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--- en:pygame:step005 [2014/01/09 11:07]
127.0.0.1 external edit
+++ en:pygame:step005 [2020/05/15 22:39] (current)
horst
@@ Line 3: / Line 3: @@
 ====== Step 005 - Frame-based Movement ======
-|  {{:en:part2:pygame:005simple.jpg?300|screenshot}}  |  {{:en:part2:pygame:005pretty.jpg?300|screenshot}}  |
+|  {{part2:pygame:005simple.jpg?300|screenshot}}  |  {{part2:pygame:005pretty.jpg?300|screenshot}}  |
 |  simple version  |  pretty version  |
@@ Line 108: / Line 108: @@
 with the "%%//%%" operator to truncate the quotients and return integers, rather than floating point numbers. And remember that print is now a function.
-//click reload in your browser if you see no code here://
+<code python>
-<html>
+#!/usr/bin/env python
- <script src="http://gist-it.appspot.com/github/horstjens/ThePythonGameBook/blob/master/pygame/005_frame_based_movement.py">
+"""
- </script></html>
+_bouncing_ball_frame_based.py
+bouncing ball and pulsating circle
+url: http://thepythongamebook.com/en:part2:pygame:step005
+author: horst.jens@spielend-programmieren.at
+licence: gpl, see http://www.gnu.org/licenses/gpl.html
+works with python3.4 and python2.7
+bouncing ball. each frame the complete screen is filled with the background,
+making this example simple to code but possible slow on larger resolutions.
+Each frame, a random-coloured circle is drawn with randomized radius directly on the screen.
+Try to manipulate the display.set_mode values to change the resolution."""
+#the next line is only needed for python2.x and not necessary for python3.x
+from __future__ import print_function, division
+import pygame
+import random
+pygame.init()
+screen=pygame.display.set_mode((640,480),) # try out larger values and see what happens !
+screenrect = screen.get_rect()
+# ------ constants ------------
+clock = pygame.time.Clock()
+mainloop = True
+FPS = 30 # desired framerate in frames per second.
+playtime = 0
+radius = 50 # for pulsating circle
+dr = 1  # change of radius in pixel per frame
+# ------- background ---------
+background = pygame.Surface(screen.get_size())
+background.fill((255,155,155))     #fill the background white (red,green,blue)
+background = background.convert()
+screen.blit(background, (0,0))     #draw background on screen (overwriting all)
+# -------- bouncing ball surface ---------
+ballsurface = pygame.Surface((50,50))     #create a new surface (black by default)
+ballsurface.set_colorkey((0,0,0))         #make black the transparent color (red,green,blue)
+#pygame.draw.circle(Surface, color, pos, radius, width=0)
+pygame.draw.circle(ballsurface, (100,175,81), (25,25),25) # paint blue circle
+ballsurface = ballsurface.convert_alpha()       # if you use tranparent colors you need convert_alpha()
+ballrect = ballsurface.get_rect() # the rectangle of the ball surface, for collision detection
+ballx, bally = 550, 240           # start position of the ball (x,y)
+dx = 10                 # x speed vector of the ball in pixel per frame
+dy = 0                 # y speed vector of the ball in pixel per frame
+# ----------- bouncing ball (drawing) ------
+x1 = 50
+y1 = 200
+dx1 = 7
+dy1 = 0
+radius1 = 40
+# --------- static big blue ball -----------
+pygame.draw.circle(background, (0,0,200), (screenrect.width//2, screenrect.height//2), screenrect.width//3)
+# --------- mainloop ----------
+while mainloop:
+    # do all this each frame
+    milliseconds = clock.tick(FPS) # do not go faster than this framerate
+    playtime += milliseconds / 1000.0
+    for event in pygame.event.get():
+        if event.type == pygame.QUIT:
+            mainloop = False # pygame window closed by user
+        elif event.type == pygame.KEYDOWN:
+            if event.key == pygame.K_ESCAPE:
+                mainloop = False # user pressed ESC
+    pygame.display.set_caption("FPS: %.2f X: %.2f Y: %.2f dx: %.2f dy:"
+                               " %.2f" % (clock.get_fps(), ballx, bally, dx, dy))
+    # ----- clean screen ----------
+    screen.blit(background, (0,0))     #draw background on screen (overwriting all)
+    # ------- bouncing ball (drawing) ---------
+    x1 += dx1
+    if x1 + radius1 >= screenrect.width:
+        x1 = screenrect.width - radius1
+        dx1 *= -1
+    elif x1 - radius1 <= 0:
+        x1 =  radius1
+        dx1 *= -1
+    pygame.draw.circle(screen, (255,255,0), (x1,y1), radius1)
+    # -------- bouncing ball surface ----------
+    ballx += dx
+    bally += dy
+    if ballx < 0: # bounce ball if out of screen
+        ballx = 0
+        dx *= -1
+    elif ballx + ballrect.width > screenrect.width:
+        ballx = screenrect.width - ballrect.width
+        dx *= -1
+    screen.blit(ballsurface, (round(ballx,0), round(bally,0)))
+    # ----- pulsating circle -----------
+    colour = (random.randint(0,255),random.randint(0,255),random.randint(0,255))
+    if radius >100 or radius < 5:
+        dr *= -1
+    radius += dr
+    pygame.draw.circle(screen, colour , (100,100), radius, 2) # draw pulsating circle
+    # --------- flip screen ------------------
+    pygame.display.flip()          # flip the screen FPS times a second
+print("This 'game' was played for {:.2f} seconds.".format(playtime))
+</code>
 ==== Pretty Version ====
@@ Line 122: / Line 214: @@
   * https://github.com/horstjens/ThePythonGameBook/blob/master/pygame/005_frame_based_movement_pretty.py
-//click reload in your browser if you see no code here://
-<html>
+<code python>
