# which can be used to store and replay a sequence of image frames.
# This is useful for caching pre-rendered effects, like a spell or an explosion.
# This is just the explosion system from the previous example in a more condensed form.
s = System(gravity=(0, 1.0))
for i in range(80):
s.append(Particle(x=200, y=250, mass=random(5.0,10.0), radius=5, life=30))
s.force(strength=4.5, threshold=70)
# Instead of drawing the system directly to the canvas,
# we render each step offscreen as an image,
# and then gather the images in an animation loop.
explosion = Animation(duration=0.75, loop=False)
for i in range(30):
s.update(limit=20)
img = render(s.draw, 400, 400)
explosion.append(img)
# This can take several seconds:
# - calculating forces in the system is costly (if possible, load Psyco to speed them up),
# - rendering each image takes time (specifically, initialising a new empty image).
# If possible, reduce the image frames in size (smaller images = faster rendering).
# When the user clicks on the canvas, the explosion animation is played.
# We keep a list of explosions currently playing:
explosions = []
def on_mouse_press(canvas, mouse):
# When the mouse is clicked, start a new explosion at the mouse position.
explosions.append((mouse.x, mouse.y, explosion.copy()))
ellipse(120, 120, 200, 200)
fill(0, 1, 0, 0.5) # Transparent green.
ellipse(170, 120, 200, 200)
fill(0, 0, 1, 0.5) # Transparent blue.
ellipse(145, 160, 200, 200)
fill(0)
font("Droid Serif")
text("hello", x=0, y=90, fontsize=70, width=300, align=CENTER)
# We call this a "procedural" image, because it is entirely created in code.
# Procedural images can be useful in many ways:
# - applying effects to text,
# - caching a complex composition that is not frequently updated (for speed),
# - creating on-the-fly textures or shapes that are different every time,
# - using NodeBox from the command line without opening an application window.
img = render(function=hello, width=300, height=300)
# Note that we make the width and height of the offscreen canvas
# a little bit larger than the actual composition.
# This creates a transparent border, so effects don't get cut off
# at the edge of the rendered image.
# Images can be saved to file, even without starting canvas.run().
# To try it out, uncomment the following line:
#img.save("hello.png")
def draw(canvas):
canvas.clear()
# Apply a blur filter to the procedural image and draw it.
# which can be used to store and replay a sequence of image frames.
# This is useful for caching pre-rendered effects, like a spell or an explosion.
# This is just the explosion system from the previous example in a more condensed form.
s = System(gravity=(0, 1.0))
for i in range(80):
s.append(Particle(x=200, y=250, mass=random(5.0, 10.0), radius=5, life=30))
s.force(strength=4.5, threshold=70)
# Instead of drawing the system directly to the canvas,
# we render each step offscreen as an image,
# and then gather the images in an animation loop.
explosion = Animation(duration=0.75, loop=False)
for i in range(30):
s.update(limit=20)
img = render(s.draw, 400, 400)
explosion.append(img)
# This can take several seconds:
# - calculating forces in the system is costly (if possible, load Psyco to speed them up),
# - rendering each image takes time (specifically, initialising a new empty image).
# If possible, reduce the image frames in size (smaller images = faster rendering).
# When the user clicks on the canvas, the explosion animation is played.
# We keep a list of explosions currently playing:
explosions = []
def on_mouse_press(canvas, mouse):
# When the mouse is clicked, start a new explosion at the mouse position.
explosions.append((mouse.x, mouse.y, explosion.copy()))
fill(0, 1, 0, 0.5) # Transparent green.
ellipse(170, 120, 200, 200)
fill(0, 0, 1, 0.5) # Transparent blue.
ellipse(145, 160, 200, 200)
fill(0)
font("Droid Serif")
text("hello", x=0, y=90, fontsize=70, width=300, align=CENTER)
# We call this a "procedural" image, because it is entirely created in code.
# Procedural images can be useful in many ways:
# - applying effects to text,
# - caching a complex composition that is not frequently updated (for speed),
# - creating on-the-fly textures or shapes that are different every time,
# - using NodeBox from the command line without opening an application window.
img = render(function=hello, width=300, height=300)
# Note that we make the width and height of the offscreen canvas
# a little bit larger than the actual composition.
# This creates a transparent border, so effects don't get cut off
# at the edge of the rendered image.
# Images can be saved to file, even without starting canvas.run().
# To try it out, uncomment the following line:
#img.save("hello.png")
def draw(canvas):
canvas.clear()
for i in range(n):
pt1 = choice(points)
pt2 = choice(points)
while distance(pt1.x, pt1.y, pt2.x, pt2.y) > radius:
pt2 = choice(points)
line(pt1.x + random(-m, m),
pt1.y + random(-m, m),
pt2.x + random(-m, m),
pt2.y + random(-m, m))
# Render the function's output to an image.
# Rendering the image beforehand is much faster than calling spider() every frame.
stroke(0.1, 0.1, 0, 0.5)
strokewidth(1)
img = render(spider, 500, 150,
string = "SPIDER",
font = "Droid Sans",
fontsize = 100,
bold = True,
x = 25,
y = 25,
radius = 30)
def draw(canvas):
canvas.clear()
translate(0, 200)
image(img)
canvas.size = 500, 500
canvas.run(draw)
while distance(pt1.x, pt1.y, pt2.x, pt2.y) > radius:
pt2 = choice(points)
line(pt1.x + random(-m, m), pt1.y + random(-m, m),
pt2.x + random(-m, m), pt2.y + random(-m, m))
# Render the function's output to an image.
# Rendering the image beforehand is much faster than calling spider() every frame.
stroke(0.1, 0.1, 0, 0.5)
strokewidth(1)
img = render(spider,
500,
150,
string="SPIDER",
font="Droid Sans",
fontsize=100,
bold=True,
x=25,
y=25,
radius=30)
def draw(canvas):
canvas.clear()
translate(0, 200)
image(img)
canvas.size = 500, 500
canvas.run(draw)
