Added the bottom half of the mothership.

The idea was that everything should be drawable in pages (256 byte chunks - 2 pages = 1 char line in mode 1 at 256x256).

I have taken a quick shortcut with the mother ship making it redraw in character rows, this should be fixable later.

The idea is that when the alien birds are diving over stars or the mothership, the background can be re-drawn in a compromise of little as possible vs enough to make redrawing efficient - this is per page for stars, but could be less for the mothership - although it is 2 pages to keep the code simple for now.

The shield doesn't rotate, but the destructible shield and bottom are drawn using the "how much has been destroyed data", so changing the data will make the correct bits get displayed correctly - I might need to add code to draw small changes when they happen and let the whole thing be redrawn only when a diving bird flies over it.


URL:http://youtu.be/8JvIePSgnY8

Graphics look fantastic and such quick progress.
Some of your YouTube videos are still marked private. Is it a setting in YouTube itself when you're logged into it?

I tried changing palette in video ula directly but couldn't change a logical colour to be all one colour... Of course you wanted opposite with stars.

How do you get the sprites to fade in around the mothership?

Just found it, I had forgotten to click "publish".


Here is what I do:
VideoULA = &FE20
VideoULAPalette = VideoULA + 1 \\ b4-7 logical colour 2c:b7xxx 4c:b7xb5x 16c:b7-4, b0-3 actual colour (^7)
\\ c0:black, c1:red, c2:green, c3:yellow, c4:blue, c5:magenta, c6:cyan, c7:white, c8-15:c0-7/c7-0
PaletteWhite = &00 : PaletteFlashWhiteBlack = &08 ; Pal2Col0 = &00;
PaletteCyan = &01 : PaletteFlashCyanRed = &09 ; Pal2Col1 = &80;
PaletteMagenta = &02 : PaletteFlashMagentaGreen = &0A
PaletteBlue = &03 : PaletteFlashBlueYellow = &0B
PaletteYellow = &04 : PaletteFlashYellowBlue = &0C : Pal4Col0 = &00;
PaletteGreen = &05 : PaletteFlashGreenMagenta = &0D : Pal4Col1 = &20;
PaletteRed = &06 : PaletteFlashRedCyan = &0E : Pal4Col2 = &80;
PaletteBlack = &07 : PaletteFlashBlackWhite = &0F : Pal4Col3 = &A0;

lda #Pal4Col1 OR PaletteMagenta : jsr set_palette_4colour

.set_palette_4colour \\ A = &pxpxcccc Palette(0=COLOUR0) Colour^7(7=black)
{
STA VideoULAPalette : EOR #&10 : STA VideoULAPalette : EOR #&40 : STA VideoULAPalette : EOR #&10 : STA VideoULAPalette
RTS
}

for 16 colour modes, lda #PaletteEntry OR (Colour EOR 7) : STA VideoULAPalette

for 2 colour, I can't remember, but 1 bit of bits 4-7 chooses the colour and you have to set all the other combinations to the same colour.



No magic really, just draw, wait 4 vsyncs and then move on to the next

Not much time tonight, been out playing board games

Added shield rotation, the "how shot up it is" data is rotated and then the dirty flags set for the two pages that contain the shield, so even if there are explosions and swooping birds, the shield will still only be drawn once. This level should have stars, but I suspect that it will be too much drawing with the ship, aliens and flying down aliens.

I could optimise the drawing, but am keeping it simple to try and get it finished before I get too distracted.


https://www.youtube.com/watch?v=YYWPfKJoyEs&feature=player_embedded

Added shooting and bullet collision, tweaked boss gfx and scrolling code.
I'll try and get explosions in later, but have to stop for a while.


https://www.youtube.com/watch?v=-u-Vm6p_fqs&feature=player_embedded

I wish I new how to make youtube do 50Hz videos, so that my game doesn't looks like 25fps!

Thanks for posting these updates and videos - it's a nice way to write a development diary. I hope you're having fun doing it.

Thanks, I am.
Posting the diary here is easier than trying to set up a page - failed again the other day.
Posting also makes me want to do some more; I think I am starting to see the attraction of blogging etc, but I'll keep mine dev related.
It is also nice to have comments and questions mixed in.

Great project. Thank you for all the tiny videos showing the progress.

Added explosions before work yesterday, but nothing last night as I had a day full of allergic sneezing!

