Game Development IWeek 2

Game Architecture

Render LoopGame Logic

Player updateSense player inputComputer restrictionsUpdate player state

World updatePassive elements

Pre-select active zone for engine useLogic-based elements

Sort according to relevanceExecute control mechanismUpdate state

AI based elementsSort according to relevanceSense internal state and goalsSense restrictionsDecision engineUpdate world

End

Presentation World presentation Select visible subset Clip Cull Occlude Select Resolution Pack geometry Render world geometry Select audible sound sources Pack audio data Send to audio hardware NPC presentation Select visible subset Animate Pack Render NPC data Player presentation Animate Pack RenderEnd

• import statements

• class definitions

• create initial objects

• main while loop

• tick clock

• process events (keypresses, etc.)

• update objects (collision detection, etc.)

• draw objects

• display screen

MainThread

AnimationThread

DynamicsThread

RenderingThread

HID

Update GameObjects

Kick off Animation

Post AnimationGame Object Update

Kick Dynamics Sim

Ragdoll Physics

Finalize Animation

Finalize Collision

Other Processing(AI Planning, Audio

Work, etc.)

Kick Redering(for next frame)

Sleep

PoseBlending

Sleep

Sleep

RagdollSkinning

Global PoseCalculation

Skin MatrixPalette

Calculation

Sleep

Simulateand

Integrate

Sleep

Sleep

Broad PhaseColl.

Narrow Phase Coll.

ResolveConstraints Wait for V-

Blank

Wait forGPU

VisibilityDetermination

Sort

SubmitPrimitives

Full-ScreenEffects

Swap Buffers

Pygame

Initialization

import pygame

pygame.init()

screen = pygame.display.set_mode(size)

• size is a tuple, common sizes are (800, 600) and (1024, 768)

Events

• pygame.event.get() - gets a list of all events since the last call. Call once per frame

• event.type:QUIT! ! ! noneKEYDOWN! ! unicode, key, mod (use pygame.locals, for comparison)KEYUP! ! ! key, modMOUSEMOTION ! pos, rel, buttonsMOUSEBUTTONUP! pos, buttonMOUSEBUTTONDOWN pos, button

Time• pygame.time.Clock() Creates a Clock object

• Clock.tick() Returns number of milliseconds since last call

• Call once per frame to lock the frame rate. Clock.tick(50) = 50FPS

• pygame.time.get_ticks() Returns the number of milliseconds passed since pygame.init() was called

Surfaces

• an image, stored in memory

• surf = pygame.Surface(size)

• surf = pygame.image.load(filename)

• PNG recommended

Surface Methods

• Surface.fill(color) Fills surface with a solid color. Argument is a tuple of RGB values

• Surface.convert() Changes pixel format of the Surface’s image to the format used by the main display. Makes things faster. Use it.

• Surface.convert_alpha() Same as above, but when the Surface’s image has alpha transparency values to deal with.

Blit

• From “BitBLT”, for “Bit Block Transfer”

• copies pixels from one surface to another

surface.blit(sourceSurface,destPos, [sourcePos])

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640

480

x coordinatey

coor

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Rects• Position and dimension

• Rect.move(x, y) Returns a Rect moved x pixels horizontally and y pixels vertically Rect.move_ip(x, y) Moves the Rect x pixels horizontally and y pixels vertically

• Attributes include: top left bottom right topleft bottomleft

topright bottomright midtop midleft midbottom midright

center centerx centery size width height

More Surface Methods

• Surface.get_rect() Returns a Rect that will tell you the dimensions and location of the surface.

• pygame.transform.rotate(Surface, angle) Rotates Surface counterclockwise by degrees

• pygame.transform.scale(Surface, (width, height)) Resizes Surface to new resolution

Fonts

•f = pygame.font.Font(None, 32)

• Creates a font object of size 32 using the default font. If you know where the .TTF file of the font you want to use is located, you can use the filename as the first argument

•surf = f.render(“Hello”, 1, (255,0,255), (255,255,0))

Audio

kaboom = pygame.mixer.Sound(filename) ! ! must be an uncompressed WAV or OGGkaboom.play(loops=0, maxtime=0)kaboom.stop()

pygame.mixer.music.load(filename)pygame.mixer.music.play(loops=0) !! set loops to number of times to repeat after first run-through, -1 ! ! ! ! ! ! ! to repeat indefinitelypygame.mixer.music.stop()

Collision Detection

Rect.contains(Rect): return True or FalseRect.collidepoint(x, y): return True or FalseRect.colliderect(Rect): return True or FalseRect.collidelist(list): return index (-1 if none)

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(x2� x1)2+(y2� y1)2

x1,y1

x2,y2d r1+ r2?

r1

r2

• import statements

• class definitions

• create initial objects

• main while loop

• tick clock

• process events (keypresses, etc.)

