interactive conways game of life

src/subcmds/arcade/conway.zig

@@ -1,4 +1,3 @@
-// TODO: make interactive
 const Conway = @This();
 
 const std = @import("std");
@@ -28,6 +27,9 @@ const Cell = struct {
 };
 
 pub fn init(width: u64, height: u64, writer: *std.Io.Writer) !Conway {
+    std.debug.assert(width > 0);
+    std.debug.assert(height > 0);
+
     var self: Conway = .{
         .width = width,
         .height = height,
@@ -36,11 +38,11 @@ pub fn init(width: u64, height: u64, writer: *std.Io.Writer) !Conway {
     };
 
     // create the world and the cells
-    self.world = try gpa.alloc([]*Cell, width);
+    self.world = try gpa.alloc([]*Cell, height);
     for (self.world, 0..) |col, i| {
-        self.world[i] = try gpa.alloc(*Cell, height);
+        self.world[i] = try gpa.alloc(*Cell, width);
         for (col, 0..) |_, j| {
-            if (j >= height) break;
+            if (j >= width) break;
             self.world[i][j] = try gpa.create(Cell);
         }
     }
@@ -52,9 +54,9 @@ pub fn init(width: u64, height: u64, writer: *std.Io.Writer) !Conway {
         // the left column has nothing on the left
         cell.neighbors[1] = if (i == 0) null else self.world[i - 1][j];
         // the right row has nothing on the right
-        cell.neighbors[2] = if (i == width - 1) null else self.world[i + 1][j];
+        cell.neighbors[2] = if (i == height - 1) null else self.world[i + 1][j];
         // the bottom row has nothing below it
-        cell.neighbors[3] = if (j == height - 1) null else self.world[i][j + 1];
+        cell.neighbors[3] = if (j == width - 1) null else self.world[i][j + 1];
         cell.alive = false;
     };
 
@@ -100,6 +102,7 @@ pub fn step(self: *Conway) void {
     for (self.world) |col| for (col) |cell| {
         cell.alive = cell.will_live;
     };
+    self.generation += 1;
 }
 
 pub fn print(self: *Conway) !void {
@@ -109,27 +112,103 @@ pub fn print(self: *Conway) !void {
         }
         _ = try self.writer.write("\n");
     }
-    try self.writer.flush();
 }
 
 pub fn play(width: u64, height: u64, writer: *std.Io.Writer) !void {
-    var con = try Conway.init(width, height, writer);
+    var con = try Conway.init(width, height - 1, writer);
 
-    con.world[4][2].alive = true;
-    con.world[4][3].alive = true;
-    con.world[4][4].alive = true;
-    con.world[4][5].alive = true;
-    con.world[4][6].alive = true;
-    con.world[4][7].alive = true;
-    con.world[5][2].alive = true;
-    con.world[5][3].alive = true;
-    con.world[5][4].alive = true;
-    con.world[5][5].alive = true;
-    con.world[5][6].alive = true;
+    // here we're disabling character echoing and newline requirements on input
+    const oldios = try std.posix.tcgetattr(std.posix.STDIN_FILENO);
+    defer std.posix.tcsetattr(std.posix.STDIN_FILENO, std.posix.TCSA.NOW, oldios) catch {
+        // oh well we've left the terminal in a shitty state, not much we can
+        // do to fix this.
+    };
+    var newios = oldios;
 
-    while (true) : (con.step()) {
+    newios.lflag.ECHO = false;
+    newios.lflag.ICANON = false;
+    try std.posix.tcsetattr(std.posix.STDIN_FILENO, std.posix.TCSA.NOW, newios);
+
+    var fd = [_]std.posix.pollfd{.{
+        .fd = std.posix.STDIN_FILENO,
+        .events = std.posix.POLL.IN,
+        .revents = 0
+    }};
+
+    var timeout: i32 = 250;
+    var cursor_x: i64 = 1;
+    var cursor_y: i64 = 1;
+    var interactive = true;
+    var running = true;
+    while (running) : (con.step()) run: while (true) {
+        // not sure why but adding one here makes the status bar refresh fully
+        try con.writer.print("\x1B[{}A", .{height + 1});
         try con.print();
-        std.posix.nanosleep(0, 250000000);
-        try con.writer.print("\x1B[{}A", .{con.height});
-    }
+
+        // keep the cursor in the game window to prevent the terminal from doing
+        // anything we can't/don't account for
+        cursor_x = std.math.clamp(cursor_x, 1, con.width);
+        cursor_y = std.math.clamp(cursor_y, 1, con.height);
+
+        // statusbar
+        try con.writer.print("ge[n]: {} | {s} [i]nteractive \x1B[0m {},{} {}x{} | [+]{}[-]", .{
+            con.generation,
+            if (interactive) "\x1B[47;30;1m" else "\x1B[40;37m",
+            cursor_x, cursor_y,
+            con.width, con.height,
+            timeout,
+        });
+
+        // position cursor in interactive mode
+        if (interactive) {
+            try con.writer.print("\x1B[{};{}H", .{cursor_y, cursor_x}); // swapped on purpose
+            try con.writer.flush();
+        }
+
+        try con.writer.flush();
+
+        const size = try std.posix.poll(@constCast(&fd), if (!interactive) @intCast(timeout) else -1);
+        if (size > 0) {
+            var buf: [50]u8 = undefined;
+            _ = try std.fs.File.stdin().read(@constCast(&buf));
+            for (buf) |c| switch (c) {
+                // we don't wanna worry about case when using +
+                '+', '=' => timeout += 50,
+                '-' => timeout = std.math.clamp(timeout - 50, 1, 1000),
+                'n' => break :run, // next generation
+                'q' => {
+                    running = false;
+                    break :run;
+                },
+                'i' => interactive = !interactive,
+
+                // interactive exclusive keys
+                else => if (interactive) switch (c) {
+                    // movement keys, all movement is clamped before it's displayed
+                    'h' => cursor_x -= 1,
+                    'j' => cursor_y += 1,
+                    'k' => cursor_y -= 1,
+                    'l' => cursor_x += 1,
+
+                    '_' => cursor_x = 1,
+                    '$' => cursor_x = @intCast(con.width),
+                    'g' => cursor_y = 1,
+                    'G' => cursor_y = @intCast(con.height),
+
+
+                    ' ' => { // toggle the current value's aliveness
+                        const cell = con.world[@intCast(cursor_y - 1)][@intCast(cursor_x - 1)];
+                        cell.alive = !cell.alive;
+                        // prevent the cell from coming back
+                        cell.will_live = false;
+                    },
+                    else => break,
+                },
+            };
+        } else break;
+    };
+
+    try con.writer.print("\n\x1B[{}A\n", .{height});
+    try con.writer.flush();
+    con.deinit();
 }