shithub: orca

--- a/main.c

+++ b/main.c

@@ -4,6 +4,7 @@

 #include <ncurses.h>

 #include <stdbool.h>

 #include <stdlib.h>

+#include <unistd.h>

 typedef struct {

   chtype* buffer;

@@ -116,6 +117,10 @@

   keypad(stdscr, TRUE);

   // Hide the terminal cursor

   curs_set(0);

+  // Don't block on calls like getch() -- have it ERR immediately if the user

+  // hasn't typed anything. That way we can mix other timers in our code,

+  // instead of being a slave only to terminal input.

+  nodelay(stdscr, TRUE);

   view_state vs;

   init_view_state(&vs);

@@ -128,18 +133,27 @@

   refresh();

   for (;;) {

-    chtype ch = getch();

+    int ch = getch();

     if (ch == 'q')

       break;

+    // ncurses gives us ERR if there was no user input. We'll sleep for 0

+    // seconds, so that we'll yield CPU time to the OS instead of looping as

+    // fast as possible. This avoids battery drain/excessive CPU usage. There

+    // are better ways to do this that waste less CPU, but they require doing a

+    // little more work on each individual platform (Linux, Mac, etc.)

+    if (ch == ERR) {

+      sleep(0);

+      continue;

+    }

     // ncurses gives us the special value KEY_RESIZE if the user didn't

     // actually type anything, but the terminal resized. If that happens to us,

     // just re-use the fill character from last time.

-    if (ch == KEY_RESIZE)

+    if (ch < CHAR_MIN || ch > CHAR_MAX || ch == KEY_RESIZE)

       ch = vs.fill_char;

     int term_height = getmaxy(stdscr);

     int term_width = getmaxx(stdscr);

     assert(term_height >= 0 && term_width >= 0);

-    update_view_state(&vs, term_height, term_width, ch);

+    update_view_state(&vs, term_height, term_width, (chtype)ch);

     draw_view_state(&vs);

     refresh();