move difficulty-to-stdev logic to lib

4 files changed, 45 insertions, 40 deletions

diff --git a/comp.c b/comp.c
index 012eea1..6b4ec26 100644
--- a/comp.c
+++ b/comp.c
@@ -9,6 +9,42 @@
 
 double horizontal_stdev = 16, vertical_stdev = 16;
 
+#define NUM_DIFF_PRESETS (sizeof(DIFF_PRESETS) / sizeof(*DIFF_PRESETS))
+static struct { int diff; double stdev; } DIFF_PRESETS[] = {
+	{ 0, 66.80}, // 10
+	{ 8, 40.24}, // 20
+	{16, 28.14}, // 30
+	{24, 21.35}, // 40
+	{32, 17.20}, // 50
+	{40, 14.34}, // 60
+	{48, 12.15}, // 70
+	{56, 10.36}, // 80
+	{64,  8.83}, // 90
+	{72,  7.48}, // 100
+	{80,  6.32}, // 110
+	{88,  5.34}, // 120
+	{99,  0.00}, // 167
+};
+
+// optional function to set stdevs using precomputed 0-99 difficulty values.
+// fixed-step interpolation is done between presets.
+void comp_set_difficulty(int diff)
+{
+	if (diff < DIFF_PRESETS[0].diff)
+		diff = DIFF_PRESETS[0].diff;
+	else if (diff > DIFF_PRESETS[NUM_DIFF_PRESETS - 1].diff)
+		diff = DIFF_PRESETS[NUM_DIFF_PRESETS - 1].diff;
+
+	size_t ind = 1;
+	while (ind < NUM_DIFF_PRESETS - 1 && DIFF_PRESETS[ind].diff <= diff)
+		ind++;
+
+	double step = (DIFF_PRESETS[ind - 1].stdev - DIFF_PRESETS[ind].stdev) /
+		(DIFF_PRESETS[ind].diff - DIFF_PRESETS[ind - 1].diff);
+	horizontal_stdev = vertical_stdev = DIFF_PRESETS[ind - 1].stdev -
+		((diff - DIFF_PRESETS[ind - 1].diff) * step);
+}
+
 static double drand()
 {
 	return (double)rand() / RAND_MAX;
@@ -63,7 +99,7 @@ static struct pcoords throw_dart(struct pcoords target, struct ccoords *cc)
 	return cart_to_pol(*cc);
 }
 
-struct segment next_dart(int rem, int darts_in_hand)
+static struct segment next_dart(int rem, int darts_in_hand)
 {
 	char *c = NULL;
 	if (rem <= NUM_CHECKOUTS)
diff --git a/comp.h b/comp.h
index 4792516..792eb3c 100644
--- a/comp.h
+++ b/comp.h
@@ -7,6 +7,7 @@ extern double horizontal_stdev, vertical_stdev;
 
 struct ccoords pol_to_cart(struct pcoords c);
 
+void comp_set_difficulty(int diff);
 void comp_visit(struct leg *l);
 
 #endif
diff --git a/dartboat.c b/dartboat.c
index fdaf6d1..952b5b7 100644
--- a/dartboat.c
+++ b/dartboat.c
@@ -138,21 +138,22 @@ void test_averages()
 {
 	int rounds = 100000;
 
-	for (int stdev = 4; stdev < 25; ++stdev) {
-		horizontal_stdev = vertical_stdev = stdev;
+	for (int diff = 0; diff <= 99; ++diff) {
+		comp_set_difficulty(diff);
 
 		int darts = 0;
 		for (int i = 0; i < rounds; ++i) {
 			struct leg *l = leg_init(501);
 			while (l->rem > 0)
 				comp_visit(l);
-			leg_free(l);
 
 			darts += (l->n_visits - 1) * 3 +
 				l->visits[l->n_visits-1].n_darts;
+			leg_free(l);
 		}
 
-		printf("%d %f\n", stdev, (double)(501*rounds)/darts*3);
+		printf("%d %f %f\n", diff, horizontal_stdev,
+			(double)(501 * rounds) / darts * 3);
 	}
 }
 
diff --git a/web/web_opts.c b/web/web_opts.c
index b593306..b880fd3 100644
--- a/web/web_opts.c
+++ b/web/web_opts.c
@@ -16,51 +16,18 @@
 int delay_ms = 1000;
 
 static int difficulty = 32;
-static struct { int diff; double stdev; } DIFF_PRESETS[] = {
-	{ 0, 66.80}, // 10
-	{ 8, 40.24}, // 20
-	{16, 28.14}, // 30
-	{24, 21.35}, // 40
-	{32, 17.20}, // 50
-	{40, 14.34}, // 60
-	{48, 12.15}, // 70
-	{56, 10.36}, // 80
-	{64,  8.83}, // 90
-	{72,  7.48}, // 100
-	{80,  6.32}, // 110
-	{88,  5.34}, // 120
-	{99,  0.00}, // 167
-};
-#define NUM_DIFF_PRESETS (sizeof(DIFF_PRESETS) / sizeof(*DIFF_PRESETS))
 
 static void set_delay(char *val)
 {
 	delay_ms = atoi(val);
 }
 
-static void set_stdev(int diff)
-{
-	if (diff < DIFF_PRESETS[0].diff)
-		diff = DIFF_PRESETS[0].diff;
-	else if (diff > DIFF_PRESETS[NUM_DIFF_PRESETS - 1].diff)
-		diff = DIFF_PRESETS[NUM_DIFF_PRESETS - 1].diff;
-
-	size_t ind = 1;
-	while (ind < NUM_DIFF_PRESETS - 1 && DIFF_PRESETS[ind].diff <= diff)
-		ind++;
-
-	double step = (DIFF_PRESETS[ind - 1].stdev - DIFF_PRESETS[ind].stdev) /
-		(DIFF_PRESETS[ind].diff - DIFF_PRESETS[ind - 1].diff);
-	horizontal_stdev = vertical_stdev = DIFF_PRESETS[ind - 1].stdev -
-		((diff - DIFF_PRESETS[ind - 1].diff) * step);
-}
-
 static void set_difficulty(char *val)
 {
 	int diff = atoi(val);
 	difficulty = diff < 0 ? 0 : diff > 99 ? 99 : diff;
 
-	set_stdev(difficulty);
+	comp_set_difficulty(difficulty);
 }
 
 static char *prefix_opt(char *opt)
@@ -105,7 +72,7 @@ void opts_init()
 {
 	read_delay();
 	if (!read_difficulty())
-		set_stdev(difficulty);
+		comp_set_difficulty(difficulty);
 
 	char buf[64];
 	sprintf(buf, "%d", delay_ms);