examples/gkurve: initial commit for resizable_label

examples/gkurve/data_structures/bit_array_list.zig

@@ -0,0 +1,67 @@
+const std = @import("std");
+
+// std.DynamicBitSet doesn't behave like std.ArrayList, it will realloc on every resize.
+// For now provide a bitset api and use std.ArrayList(bool) as the implementation.
+pub const BitArrayList = struct {
+    const Self = @This();
+
+    buf: std.ArrayList(bool),
+
+    pub fn init(alloc: std.mem.Allocator) Self {
+        return .{
+            .buf = std.ArrayList(bool).init(alloc),
+        };
+    }
+
+    pub fn deinit(self: Self) void {
+        self.buf.deinit();
+    }
+
+    pub fn clearRetainingCapacity(self: *Self) void {
+        self.buf.clearRetainingCapacity();
+    }
+
+    pub fn appendUnset(self: *Self) !void {
+        try self.buf.append(false);
+    }
+
+    pub fn appendSet(self: *Self) !void {
+        try self.buf.append(true);
+    }
+
+    pub fn isSet(self: Self, idx: usize) bool {
+        return self.buf.items[idx];
+    }
+
+    pub fn set(self: *Self, idx: usize) void {
+        self.buf.items[idx] = true;
+    }
+
+    pub fn unset(self: *Self, idx: usize) void {
+        self.buf.items[idx] = false;
+    }
+
+    pub fn setRange(self: *Self, start: usize, end: usize) void {
+        std.mem.set(bool, self.buf.items[start..end], true);
+    }
+
+    pub fn unsetRange(self: *Self, start: usize, end: usize) void {
+        std.mem.set(bool, self.buf.items[start..end], false);
+    }
+
+    pub fn resize(self: *Self, size: usize) !void {
+        try self.buf.resize(size);
+    }
+
+    pub fn resizeFillNew(self: *Self, size: usize, comptime fill: bool) !void {
+        const start = self.buf.items.len;
+        try self.resize(size);
+        if (self.buf.items.len > start) {
+            if (fill) {
+                self.setRange(start, self.buf.items.len);
+            } else {
+                self.unsetRange(start, self.buf.items.len);
+            }
+        }
+    }
+};