• update objects (collision detection, etc.)

• draw objects

• pygame.display.flip()

The Secret of Successful Teamwork

Love

Meet people properly. It all starts with the introduction. Then, exchange contact information, and make sure you know how to pronounce everyone’s names. Exchange phone numbers, and find out during what hours are acceptable to call

Find things you have in common. You can almost always find something in common with another person, and starting from that baseline, it’s much easier to then address issues where you have differences.

Make meeting conditions good. Have a large surface to write on, make sure the room is quiet and warm enough, and that there aren’t lots of distractions. Make sure no one is hungry, cold, or tired. Meet over a meal if you can – food softens a meeting.

Let everyone talk, even if you think what they’re saying is stupid. Cutting someone off is rude, and not worth whatever small time gain you might make. Don’t finish someone’s sentences for him or her; they can do it for themselves.

Talking louder or faster doesn’t make your idea any better

Check your egos at the door. When you discuss ideas, immediately label them and write them down. The labels should be descriptive of the idea, not the originator: “the troll bridge story,” not “Rob’s story.”

Praise each other. Find something nice to say, even if it’s a stretch. Even the worst of ideas has a silver lining inside it, if you just look hard enough. Focus on the good, praise it, and then raise any objections or concerns you have about the rest of it.

Put it in writing. Always write down who is responsible for what, by when. Be concrete. Arrange meetings by email, and establish accountability. Never assume that someone’s roommate will deliver a phone message. Also, remember that “politics is when you have more than 2 people.” With that in mind, always CC any piece of email within the group, or to either of us, to all members of the group.

Be open and honest. Talk with your group members if there’s a problem, and talk with us if you think you need help. The whole point of this course is that it’s tough to work across cultures. If we all go into it knowing that’s an issue, we should be comfortable discussing problems when they arise – after all, that’s what it’s really about. Be forgiving when people make mistakes, but don’t be afraid to raise the issues when they come up.

Phrase alternatives as questions. Instead of “I think we should do A, not B,” try “What if we did A, instead of B?” That allows people to offer comments, rather than defend one choice.

Avoid conflict at all costs. When stress occurs and tempers flare, take a short break. Clear your heads, apologize, and take another stab at it. Apologize for upsetting your peers, even if you think someone else was primarily at fault – the goal is to work together, not start a legal battle over whose transgressions were worse. It takes two to have an argument, so be the peacemaker.

All Rise

Team 1Kevin ChangDennis Co

Victor CortesKelly DeBarrChris Wise

Team 2Sebastian DalbyDaniel Newton

Nathan PaloAnthony Szymczyk

Ashley Tanski

Team 3Alex BurkholderJavier Camino

Kevin HendricksIan Ooi

Matthew McMullan

Team 4Matthew Chapman

Tif EntwhistleGerald Franklin

Nick LewisAndrew Ryther

Team 5Andrew LeingMichael Maris

Themos PanotopoulosJeffrey Steel

Kai VanDrunen

Team 6Sebastian Basch

Chris DeBartolomeoJulian Eden

Michael LechnerJames McCarthy

Team 7PJ Castracucco

Mitchell CooperGeo KerseyJames Ross

Gabriel Violette

Team 8Nicholas Cesare

Jay LeeGrace Rhee

Robert Stewart

Team 9Marcus Baker

Vincent KocherHarrison Krug

Chayut NapombejaraTom Weithers

Assignment #1• Aesthetics:

• Choose a visual style that fits with your game

• In your writeup, include the motivations for your choices and how it helps the game experience.  These include the images, colors, fonts, and other visual decisions

• Do the elements fit together in a coherent visual look?  for example, if you're going for a 16-bit retro style, then everything should fit with that look; similarly, the UI elements like on-screen text, score, meters, menus, should all fit with the game's look. 

Assignment #1• Shmup-like

• 3 different abilities

• 3 different obstacles

• 1 final challenge

• 3-5 minutes of gameplay

• Creative setting (e.g. sketches on a notebook)