Lady Bug

[lovebug]

i shouldnt give up on this, im very sorry but i just cant seem to make it work well

[fizgog]

You might want to leave it for a few months and come back to it later with a fresh pair of eyes.

Take your mind off it by creating a new game instead

[lovebug]

Build 003338

(fixed) im now clearing player input when a level restarts after ladybug dies as it was possible for ladybug to turn the wrong way when the level restarts due to the previous pending player input

(fixed) missing pixels in enemy set 1

(change) altered the colors a little in boot.bas instructions

(change) [Conf] [ConfR] [Maps] [Maze1] [Maze2] [Maze3] renamed to _Conf _ConfR _Maps _Maze1 _Maze2 _Maze3
 

Lady Bug.ssd

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[lovebug]

You might want to leave it for a few months and come back to it later with a fresh pair of eyes.

Take your mind off it by creating a new game instead

true

[lovebug]

only a slight slowdown when all the nasties are patrolling at full whack.

@maniac miner I really must thank you for this comment,the automatic frameskip does make the game look like its slowing down and it got me thinking about the problem and I think I have found a solution
 

---

In all builds so far this is how the frameskip functioned

The screen is split into two halves (upper and lower) and in each half up to 3 sprites can be drawn within 1 frame at 50Hz

If more than 3 sprites appear in a half screen then the extra sprites will be postponed until the next frame which causes the update rate for those sprites to be 2 frames (25Hz)

This automatic frameskip was applied to ladybug and enemies both

---

 
In this new build I have altered the sprite processing code in .redrawSprites so that ladybug is given priority and will always be drawn within 1 frame at 50Hz without frameskip, only enemies will have frameskip applied when needed so this should make things look smoother

Build 003340
 

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[lovebug]

ERROR! this is completely wrong, please ignore !
I removed ladybug from the auto frameskip in the previous build but I forgot to reduce the sprite processing length by 1 so the .redrawSprites was still trying to process 5 sprites instead of just the 4 enemies, fixed now

Build 003341
 

 

[lovebug]

ERROR! this is completely wrong, please ignore !
hmm I noticed that theres an issue with the enemy movement not looking smooth so I slowed the game down in beebem and can see that even when theres only 1 active enemy that its being drawn for 3 frames and then skips 1 frame

looking into the issue

[lovebug]

Build 003340 is correct and wasnt skipping a frame

I have recorded video and single frame stepped the game and its seems ok, please use 003340 thanks
Im still not sure what was causing the issue but it seems ok now
viewtopic.php?p=372315#p372315

Build 003341 is incorrect and has been deleted
Sorry guys

---- edit ----
Actually it was probably me poking around with things late at night and half asleep then thinking it was the build I had just posted

[lovebug]

I just discovered an error in beebem's 6502 core

the SED (set decimal) and CLD (clear decimal) instructions are not clearing the carry and this is causing ladybug to give an extra 10 points on some items



you can test this with

Code: Select all

DIM C% 100:P%=C%:[SEC:SED:LDA#0:ADC#0:CLD:RTS:]:PRINT USR C% AND 255

answer should be 0


---- edit ----
ignore this, the information on 6502 im using is wrong

time to fix ladybug !

[lovebug]

Build 003343 fixed missing clc instructions in the bcd math routines
 

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this is kind of annoying because I originally had clc instructions but removed them after reading a dodgy 6502 datasheet that showed the sed and cld instructions also clear the carry

well that datasheet is now burning in silicon hell

[lovebug]

i just checked back on my old builds and up to build 003333 i had the clc instrructions, build 003334 i had removed them because of that crappy 6502.txt file i was using from some random bbs backup. sorry guys

im going to stick with this reference from now on

[tricky]

I know I've shared this somewhere, but this is my little cheat sheet that I have on my desk, stuck to a piece of porridge box!
I can't guarantee that it is correct as I only occasionally look at what can be ,x and ,y when I forget!
I just had a look and thought that I had missed SEV, but it seems that there isn't one!
It is 6502 only, no undocumented/illegal opcodes.

Warning!
TobyLobster has stopped a mistake in branch timing when crossing a page.

