Denial

Name: Emu's Massive Hunt (title may change)
Status: Work In Progress
Author: Andy H (HEWCO)
Genre: Platformer
Code: TRSE/Assembler
Requirements: 32K VIC-20, joystick

Description:
Sequel to Pink Windmill Blitz, Emu has made it through the vines to find Grotbags has caused chaos in the Pink Windmill. All of Rod's Future Was 8 Bit orders are strewn across the windmill and worse still Rod himself is missing! Collect all the games, cartridges and other goodies and free Rod so the orders can be sent out to all the nice boys and girls.
Click to view animated GIF

The game plays as a regular platformer, where you control Emu and can run and jump around the levels, avoiding the nasties and collecting items. Doors requiring keys will block your way and there's also some water which you'll need to find something to help you with.

I started it just after Christmas and so far everything is going well, so I hope it will be done in a month or two if I am able to keep up some spare time in the evenings.

The game is being made with Turbo Rascal and a bit of assembler. I've implemented some neat little tricks, in large thanks to the help of the supportive Denial community and of course have Jeff's Vic 20 Quick Reference Handbook by my side which is proving very useful.

Raster split
I have a screen split at the bottom thanks to this thread which allows me to have a set of 'tile' graphics for the rooms and a separate custom text character set for the status area.

Local 'sprites'
Some time back I was intrigued by a missing snippet of code for creating sprite-like movement in a regular character display. I had already implemented a full screen bitmap mode (VBM) in Turbo Rascal some years back, again with many pointers and help from Denial to get me started, and this mode has a lot of commands to help you build games with a bitmap, including sprites, tiles and text. However, the disadvantage of a bitmap on the Vic is the size and effect of the colour memory on the bitmap images you can create. I have one game in progress using all multicolour graphics which are generally 16x16 pixels in size and this works great. However, for games with smaller images (eg: 8x8 pixels) it can be a challenge as you may know.

This is where I returned to my LBM (local Bitmap Mode) unit to address that. My first attempt at this unit did the job, creating free moving 8x8 'sprites' by creating those small local bitmaps of characters around where the sprite is displayed, copying in the character data underneath and overlaying the sprite on top. Unfortunately this first attempt was awkward to use. It was included with Turbo Rascal but I never used it in a game.

More recently when I read the thread linked above it got me thinking again, resulting a rewrite from scratch. The LBM8 unit was created and it has just two commands. One to place a 'sprite' on the screen which you use as many times as needed at the beginning of the game loop and another to remove all the sprites and restore the original characters underneath at the end of the game loop after the raster reaches the bottom of the display area. There are some variations on the sprite drawing functions, most for 8x8 sprites, one for 8x16 and a set for compiled sprites. Compiled sprites use code instead of binary data to draw the sprites (which I have added an export directive to Turbo Rascal to generate) which can have some small advantages over drawing with binary data. For starters, the assembler instructions needed are simpler so you get some cycles back and the exporter generating the code is able to remove any lines (bytes) where a 0 would be drawn (ie: no pixels or blanks) saving more cycles and space. The size in memory of compiled sprites is roughly the same as having binary data, sometimes a little smaller depending on the shape of the sprite.

Other stuff
The game has some music in already, thanks to the talents of Mince: Unknown, and warning its an ear worm you'll be humming all day if you end up playing the game for any period of time!

I'm able to build and run as a cartridge quite quickly in VICE from Turbo Rascal and have a script to convert to a D64 image loading in blocks for testing, thanks to some help from Mike.

I've had an itch about the unused colour memory in the vic and have wanted to use it 'just because' for some time. In this game I've got up to four item pickups per room and I'm using the lower nybbles to store the collected state of the items in each room. I could probably spare the bytes in regular RAM but this is something I wanted to do just because.

I've got 64 rooms, placing most of them compressed in the $A000 block but will likely need to put some elsewhere. Compression is working out at about 50% or better depending upon how detailed the rooms are.

The game will possibly be released in some physical form and later as a free download. That's about it for now, I'll post some updates as I add anything new that is of interest.

Looks really good what enemies are you going to use ,I think grotbags had a crocodile? Looking forward to playing it

You're right! I was trying to think what were the main characters and now you say it I can almost hear that crocodile!

Yes, that's now in. So far I have these characters to put in:

• crocodile (left/right patrolling)

• Eyeball (diagonals)

• Spider (up/down)

• Invader(up/down)

• Amoeba (up/down)

• Bat (up/down)

• Skull (up/down)

There was a budget C3PO too - (thankfully, possibly) I'd forgotten so much of this TV show haha.

Neat mix of hi-res and multicolor. Multicolor is used sparingly but enough to spice it up. The hi-res->mc change when the emu drops into water works and can almost be viewed as a "water fx"

How well the water works was a happy accident. I was expecting to be able to see Emu but was pleasantly surprised at it's visual effect.

Hi Andy,

Looks really cool, the movements of the player is very nice implemented. I question myself how the gameplay might be, is it more jump and run or are you planning some puzzles in metrovania style? Maybe you need some more elements beside the enemies… like switches, doors, boxes and a bit of progression… power ups like flying, morphing, more power etc…

Ad

Thank you, it's one of those projects I'm enjoying and is flowing right out of the code editor!

For the player movement I'm using integer values so it comes out nice and smooth (sub-pixel movement on a rigid character pixel display).

I'm trying not to let the scope grow too much and depending upon memory some things might get cut. I do have doors and water to restrict access. You have to find the colour coded keys and something else to get through these. I'm planning on having some dark rooms and may have a double jump upgrade along the way. Otherwise, it is a simple Jet Set Willy type of thing where your goal is to collect all the items and get to Rod Hull at the end. Rod did ask for jetpacks but I can't see how to implement that without it making you overpowered.

I've just implemented a block you can push, so that might lead to some puzzle elements.

This "incoming" game shows how our "old viccy" could manage multi screen games with smooth graphics/sprites! Good job, I hope to play it as soon as possible!

It is so much easier to create stuff for the Vic these days, great tools and abundance of information.

Here's a couple of new additions (click to view anim):

Love the block pushing. In my opinion, all platform games benefit from at least one block to push! And the game as a whole looks great. Very pleasant colors and, as in all your games, the animation is very expressive and stylish.

Oh thank you. I think I am in my element with tiny 8x8 graphics...I certainly enjoy the challenge anyway.

Have to have these in a platform game right? Click to view anim

Working on plumbing right now.

Oh yes, I love the conveyors. This is looking great so far.

Great work!