tiny.windowing.GamepadCapacity

1pub const Capacity = struct {2    retained_gamepad_count: usize,3    retained_name_byte_count_per_gamepad: usize,4    read_event_count: usize,5    scanned_source_count: u32,6    slot_bytes: usize,7    name_bytes: usize,8    read_event_bytes: usize,9    retained_storage_bytes: usize,1011    pub fn derive(limits: Limits) CapacityError!Capacity {12        if (limits.retained_gamepad_count == 0) return error.GamepadStorageEmpty;13        if (limits.retained_name_byte_count_per_gamepad == 0) return error.NameStorageEmpty;14        if (source_kind == .evdev and15            limits.retained_name_byte_count_per_gamepad > sys.evdev.max_query_bytes)16        {17            return error.NameStorageTooLarge;18        }19        if (source_kind == .evdev and limits.read_event_count == 0) {20            return error.EventReadStorageEmpty;21        }22        if (limits.scanned_source_count == 0) return error.SourceScanEmpty;23        const slot_bytes = std.math.mul(24            usize,25            limits.retained_gamepad_count,26            @sizeOf(?Slot),27        ) catch return error.CapacityOverflow;28        const name_bytes = std.math.mul(29            usize,30            limits.retained_gamepad_count,31            limits.retained_name_byte_count_per_gamepad,32        ) catch return error.CapacityOverflow;33        const read_event_count = if (source_kind == .evdev) limits.read_event_count else 0;34        const read_event_bytes = if (source_kind == .evdev)35            std.math.mul(36                usize,37                read_event_count,38                @sizeOf(sys.evdev.InputEvent),39            ) catch return error.CapacityOverflow40        else41            0;42        const retained_gamepad_bytes = std.math.add(43            usize,44            slot_bytes,45            name_bytes,46        ) catch return error.CapacityOverflow;47        const retained_storage_bytes = std.math.add(48            usize,49            retained_gamepad_bytes,50            read_event_bytes,51        ) catch return error.CapacityOverflow;52        return .{53            .retained_gamepad_count = limits.retained_gamepad_count,54            .retained_name_byte_count_per_gamepad = limits.retained_name_byte_count_per_gamepad,55            .read_event_count = read_event_count,56            .scanned_source_count = limits.scanned_source_count,57            .slot_bytes = slot_bytes,58            .name_bytes = name_bytes,59            .read_event_bytes = read_event_bytes,60            .retained_storage_bytes = retained_storage_bytes,61        };62    }63};

1pub const GamepadCapacity = gamepad_module.Capacity;