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Jerome Newman
6 years ago
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http://creativecommons.org/licenses/by/4.

Al has written a really great series on creating

1 A worksheet by Andrew Hague Flappy Wormy is based on work in Al Sweigart s Invent with Python: a free e-book. Al has written a really great series on creating some simple games using Python. His games are preinstalled on Raspbian OS.

2 Step 1: Start up your Raspberry Pi You ll need an SD Card with Raspbian on it, a Raspberry Pi, an HDMI TV or monitor, a keyboard, a mouse, and a mini-usb power cable. Let s assume you know how to plug all this together and get going power should go in last Wait for this screen..

http://creativecommons.org/licenses/by/4.0/ However, if you see something like this, don t worry.

3 However, if you see something like this, don t worry.. When it says this, type pi and then press the return key. Then type the password raspberry and press return. Then once it has logged you in and you see a $ type startx and press return.

4 Step 2: Let s be IDLE Look for IDLE (not IDLE3) and double click on it. This is a program editor for Python named after Eric Idle. When you see >>> start typing stuff like this. Press the return key after each line * spam = 10 spam+5 spam =1 spam = spam+5 spam spam = 'Andrew' spam print(spam) spam = spam + ' is clever' print(spam)

http://creativecommons.org/licenses/by/4.0/ Step 3: Playing a game At the top of the IDLE window can you select File->Open and type python_games/wormy.py and click OPEN to open the game file.

5 Step 3: Playing a game At the top of the IDLE window can you select File->Open and type python_games/wormy.py and click OPEN to open the game file. Press F5 to run the game. A game with a green worm made of squares that you can steer around a grid trying to picking up a red square to make you longer. You score more as the worm gets longer. The game ends if you hit the edge of the grid, or run into yourself.

6 Step 4: Changing the game At the top of the IDLE screen, Select File->Save As.. and type python_games/flappyworm.py and SAVE to save the new game file. Let s see if we can make a simple change like changing the name of the game. Look for titlesurf1 = titlefont.render('wormy', True, WHITE, DARKGREEN) Change the game's name: titlesurf1 = titlefont.render('flappy', True, WHITE, DARKGREEN) Also change the line below in the same way. titlesurf2 = titlefont.render('wormy', True, GREEN) Press F5 Throughout the rest of this worksheet, you will be adding code to existing code. I've marked the existing lines of code in italics and any new code is written in bold. HINT : I ve mark existing code in italics and new code in bold.

7 Step 5 : Make a blank game Let s start by making a new game to run and forget the old game. Look for : And replace it with this: def rungame(): (HINT: You don t need to type in all of this. You can delete lines from rungame() that is currently there.) def rungame(): score = 0 while True: for event in pygame.event.get(): if event.type == QUIT: terminate() elif event.type == KEYDOWN: if event.key == K_ESCAPE: terminate() DISPLAYSURF.fill(BGCOLOR) drawgrid() drawscore(score) pygame.display.update() FPSCLOCK.tick(FPS) def drawpresskeymsg(): Press F5 You should see nothing but a score.

8 Step 6: A worm Let s set up a new type of worm that will be able to fly. Add these lines to set up where the worms starts after you make the score = 0 score = 0 wormcoords = [ {'x': 5, 'y': 5} ] Then after drawing the grid and before drawing the score, let s draw this worm. drawgrid() drawworm(wormcoords) drawscore(score) Press F5 That ll draw a worm but it won t move. This bit of program will make the worm fall but if you press SPACEBAR you can make it fly. You are adding new code between the terminate() and DISPLAYSURF in rungame(). if event.key == K_ESCAPE: terminate() keys = pygame.key.get_pressed() if keys[k_space]: move = -1 else: move = 1 wormcoords[head]['y'] += move DISPLAYSURF.fill(BGCOLOR)

9 Step 7: Drawing some walls You want something to fly around, so we need to make some walls that race towards the flappy worm. Here is a big bit of program that draws walls. FPSCLOCK.tick(FPS) def drawwall(wallcoords): for coord in wallcoords: x = coord['x'] * CELLSIZE y = coord['y'] * CELLSIZE dir = coord['dir'] if dir == UP: h = y+cellsize y = 0 elif dir == DOWN: h = WINDOWHEIGHT-y wallrect = pygame.rect(x, y, CELLSIZE, h) pygame.draw.rect(displaysurf, RED, wallrect) def drawpresskeymsg(): That is a new bit of computer program. In computing terminology, we are defining a new function of the computer program. We can put this anywhere but we ve put it close to the other drawing function. Yet this isn t going to draw the walls unless we tell it when to draw the walls. That s here. drawgrid() drawworm(wormcoords) drawwall(wallcoords) drawscore(score) Finally, those wallcoords don t exist yet. So we need to set those up at the start of our rungame. score = 0 SPACEGAP = 5 gap = random.randint(5, CELLHEIGHT - 6) wallcoords = [{'x': CELLWIDTH-1, 'y': gap-spacegap, 'dir':up}, {'x': CELLWIDTH-1, 'y': gap+spacegap, 'dir':down}] while True:

10 Press F5 to see the first walls.. but they won t be moving. This next couple of lines of program will make the walls move towards you. wormcoords[head]['y'] += move for wallbody in wallcoords: wallbody['x'] -= 1 DISPLAYSURF.fill(BGCOLOR) Press F5 And these few lines will create more walls all of which will move towards you. score = 0 WALLGAP = 10 wallspace = WALLGAP SPACEGAP = 5 wallbody['x'] -= 1 wallspace -= 1 if wallspace == 0: wallspace = WALLGAP gap = random.randint(5, CELLHEIGHT - 6) wallcoords.append( {'x': CELLWIDTH, 'y': gap-spacegap, 'dir':up} ) wallcoords.append( {'x': CELLWIDTH, 'y': gap+spacegap, 'dir':down} ) DISPLAYSURF.fill(BGCOLOR)

11 Step 8: Hitting the walls and scoring Almost at the end. You can fly through the walls, so we need to detect when you hit a wall and keep a score. for wallbody in wallcoords: wallbody['x'] -= 1 if wormcoords[head]['x'] == wallbody['x']: # check if hit a wall going up or wall going down if ((wallbody['dir'] == DOWN and wormcoords[head]['y'] >= wallbody['y']) or (wallbody['dir'] == UP and wormcoords[head]['y'] <= wallbody['y'])): return # not hit either but only add the score # for passing one of those two walls elif wallbody['dir'] == UP: score += 1 # check if the worm has hit the top or bottom edge if (wormcoords[head]['y'] == -1 or wormcoords[head]['y'] == CELLHEIGHT): return # game over wallspace -= 1

12 Step9: A Longer Worm Change these lines to make a longer worm. The body needs to follow the head which is the last big bit of program. import random, pygame, sys, math wormcoords = [ {'x': 5, 'y': 5}, {'x': 4, 'y': 5}, {'x': 3, 'y': 5} ] wormcoords[head]['y'] += move lastbody = wormcoords[head] for wormbody in wormcoords[1:]: distance = (wormbody['y'] - lastbody['y']) if abs(distance) > 1: distance = math.copysign(1, distance) wormbody['y'] = lastbody['y'] + distance lastbody = wormbody

pygame Lecture #5 (Examples: fruitgame)

pygame Lecture #5 (Examples: fruitgame) MOUSE INPUT IN PYGAME I. Detecting Mouse Input in pygame In addition to waiting for a keyboard event to precipitate some action, pygame allows us to wait for a mouse