- <script src="http://gist-it.appspot.com/github/horstjens/ThePythonGameBook/blob/master/pygame/005_frame_based_movement_pretty.py">
+#!/usr/bin/env python
- </script></html>
+"""
+Name   : blit_pulse2.py
+URL    : http://thepythongamebook.com/en:part2:pygame:step003
+Author : yipyip
+Licence: gpl, see http://www.gnu.org/licenses/gpl.html
+works with pyhton3.4 and python2.7
+"""
+####
+import pygame as pyg
+import random as rand
+####
+def random_rgb():
+   return rand.randint(0, 255), rand.randint(0,255), rand.randint(0, 255)
+####
+class PygView(object):
+    def __init__(self, width=800, height=600, fps=50):
+        """Initializing background surface for static drawing
+           and screen surface for dynamic drawing
+        """
+        pyg.init()
+        pyg.display.set_caption("Press ESC to quit")
+        self.width = width
+        self.height = height
+        self.screen = pyg.display.set_mode((self.width, self.height), pyg.DOUBLEBUF)
+        self.background = pyg.Surface(self.screen.get_size()).convert()
+        # white blackground
+        self.background.fill((255, 255, 255))
+        self.act_surface = self.screen
+        self.act_rgb = 255, 0, 0
+    def draw_static(self):
+        self.act_surface = self.background
+    def draw_dynamic(self):
+        self.act_surface = self.screen
+    def set_color(self, rgb):
+        self.act_rgb = rgb
+    def circle(self, x, y, radius, width):
+        """Allocate surface for blitting and draw circle
+        """
+        rad2 = 2 * radius
+        surface = pyg.Surface((rad2, rad2))
+        pyg.draw.circle(surface, self.act_rgb, (radius, radius), radius, width)
+        surface.set_colorkey((0, 0, 0))
+        self.act_surface.blit(surface.convert_alpha(), (x, y))
+    def run(self, draw_dynamic):
+        """The mainloop
+        """
+        running = True
+        while running:
+            for event in pyg.event.get():
+                if event.type == pyg.QUIT:
+                    running = False
+                elif event.type == pyg.KEYDOWN:
+                    if event.key == pyg.K_ESCAPE:
+                        running = False
+            draw_dynamic()
+            pyg.display.flip()
+            self.screen.blit(self.background, (0, 0))
+        pyg.quit()
+####
+class Ball(object):
+    """A circle object with no hardcoded dependency on pygame
+       (and other libs too, obviously...)
+    """
+    def __init__(self, x, y, radius, speed_x=1, speed_pulse=0, color=(0,0,255), width=0):
+        self.x = x
+        self.y = y
+        self.radius = radius
+        self.act_radius = radius
+        self.speed_x = speed_x
+        self.speed_pulse = speed_pulse
+        self.color = color
+        self.width = width
+        self.shrinking = True
+    @property
+    def max_x(self):
+        return self.x + self.radius * 2
+    def rel_move(self, dx, dy):
+        self.x += dx
+        self.y += dy
+    def pulse(self):
+        """Shrink or expand ball
+        """
+        if not self.speed_pulse:
+            return
+        # balls are shrinking first
+        if self.shrinking:
+            if self.act_radius > self.width:
+                self.act_radius -= self.speed_pulse
+                self.act_radius = max(self.act_radius, self.width)
+            else:
+                self.shrinking = False
+        else:
+            if self.act_radius < self.radius:
+                self.act_radius += self.speed_pulse
+            else:
+                self.shrinking = True
+    def draw(self, view):
+        """ Draw on a device with an appropriate interface
+        """
+        if self.speed_pulse:
+            color = random_rgb()
+        else:
+            color = self.color
+        view.set_color(color)
+        view.circle(self.x, self.y, self.act_radius, self.width)
+####
+def action(balls, width, view):
+    """ Return a function for the pygame mainloop
+    """
+    # balls move to the right first
+    right_moving = [True] * len(balls)
+    def animate_balls():
+        """ Draw moving balls
+        """
+        for i, ball in enumerate(balls):
+            if right_moving[i]:
+                if ball.max_x < width:
+                    ball.rel_move(ball.speed_x, 0)
+                else:
+                    right_moving[i] = False
+            else:
+                if ball.x > 0:
+                    ball.rel_move(-ball.speed_x, 0)
+                else:
+                    right_moving[i] = True
+            ball.pulse()
+            ball.draw(view)
+    return animate_balls
+####
+def main(width):
+    """Simple example with stationary and moving balls
+    """
+    view = PygView(width)
+    view.draw_static()
+    # args:  x, y, radius, speed_x, speed_pulse, color, border_width
+    # border_width <= radius !
+    ball01 = Ball(50, 60, 50, 0, 0, (255, 255, 0))
+    ball01.draw(view)
+    ball02 = Ball(250, 150, 190, 0, 0, (66, 1, 166))
+    ball02.draw(view)
+    view.draw_dynamic()
+    ball1 = Ball(15, 130, 100, 1, 0, (255, 0, 0))
+    ball2 = Ball(25, 200, 80, 2, 0, (0, 255, 155))
+    ball3 = Ball(20, 220, 110, 1, 1, (100, 55, 155))
+    ball4 = Ball(20, 400, 70, 3, 0, (250, 100, 255))
+    ball5 = Ball(90, 390, 70, 0, 1, (250, 100, 255), 1)
+    loopfunc = action((ball1, ball2, ball4, ball5), width, view)
+    view.run(loopfunc)
+####
+if __name__ == '__main__':
+    main(900)
+</code>
 ^ [[:en:pygame:step004| ← previous]] ^ [[en:pygame:start| ↑ Overview]] ^ [[:en:pygame:step006| → next ]] ^
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