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*                                                                             *
*   Game:   Gryzor Clone       Type:    Amstrad CPC Emulator DSK File         *
*   Author: Odiesoft           Webpage: http://www.odiesoft.de                *
*   Size:   1 * 194816 Bytes   Date:    18. February 2003                     *
*   File:   Odiesoft Games - Gryzor Clone (1990).dsk                          *
*                                                                             *
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Title: Gryzor Clone
Year:  1990


This game of mine was a clear cut copy of Ocean’s 1987 CPC smash hit "Gryzor". I
used to play Gryzor a lot. In the end I was even so good at the game that I was
able to win it without loosing a single life!

Gryzor was really an amazing game, incredible graphics, great gameplay, just the
right amount of difficulty so that it was hard, but still playable, some cool
extra weapons, three different types of levels (horizontal fighting, vertical
fighting and 3d tunnel levels) and a cool soundtrack.

It was just lacking one thing: scrolling! Unfortunately the game was divided
into individual screens. Sometimes going from one screen to another meant
instant death, because you ran right into the arms of an enemy soldier or cannon
on the new screen!

With this Gryzor clone of mine I wanted to remedy this single drawback about the
original game. The primal idea was to create a junge fighting game where the
player had to shoot enemy soldiers. But I realized that the graphics I had
created looked so much like the original Ocean game that I couldn’t fool anybody
about the origin of this idea. I was obviously searching my inspiration a little
too hard in the original game...

Anyway, the scrolling I’ve created was just a simple software scrolling with
double buffering, so that it didn’t flicker too much. I also made a conceptual
error with inserting the new graphics at the right end of the screen, so that
every time the screen was moved by one byte to the left the last column on the
right came out to be an exact copy of the last but one column. This was due to
the fact that I had the computer insert the new column on the right hand side of
the screen and move the screen afterwards. I should have done it the other way
round...

But this wasn’t the real problem I had with this game. I ran into similar
problems like in "The enchanted forest" when it came to finding out where the
character was allowed to walk on the screen and where he couldn’t walk or stand.
Since I wasn’t able to think of an easy way to test that in the memory I tried
to devise a method so that I could find out on the screen whether the character
can walk on the next byte or if the road is blocked or ends there.

Since the graphics was very colorful there wasn’t a distinct two-pixel
combination (a Mode 0 byte) that I could use to define as ground. I tried to
mark the walkable parts on the screen with a brown colored byte. That meant that
I would have to change the palm trees in the graphics so that they didn’t
contain bytes with two brown pixles anymore, but I was willing to accept that
change. 

The first tests with this brown walkways on the screen were promising. The
program was able to determine where the character was able to walk and where he
couldn’t walk. But marking all the walkable parts on the screen with brown bytes
looked really stupid. Also finding out where the next brown byte was on the
screen took a lot of time. So when I used that walkway identification routine
with the software scrolling it was so slow that the guy on the screen was
continuously wobbling left and right.

Since the game was already very slow and at that time I didn't have the means or
knowledge to create a faster scrolling I soon started to divert my attention to
other programs and demos. Thus this Gryzor clone grew to become another
unfinished project in my CPC career...

Of course I had already created a map editor with which I was able to draw the
landscape that was being scrolled on the screen in the test version of the game.
With this editor I was able to select one of several background elements and
insert it in one of the three height levels that were used in the game. Since
this background elements were very large the combination possibilities of these
elements were rather limited.

At that time I obviously had a lot of leisure time. The editor was a regular
BASIC-Assembler mix, i. e. the background elements were painted on the screen
with an Assembler program, the keyboard input and the loading and saving of data
was done in BASIC.

Every time I started the editor a very slow BASIC algorithm added some colored
points to the "Landschaft Editor" text on the top of the screen. It took a
minute or two to change the points in the whole text, but obviously I had enough
time to wait for that algorithm to get finished when I wanted to change the map
for the demo. I'm a lot less patient nowadays and was very happy that Caprice
had an option to run the CPC Emulation with more than 100% speed.


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*                                                                             *
* This program can be distributed freely and without the need of a written    *
* of a written permission by Odiesoft, as long as it is distributed free of   *
* charge!                                                                     *
*                                                                             *
* If you had to pay for this, you've been ripped off!                         *
*                                                                             *
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