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R-Type Clone


R-Type Clone
Heating up the lasers for the action to come...
From the first day I saw R-Type in an arcade I was possessed with the idea of creating a horizontal scrolling space shoot'em'up game. At first I've tried it with software scrolling hoping to be able to create a software parallax scrolling. One such try was the interrupt Parallax scrolling program shown somewhere else on this page, another try was a little more sophisticated, but got lost during a disc crash, so it isn't being shown on my pages...

I soon had to admit that the CPC wasn't capable to create a decent parallax scrolling with a decent screen size. So I've switched over to a different approach and tried to create an R-Type clone using a hardware scrolling.

First enemy
The first enemy trying to stop me...
I once even considered buying a PC Engine, just because there was a very good R-Type conversion for this video game system. (Later I wanted to buy a Nomad, the Handheld version of the PC Engine, just to be able to play R-Type). But I never bought neither of these two and when my brother got the conversion for the Amiga I was satisfied with playing it there. It was as good as it gets.

I didn't really like the CPC conversion of the game. I've bought it when it came out as a low budget game, because I've heard so many bad things about the game. Unfortunately these bad reputation proved to be right. The CPC conversion was done in Mode 1 with four colors. You can do a lot with four colors if you want to (as later Siggi from Bollaware impressively demonstrated), but obviously the guys from Activision didn't wanted to create a better graphics and just used the graphics ported from the Spectrum computer.

First enemy shot!
... is the first one to become toast!
The scrolling of the game was some weird 1 pixel Mode 1 scrolling. It was slow and very unsteady. Also on the left side of the screen every now and then random bytes were erased from the graphics, right before it was scrolled out of the screen.

The game play was somewhat similar to the arcade. The enemies seemed to be the same (as far I as I can tell. But my knowledge is limited, since I never really advanced very far in the original arcade game) and the weapons were also all there. But the ugly graphics and the slow speed made playing the game rather strenuous. Never less I've played it a lot and even managed to advance to level 5 or 6. Since I had the game on tape and every new level had to be loaded in separately I obviously was very patient with this game.

Anyway I thought the CPC can do better than that and with my R-Type clone I wanted to prove it.

Lurking enemy
Something's lurking at the right border...
Please don't ask me why I've painted the star fighter the way it is. For some reason that eludes me today I've painted a star fighting ship that looks like a flying wale with mean looking eyes. Probably I wanted to convert this bend nose of the original R-Type ship but wanted to do it inconspicuously or so. I don't know. It just looks stupid!

Anyway I've advanced pretty far with that game. It was even playable with some different waves of attackers, some huge background elements like the destroyed star ship base and the lookout towers. The scrolling was interrupt controlled, so sometimes when it got stuck for some reasons I wasn't able to discover it suddenly scrolled in fast forward for some steps. It looks weird, but makes sense, since the interrupt requests pile up until they can be processed. I also was able to animate the own shots and the collision detection was working too!

So the game was about 60% finished and just needed some more graphics, enemy ships and waveforms and some extra weapons. But once again I've felt that with all those necessary additions the game would be come unplayable slow. I've conducted some tests on an extra weapon that fires 7 shots at a time and ended up having over 40 shots on the screen that all had to be animated individually, which took way too much time.

Sky walker
... it's one of those "sky walking" enemies!
Also the way I've conducted the collision detection was getting me into trouble. I did on the screen collision detection, by testing whether or not any of the bytes in the area where the ship or the shots were going to be painted next contained anything besides an empty byte. It was the best collision detection possible, since only a collision with a part of the ship with any other element on the screen was tested and not a collision of a rectangular box around the ship with the rectangular box of the enemy ship or shot which often results in false collisions.

But that restricted the background graphics to a black void, since anything else would have created a collision with the ship. So I couldn't even add some moving stars or so into the background.

Also sometimes exploding ships or a collision with anything on the screen resulted in the erasing of a part of the background graphics. Since when a collision with a ship and the background was detected the ship is very close to the background element, but the explosion of this ship may be bigger than the ship itself resulting in the erasion of everything that is being engulfed in the explosion.

It was a shame to abandon this project. Unfortunately I wasn't aware of any tricks to increase the speed with which sprites and graphic elements can be painted to the screen like avoiding loops or commands with long execution times. Direct addressing was still a inexpressive term to most of the CPC users at that time including me.

Colorful explosion of an enemy fighter.
Besides the test game, two editors, one to create the backgrounds and one to setup the waveforms of the enemies I've also already created one of the end-of-stage enemies. Actually it was this huge enemy space ship with which I began creating this game.

Before I started with all of the rest I first wanted to find out whether the CPC was possible to paint and move such a big enemy ship on the screen. It is obviously a copy of the middle-of-stage enemy in the 3rd (or 4th?) level of R-Type, but it also bears a striking resemblance to the Battlestar Galactica from the TV show of the same name.

This huge enemy ship was composed of three full screen images put together at two vertical intersections. I probably wouldn't have been able to really include this ship in the game since it already took up most of the memory. But I think unfinished as it is it still looks quite impressive.

Just imagine how the CPC community would have responded to a game like this, if I ever had finished it...


3rd enemy
The third enemy fighter I've created for the game
Giant enemy ship #1
Propulsion engine of the end of stage enemy ship
Giant enemy ship #2
Vertical engines of the giant end of stage enemy ship
Giant enemy ship #3
The stern of the end of stage enemy ship

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last updated on Saturday, December 21. 2002 by Odiesoft

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