04 input

Tutorial 04 — Input

Copyright (c) 2024-2026 Jack Waechter. MIT licensed.

Input is sampled after AP_PumpEvents(). Each call is “this frame” relative to the last pump.

Keyboard

if (AP_IsKeyPressed(AP_KEY_ESCAPE)) {
  AP_RequestClose();
}

if (AP_IsKeyDown(AP_KEY_W)) {
  y -= speed * dt;
}

if (AP_IsKeyReleased(AP_KEY_SPACE)) {
  /* just let go */
}

Query	Meaning
AP_IsKeyDown	Held
AP_IsKeyPressed	Went down this frame
AP_IsKeyReleased	Went up this frame
AP_IsKeyRepeat	OS key-repeat

Modifiers: AP_IsShiftDown(), AP_IsCtrlDown(), AP_IsAltDown().

Key names match GLFW (AP_KEY_A … AP_KEY_Z, AP_KEY_LEFT, AP_KEY_SPACE, function keys).

Mouse

Coordinates are window pixels, top-left origin.

float mx = (float)AP_GetMouseX();
float my = (float)AP_GetMouseY();

if (AP_IsMousePressed(AP_MOUSE_LEFT)) {
  /* click */
}

if (AP_IsMouseDown(AP_MOUSE_RIGHT)) {
  /* drag */
}

AP_GetMouseDeltaX() / AP_GetMouseDeltaY() are motion since last pump. Useful for look / camera.

If you are using the immediate GUI, skip game clicks when the UI wants the pointer:

if (!AP_GuiWantCaptureMouse() && AP_IsMousePressed(AP_MOUSE_LEFT)) {
  /* world click */
}

Gamepad

Indices are 0 .. AP_GAMEPAD_MAX-1. Stick Y is up = negative, same as GLFW.

int pad = AP_GetFirstGamepad();
if (pad >= 0 && AP_IsGamepadConnected(pad)) {
  AP_Vec2 stick = AP_GetGamepadStick(pad, AP_GAMEPAD_STICK_LEFT);
  x += stick.x * speed * dt;
  y += stick.y * speed * dt; /* up is negative */

  if (AP_IsGamepadButtonPressed(pad, AP_GAMEPAD_A)) {
    jump = true;
  }

  float trigger = AP_GetGamepadTrigger(pad, AP_GAMEPAD_AXIS_RIGHT_TRIGGER);
}

AP_SetGamepadDeadzone(0.15f) if the stick chatters at rest.

Frame time

AP_Tick() is pygame's Clock.tick: it waits so the frame hits AP_SetTargetFPS, then returns delta time in seconds. 0 means uncapped.

AP_SetTargetFPS(60);

while (AP_IsRunning()) {
  AP_PumpEvents();
  double dt = AP_Tick(); /* or AP_GetDeltaTime() after Tick */
  AP_SpriteUpdate(&walk, (float)dt);
}

AP_TickFPS(60) is the one-liner. AP_GetFPS() is a smoothed measurement, not the cap. Hitch frames are clamped to 0.1s.

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Audio