[lovebug]

thanks tricky, very handy

the 6502.pdf I just posted is from the acorn atom user manual

[0xC0DE]

I usually keep a browser tab open with https://www.masswerk.at/6502/6502_instruction_set.html

[lovebug]

thanks 0xC0DE very handy

[TobyLobster]

Tricky: I think branches take 4 cycles to branch to a new page don’t they (not 5 as your pdf shows)?
0xC0DE: I use that same page.

[lovebug]

yeah its 3 cycles normally +1 cycle if to new page

[lovebug]

Build 003345 I just managed to squeeze in an indication of the diamond bonus available in the lower panel just below the lives value, disapeers if you die, collect non-cyan objects or get the diamond bonus
 

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[lovebug]

I couldnt do a more fancy looking indicator as the game is totally out of memory now

Sorry

[lovebug]

oh it turns out that I had loads of free space in the sideways ram but due to a mistake in loader.asm and memory.asm (and my lack of skill when it comes to math) it was reporting incorrectly

i'll work on making a nice sparkly diamond sprite and the code to display it

[lovebug]

Build 003346

Added sparkly diamond bonus available tiles and code replacing the previous

Fixed yet another memory report error this time in build.asm

Altered the map editor tiles to better show the end pieces

Added a long overdue thank you to the github readme.md

Code: Select all

A big thank you to
Kieranhj for their image2mode7 utility allowing me to make the lovebyte loading screen
Dreamland Fantasy's for their image2bbc utility allowing me to make the maze editor tiles
HeadHunter for recreating the enemy release sound for 50Hz using math !
And to everyone at the stardot forums for their kind words, help and support

 

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[lovebug]

Build 003347 fixed a mistake

vegetable bonus score update

when vegetable bonus score is displayed it draws over the center enemy box, when the score is removed I was drawing the two vertical bars of the enemy box but if a player creates their own map that didnt contain a center box then this action is incorrect

fixed it by reading the tileMap background buffer and drawing the correct content
 

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[lovebug]

Build 003348

A while back i modified boot.bas so that the instructions page in the basic $.Boot showed the user defined keys

One thing that bugged me about the instruction pages is that the information about extra lives, special bonus, diamond bonus were hard coded into the page which will be incorrect if someone reassembled the game and altered these constants for more lives etc

To fix this ive added an extra file bonus.asm which sets up the constants in memory which is then saved by build.asm to $._Bonus so that the $.Boot can read the values and display the correct information in the instruction pages
 

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source.zip

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[lovebug]

Final Build 003350

ages ago I noticed that when redefining the keys in the lady bug menu when using jsbeeb emulator that the turnstile sound was incorrect for the first 3 keypresses but the final key sounded ok, strangely all 4 key presses sounded ok in beebem

I just discovered the cause was down to the function .keyboardScan which was setting via1 porta ddr bit 7 as input for the keyscan but wasnt setting it as output for the psg before exiting which caused sound data corruption from the missing bit 7

fixed now so final build again
 

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[fizgog]

fixed now so final build again

[lovebug]

wow I just spotted a silly mistake in the function that draws 4 random enemies on the main menu screen

in .mainMenuDrawEnemies I call .random at the start to get the first random enemy and direction from randomSeed + 1 and randomSeed
but in the loop I do this

Code: Select all

	inc randomSeed				; increment direction for next sprite
	inc randomSeed + 1			; increment sprite image for next sprite

well this is very bad because if by chance the seed contained &FCFC when entering this function the seed would end up set to &0000 on exit after drawing the the 4 enemies and thats game over for the random number generator, this would cause the game to lockup completely as .random would only generate an infinite string of 0's

ive fixed this silly mistake by using a copy of the seed keeping the original safe

theres been a few other things like optimizations, allowing the last dot munch sound to play fully before ending the level, a new clear screen function for the map editor and more... check out the github repo history for details

Lady Bug Build 003351
 

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[lovebug]

ive always wondered why the sprites flicker when crossing the center line threshold between the lower and upper half of the screen
I think I found it, well it seems to work

I havent seen any side effects from this change

Build 003353
 

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[lovebug]

I did spot two side effects with the recent change, the cursor box and ladybug on the high score name registration screen flickered so ive fixed that

Build 003356
 

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[lovebug]

thats gotta be the final build

[marcusjambler]

Congrats