ytz -> yhtz

1 files changed, 175 insertions, 0 deletions

diff --git a/yhtz.c b/yhtz.c
new file mode 100644
index 0000000..cf556db
--- /dev/null
+++ b/yhtz.c
@@ -0,0 +1,175 @@
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+
+/*
+   0000 0000 0000 0000 0000 0000 0000 0000
+   rc         topscore  botflag. botscore.
+     topflag x         x
+
+   0000 0000 0000 0000 0000 0000 0000 0000
+   xd4. d3.d 2.d1 .d0. prng state.... ....
+*/
+
+typedef struct {
+	uint8_t topflag_w_roll;
+	uint8_t topscore;
+	uint8_t botflag;
+	uint8_t botscore;
+	uint16_t dice;
+	uint16_t seed;
+} yhtz_state;
+
+/* ROLLS */
+#define GET_ROLL(s) ((uint8_t)((s & 0xC0) >> 6))  /* top 2 bits */
+#define SET_ROLL(s, x) (s & 0x3F | ((uint8_t)x << 6))
+
+/* TOP NUMBERS */
+#define GET_NUM(s, x) ((uint8_t)((s & (1 << x)) >> x))
+#define GET_ACE(s) (GET_NUM(s, 0))
+#define GET_TWO(s) (GET_NUM(s, 1))
+#define GET_THREE(s) (GET_NUM(s, 2))
+#define GET_FOUR(s) (GET_NUM(s, 3))
+#define GET_FIVE(s) (GET_NUM(s, 4))
+#define GET_SIX(s) (GET_NUM(s, 5))
+
+#define SET_NUM(s, x) (s | (1 << x))
+#define SET_ACE(s) (SET_NUM(s, 0))
+#define SET_TWO(s) (SET_NUM(s, 1))
+#define SET_THREE(s) (SET_NUM(s, 2))
+#define SET_FOUR(s) (SET_NUM(s, 3))
+#define SET_FIVE(s) (SET_NUM(s, 4))
+#define SET_SIX(s) (SET_NUM(s, 5))
+
+/* DICE */
+#define GET_D(s, x) ((uint8_t)((s & (0x07 << (3 * x))) >> (3 * x)))
+#define GET_D0(s) (GET_D(s, 0))
+#define GET_D1(s) (GET_D(s, 1))
+#define GET_D2(s) (GET_D(s, 2))
+#define GET_D3(s) (GET_D(s, 3))
+#define GET_D4(s) (GET_D(s, 4))
+
+#define SET_D(s, x, y) (s & (0xFFFF ^ (0x0007 << (3 * x))) | (y << (3 * x)))
+#define SET_D0(s, y) (SET_D(s, 0, y))
+#define SET_D1(s, y) (SET_D(s, 1, y))
+#define SET_D2(s, y) (SET_D(s, 2, y))
+#define SET_D3(s, y) (SET_D(s, 3, y))
+#define SET_D4(s, y) (SET_D(s, 4, y))
+
+/* 16-bit prng, with thanks/apologies to Dr. Lemire (https://lemire.me/blog/2019/07/03/a-fast-16-bit-random-number-generator/) */
+uint32_t hash16(uint32_t input, uint32_t key) {
+	uint32_t hash = input * key;
+	return ((hash >> 16) ^ hash) & 0xFFFF;
+}
+
+uint16_t wyhash16(uint16_t* seed) {
+	*seed += 0xfc15;
+	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 print_dice(yhtz_state* state) {
+	char* label = "die %d ";
+	char* top = ",---,";
+	char* mid = "| %d | ";
+	char* bot = "'---'";
+
+	for (int i = 0; i < 5; i++)
+		printf(label, i);
+	printf("\n%s %s %s %s %s\n", top, top, top, top, top);
+	for (int i = 0; i < 5; i++)
+		printf(mid, GET_D(state->dice, i));
+	printf("\n%s %s %s %s %s\n", bot, bot, bot, bot, bot);
+}
+
+void ask_for_rerolls(yhtz_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(yhtz_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_yhtz_state(yhtz_state* state) {
+	state->topflag_w_roll = 0;
+	state->topscore = 0;
+	state->botflag = 0;
+	state->botscore = 0;
+	state->dice = 0;
+	state->seed = 13;  /* TODO this isn't random */
+}
+
+void main() {
+	yhtz_state y;
+	init_yhtz_state(&y);
+
+	/*
+	 * until the win condition is met
+	 *  - roll all dice
+	 *  - up to 2 times, ask user which dice to reroll
+	 *  - ask user which category to mark it in
+	 *  - validate and update state
+	 *
+	 *
+	 */
+
+	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));
+
+	print_dice(&y);
+	
+	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));
+}