Playing with Pygame

Time-Based Animation

2010-01-13T14:56:00.000-08:00

The game now uses time-based animation, making it independent of the speed of the processor. Frame-based animation is highly dependent on processor speed so the game would not have been playable on very fast or very slow computers.

Invincibility Mode

2010-01-12T16:22:00.001-08:00

Finished implementing the invincibility mode. The ghosts turn to the same pale color and pacman is able to eat them for 50 points. Eaten ghosts will reemerge at their spawning position.

Intelligent Ghosts

2010-01-11T19:28:00.001-08:00

Finished implementing ghost algorithm. Ghosts proceed in the direction that brings them closer to pacman in an absolute sense, with a few random decisions thrown in. Higher levels have a lower degree of randomness. Decisions are made at intersections or dead-ends.

Fruit

2010-01-10T19:49:00.000-08:00

Fruits have been added - they pop up at random positions at random times during the game and last for 5 seconds. Eating them gives the player 10 points. Also added sound effects for them.

Score

2010-01-10T18:50:00.001-08:00

The game now keeps track of the score. It seems the Pygame requires conversion of text to an image, which can then be 'pasted' on to the screen.

Enhanced Animation

2010-01-10T14:42:00.000-08:00

Pacman now faces the direction of motion and 'chews' as he goes along:

Down:

Up:

Left:

Right:

Sound

2010-01-10T13:58:00.000-08:00

Added sounds! At the moment, there are two distinct sounds that play alternately when pellets are eaten.

Lives

2010-01-10T13:56:00.000-08:00

Game is now restricted to three lives per level. The game ends thereafter. Also working on implementing +1 health eatables.

Levels

2009-11-15T11:59:00.000-08:00

13 levels have been implemented and the game moves to the next level once all pellets have been eaten.

Pellets

2009-11-15T09:03:00.000-08:00

Added pellets on the map. Pacman 'eats' them as he passes over them. Pygame rects have proved to be very useful so far.

Refining Walls

2009-11-14T18:28:00.001-08:00

Using a variety of tiles to represent walls apparently gives a much better appearance:

Improving Maneuverability

2009-11-14T16:59:00.000-08:00

I realized that making pacman change direction into a new tunnel was very hard since the key had to be pressed at the exact pixel to avoid collision. This would have led to frustrating gameplay. The solution was to keep track of the arrow key that was pressed last - the game knows where the player would like to go and checks at each step if the move can be made. Making turns is now much easier.

Resize Screen/Apply Background

2009-11-14T16:42:00.000-08:00

Alright, I have resized the screen and removed the world map as background and now it actually looks like pacman:

Legal Ghosts

2009-11-14T13:25:00.000-08:00

The ghosts now check for collisions and make a random decision for the new direction. Pacman follows keyboard input but the icon does not represent the correct direction yet. However, everything stays within the map and makes legal moves.

Continuous Motion

2009-11-14T13:23:00.000-08:00

After adding the ghosts, I worked on implementing continuous motion - not step by step. The ghosts and pacman all move smoothly now, but only pacman checks for collisions - the ghosts can still go through walls and through each other.

Added Ghosts

2009-11-14T13:20:00.000-08:00

Added ghosts today. At the moment they do not move - I am yet to implement continuous motion.

Moving Within Maps

2009-10-25T17:50:00.000-07:00

Ok enough with the monkey, I'll now use actual Pacman icons. I figured out how to move a 'ghost' within the map such that it is confined within the walls. For now, I'm still using turn by turn movement - as in pressing left once moves the ghost left by one step.

Drawing Maps

2009-10-25T17:46:00.001-07:00

I learnt about how to read from a text file and paste 'tiles' at the correct positions on the screen so that I can represent maps. For now, I am not going to worry about legal movements or collisions - the walls only appear on screen; the monkey can still go over them.

Basic Pygame

2009-10-25T17:37:00.001-07:00

I've been reading Python and Pygame code over the last few days and now feel comfortable experimenting.

I made a simple game where you can move a monkey across the screen by using the arrow keys on your keyboard. I used the world map as a background and added wrap-around functionality. Very basic stuff.

Representing Maps

2009-10-10T21:28:00.000-07:00

I'm considering how best to represent and store maps. At the moment, a simple text file with distinct rows and columns seems to be the obvious choice. Each 'element' in the text file will be an integer that represents a 'tile' in the game. Every tile must either be 'wall' or 'tunnel', where the latter can hold pacman, ghost, fruit etc.

To be updated.

Ghost Algorithm

2009-10-10T21:22:00.000-07:00

The original pacman seems to have had a fairly simple algorithm for ghost movements - at each intersection, they simply choose the direction that takes them closer to pacman in an absolute sense. Some modern games seem to use more sophisticated algorithms like the A* etc.

To begin with, I think I'm going to stick to tradition and use the simple logic, mixed with randomness. Lower difficulty levels will have a higher proportion of random decisions. I may work on a more sophisticated algorithm later on.

Installing Python and Pygame

2009-10-04T07:13:00.000-07:00

It seems there isn't much support for Snow Leopard yet so installing the packages hasn't been easy. I'm currently trying to do it with fink, lets see how it goes.

Update: Nope, nothing worked on OSX 10.6. I had to switch down to Leopard and install the following:

Python 2.6.3 for Mac from http://python.org/download/
Pygame-1.9.1 from http://www.pygame.org/download.shtml

Update: I just upgraded to Snow Leopard once again (the installer moved everything automatically) and both Python and Pygame still work. I guess compatibility is no longer an issue.