die roll, prompt for rerolls

1 files changed, 69 insertions, 28 deletions

diff --git a/ytz.c b/ytz.c
index acfdfde..3ca9b76 100644
--- a/ytz.c
+++ b/ytz.c
@@ -1,3 +1,4 @@
+#include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
 
@@ -66,8 +67,57 @@ uint16_t wyhash16(uint16_t* seed) {
 	return hash16(*seed, 0x2ab);
 }
 
+uint16_t roll_die(uint16_t* seed) {
+	const uint16_t s = 6;  /* generating in the range of [0,6) */
+	uint16_t x = wyhash16(seed);
+	uint32_t m = (uint32_t)x * (uint32_t)s;  
+	uint32_t l = (uint16_t)m;
+	if (l < s) {
+		uint16_t t = -s % s;
+		while (l < t) {
+			x = wyhash16(seed);
+			m = (uint32_t)x * (uint32_t)s;
+			l = (uint16_t)m;
+		}
+	}
+	return (m >> 16) + 1;  /* we ultimately want [1,7) */
+}
+
+void ask_for_rerolls(ytz_state* state) {
+	char buf[10];
+	printf("which dice should be re-rolled? ");
+	fgets(buf, sizeof(buf), stdin);
+
+	int dice[6] = { -1, -1, -1, -1, -1, -1 }; /* we only ever look for 5 dice, so should always hit -1 at some point */
+	sscanf(buf, "%d %d %d %d %d", &dice[0], &dice[1], &dice[2], &dice[3], &dice[4]);
+
+	for (int i = 0; i < 5; i++) {
+		if (dice[i] == -1)
+			break;
+		state->dice = SET_D(state->dice, dice[i], 0);
+	}
+}
+
+void do_turn(ytz_state* state) {
+	int roll = GET_ROLL(state->topflag_w_roll);
+	bool reset = false;
+
+	// if we're out of rolls, reset
+	if (roll == 3) {
+		reset = true;
+		roll = 0;
+	}
+
+	for (int i = 0; i < 5; i++) {
+		if (reset || (GET_D(state->dice, i) == 0)) {
+			state->dice = SET_D(state->dice, i, roll_die(&(state->seed)));
+		}
+	}
+	state->topflag_w_roll = SET_ROLL(state->topflag_w_roll, ++roll);
+}
+
 void init_ytz_state(ytz_state* state) {
-	state->topflag_w_roll = 0x70;  /* roll 1, no flags */
+	state->topflag_w_roll = 0;
 	state->topscore = 0;
 	state->botflag = 0;
 	state->botscore = 0;
@@ -89,37 +139,28 @@ void main() {
 	 *
 	 */
 
-	y.dice = SET_D0(y.dice, 1);
-	y.dice = SET_D1(y.dice, 6);
-	y.dice = SET_D2(y.dice, 4);
-	y.dice = SET_D3(y.dice, 3);
-	y.dice = SET_D4(y.dice, 2);
-
+	printf("roll: %d\n", GET_ROLL(y.topflag_w_roll));
 	printf("d1: %d\n", GET_D0(y.dice));
 	printf("d2: %d\n", GET_D1(y.dice));
 	printf("d3: %d\n", GET_D2(y.dice));
 	printf("d4: %d\n", GET_D3(y.dice));
 	printf("d5: %d\n", GET_D4(y.dice));
-	printf("size: %d\n", sizeof(y));
-
-	printf("roll: %d\n", GET_ROLL(y.topflag_w_roll));
-
-	y.topflag_w_roll = SET_ROLL(y.topflag_w_roll, 2);
-	printf("roll: %d\n", GET_ROLL(y.topflag_w_roll));
-
-	printf("ace: %d\n", GET_ACE(y.topflag_w_roll));
-	y.topflag_w_roll = SET_ACE(y.topflag_w_roll);
-	printf("ace: %d\n", GET_ACE(y.topflag_w_roll));
-
-	printf("seed: %d\n", y.seed);
-	uint16_t hash;
-	for (int i = 0; i < 10; i++) {
-		hash = wyhash16(&(y.seed));
-		printf("hash: %d\n", hash);
-		printf("new seed: %d\n", y.seed);
-	}
 
-	hash = wyhash16(&(y.seed));
-	printf("hash: %d\n", hash);
-	printf("new seed: %d\n", y.seed);
+	do_turn(&y);
+
+	printf("new roll: %d\n", GET_ROLL(y.topflag_w_roll));
+	printf("new d1: %d\n", GET_D0(y.dice));
+	printf("new d2: %d\n", GET_D1(y.dice));
+	printf("new d3: %d\n", GET_D2(y.dice));
+	printf("new d4: %d\n", GET_D3(y.dice));
+	printf("new d5: %d\n", GET_D4(y.dice));
+	
+	ask_for_rerolls(&y);
+	do_turn(&y);
+	printf("newer roll: %d\n", GET_ROLL(y.topflag_w_roll));
+	printf("newer d1: %d\n", GET_D0(y.dice));
+	printf("newer d2: %d\n", GET_D1(y.dice));
+	printf("newer d3: %d\n", GET_D2(y.dice));
+	printf("newer d4: %d\n", GET_D3(y.dice));
+	printf("newer d5: %d\n", GET_D4(y.dice));
 }