Added PyGame examples described in blog post

PyGame/arm/arm1.py

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+import numpy as np
+import pygame
+import pygame.locals
+
+from armpart import ArmPart
+
+black = (0, 0, 0)
+white = (255, 255, 255)
+
+pygame.init()
+
+width = 500
+height = 500
+display = pygame.display.set_mode((width, height))
+fpsClock = pygame.time.Clock()
+
+upperarm = ArmPart('upperarm.png', scale=.7)
+
+base = (width / 2, height / 2)
+
+while 1:
+
+    display.fill(white)
+
+    ua_image, ua_rect = upperarm.rotate(.01) 
+    ua_rect.center += np.asarray(base)
+    ua_rect.center -= np.array([np.cos(upperarm.rotation) * upperarm.offset,
+                                -np.sin(upperarm.rotation) * upperarm.offset])
+
+    display.blit(ua_image, ua_rect)
+    pygame.draw.circle(display, black, base, 30)
+
+    # check for quit
+    for event in pygame.event.get():
+        if event.type == pygame.locals.QUIT:
+            pygame.quit()
+            sys.exit()
+
+    pygame.display.update()
+    fpsClock.tick(30)

PyGame/arm/arm3.py

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+import numpy as np
+import pygame
+import pygame.locals
+
+from armpart import ArmPart
+
+black = (0, 0, 0)
+white = (255, 255, 255)
+
+pygame.init()
+
+width = 750
+height = 750
+display = pygame.display.set_mode((width, height))
+fpsClock = pygame.time.Clock()
+
+upperarm = ArmPart('upperarm.png', scale=.7)
+forearm = ArmPart('forearm.png', scale=.8)
+hand = ArmPart('hand.png', scale=1.0)
+
+origin = (width / 2, height / 2)
+
+while 1:
+
+    display.fill(white)
+
+    # rotate our joints
+    ua_image, ua_rect = upperarm.rotate(.03) 
+    fa_image, fa_rect = forearm.rotate(-.02) 
+    h_image, h_rect = hand.rotate(.03) 
+
+        # generate (x,y) positions of each of the joints
+    joints_x = np.cumsum([0, 
+                          upperarm.scale * np.cos(upperarm.rotation),
+                          forearm.scale * np.cos(forearm.rotation),
+                          hand.length * np.cos(hand.rotation)]) + origin[0]
+    joints_y = np.cumsum([0, 
+                          upperarm.scale * np.sin(upperarm.rotation),
+                          forearm.scale * np.sin(forearm.rotation), 
+                          hand.length * np.sin(hand.rotation)]) * -1 + origin[1]
+    joints = [(int(x), int(y)) for x,y in zip(joints_x, joints_y)]
+
+    def transform(rect, base, arm_part):
+        rect.center += np.asarray(base)
+        rect.center += np.array([np.cos(arm_part.rotation) * arm_part.offset,
+                                -np.sin(arm_part.rotation) * arm_part.offset])
+
+    transform(ua_rect, joints[0], upperarm)
+    transform(fa_rect, joints[1], forearm)
+    transform(h_rect, joints[2], hand)
+    # transform the hand a bit more because it's weird
+    h_rect.center += np.array([np.cos(hand.rotation), 
+                              -np.sin(hand.rotation)]) * -10
+
+    display.blit(ua_image, ua_rect)
+    display.blit(fa_image, fa_rect)
+    display.blit(h_image, h_rect)
+
+    # check for quit
+    for event in pygame.event.get():
+        if event.type == pygame.locals.QUIT:
+            pygame.quit()
+            sys.exit()
+
+    pygame.display.update()
+    fpsClock.tick(30)