Added explosions when something is hit, the birds don't know they have been hit, but are just erased by the explosion. The mothership doesn't know either but it uses the redraw if something has happened in its pages technique I talked about before.


https://www.youtube.com/watch?v=FUNQz61-d2w&feature=player_embedded

Added mothership hull and shield receive damage now, redrawing of hull is just clear char and wait to be redrawn, so that will have to be tidied up.


https://www.youtube.com/watch?v=hh1fcsR3jYs&feature=player_embedded

added birds walking for the first two levels and the boss level, you can hit them, causing an explosion, but they don't know they have been hit.


https://www.youtube.com/watch?v=Q-E5eppbV_M&feature=player_embedded

birds on star levels now die when you hit them. I need to add the second bullet to the second level to make it feel right.


https://www.youtube.com/watch?v=WrXXJ3c53cg&feature=player_embedded

Added the second bullet to the second level, it feels much more like Phoenix now.
walking birds die on mothership level which now.
I am pretty happy with the way that the mothership descends.
You may notice that all but the two outside aliens are hard to kill on the mothership level, this is because there are actually two in each spot (as per the original).


https://www.youtube.com/watch?v=JWYgypgCR4c&feature=player_embedded

Here is a .ssd, I haven't tried it on a real beeb for a few days.
Keys are Z,X (left,right) RETURN (fire) and SHIFT (next level - will be shield).
I haven't really started on levels 3 and 4, but the others should give an idea of what the game should be like on a beeb.

Hi Tricky,

WOW..... ... this is looking very good ..... applause!!!
And you're progressing very fast, compliments.

I'm missing the stars on the boss level, are they different from the other levels?
Is this game completely character based?

Greetings
Kees

Thanks, yesterday was do a bit, get off the pc for a while, repeat


There should be stars on the boss level and on the last few rows of the first two screens.
I am using colour 1 to draw the three coloured (blue,cyan and some red) stars, but I need it for the player ship's red body, so can't have them at the bottom of the screen without loosing the red part of the ship, which I consider iconic.
For the mothership and swinging aliens on levels 3 and 4, I am using vertical rupture to move vertically while staying row based for speed. I am using colour 1 to allow three colours on the mothership as I think this level is already interesting enough without the stars. If I added them, you would see them disappear as they got near the bottom of the screen.
There is quite a bit of drawing to do on these screens and with the extra burden of stars+mothership, I am worried that I won't be able to draw it all without flicker at 50Hz.

As far as I can tell, the arcade machine was entirely character based, but with two planes, where the background one could scroll vertically in pixel increments.
If you look around the mothership on the arcade version you will see a gap with no stars, I suspect this might be due to a limit on the number of colours per 8x8 pixel char, but haven't checked.

I added some test bird bombs. I have had all sorts of bugs with this faily simple piece of code and am taking a break as it just isn't going well. (skipping 19, as it was behind the scenes tidy up).

https://www.youtube.com/watch?v=KIWmvLsK35s&feature=player_embedded


https://www.youtube.com/watch?v=LRvcdgrJ2J4&feature=player_embedded

Fixed the bug with bird shot moving left/right as it fell.
I had a list of bomb addresses and bytes for bomb position within the byte, but for the drawing routine I was using the address in the opposite order to the bytes. This wasn't obvious as I build a custom version of the draw routine by self modding the draw code with updated addresses and bytes to write bottom up!

I haven't decided on the colour of the bombs yet; it doesn't really matter on the other screens, but they can be hard to see on the boss level, so I have left some one colour and some the other (sorry, only two choices) to allow you to tell me what you think.

https://www.youtube.com/watch?v=QjkdJBFuQ6E&feature=player_embedded
PS I seem to have messed up my version numbers, so this is 21 again

Hi, commenting from work without access to youtube or emulator. I took a look last night.

- I think both the falling bullet colours are a bit hard to see when they fall through the mothership. I'd say the green a bit easier to see rather than purple.

Overall - this is looking fantastic and close to the real thing. I loved watching the video with the ship now moving and shooting the bird sprites. It's incredible that you're putting this together so quickly - even quicker than Carnivale. Showed your WIP YT vids to my other half (a big fan of Phoenix) and she too is very impressed and looking forward to playing it on our Beeb.

Did you get the sprite and font data from the arcade ROMs?

Do you plan on doing the various animations and movements , such as the birds swooping down and growing in size/ taking more than one shot/splitting in two when being shot (if memory serves on the latter)?

I'm planning to do it all
I mostly grabbed the "sprites" from a video I made using MAME.
There seem to be a few "typos" in the gfx - a few pixels that are the wrong colour or out of place, so I have "tidied" them up - made one "nice" one and mirrored/flipped it.
I have currently cut out a few frames of the big birds as they grow, but the largest ones are still there, including the big horizontal explosions. There are also a few sprites that are squashed on to one horizontal line in one direction, but spread over two in another, so I have made these bigger and flipped and mirrored them.
I am planning on making a few minor tweaks to the animation sequences as the dive and roll, but you shouldn't notice them unless you compare frame by frame, and then hopefully mine will be as good.