Port processing4 examples to Python. (#260)

Author: tychedelia

crates/processing_pyo3/examples/Basics/Arrays/array_2d.py

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+# Array 2D.
+#
+# Demonstrates the syntax for creating a two-dimensional (2D) array.
+# Values in a 2D array are accessed through two index values.
+# 2D arrays are useful for storing images. In this example, each dot
+# is colored in relation to its distance from the center of the image.
+from mewnala import *
+
+distances = []
+max_distance = 0.0
+spacer = 0
+
+
+def setup():
+    global max_distance, spacer
+    size(640, 360)
+    max_distance = dist(width / 2, height / 2, width, height)
+    for x in range(width):
+        distances.append([0.0] * height)
+    for y in range(height):
+        for x in range(width):
+            distance = dist(width / 2, height / 2, x, y)
+            distances[x][y] = distance / max_distance
+    spacer = 10
+    stroke_weight(6)
+    no_loop()  # Run once and stop
+
+
+def draw():
+    background(0.0)
+    # This embedded loop skips over values in the arrays based on
+    # the spacer variable, so there are more values in the array
+    # than are drawn here. Change the value of the spacer variable
+    # to change the density of the points
+    for y in range(0, height, spacer):
+        for x in range(0, width, spacer):
+            stroke(distances[x][y])
+            point(x + spacer // 2, y + spacer // 2)
+
+
+run()

crates/processing_pyo3/examples/Basics/Arrays/array_objects.py

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+# Array Objects.
+#
+# Demonstrates the syntax for creating a list of custom objects.
+from mewnala import *
+
+unit = 40
+count = 0
+mods = []
+
+
+def setup():
+    global count
+    size(640, 360)
+    no_stroke()
+    wide_count = width // unit
+    high_count = height // unit
+    count = wide_count * high_count
+
+    for y in range(high_count):
+        for x in range(wide_count):
+            mods.append(Module(x * unit, y * unit, unit / 2, unit / 2, random(0.05, 0.8), unit))
+
+
+def draw():
+    background(0.0)
+    for mod in mods:
+        mod.update()
+        mod.display()
+
+
+class Module:
+    def __init__(self, x_offset, y_offset, x, y, speed, unit):
+        self.x_offset = x_offset
+        self.y_offset = y_offset
+        self.x = x
+        self.y = y
+        self.speed = speed
+        self.unit = unit
+        self.x_direction = 1
+        self.y_direction = 1
+
+    # Custom method for updating the variables
+    def update(self):
+        self.x = self.x + (self.speed * self.x_direction)
+        if self.x >= self.unit or self.x <= 0:
+            self.x_direction *= -1
+            self.x = self.x + (1 * self.x_direction)
+            self.y = self.y + (1 * self.y_direction)
+        if self.y >= self.unit or self.y <= 0:
+            self.y_direction *= -1
+            self.y = self.y + (1 * self.y_direction)
+
+    # Custom method for drawing the object
+    def display(self):
+        fill(1.0)
+        ellipse(self.x_offset + self.x, self.y_offset + self.y, 6, 6)
+
+
+run()

crates/processing_pyo3/examples/Basics/Arrays/array_sketch.py

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+# Array.
+#
+# An array is a list of data. Each piece of data in an array
+# is identified by an index number representing its position in
+# the array. Arrays are zero based, which means that the first
+# element in the array is [0], the second element is [1], and so on.
+# In this example, an array named "coswave" is created and
+# filled with the cosine values. This data is displayed three
+# separate ways on the screen.
+from mewnala import *
+
+coswave = []
+
+
+def setup():
+    size(640, 360)
+    for i in range(width):
+        amount = remap(i, 0, width, 0, PI)
+        coswave.append(abs(cos(amount)))
+    background(1.0)
+    no_loop()
+
+
+def draw():
+    y1 = 0
+    y2 = height // 3
+    for i in range(width):
+        stroke(coswave[i])
+        line(i, y1, i, y2)
+
+    y1 = y2
+    y2 = y1 + y1
+    for i in range(width):
+        stroke(coswave[i] / 4)
+        line(i, y1, i, y2)
+
+    y1 = y2
+    y2 = height
+    for i in range(width):
+        stroke(1.0 - coswave[i])
+        line(i, y1, i, y2)
+
+
+run()

