First action (delete) for testing, misc improvements here and there.

src/level.zig

@@ -34,10 +34,10 @@ pub fn init(allocator: *std.mem.Allocator, width: u16, height: u16) !Self {
     errdefer allocator.free(self.content);
     self.selection = try allocator.alloc(bool, size);
 
-    // Fill with 0s to avoid undefined behavior.
+    // Fill with default value to avoid undefined behavior.
     var i: u32 = 0;
     while (i < size) : (i += 1) {
-        self.content[i] = 0;
+        self.content[i] = 1;
         self.selection[i] = false;
     }
     return self;
@@ -62,7 +62,7 @@ pub fn draw(self: *Self, scale: u16, offset: Vec2) void {
             const cell_content: cell_t = self.content[cy * self.width + cx];
             const color = switch (cell_content) {
                 0 => ray.GRAY,
-                1 => ray.WHITE,
+                1 => ray.RAYWHITE,
                 else => ray.PURPLE, //unknown
             };
             ray.DrawRectangle(x + 1, y + 1, scale - 2, scale - 2, color);
@@ -125,6 +125,7 @@ fn select_rect(self: *Self, rect: Rect, state: bool) void {
     }
 }
 
+/// Apply selection update to selection *kof*.
 pub fn apply_selection_update(self: *Self, selection_update: SelectionUpdate) void {
     // The update is exclusive, forget everything before it.
     if (selection_update.exclusive) {
@@ -136,6 +137,15 @@ pub fn apply_selection_update(self: *Self, selection_update: SelectionUpdate) vo
     self.select_rect(selection_update.area, selection_update.state);
 }
 
+/// Delete selected cells (set to 0).
+pub fn action_delete(self: *Self) void {
+    var i: u32 = 0;
+    while (i < self.width * self.height) : (i += 1) {
+        if (self.selection[i])
+            self.content[i] = 0;
+    }
+}
+
 test "create level buffer" {
     // Create allocator.
     var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);

src/main.zig

@@ -34,7 +34,8 @@ pub fn main() !void {
 
     // Scale, used by drawing code.
     const scale_type = u16;
-    var scale: scale_type = 16;
+    const scale_default = 16;
+    var scale: scale_type = scale_default;
 
     // Create cursor.
     var cursor: Vec2 = Vec2.init(0, 0);
@@ -93,6 +94,8 @@ pub fn main() !void {
                 'U' => selection_update = movement.move_up_right(&cursor, 1, false),
                 'B' => selection_update = movement.move_down_left(&cursor, 1, false),
                 'N' => selection_update = movement.move_down_right(&cursor, 1, false),
+                // Actions.
+                'd' => level.action_delete(),
                 // Zoom (pog feature).
                 '-' => if (scale > 3) {
                     scale -= 1;
@@ -101,7 +104,7 @@ pub fn main() !void {
                     scale += 1;
                 },
                 // Reset zoom.
-                '0' => scale = 4,
+                '0' => scale = scale_default,
                 else => log("No action mapped to key {}.", .{action}),
             }