @@ static void shapes_render_fragment(void *context, unsigned ticks, unsigned cpu,
 			for (unsigned y = yoff; y < yoff + size; y++, Y += s) {
 				X = -1.f;
 				for (unsigned x = xoff; x < xoff + size; x++, X += s) {
-					float	rad = atan2f(Y, X) + (float)ticks * .001f;
+					float	rad = atan2f(Y, X) + (float)ticks * ctxt->setup.spin * .01f;
 					float	r = cosf((float)ctxt->setup.n_points * rad) * .5f + .5f;
 
 					if (X * X + Y * Y < r * r)
@@ -212,7 +214,7 @@ static void shapes_render_fragment(void *context, unsigned ticks, unsigned cpu,
 			for (unsigned y = yoff; y < yoff + size; y++, Y += s) {
 				X = -1.f;
 				for (unsigned x = xoff; x < xoff + size; x++, X += s) {
-					float	rad = atan2f(Y, X) + (float)ticks * .001f;
+					float	rad = atan2f(Y, X) + (float)ticks * ctxt->setup.spin * .01f;
 					float	r = (M_2_PI * asinf(sinf((float)ctxt->setup.n_points * rad) * .5f + .5f)) * .5f + .5f;
 						/*   ^^^^^^^^^^^^^^^^^^^ approximates a triangle wave */
 
@@ -232,6 +234,7 @@ static int shapes_setup(const til_settings_t *settings, til_setting_t **res_sett
 {
 	const char	*type;
 	const char	*points;
+	const char	*spin;
 	const char	*type_values[] = {
 				"circle",
 				"pinwheel",
@@ -260,6 +263,24 @@ static int shapes_setup(const til_settings_t *settings, til_setting_t **res_sett
 				"20",
 				NULL
 			};
+	const char	*spin_values[] = {
+				"-1",
+				"-.9",
+				"-.75",
+				"-.5",
+				"-.25",
+				"-.1",
+				"-.01",
+				"0",
+				".01",
+				".1",
+				".25",
+				".5",
+				".75",
+				".9",
+				"1",
+				NULL
+			};
 	int		r;
 
 	r = til_settings_get_and_describe_value(settings,
@@ -293,6 +314,20 @@ static int shapes_setup(const til_settings_t *settings, til_setting_t **res_sett
 		if (r)
 			return r;
 
+		r = til_settings_get_and_describe_value(settings,
+							&(til_setting_desc_t){
+								.name = "Spin factor",
+								.key = "spin",
+								.regex = "-?(0|1|0\\.[0-9]{1,2})", /* Derived from pixbounce, I'm sure when regexes start getting actually applied we're going to have to revisit all of these and fix them with plenty of lols. */
+								.preferred = TIL_SETTINGS_STR(SHAPES_DEFAULT_SPIN),
+								.values = spin_values,
+								.annotations = NULL
+							},
+							&spin,
+							res_setting,
+							res_desc);
+		if (r)
+			return r;
 	}
 
 	if (res_setup) {
@@ -316,8 +351,10 @@ static int shapes_setup(const til_settings_t *settings, til_setting_t **res_sett
 			return -EINVAL;
 		}
 
-		if (setup->type == SHAPES_TYPE_STAR || setup->type == SHAPES_TYPE_PINWHEEL)
+		if (setup->type == SHAPES_TYPE_STAR || setup->type == SHAPES_TYPE_PINWHEEL) {
 			sscanf(points, "%u", &setup->n_points); /* TODO: -EINVAL parse errors */
+			sscanf(spin, "%f", &setup->spin); /* TODO: -EINVAL parse errors */
+		}
 
 		*res_setup = &setup->til_setup;
 	}