crates/processing_pyo3/examples/Basics/Camera/move_eye.py

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+# Move Eye.
+# by Simon Greenwold.
+#
+# The camera lifts up (controlled by mouseY) while looking at the same point.
+from mewnala import *
+
+light = None
+
+
+def setup():
+    global light
+    size(640, 360)
+    mode_3d()
+    fill(0.8)
+    light = directional_light((1.0, 1.0, 1.0), 4000.0, position=(0, 0, 1), look_at=(0, 0, 0))
+    roughness(0.6)
+
+
+def draw():
+    background(0.0)
+
+    # Change height of the camera with mouseY (the world is y-up)
+    camera(30.0, -mouse_y, 220.0,  # eyeX, eyeY, eyeZ
+           0.0, 0.0, 0.0,  # centerX, centerY, centerZ
+           0.0, 1.0, 0.0)  # upX, upY, upZ
+
+    no_stroke()
+    box(90)
+    stroke(1.0)
+    line(-100, 0, 0, 100, 0, 0)  # GAP: 3D line(x1, y1, z1, x2, y2, z2)
+    line(0, -100, 0, 0, 100, 0)  # GAP: 3D line(x1, y1, z1, x2, y2, z2)
+    line(0, 0, -100, 0, 0, 100)  # GAP: 3D line(x1, y1, z1, x2, y2, z2)
+
+
+run()

crates/processing_pyo3/examples/Basics/Camera/orthographic.py

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+# Perspective vs. Ortho
+#
+# Move the mouse left to right to change the "far"
+# parameter for the perspective() and ortho() functions.
+# This parameter sets the maximum distance from the
+# origin away from the viewer and will clip the geometry.
+# Click a mouse button to switch between the perspective and
+# orthographic projections.
+from mewnala import *
+
+show_perspective = False
+light = None
+
+
+def setup():
+    global light
+    size(600, 360)
+    mode_3d()
+    no_fill()
+    fill(1.0)
+    no_stroke()
+    light = directional_light((1.0, 1.0, 1.0), 4000.0, position=(0, 0, 1), look_at=(0, 0, 0))
+    roughness(0.6)
+
+
+def draw():
+    background(0.0)
+    far = remap(mouse_x, 0, width, 120, 400)
+    if show_perspective:
+        perspective(PI / 3.0, width / height, 10, far)
+    else:
+        ortho(-width / 2.0, width / 2.0, -height / 2.0, height / 2.0, 10, far)
+    # Rotations about x run the other way in the y-up world
+    rotate_x(PI / 6)
+    rotate_y(PI / 3)
+    box(180)
+
+
+def mouse_pressed():
+    global show_perspective
+    show_perspective = not show_perspective
+
+
+run()

