allow camera movement with the keyboard

2025-08-03 13:11:33 +00:00 · 2024-08-22 17:08:28 +10:00
parent 83fc86d2a5
commit 39d46da7f7
5 changed files with 231 additions and 40 deletions
--- a/Sources/Voxelotl/Keyboard.swift
+++ b/Sources/Voxelotl/Keyboard.swift
@ -0,0 +1,137 @@
+import SDL3
+
+public class Keyboard {
+  public enum Keys {
+    case a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z
+    case right, left, up, down
+    case space
+  }
+
+  public static func down(_ key: Keys) -> Bool {
+     keyState(key) & Self._DOWN == Self._DOWN
+  }
+
+  public static func pressed(_ key: Keys, repeat rep: Bool = false) -> Bool {
+    var state = keyState(key)
+    if rep {
+      state &= ~Self._REPEAT
+    }
+    return state == Self._PRESS
+  }
+
+  public static func released(_ key: Keys) -> Bool {
+    keyState(key) == Self._RELEASE
+  }
+
+  //MARK: - Private
+
+  private static let _instance = Keyboard()
+  public static var instance: Keyboard { _instance }
+
+  @inline(__always) private static func keyState(_ key: Keys) -> UInt8 {
+    self._instance._state[Int(key.sdlScancode.rawValue)]
+  }
+
+  private static let _UP = UInt8(0b000), _DOWN = UInt8(0b010), _IMPULSE = UInt8(0b001)
+  private static let _REPEAT = UInt8(0b100)
+  private static let _PRESS: UInt8 = _DOWN | _IMPULSE
+  private static let _RELEASE: UInt8 = _UP | _IMPULSE
+  
+  private var _state = [UInt8](repeating: _UP, count: Int(SDL_NUM_SCANCODES.rawValue))
+
+  internal func keyDownEvent(scan: SDL_Scancode, repeat rep: Bool) {
+    var newState = Self._PRESS
+    if rep {
+      newState |= Self._REPEAT
+    }
+    self._state[Int(scan.rawValue)] = newState
+  }
+
+  internal func keyUpEvent(scan: SDL_Scancode) {
+    self._state[Int(scan.rawValue)] = Self._RELEASE
+  }
+
+  internal func newFrame() {
+    self._state = self._state.map({ $0 & ~(Self._IMPULSE | Self._REPEAT) })
+  }
+}
+
+internal extension Keyboard.Keys {
+  var sdlKeycode: SDL_Keycode {
+    switch self {
+    case .a:     SDLK_A
+    case .b:     SDLK_B
+    case .c:     SDLK_C
+    case .d:     SDLK_D
+    case .e:     SDLK_E
+    case .f:     SDLK_F
+    case .g:     SDLK_G
+    case .h:     SDLK_H
+    case .i:     SDLK_I
+    case .j:     SDLK_J
+    case .k:     SDLK_K
+    case .l:     SDLK_L
+    case .m:     SDLK_M
+    case .n:     SDLK_N
+    case .o:     SDLK_O
+    case .p:     SDLK_P
+    case .q:     SDLK_Q
+    case .r:     SDLK_R
+    case .s:     SDLK_S
+    case .t:     SDLK_T
+    case .u:     SDLK_U
+    case .v:     SDLK_V
+    case .w:     SDLK_W
+    case .x:     SDLK_X
+    case .y:     SDLK_Y
+    case .z:     SDLK_Z
+    case .left:  SDLK_LEFT
+    case .right: SDLK_RIGHT
+    case .up:    SDLK_UP
+    case .down:  SDLK_DOWN
+    case .space: SDLK_SPACE
+    }
+  }
+
+  var sdlScancode: SDL_Scancode {
+    switch self {
+    case .a:     SDL_SCANCODE_A
+    case .b:     SDL_SCANCODE_B
+    case .c:     SDL_SCANCODE_C
+    case .d:     SDL_SCANCODE_D
+    case .e:     SDL_SCANCODE_E
+    case .f:     SDL_SCANCODE_F
+    case .g:     SDL_SCANCODE_G
+    case .h:     SDL_SCANCODE_H
+    case .i:     SDL_SCANCODE_I
+    case .j:     SDL_SCANCODE_J
+    case .k:     SDL_SCANCODE_K
+    case .l:     SDL_SCANCODE_L
+    case .m:     SDL_SCANCODE_M
+    case .n:     SDL_SCANCODE_N
+    case .o:     SDL_SCANCODE_O
+    case .p:     SDL_SCANCODE_P
+    case .q:     SDL_SCANCODE_Q
+    case .r:     SDL_SCANCODE_R
+    case .s:     SDL_SCANCODE_S
+    case .t:     SDL_SCANCODE_T
+    case .u:     SDL_SCANCODE_U
+    case .v:     SDL_SCANCODE_V
+    case .w:     SDL_SCANCODE_W
+    case .x:     SDL_SCANCODE_X
+    case .y:     SDL_SCANCODE_Y
+    case .z:     SDL_SCANCODE_Z
+    case .left:  SDL_SCANCODE_LEFT
+    case .right: SDL_SCANCODE_RIGHT
+    case .up:    SDL_SCANCODE_UP
+    case .down:  SDL_SCANCODE_DOWN
+    case .space: SDL_SCANCODE_SPACE
+    }
+  }
+}
+
+fileprivate extension SDL_Keycode {
+  init(scancode: SDL_Scancode) {
+    self.init(scancode.rawValue | UInt32(SDLK_SCANCODE_MASK))
+  }
+}