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Add PutChars library page
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‎docs/library/putchars.bas.md‎

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#Putchars.bas
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##Putchars
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> **WARNING: This subroutine does not check to see if it's writing over the edge of the screen.
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This is done for speed, but it is the user's job to make sure that all data will fit on the screen!**
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###Usage
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There is a an example program that uses this at the end of the page.
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```
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putChars(x as uByte,y as uByte, width as uByte, height as uByte, dataAddress as uInteger)
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```
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Where
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* x is the x value in character co-ordinates
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* y is the y value in character co-ordinates
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* width is the width in characters
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* height is the height in characters
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* dataaddress is the memory address of the UDG style bytes for the character being printed. 8 Bytes to a character. The order is top left to bottom right, first column, then second column, and so forth.
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Prints the graphics data to the screen at the given character co-ordinates.
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```
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SUB putChars(x as uByte,y as uByte, width as uByte, height as uByte, dataAddress as uInteger)
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' Copyleft Britlion. Feel free to use as you will. Please attribute me if you use this, however!
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Asm
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BLPutChar:
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LD a,(IX+5)
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;AND 31
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ld l,a
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ld a,(IX+7) ; Y value
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ld d,a
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AND 24
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add a,64 ; 256 byte "page" for screen - 256*64=16384. Change this if you are working with a screen address elsewhere, such as a buffer.
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ld h,a
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ld a,d
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AND 7
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rrca
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rrca
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rrca
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OR l
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ld l,a
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PUSH HL ; save our address
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LD E,(IX+12) ; data address
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LD D,(IX+13)
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LD B,(IX+9) ; width
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PUSH BC ; save our column count
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BLPutCharColumnLoop:
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LD B,(IX+11) ; height
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BLPutCharInColumnLoop:
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; gets screen address in HL, and bytes address in DE. Copies the 8 bytes to the screen
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ld a,(DE) ; First Row
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LD (HL),a
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INC DE
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INC H
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ld a,(DE)
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LD (HL),a ; second Row
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INC DE
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INC H
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ld a,(DE)
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LD (HL),a ; Third Row
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INC DE
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INC H
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ld a,(DE)
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LD (HL),a ; Fourth Row
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INC DE
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INC H
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ld a,(DE)
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LD (HL),a ; Fifth Row
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INC DE
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INC H
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ld a,(DE)
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LD (HL),a ; Sixth Row
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INC DE
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INC H
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ld a,(DE)
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LD (HL),a ; Seventh Row
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INC DE
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INC H
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ld a,(DE)
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LD (HL),a ; Eigth Row
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INC DE ; Move to next data item.
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DEC B
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JR Z,BLPutCharNextColumn
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;The following code calculates the address of the next line down below current HL address.
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PUSH DE ; save DE
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ld a,l
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and 224
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cp 224
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jp z,BLPutCharNextThird
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BLPutCharSameThird:
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ld de,-1760
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;and a
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add hl,de
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POP DE ; get our data point back.
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jp BLPutCharInColumnLoop
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BLPutCharNextThird:
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ld de,32
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;and a
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add hl,de
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POP DE ; get our data point back.
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JP BLPutCharInColumnLoop
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BLPutCharNextColumn:
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POP BC
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POP HL
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DEC B
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JP Z, BLPutCharsEnd
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INC L ; Note this would normally be Increase HL - but block painting should never need to increase H, since that would wrap around.
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PUSH HL
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PUSH BC
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JP BLPutCharColumnLoop
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BLPutCharsEnd:
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End Asm
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END SUB
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```
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##Paint
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Prints the colour data to the screen at the given character co-ordinates.
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## Syntax
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```
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paint (x as uByte,y as uByte, width as uByte, height as uByte, attribute as ubyte)
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```
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Where
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* x is the x value in character co-ordinates
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* y is the y value in character co-ordinates
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* width is the width in characters
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* height is the height in characters
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* attribute is the byte value of the attribute to paint to the given co-ordinates. (As one would get from the ATTR function)
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###Usage
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There is a an example program after the source code.