PyGame/arm/arm3wlines.py

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+import numpy as np
+import pygame
+import pygame.locals
+
+from armpart import ArmPart
+
+black = (0, 0, 0)
+white = (255, 255, 255)
+arm_color = (50, 50, 50, 200) # fourth value specifies transparency
+
+pygame.init()
+
+width = 750
+height = 750
+display = pygame.display.set_mode((width, height))
+fpsClock = pygame.time.Clock()
+
+upperarm = ArmPart('upperarm.png', scale=.7)
+forearm = ArmPart('forearm.png', scale=.8)
+hand = ArmPart('hand.png', scale=1.0)
+
+line_width = 15
+line_upperarm = pygame.Surface((upperarm.scale, line_width), pygame.SRCALPHA, 32)
+line_forearm = pygame.Surface((forearm.scale, line_width), pygame.SRCALPHA, 32)
+line_hand = pygame.Surface((hand.scale, line_width), pygame.SRCALPHA, 32)
+
+line_upperarm.fill(arm_color)
+line_forearm.fill(arm_color)
+line_hand.fill(arm_color)
+
+origin = (width / 2, height / 2)
+
+while 1:
+
+    display.fill(white)
+
+    # rotate our joints
+    ua_image, ua_rect = upperarm.rotate(.03) 
+    fa_image, fa_rect = forearm.rotate(-.02) 
+    h_image, h_rect = hand.rotate(.03) 
+
+    # generate (x,y) positions of each of the joints
+    joints_x = np.cumsum([0, 
+                          upperarm.scale * np.cos(upperarm.rotation),
+                          forearm.scale * np.cos(forearm.rotation),
+                          hand.length * np.cos(hand.rotation)]) + origin[0]
+    joints_y = np.cumsum([0, 
+                          upperarm.scale * np.sin(upperarm.rotation),
+                          forearm.scale * np.sin(forearm.rotation), 
+                          hand.length * np.sin(hand.rotation)]) * -1 + origin[1]
+    joints = [(int(x), int(y)) for x,y in zip(joints_x, joints_y)]
+
+    def transform(rect, base, arm_part):
+        rect.center += np.asarray(base)
+        rect.center += np.array([np.cos(arm_part.rotation) * arm_part.offset,
+                                -np.sin(arm_part.rotation) * arm_part.offset])
+
+    transform(ua_rect, joints[0], upperarm)
+    transform(fa_rect, joints[1], forearm)
+    transform(h_rect, joints[2], hand)
+    # transform the hand a bit more because it's weird
+    h_rect.center += np.array([np.cos(hand.rotation), 
+                              -np.sin(hand.rotation)]) * -10
+
+    display.blit(ua_image, ua_rect)
+    display.blit(fa_image, fa_rect)
+    display.blit(h_image, h_rect)
+
+    # rotate arm lines
+    line_ua = pygame.transform.rotozoom(line_upperarm, 
+                                        np.degrees(upperarm.rotation), 1)
+    line_fa = pygame.transform.rotozoom(line_forearm, 
+                                        np.degrees(forearm.rotation), 1)
+    line_h = pygame.transform.rotozoom(line_hand, 
+                                        np.degrees(hand.rotation), 1)
+    # translate arm lines
+    lua_rect = line_ua.get_rect()
+    transform(lua_rect, joints[0], upperarm)
+    lua_rect.center += np.array([-lua_rect.width / 2.0, -lua_rect.height / 2.0])
+
+    lfa_rect = line_fa.get_rect()
+    transform(lfa_rect, joints[1], forearm)
+    lfa_rect.center += np.array([-lfa_rect.width / 2.0, -lfa_rect.height / 2.0])
+
+    lh_rect = line_h.get_rect()
+    transform(lh_rect, joints[2], hand)
+    lh_rect.center += np.array([-lh_rect.width / 2.0, -lh_rect.height / 2.0])
+
+    display.blit(line_ua, lua_rect)
+    display.blit(line_fa, lfa_rect)
+    display.blit(line_h, lh_rect)
+
+    # draw circles at joints for pretty
+    pygame.draw.circle(display, black, joints[0], 30)
+    pygame.draw.circle(display, arm_color, joints[0], 12)
+    pygame.draw.circle(display, black, joints[1], 20)
+    pygame.draw.circle(display, arm_color, joints[1], 7)
+    pygame.draw.circle(display, black, joints[2], 15)
+    pygame.draw.circle(display, arm_color, joints[2], 5)
+
+    # check for quit
+    for event in pygame.event.get():
+        if event.type == pygame.locals.QUIT:
+            pygame.quit()
+            sys.exit()
+
+    pygame.display.update()
+    fpsClock.tick(30)

