refactor c rewrite

1 files changed, 61 insertions, 36 deletions

diff --git a/dartbot.c b/dartbot.c
index 263bbc1..7367648 100644
--- a/dartbot.c
+++ b/dartbot.c
@@ -1,5 +1,6 @@
 #include <math.h>
 #include <ncurses.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
@@ -7,6 +8,7 @@
 #define HORIZONTAL_STDEV 50
 #define VERTICAL_STDEV 50
 
+// board spec from WDF rules
 #define WIRE_WIDTH 1.56
 #define INNER_DIAMETER_BULL 12.7
 #define INNER_DIAMETER_25 31.8
@@ -15,14 +17,19 @@
 #define DOUBLE_INSIDE_WIDTH 8.0
 #define TREBLE_INSIDE_WIDTH 8.0
 
+#define SEGMENT_MAX_LEN 5
+// distance from centre to apex of outer wire
+// must be ordered outwards from centre
 #define FOREACH_RING(M) \
-	M(R_BULL, INNER_DIAMETER_BULL/2 + WIRE_WIDTH/2) \
-	M(R_25, INNER_DIAMETER_25/2 + WIRE_WIDTH/2) \
-	M(R_SMALL, TREBLE_OUTER_EDGE - WIRE_WIDTH - TREBLE_INSIDE_WIDTH - WIRE_WIDTH/2) \
-	M(R_TREBLE, TREBLE_OUTER_EDGE - WIRE_WIDTH/2) \
-	M(R_BIG, DOUBLE_OUTER_EDGE - WIRE_WIDTH - DOUBLE_INSIDE_WIDTH - WIRE_WIDTH/2) \
-	M(R_DOUBLE, DOUBLE_OUTER_EDGE - WIRE_WIDTH/2)
-#define GEN_RING_ENUM(X, D) X,
+	M(BULL, INNER_DIAMETER_BULL/2 + WIRE_WIDTH/2) \
+	M(25, INNER_DIAMETER_25/2 + WIRE_WIDTH/2) \
+	M(SMALL, TREBLE_OUTER_EDGE - WIRE_WIDTH - TREBLE_INSIDE_WIDTH - \
+		WIRE_WIDTH/2) \
+	M(TREBLE, TREBLE_OUTER_EDGE - WIRE_WIDTH/2) \
+	M(BIG, DOUBLE_OUTER_EDGE - WIRE_WIDTH - DOUBLE_INSIDE_WIDTH - \
+		WIRE_WIDTH/2) \
+	M(DOUBLE, DOUBLE_OUTER_EDGE - WIRE_WIDTH/2)
+#define GEN_RING_ENUM(X, D) R_ ## X,
 #define GEN_RING_STRING(X, D) #X,
 #define GEN_RING_OUTER_DIST(X, D) D,
 
@@ -44,7 +51,8 @@ double OUTER_DISTS[] = {
 };
 
 double CENTRE_DISTS[sizeof(OUTER_DISTS)/sizeof(*OUTER_DISTS)];
-void init_centre_dists() {
+void init_centre_dists()
+{
 	CENTRE_DISTS[0] = 0;
 	for (int i = R_25; i < R_OUT; ++i)
 		CENTRE_DISTS[i] = (OUTER_DISTS[i] -
@@ -80,25 +88,43 @@ enum ring get_ring(double radius)
 	return R_OUT;
 }
 
-struct ccoords gauss()
+double drand()
 {
-	double theta = 2 * M_PI * ((double)rand() / RAND_MAX);
-	double r = sqrt(-2 * log(1 - (double)rand() / RAND_MAX));
-	return (struct ccoords){ .x = r * cos(theta), .y = r * sin(theta) };
+	return (double)rand() / RAND_MAX;
+}
+
+double gauss(double mean, double stdev)
+{
+	static bool have_next;
+	static double next;
+
+	double curr;
+
+	if (have_next) {
+		curr = next;
+	} else {
+		double theta = 2 * M_PI * drand();
+		double r = sqrt(-2 * log(1 - drand()));
+
+		curr = r * cos(theta);
+		next = r * sin(theta);
+	}
+
+	have_next = !have_next;
+	return mean + (curr * stdev);
 }
 
 struct ccoords get_offset()
 {
-	struct ccoords g = gauss();
-	return (struct ccoords){ .x = g.x * HORIZONTAL_STDEV,
-		.y = g.y * VERTICAL_STDEV };
+	return (struct ccoords){ .x = gauss(0, HORIZONTAL_STDEV),
+		.y = gauss(0, VERTICAL_STDEV) };
 }
 
-struct ccoords pol_to_cart(struct pcoords a)
+struct ccoords pol_to_cart(struct pcoords c)
 {
-	double t = a.a * (M_PI / 180);
-	double x = a.r * cos(t);
-	double y = a.r * sin(t);
+	double t = c.a * (M_PI / 180);
+	double x = c.r * cos(t);
+	double y = c.r * sin(t);
 
 	return (struct ccoords){ .x = x, .y = y };
 }
@@ -120,28 +146,26 @@ struct pcoords throw_dart(struct pcoords target)
 		.y = cc.y + offset.y });
 }
 
-struct segment get_segment(struct pcoords pos)
+struct segment get_segment(struct pcoords c)
 {
-	return (struct segment){ .sector = get_sector(pos.a),
-		.ring = get_ring(pos.r) };
+	return (struct segment){ .sector = get_sector(c.a),
+		.ring = get_ring(c.r) };
 }
 
 char *segment_name(struct segment seg)
 {
-	char *str = malloc(5);
-
-	if (seg.ring == R_BULL)
-		strncpy(str, "BULL", 5);
-	else if (seg.ring == R_25)
-		strncpy(str, "25", 5);
-	else if (seg.ring == R_OUT)
-		strncpy(str, "OUT", 5);
-	else if (seg.ring == R_TREBLE)
-		snprintf(str, 5, "T%d", seg.sector);
-	else if (seg.ring == R_DOUBLE)
-		snprintf(str, 5, "D%d", seg.sector);
+	char *str = malloc(SEGMENT_MAX_LEN);
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wstringop-truncation"
+	if (seg.ring == R_BULL || seg.ring == R_25 || seg.ring == R_OUT)
+		strncpy(str, RING_NAMES[seg.ring], SEGMENT_MAX_LEN);
 	else
-		snprintf(str, 5, "%d", seg.sector);
+		snprintf(str, SEGMENT_MAX_LEN,
+			(seg.ring == R_TREBLE ? "T%d" :
+				(seg.ring == R_DOUBLE ? "D%d" : "%d")),
+			seg.sector);
+#pragma GCC diagnostic pop
 
 	return str;
 }
@@ -167,7 +191,8 @@ int main()
 		res = throw_dart(t);
 		seg = get_segment(res);
 		char *name = segment_name(seg);
-		printf("%d %f %f %d %s %s\n", seg.sector, res.a, res.r, seg.ring, RING_NAMES[seg.ring], name);
+		printf("%d %f %f %d %s %s\n", seg.sector, res.a, res.r, seg.ring,
+			RING_NAMES[seg.ring], name);
 		free(name);
 	}