glfw: ziggify gamepad button enumerations

Helps hexops/mach#37

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>

glfw/src/Joystick.zig

@@ -9,7 +9,9 @@ const c = @import("c.zig").c;
 const Window = @import("Window.zig");
 const Error = @import("errors.zig").Error;
 const getError = @import("errors.zig").getError;
+const Action = @import("action.zig").Action;
 const GamepadAxis = @import("gamepad_axis.zig").GamepadAxis;
+const GamepadButton = @import("gamepad_button.zig").GamepadButton;
 
 const Joystick = @This();
 
@@ -44,6 +46,8 @@ pub const last = c.GLFW_JOYSTICK_LAST;
 /// see also: gamepad, glfwGetGamepadState
 const GamepadState = extern struct {
     /// The states of each gamepad button (see gamepad_buttons), `glfw.Action.press` or `glfw.Action.release`.
+    ///
+    /// Use the enumeration helper e.g. `.getButton(.dpad_up)` to access these indices.
     buttons: [15]u8,
 
     /// The states of each gamepad axis (see gamepad_axes), in the range -1.0 to 1.0 inclusive.
@@ -51,9 +55,16 @@ const GamepadState = extern struct {
     /// Use the enumeration helper e.g. `.getAxis(.left_x)` to access these indices.
     axes: [6]f32,
 
+    /// Returns the state of the specified gamepad button.
+    pub fn getButton(self: @This(), which: GamepadButton) Action {
+        _ = self;
+        return @intToEnum(Action, self.buttons[@intCast(usize, @enumToInt(which))]);
+    }
+
     /// Returns the status of the specified gamepad axis, in the range -1.0 to 1.0 inclusive.
     pub fn getAxis(self: @This(), which: GamepadAxis) f32 {
-        return self.axis[which];
+        _ = self;
+        return self.axes[@intCast(usize, @enumToInt(which))];
     }
 };
 
@@ -548,5 +559,6 @@ test "getGamepadState" {
 
     const joystick = glfw.Joystick{ .jid = glfw.Joystick.one };
     _ = joystick.getGamepadState() catch |err| std.debug.print("failed to get gamepad state, joysticks not supported? error={}\n", .{err});
-    _ = (GamepadState{}).getAxis(.left_x);
+    _ = (std.mem.zeroes(GamepadState)).getAxis(.left_x);
+    _ = (std.mem.zeroes(GamepadState)).getButton(.dpad_up);
 }

glfw/src/gamepad_axis.zig

@@ -10,5 +10,7 @@ pub const GamepadAxis = enum(c_int) {
     right_y = c.GLFW_GAMEPAD_AXIS_RIGHT_Y,
     left_trigger = c.GLFW_GAMEPAD_AXIS_LEFT_TRIGGER,
     right_trigger = c.GLFW_GAMEPAD_AXIS_RIGHT_TRIGGER,
-    last = .right_trigger,
 };
+
+/// Not in the GamepadAxis enumeration as it is a duplicate value which is forbidden.
+pub const last = GamepadAxis.right_trigger;

glfw/src/gamepad_button.zig

@@ -1,27 +1,37 @@
-//! Gamepad buttons.
-//!
-//! See glfw.getGamepadState for how these are used.
-
 const c = @import("c.zig").c;
 
-pub const a = c.GLFW_GAMEPAD_BUTTON_A;
-pub const b = c.GLFW_GAMEPAD_BUTTON_B;
-pub const x = c.GLFW_GAMEPAD_BUTTON_X;
-pub const y = c.GLFW_GAMEPAD_BUTTON_Y;
-pub const left_bumper = c.GLFW_GAMEPAD_BUTTON_LEFT_BUMPER;
-pub const right_bumper = c.GLFW_GAMEPAD_BUTTON_RIGHT_BUMPER;
-pub const back = c.GLFW_GAMEPAD_BUTTON_BACK;
-pub const start = c.GLFW_GAMEPAD_BUTTON_START;
-pub const guide = c.GLFW_GAMEPAD_BUTTON_GUIDE;
-pub const left_thumb = c.GLFW_GAMEPAD_BUTTON_LEFT_THUMB;
-pub const right_thumb = c.GLFW_GAMEPAD_BUTTON_RIGHT_THUMB;
-pub const dpad_up = c.GLFW_GAMEPAD_BUTTON_DPAD_UP;
-pub const dpad_right = c.GLFW_GAMEPAD_BUTTON_DPAD_RIGHT;
-pub const dpad_down = c.GLFW_GAMEPAD_BUTTON_DPAD_DOWN;
-pub const dpad_left = c.GLFW_GAMEPAD_BUTTON_DPAD_LEFT;
-pub const last = dpad_left;
+/// Gamepad buttons.
+///
+/// See glfw.getGamepadState for how these are used.
+pub const GamepadButton = enum(c_int) {
+    a = c.GLFW_GAMEPAD_BUTTON_A,
+    b = c.GLFW_GAMEPAD_BUTTON_B,
+    x = c.GLFW_GAMEPAD_BUTTON_X,
+    y = c.GLFW_GAMEPAD_BUTTON_Y,
+    left_bumper = c.GLFW_GAMEPAD_BUTTON_LEFT_BUMPER,
+    right_bumper = c.GLFW_GAMEPAD_BUTTON_RIGHT_BUMPER,
+    back = c.GLFW_GAMEPAD_BUTTON_BACK,
+    start = c.GLFW_GAMEPAD_BUTTON_START,
+    guide = c.GLFW_GAMEPAD_BUTTON_GUIDE,
+    left_thumb = c.GLFW_GAMEPAD_BUTTON_LEFT_THUMB,
+    right_thumb = c.GLFW_GAMEPAD_BUTTON_RIGHT_THUMB,
+    dpad_up = c.GLFW_GAMEPAD_BUTTON_DPAD_UP,
+    dpad_right = c.GLFW_GAMEPAD_BUTTON_DPAD_RIGHT,
+    dpad_down = c.GLFW_GAMEPAD_BUTTON_DPAD_DOWN,
+    dpad_left = c.GLFW_GAMEPAD_BUTTON_DPAD_LEFT,
+};
 
-pub const cross = a;
-pub const circle = b;
-pub const square = x;
-pub const triangle = y;
+/// Not in the GamepadAxis enumeration as it is a duplicate value which is forbidden.
+pub const last = GamepadButton.dpad_left;
+
+/// Not in the GamepadAxis enumeration as it is a duplicate value which is forbidden.
+pub const cross = GamepadButton.a;
+
+/// Not in the GamepadAxis enumeration as it is a duplicate value which is forbidden.
+pub const circle = GamepadButton.b;
+
+/// Not in the GamepadAxis enumeration as it is a duplicate value which is forbidden.
+pub const square = GamepadButton.x;
+
+/// Not in the GamepadAxis enumeration as it is a duplicate value which is forbidden.
+pub const triangle = GamepadButton.y;

glfw/src/main.zig

@@ -11,7 +11,7 @@ const getError = @import("errors.zig").getError;
 
 pub const Action = @import("action.zig").Action;
 pub const GamepadAxis = @import("gamepad_axis.zig").GamepadAxis;
-pub const gamepad_button = @import("gamepad_button.zig");
+pub const GamepadButton = @import("gamepad_button.zig").GamepadButton;
 pub const GammaRamp = @import("GammaRamp.zig");
 pub const hat = @import("hat.zig");
 pub const Image = @import("Image.zig");