class HeightAndColourMap:
def __init__(self):
self.noise = Noise()
self.cache = PagedDataCache(self._get_height_and_colour_non_cached,
IsoCraftConstants.VOLUME_DEPTH,
IsoCraftConstants.VOLUME_DEPTH)
def get_height_and_colour(self, x, y):
# Cached version of below
return self.cache.get(x, y)
def _get_height_and_colour_non_cached(self, x, y):
# Uses noise to determine the height of a given point.
# Return a tuple of this height and the colour to render
noise = HeightAndColourMap._normalise_noise(
self.noise.get_with_octaves(x * IsoCraftConstants.NOISE_STEP,
y * IsoCraftConstants.NOISE_STEP,
IsoCraftConstants.OCTAVES))
colour = HeightAndColourMap._colour_from_normalised_noise(noise)
# Scale
height = int(noise * IsoCraftConstants.VOLUME_HEIGHT)
return height, colour
@staticmethod
def _normalise_noise(n):
# Noise will typically be in the range of -Sqrt(N/4) to + Sqrt(N/4) where N is the number of dimension
# In our case we are using 2D noise - approximately -0.7 to 0.7
# We want to discount any noise <= Water_Level, then normalise the remaining portion.
water_level = max(-0.7, IsoCraftConstants.WATER_LEVEL)
return max(n - water_level, 0.0) / (0.7 - water_level)
@staticmethod
def _colour_from_normalised_noise(noise):
return IsoCraftConstants.COLOUR_WATER if noise <= IsoCraftConstants.THRESHOLD_WATER \
else IsoCraftConstants.COLOUR_BEACH if noise <= IsoCraftConstants.THRESHOLD_BEACH \
else IsoCraftConstants.COLOUR_GRASS if noise <= IsoCraftConstants.THRESHOLD_GRASS \
else IsoCraftConstants.COLOUR_ROCK if noise <= IsoCraftConstants.THRESHOLD_ROCK \
else IsoCraftConstants.COLOUR_SNOW
class NoiseDemo:
STEP = 0.02
def __init__(self, width, height):
self.noise = Noise(256)
self.cache = dict()
self.width = width
self.height = height
self.screen = pygame.display.set_mode((width, height))
pygame.display.set_caption('Perlin Noise Demo')
pygame.font.init()
self.font = pygame.font.SysFont('Arial', 30)
self.background = (2, 2, 2)
def run(self):
running = True
octaves = 1
while running:
print(f"Rendering {octaves} octaves")
self._display(octaves)
pygame.display.flip()
print(f"Rendered {octaves} octaves - waiting")
waiting = True
pygame.event.clear()
while waiting:
event = pygame.event.wait()
if event.type == pygame.QUIT:
waiting = False
running = False
elif event.type == pygame.KEYDOWN:
if event.key == pygame.K_UP:
waiting = False
octaves = min(10, octaves + 1)
if event.key == pygame.K_DOWN:
waiting = False
octaves = max(1, octaves - 1)
def _display(self, octaves):
self.screen.fill(self.background)
self.screen.blit(
self.font.render(
f"Number of Octaves: {octaves} - Use KEYUP and KEYDOWN to change number.",
False, (255, 255, 255)),
(40, 40)
)
pygame.draw.line(self.screen, (255, 255, 255), (0, self.height / 2), (self.width, self.height / 2))
prev_x = 0
prev_y = self.height / 2
for i in range(1280):
current = self.noise.get_with_octaves(i * NoiseDemo.STEP, 0, octaves)
cur_x = i * 1280 / self.width
cur_y = current * self.height * 0.4 + self.height / 2
pygame.draw.line(
self.screen,
(255, 255, 255),
(prev_x, prev_y),
(cur_x, cur_y))
prev_x = cur_x
prev_y = cur_y
for x in range(200):
for y in range(200):
current = self.noise.get_with_octaves(x * NoiseDemo.STEP, y * NoiseDemo.STEP, octaves)
current += 0.7
current /= 1.4
current = int(current * 255)
pygame.draw.line(
self.screen,
(current, current, current),
(x + self.width * 0.75, y + self.height * 0.75),
(x + self.width * 0.75, y + self.height * 0.75)
)
def get_with_octaves(self, x, y, octaves):
key = (x, y, octaves)
if key not in self.cache:
self.cache[key] = self.noise.get_with_octaves(x, y, octaves)
return self.cache[key]
