Extra tiles at the left of BG window

Bluescreen2001

Hi,
I am just starting to write a Loderunner clone to get a grip on the basic engines BASIC dialect. I have no real basic engine yet, so I use the hosted version.

I drawed a small PCX with my tiles in it and load them as bg0 with the following command:
BG 0 TILES 28,16 SIZE 16,14 WINDOW 0,0,28*16-16,16*14 ON
I use screen 1. My tiles are 16x14 pixels. They are extracted from the PCX without problems. The game levels are 28x16 tiles. So I set the windows width to 28 tiles x 16 pixels
Then draw a sample pattern on it with a PLOT loop. Works fine.

But I see at the end of each line one extra half tile which repeats the first tile in this line. If I reduce window width nothing happens until I reduce by 16 pixels. Then the window becomes one tile smaller, but my last tile is cut in half then.

Here is my complete program:
100 SCREEN 1 105 LOAD PCX "tiles.pcx" AS BG 0 110 BG 0 TILES 28,16 SIZE 16,14 WINDOW 0,0,28*16-16,16*14 ON 120 FOR y=0 TO 15 125 PLOT 0,0,y,6 130 FOR x=1 TO 26 140 PLOT 0,x,y,3 150 NEXT x 155 PLOT 0,27,y,5 160 NEXT y 170 PLOT 0,0,8,7 200 WHILE INKEY$ ="":WEND 210 BG 0 OFF

BTW: is there a way to save a program without line numbers?
I noted a strange behaviour with my hosted basic engine. If I started/stopped my basic program many times suddenly it does not work anymore. The screen becomes blank. I have to restart the basic engine then, to get it working again. Maybe some kind of memory leak.

konimaru

Any chance of getting the tiles.pcx file? Attachments don't seem to work here so you could send me an email: marko.lukat@biglobe.jp

Bluescreen2001

Sent you a mail.

konimaru

Bluescreen2001 Just checking, did you get my response from Thursday (in case it ended up as SPAM)?

konimaru

I'm not entirely up to speed yet with the BG engine (just started a few weeks ago). But there is code in vs23s010.cpp which specifically handles the right/left columns. Not sure if this wrapping behaviour can be controlled at run-time though. HTH

Bluescreen2001

Do you have a real basic engine on which you can try if the problem also arises on the hardware machine or only on the software emulation.
I am unsure if I want to build a hardware. It's cheap parts is only half of the story. The problem is the PCB. As a single piece it's expensive. Maybe there is someone out there who has a spare one and lives in Germany or Europe. Shipping from US is also too expensive I think.

konimaru

Behaviour on the h/w is the same. You get half a copy of the tile in column 0. Feel free to raise an issue on github.

That being said, I think I have a look as well ...

konimaru

konimaru That issue is now fixed.

konimaru

Window clipping seems to be non-functional. Anyway, don't let that scare you!

Bluescreen2001

I noticed one more bug. If you load a BASIC file which you have written as text without line numbers, which contains a variable which begins with a keyword (like map_sprite) it will generate wrong basic text.

x = map_sprite + y

becomes

x = MAP sprite + y

But what scares me more is the lack of memory. My PCX file containing the tiles and the sprites is now 7KB of size, which is 144x60 pixels, cannot be loaded. "Out of video memory". Maybe it is because the PCX file ist 24bpp, but I don't know how to save a PCX with less bpp. I have no program to edit PCX directly, so I use irfan view to convert from PNG.

Bluescreen2001

I just managed to save the PCX as 4 bpp, but I get out of memory anyway.

bitartrate

I think I have a solution for your "out of memory issue". Write a small program to load your PCX on screen at coordinates 0,0. Second line would be SAVE PCX. Engine BASIC will automatically save at it's native bpp for you.
Also, your PCX must be at the same resolution as the SCREEN mode you are working in if you want to use the offscreen loading feature. I don't know if it can be smaller resolution but it definitely cannot be larger.

Bluescreen2001

I was already able to load my PCX. I split it in two. One with the backgrounds tile map and one with the two sprite sets. That works. I can now display the sprites and move them around. But I have problems with keyboard control.

If I use PAD() everything works smooth. But then I cannot assign my own keyboard mapping. Or is there a way for that?
If I use INKEY it uses the standard OS keyboard repeat, what is much to slow for gaming. Is there a way to query the keyboard as quickly as the pad or is there a way to map keyboard keys to the non directional PAD keys. Then I can use PAD which would be nicer anyway. But I need more keys then the directional ones.

One very annoying bug is that variable names beginning with keywords does not work:
dimension=42 Syntax error (not an array variable) dmension=42 OK

bitartrate

I have not found a good way to map the keyboard for use in games. I have resorted to PAD() and then use INKEY if I need input that is not an "action". I also wish we could use keywords in our vars. On the subject of my earlier post about having the BASIC Engine convert your PCX images; I have found that my images load a lot faster after I have done this. I have not been able to make a PCX that the BE considers 'native' even with GIMP. But I did find if I used the BE itself to 'convert' them then using them goes more smoothly for me.

bitartrate

In the newest firmware Ver.534 that Uli posted 10/02/2019 he has added a KEY() command that looks like the PAD() command but for keyboard input. Let's test this and see if it solves our keyboard 'action' input needs.
https://basicengine.org/git_builds/