PyGame/arm/armpart.py

@@ -0,0 +1,30 @@
+import numpy as np
+import pygame
+
+class ArmPart:
+    """
+    A class for storing relevant arm segment information.
+    """
+    def __init__(self, pic, scale=1.0):
+        self.base = pygame.image.load(pic)
+        # some handy constants
+        self.length = self.base.get_rect()[2]
+        self.scale = self.length * scale
+        self.offset = self.scale / 2.0
+
+        self.rotation = 0.0 # in radians
+
+    def rotate(self, rotation):
+        """
+        Rotates and re-centers the arm segment.
+        """
+        self.rotation += rotation 
+        # rotate our image 
+        image = pygame.transform.rotozoom(self.base, np.degrees(self.rotation), 1)
+        # reset the center
+        rect = image.get_rect()
+        rect.center = (0, 0)
+
+        return image, rect
+
+

PyGame/rotations/rotations-bad-1.py

@@ -0,0 +1,29 @@
+import pygame
+import pygame.locals
+
+white = (255, 255, 255)
+
+pygame.init()
+
+display = pygame.display.set_mode((300, 300))
+fpsClock = pygame.time.Clock()
+
+image = pygame.image.load('pic.png')
+
+while 1:
+
+    display.fill(white)
+
+    image = pygame.transform.rotate(image, 1)
+    rect = image.get_rect()
+
+    display.blit(image, rect)
+
+    # check for quit
+    for event in pygame.event.get():
+        if event.type == pygame.locals.QUIT:
+            pygame.quit()
+            sys.exit()
+
+    pygame.display.update()
+    fpsClock.tick(30)

PyGame/rotations/rotations-bad-2.py

@@ -0,0 +1,30 @@
+import pygame
+import pygame.locals
+
+white = (255, 255, 255)
+
+pygame.init()
+
+display = pygame.display.set_mode((300, 300))
+fpsClock = pygame.time.Clock()
+
+image = pygame.image.load('pic.png')
+
+while 1:
+
+    display.fill(white)
+
+    image = pygame.transform.rotate(image, 1)
+    rect = image.get_rect()
+    rect.center = (150, 150)
+
+    display.blit(image, rect)
+
+    # check for quit
+    for event in pygame.event.get():
+        if event.type == pygame.locals.QUIT:
+            pygame.quit()
+            sys.exit()
+
+    pygame.display.update()
+    fpsClock.tick(30)

PyGame/rotations/rotations-bad-3.py

@@ -0,0 +1,33 @@
+import pygame
+import pygame.locals
+
+white = (255, 255, 255)
+
+pygame.init()
+
+display = pygame.display.set_mode((300, 300))
+fpsClock = pygame.time.Clock()
+
+image = pygame.image.load('pic.png')
+radians = 0
+
+while 1:
+
+    display.fill(white)
+
+    radians += .5
+
+    rotated_image = pygame.transform.rotate(image, radians)
+    rect = rotated_image.get_rect()
+    rect.center = (150, 150)
+
+    display.blit(rotated_image, rect)
+
+    # check for quit
+    for event in pygame.event.get():
+        if event.type == pygame.locals.QUIT:
+            pygame.quit()
+            sys.exit()
+
+    pygame.display.update()
+    fpsClock.tick(30)

PyGame/rotations/rotations-good.py

@@ -0,0 +1,33 @@
+import pygame
+import pygame.locals
+
+white = (255, 255, 255)
+
+pygame.init()
+
+display = pygame.display.set_mode((300, 300))
+fpsClock = pygame.time.Clock()
+
+image = pygame.image.load('pic.png')
+degrees = 0
+
+while 1:
+
+    display.fill(white)
+
+    degrees += 1
+
+    rotated = pygame.transform.rotozoom(image, degrees, 1)
+    rect = rotated.get_rect()
+    rect.center = (150, 150)
+
+    display.blit(rotated, rect)
+
+    # check for quit
+    for event in pygame.event.get():
+        if event.type == pygame.locals.QUIT:
+            pygame.quit()
+            sys.exit()
+
+    pygame.display.update()
+    fpsClock.tick(30)