crates/processing_pyo3/examples/Basics/Camera/perspective.py

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+# Perspective.
+#
+# Move the mouse left and right to change the field of view (fov).
+# Click to modify the aspect ratio. The perspective() function
+# sets a perspective projection applying foreshortening, making
+# distant objects appear smaller than closer ones. The parameters
+# define a viewing volume with the shape of truncated pyramid.
+# Objects near to the front of the volume appear their actual size,
+# while farther objects appear smaller. This projection simulates
+# the perspective of the world more accurately than orthographic projection.
+# The version of perspective without parameters sets the default
+# perspective and the version with four parameters allows the programmer
+# to set the area precisely.
+from mewnala import *
+
+light = None
+
+
+def setup():
+    global light
+    size(640, 360)
+    mode_3d()
+    no_stroke()
+    light = directional_light((1.0, 1.0, 1.0), 4000.0, position=(0, 0, 1), look_at=(0, 0, 0))
+    roughness(0.6)
+
+
+def draw():
+    background(0.0)
+    camera_y = height / 2.0
+    # A fov of 0 would divide by zero below
+    fov = max(mouse_x, 1) / width * PI / 2
+    camera_z = camera_y / tan(fov / 2.0)
+    aspect = width / height
+    if mouse_is_pressed:
+        aspect = aspect / 2.0
+    perspective(fov, aspect, camera_z / 10.0, camera_z * 10.0)
+
+    translate(30, 0, 0)
+    # Rotations about x run the other way in the y-up world
+    rotate_x(PI / 6)
+    rotate_y(PI / 3 + mouse_y / height * PI)
+    box(45)
+    translate(0, 0, -50)
+    box(30)
+
+
+run()

crates/processing_pyo3/examples/Basics/Color/brightness.py

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+# Brightness
+# by Rusty Robison.
+#
+# Brightness is the relative lightness or darkness of a color.
+# Move the cursor vertically over each bar to alter its brightness.
+from mewnala import *
+
+bar_width = 20
+last_bar = -1
+
+
+def setup():
+    size(640, 360)
+    no_stroke()
+    background(0.0)
+
+
+def draw():
+    global last_bar
+    which_bar = int(mouse_x) // bar_width
+    if which_bar != last_bar:
+        bar_x = which_bar * bar_width
+        fill(hsva(bar_x / width * 360, 1.0, mouse_y / height))
+        rect(bar_x, 0, bar_width, height)
+        last_bar = which_bar
+
+
+run()

crates/processing_pyo3/examples/Basics/Color/color_variables.py

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+# Color Variables (Homage to Albers).
+#
+# This example creates variables for colors that may be referred to
+# in the program by a name, rather than a number.
+from mewnala import *
+
+inside = None
+middle = None
+outside = None
+
+
+def setup():
+    global inside, middle, outside
+    size(640, 360)
+    no_stroke()
+    no_loop()
+
+    inside = color(0.8, 0.4, 0.0)
+    middle = color(0.8, 0.6, 0.0)
+    outside = color(0.6, 0.2, 0.0)
+
+    # These statements are equivalent to the statements above.
+    # Programmers may use the format they prefer.
+    # inside = color("#CC6600")
+    # middle = color("#CC9900")
+    # outside = color("#993300")
+
+
+def draw():
+    background(0.2, 0.0, 0.0)
+
+    push_matrix()
+    translate(80, 80)
+    fill(outside)
+    rect(0, 0, 200, 200)
+    fill(middle)
+    rect(40, 60, 120, 120)
+    fill(inside)
+    rect(60, 90, 80, 80)
+    pop_matrix()
+
+    push_matrix()
+    translate(360, 80)
+    fill(inside)
+    rect(0, 0, 200, 200)
+    fill(outside)
+    rect(40, 60, 120, 120)
+    fill(middle)
+    rect(60, 90, 80, 80)
+    pop_matrix()
+
+
+run()

crates/processing_pyo3/examples/Basics/Color/hue.py

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+# Hue.
+#
+# Hue is the color reflected from or transmitted through an object
+# and is typically referred to as the name of the color such as
+# red, blue, or yellow. In this example, move the cursor vertically
+# over each bar to alter its hue.
+from mewnala import *
+
+bar_width = 20
+last_bar = -1
+
+
+def setup():
+    size(640, 360)
+    no_stroke()
+    background(0.0)
+
+
+def draw():
+    global last_bar
+    which_bar = int(mouse_x) // bar_width
+    if which_bar != last_bar:
+        bar_x = which_bar * bar_width
+        fill(hsva(mouse_y / height * 360, 1.0, 1.0))
+        rect(bar_x, 0, bar_width, height)
+        last_bar = which_bar
+
+
+run()