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```
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SUB paint (x as uByte,y as uByte, width as uByte, height as uByte, attribute as ubyte)
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REM Copyleft Britlion. Feel free to use as you will. Please attribute me if you use this, however!
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Asm
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ld a,(IX+7) ;ypos
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rrca
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rrca
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rrca ; Multiply by 32
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ld l,a ; Pass to L
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and 3 ; Mask with 00000011
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add a,88 ; 88 * 256 = 22528 - start of attributes. Change this if you are working with a buffer or somesuch.
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ld h,a ; Put it in the High Byte
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ld a,l ; We get y value *32
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and 224 ; Mask with 11100000
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ld l,a ; Put it in L
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ld a,(IX+5) ; xpos
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add a,l ; Add it to the Low byte
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ld l,a ; Put it back in L, and we're done. HL=Address.
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push HL ; save address
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LD A, (IX+13) ; attribute
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LD DE,32
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LD c,(IX+11) ; height
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BLPaintHeightLoop:
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LD b,(IX+9) ; width
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BLPaintWidthLoop:
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LD (HL),a ; paint a character
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INC L ; Move to the right (Note that we only would have to inc H if we are crossing from the right edge to the left, and we shouldn't be needing to do that)
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DJNZ BLPaintWidthLoop
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BLPaintWidthExitLoop:
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POP HL ; recover our left edge
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DEC C
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JR Z, BLPaintHeightExitLoop
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ADD HL,DE ; move 32 down
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PUSH HL ; save it again
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JP BLPaintHeightLoop
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BLPaintHeightExitLoop:
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end asm
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END SUB
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```
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##PaintData
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Copies the colour data to the screen at the given character co-ordinates.
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The order here is Rows and then Columns; so first row, then second row and so on.
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While this may be awkward, being the other way around to the pixel data, these orders
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are the most efficient speedwise.
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Where
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* x is the x value in character co-ordinates
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* y is the y value in character co-ordinates
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* width is the width in characters
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* height is the height in characters
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* address is the address of the data to copy to the screen's attribute area.
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###Usage
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There is a an example program that uses this at the end of the page.
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```
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paintData (x as uByte,y as uByte, width as uByte, height as uByte, address as uInteger)
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```
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```
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SUB paintData (x as uByte,y as uByte, width as uByte, height as uByte, address as uInteger)
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REM Copyleft Britlion. Feel free to use as you will. Please attribute me if you use this, however!
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Asm
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ld a,(IX+7) ;ypos
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rrca
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rrca
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rrca ; Multiply by 32
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ld l,a ; Pass to L
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and 3 ; Mask with 00000011
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add a,88 ; 88 * 256 = 22528 - start of attributes. Change this if you are working with a buffer or somesuch.
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ld h,a ; Put it in the High Byte
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ld a,l ; We get y value *32
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and 224 ; Mask with 11100000
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ld l,a ; Put it in L
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ld a,(IX+5) ; xpos
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add a,l ; Add it to the Low byte
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ld l,a ; Put it back in L, and we're done. HL=Address.
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push HL ; save address
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LD D, (IX+13)
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LD E, (IX+12)
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LD c,(IX+11) ; height
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BLPaintDataHeightLoop:
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LD b,(IX+9) ; width
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BLPaintDataWidthLoop:
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LD a,(DE)
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LD (HL),a ; paint a character
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INC L ; Move to the right (Note that we only would have to inc H if we are crossing from the right edge to the left, and we shouldn't be needing to do that)
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INC DE
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DJNZ BLPaintDataWidthLoop
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BLPaintDataWidthExitLoop:
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POP HL ; recover our left edge
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DEC C
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JR Z, BLPaintDataHeightExitLoop
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PUSH DE
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LD DE,32
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ADD HL,DE ; move 32 down
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POP DE
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PUSH HL ; save it again
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JP BLPaintDataHeightLoop
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BLPaintDataHeightExitLoop:
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End Asm
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END SUB
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```
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##Example Program
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```
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goto start
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datapoint:
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Asm
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defb 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32
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defb 33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64
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defb 65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96
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defb 97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128
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End Asm
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start:
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cls
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putChars(10,10,3,3,@datapoint)
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paint(10,10,3,3,79)
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```

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