Chapter 26 - April 1st, 2016
The Final Countdown
few weeks have been spent doing fixes, refinements and adjustments of various
gameplay elements. The game is now at the final stages of completion and I now
have to define the 80+ screens of scrolling terrain.
final stages of this project, I have titled this chapter... The Final
Countdown and in keeping with the 80's music theme I have been using in
previous instalments, I have located the following link to keep me in the right frame of
mind... CLICK ME
a list of the changes and refinements I have done.
the frequency and randomness of the balloon launches.
- Added a
simple graphic effect for the balloon pop.
I also found that it was possible to pop two balloons in quick
succession so I made the routine handle two balloon pops simultaneously to give
a better effect. Thanks to Torsten Dittel for the initial feedback on
with various death routines. After several attempts, I decided that when
the plane collides with anything, it will stop moving forward, wedged into the
object it collided into and scroll to the left with the terrain. If a collision
with a balloon or other suspended object occurs, the plane will fall from the
sky till it hits the ground or lands on a grounded object. The plane will flash
on/off from the moment of collision, all fuel will be depleted and the engine/propeller
will shut off.
terrain will cease to scroll in from the right and the plane will continued to
scroll with the remaining terrain until everything disappears off the left edge
of the screen. If another plane is available, it then will scroll back into
view from the left as the terrain starts to reappear scrolling from the right
edge, beginning back to the last checkpoint obtained. If no additional planes
are available, the screen will switch to a GAME OVER screen and if a new
session High Score has been achieved, it will also print text to inform you of
this. Phew! A very busy part of the game and thanks to Curtis Boyle for
feedback in this area.
and optimised the joystick reading routine. Because the sound interrupt routine
uses common I/O control lines as the joystick (both use the 6-bit DAC), there
was a need to do a short interruption of the main interrupt driven sound and
video raster routine so as to read the joystick. This had to be done quickly so
as not to interrupt the main interrupt routine for any noticeable period while
not allowing joystick data to pass through to the sound output.
routine also had to decide if your plane was out of fuel whereby the plane propeller
and engine were shut down and you lost all vertical control of the plane. The
plane would glide towards the ground where it would crash to its doom. During
this freefall mode, the player can still control the horizontal movement of the
plane as well as the firing of the gun. This gives you one last chance to glide your plane close to a fuel object
if available, shoot it during freefall which will replenish your fuel and
re-start the engine, allowing you to veer back up into the sky at the last
second. A tricky manoeuvrer designed for the pro players and very rewarding if
one can pull it off!
- I altered
the color of the fuel bar at the top of the screen. It was red (fuel level) and
yellow (empty fuel level) but I found that the yellow stood out over the red and
it took a split second to interpret accurately when glanced during the heat of
gameplay. The yellow has been replaced with a dark red which allows
the actual fuel capacity to be highlighted and can be interpreted faster.
- Quashed a
variety of minor bugs. In particular, a slight flickering on the edge of the
split screen scrolling has been reduced to almost nil. The overall screen and
presentation of graphics looks smooth and clean.
I can now move into the 80+ terrain level design. This will take some time and
a lot of play testing to get things right.
Future YouTube Video Preview
I have now got access to a fast Intel i7 gamers PC that can run the latest MAME
and CoCo3 emulation at full speed. I have also acquired a USB joypad so that I
can run the game to obtain an accurate and clean video capture. I hope to have
a near-to-completion video in my next blog chapter.
MESS appears to run the game quite well. VCC unfortunately does not handle the
interrupts accurately enough and causes the background raster lines effect to
jitter. Hopefully the VCC engineers will fix this sometime in the future.
Till next chapter, upwards and onwards!