From 0bdf1f5608fc18fe9d999bd400e951df9342c831 Mon Sep 17 00:00:00 2001
From: John Tsiombikas <nuclear@member.fsf.org>
Date: Sat, 9 Feb 2019 13:46:41 +0200
Subject: [PATCH] test timing and input handling

---
 src/ansi.c |    6 ++++++
 src/ansi.h |    1 +
 src/game.c |   48 ++++++++++++++++++++++++++++++++++++++++++++++--
 src/game.h |    4 +++-
 src/main.c |   49 ++++++++++++++++++++++++++++++++++++++++++++-----
 5 files changed, 100 insertions(+), 8 deletions(-)

diff --git a/src/ansi.c b/src/ansi.c
index ac5185f..07ae749 100644
--- a/src/ansi.c
+++ b/src/ansi.c
@@ -63,6 +63,12 @@ void ansi_setcursor(int row, int col)
 	printf("\033[%d;%dH", row + 1, col + 1);
 }
 
+void ansi_cursor(int show)
+{
+	printf("\033[?25%c", show ? 'h' : 'l');
+	fflush(stdout);
+}
+
 void ansi_ibmchar(unsigned char c, unsigned char attr)
 {
 	char cmd[32];
diff --git a/src/ansi.h b/src/ansi.h
index 5e1e482..b63ed8e 100644
--- a/src/ansi.h
+++ b/src/ansi.h
@@ -5,6 +5,7 @@ void ansi_reset(void);
 void ansi_clearscr(void);
 
 void ansi_setcursor(int row, int col);
+void ansi_cursor(int show);
 
 /* convert a PC cga/ega/vga char+attr to an ANSI sequence and write it to stdout */
 void ansi_ibmchar(unsigned char c, unsigned char attr);
diff --git a/src/game.c b/src/game.c
index f1622aa..e8b47f3 100644
--- a/src/game.c
+++ b/src/game.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <string.h>
 #include <inttypes.h>
 #include "game.h"
 #include "pieces.h"
@@ -46,7 +47,10 @@ int init_game(void)
 	int i, j;
 	uint16_t *row = scr;
 
+	tick_interval = 1000;
+
 	ansi_clearscr();
+	ansi_cursor(0);
 
 	/* fill the screen buffer, and draw */
 	for(i=0; i<SCR_ROWS; i++) {
@@ -77,15 +81,55 @@ void cleanup_game(void)
 	ansi_reset();
 }
 
-void proc_input(void)
+static int pos[2] = {0, PF_COLS / 2};
+static int next_pos[2] = {0, PF_COLS / 2};
+
+long update(long msec)
 {
-	int c = fgetc(stdin);
+	static long prev_tick;
+	long dt;
+
+	dt = msec - prev_tick;
+
+	/* fall */
+	while(dt >= tick_interval) {
+		next_pos[0] = (pos[0] + 1) % PF_ROWS;
+		dt -= tick_interval;
+		prev_tick = msec;
+	}
 
+	if(memcmp(pos, next_pos, sizeof pos) != 0) {
+		ansi_setcursor(pos[0], (PF_XOFFS + pos[1]) * 2);
+		wrchar(CHAR(' ', BLACK, WHITE));
+
+		memcpy(pos, next_pos, sizeof pos);
+		ansi_setcursor(pos[0], (PF_XOFFS + pos[1]) * 2);
+		wrchar(CHAR(' ', RED, RED));
+
+		fflush(stdout);
+	}
+	return tick_interval - dt;
+}
+
+void game_input(int c)
+{
 	switch(c) {
 	case 27:
 		quit = 1;
 		break;
 
+	case 'a':
+		if(pos[1] > 0) {
+			next_pos[1] = pos[1] - 1;
+		}
+		break;
+
+	case 'd':
+		if(pos[1] < PF_COLS - 1) {
+			next_pos[1] = pos[1] + 1;
+		}
+		break;
+
 	default:
 		break;
 	}
diff --git a/src/game.h b/src/game.h
index 0fe598e..14a6620 100644
--- a/src/game.h
+++ b/src/game.h
@@ -2,10 +2,12 @@
 #define GAME_H_
 
 int quit;
+long tick_interval;
 
 int init_game(void);
 void cleanup_game(void);
 
-void proc_input(void);
+long update(long msec);
+void game_input(int c);
 
 #endif	/* GAME_H_ */
diff --git a/src/main.c b/src/main.c
index 6f27d73..dc240fd 100644
--- a/src/main.c
+++ b/src/main.c
@@ -5,16 +5,24 @@
 #include <fcntl.h>
 #include <termios.h>
 #include <sys/stat.h>
+#include <sys/select.h>
+#include <sys/time.h>
 #include "game.h"
 
 int init(void);
 void cleanup(void);
+long get_msec(void);
 
-const char *termfile = "/dev/tty";
-struct termios saved_term;
+static const char *termfile = "/dev/tty";
+static struct termios saved_term;
+static struct timeval tv0;
 
 int main(int argc, char **argv)
 {
+	int res, c;
+	long msec, next;
+	struct timeval tv;
+
 	if(argc > 1) {
 		termfile = argv[1];
 	}
@@ -23,11 +31,33 @@ int main(int argc, char **argv)
 		return 1;
 	}
 
+	gettimeofday(&tv0, 0);
+
+	tv.tv_sec = tick_interval / 1000;
+	tv.tv_usec = (tick_interval % 1000) * 1000;
+
 	for(;;) {
-		proc_input();
-		if(quit) break;
+		fd_set rdset;
+		FD_ZERO(&rdset);
+		FD_SET(0, &rdset);
+
+		while((res = select(1, &rdset, 0, 0, &tv)) == -1 && errno == EINTR);
+
+		if(res > 0 && FD_ISSET(0, &rdset)) {
+			while((c = fgetc(stdin)) >= 0) {
+				game_input(c);
+				if(quit) goto end;
+			}
+		}
+
+		msec = get_msec();
+		next = update(msec);
+
+		tv.tv_sec = next / 1000;
+		tv.tv_usec = (next % 1000) * 1000;
 	}
 
+end:
 	cleanup();
 	return 0;
 }
@@ -37,7 +67,7 @@ int init(void)
 	int fd;
 	struct termios term;
 
-	if((fd = open(termfile, O_RDWR)) == -1) {
+	if((fd = open(termfile, O_RDWR | O_NONBLOCK)) == -1) {
 		fprintf(stderr, "failed to open terminal device: %s: %s\n", termfile, strerror(errno));
 		return -1;
 	}
@@ -79,3 +109,12 @@ void cleanup(void)
 	cleanup_game();
 	tcsetattr(0, TCSAFLUSH, &saved_term);
 }
+
+long get_msec(void)
+{
+	struct timeval tv;
+
+	gettimeofday(&tv, 0);
+
+	return (tv.tv_sec - tv0.tv_sec) * 1000 + (tv.tv_usec - tv0.tv_usec) / 1000;
+}
-- 
1.7.10.4