New @Export directive for VBM sprites

[AndyHOvine]

While this is initially for VBM Sprites, it will be useful for other situations and build targets. Later on I want to make a local S/W sprite feature that uses less RAM and would work on any Commodore machine inc, C64, Plus4 etc..

Anyway the detail of this request, add a new @ export directive to take data out of a TRSE character editor and produce BIN data in a required format.

@vbmsprExport startChar, CharWidth, CharHeight, ShiftIndex, AddressToStoreShiftedSpriteAt

This creates just one small BIN file.

• StartChar is the character to start from
• CharWidth is the width, in characters, of the data to export
• CharHeight is the height, in characters, of the data to export
• ShiftIndex - a number from 0 to 7, denoting how many pixels to shift to the right.
• Address - the address to store / load the BIN result

eg: @vbmSprExport 100, 2, 2, 4, $2400

This would export from character 100, a 2 x 2 character, shifted 4 pixels * (see note) and stored at $2400

• note: as we are exporting a shifted sprite, this is what the export would do:

1. Create a block of memory that is big enough for 3x2 characters (as shifting requires one extra character column)

2. From character 100, extract 100, 140, 101, 141 in that order (the full screen char editor is 40 chars wide, char 140 is directly beneath 100)

3. shift these characters by 4 pixels to the right and store in the 3x2 memory reserved in step 1.

4. Save this 3x2 memory to a BIN file and load in to the TRSE program.

The programmer can then do one of two things:

1) use multiple exports for each preshifted frame 2) or use a different character for each preshifted frame (producing animation like in Jet Set Willy when he walks) * hope that makes sense.

[AndyHOvine]

BTW, char width and height could be a value from 1 to (a big number) - eg: say 10.

[AndyHOvine]

Example - exporting an 8x16 sprite character set. Imagine the TRSE character editor was only 6 characters wide for this example...

[AndyHOvine]

I'll close this - Think of a simpler export that we can use for VBM, for double height character mode (vic 20) and for other purposes in the future!