def on_update(self, dt):
""" Center the camera on target """
if not self._track_target:
return
# -- clamp target to camera bounds
sx, sy = self.size / 2
px, py = self._track_target.position
position = Vec2(
clamp(px, self.bounds.left + sx, self.bounds.right - sx),
clamp(py, self.bounds.bottom + sy, self.bounds.top - sy),
)
# -- set camera offset (distance from center of camera to target_pos)
self.offset = self._size / 2 - position
# -- move the camera steadily to reduce offset
epsilon = 2.0
dist = self.offset.get_distance(self._position)
norm = (self.offset - self._position).normalized()
if dist >= epsilon:
# XXX NOTE: dist is added to speed to prevent camera from lagging behind
self._position += norm * dt * (self.speed + dist)
pg.gl.glMatrixMode(pg.gl.GL_MODELVIEW)
pg.gl.glLoadIdentity()
pg.gl.glTranslatef(*self._position, 0)
pg.gl.glScalef(*self._scale, 1)
def on_mouse_scroll(self, x, y, sx, sy):
if not mouse_over_rect((x, y), *self.get_rect()):
return
# -- update active level based on scroll
self.active_level = clamp(self.active_level + sy, 0,
len(self.tabs) - 1)
self.switch_level(self.tabs[self.active_level].text)
def zoom_camera(self, dy):
# TODO minimum and maximum zoom levels
# TODO user-configurable scale_factor (or not???)
dy = clamp(dy, -1.1, 1.1)
# prevent view from transforming weirdly (i.e. flipping upside down)
if dy < 0:
dy = 1 / -dy
self.scale(dy, dy)
def on_mouse_scroll(self, x, y, sx, sy):
if not mouse_over_rect((x, y), *self.get_rect()):
return
_sum = lambda x, y, val: (x + val, y + val)
if sy < 0:
self._zoom = _sum(*self._zoom, -self._zoom_sensitivity)
else:
self._zoom = _sum(*self._zoom, self._zoom_sensitivity)
# -- clamp zoom to (0.2, 10.0) and round to d.p
self._zoom = tuple(map(lambda x: clamp(x, 0.2, 10.0), self._zoom))
self._zoom = tuple(map(lambda x: round(x, 1), self._zoom))
def test_clamp_maximum():
assert clamp(2, 0, 1) == 1
assert clamp(5, -2, -1) == -1
assert clamp(10, 6, 8) == 8
def test_clamp_minimum():
assert clamp(-1, 0, 1) == 0
assert clamp(-5, -2, -1) == -2
assert clamp(2, 4, 8) == 4
def test_clamp_untouched():
assert clamp(0.5, 0, 1) == 0.5
assert clamp(-2, -4, 1) == -2