clear ink from attr - Printable Version +- Forum (https://www.boriel.com/forum) +-- Forum: Compilers and Computer Languages (https://www.boriel.com/forum/forumdisplay.php?fid=12) +--- Forum: ZX Basic Compiler (https://www.boriel.com/forum/forumdisplay.php?fid=11) +---- Forum: Help & Support (https://www.boriel.com/forum/forumdisplay.php?fid=16) +---- Thread: clear ink from attr (/showthread.php?tid=311) |
clear ink from attr - slenkar - 02-22-2011 How do you use print to remove all ink from an attribute (8*8 square) the opposite is 'print /::' to draw a block but i want to clear all ink away and leave the paper Re: clear ink from attr - LCD - 02-22-2011 Just " " (space) or "/ " (with two spaces). But if you want only to clear Attr, use and PAPER 8, BRIGHT 8, maybe FLASH 8 and set INK to any colour you like. If you don't want to clear pixels use OVER 1. Re: clear ink from attr - boriel - 02-22-2011 LCD Wrote:Just " " (space) or "/ " (with two spaces). But if you want only to clear Attr, use and PAPER 8, BRIGHT 8, maybe FLASH 8 and set INK to any colour you like. If you don't want to clear pixels use OVER 1.There's also a SET_ATTR that, If recall correctly, also do that (e.g. SETATTR(x, y, attr)), but better try LCD's recommendation first. Libraries are ALPHA :mrgreen: Re: clear ink from attr - LCD - 02-22-2011 SETATTR only for paper needs BAND function to work. I myself use pokes, especialy for the whole screen (768 bytes), but SATATTR is fast too. You will need ATTR to read the Attribute at given coordinate, then binary AND it with a mask (BIN 11000111) to get a value without paper. Then you can use a new paper if it is different than zero by binary OR-ing (BOR) it with Paper shifted to left 3 times ( newpaper<<3 ). Re: clear ink from attr - boriel - 02-22-2011 LCD Wrote:SETATTR only for paper needs BAND function to work. I myself use pokes, especialy for the whole screen (768 bytes), but SATATTR is fast too. You will need ATTR to read the Attribute at given coordinate, then binary AND it with a mask (BIN 11000111) to get a value without paper. Then you can use a new paper if it is different than zero by binary OR-ing (BOR) it with Paper shifted to left 3 times ( newpaper<<3 ).BAND is already implemented as an operator! :!: It should be working since 1.2.6 (to say the least). So Code: DIM a as Ubyte = 5 Re: clear ink from attr - slenkar - 02-22-2011 Code: ink 0 this just prints black ones to the screen Code: ink0 this works Re: clear ink from attr - boriel - 02-22-2011 slenkar Wrote:And that's ok. bAND is an OPERATOR. It calculates (a AND 1). The difference with normal AND is that, AND uses boolean logic (0 = False, any other value = True). bAND is for BINARY (or BITWISE) operations (hence the 'b' Prefix). You have bAND, bOR, bXOR and bNOT. For what you want, do as LCD suggested: Code: PRINT AT y, x; OVER 1; PAPER 8; INK value; " " |