MASHOOQ,RAHUL,SANAT AND YIBIN,
SAVING MANKIND SINCE SPRING 2011
Game Overview
• All Invaders Are Belong To Us! is a 2D one
player shooting game.
• The objective of the game is to kill all the
aliens that are coming to attack the
home-ship.
• As the game progresses, the difficulty
levels increase. (the number of missiles
and the speed at which the wave comes
to attack the home-ship increases)
• The game has 3 phases namely, GameStart , Game-Play and Game-Over.
• The game can end by either losing all
lives, or by allowing the aliens to
“INVADE” by letting them reach the
barricades.
• By killing each alien, the score gets
updated by 10 points and on clearing a
level, we go to a harder level.
• The game is really exciting and believe
it or not, It is FUN to save the Planet.
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disp_bit when v_count =
Drawing Sprites
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TimeGen
Barricade Blocks
Alien Wave
Barricade
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Alien alive/killed bitmap
Software Update
Actual display bit
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starting coordinate of sprite
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• Only update state vectors when we know we
are not drawing sprites. Or else …
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Software Architecture
while ( true )
{
read keyboard, update state
counter = 0
if ( counter == delay )
respond to keyboard: move home ship/ spawn home missile
collision detection for home missile and aliens
collision detection for home missile and barricades
collision detection for alien missiles and barricade
send update to hardware
if ( num_active_missiles < num_missiles_for_current level
spawn new alien missile
if all aliens killed
setup parameters to start new level
counter = 0
else
counter++
}
Experience and Issue in
Implementation
• Timing and clock cycle.
– In animation, e.g the one time explosion
• Hardware or software
– Decision on whether to implement certain
functions in hardware or software. E.g
• Animation in hardware
• PS/2 State Machine in Software due to the need to
update coordinates which is used ion both software
and hardware.
Experience and Issue in
Implementation
• State Machine and loop holes
– Restrict the use of delays when polling in software
Lessons Learnt
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Work Thoroughly on your design, Spending time on it early saves time later
Get all the hardware to work EARLIEST POSSIBLE
Divide work and plan well
Test hardware using ‘hard coding’
Timing is critical in hardware, know whats happening when
Draw state machine diagrams, they give a good vision
Comment out parts when debugging VHDL, you will save a lot of time
Summary
• Choosing a game project was a good idea
• The end result is fun!
• Teamwork is awesome..