Putchars.bas
Putchars
WARNING: This subroutine does not check to see if it's writing over the edge of the screen. This is done for speed, but it is the user's job to make sure that all data will fit on the screen!
Usage
There is a an example program that uses this at the end of the page.
putChars(x as uByte,y as uByte, width as uByte, height as uByte, dataAddress as uInteger)
Where
- x is the x value in character co-ordinates
- y is the y value in character co-ordinates
- width is the width in characters
- height is the height in characters
- 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.
Prints the graphics data to the screen at the given character co-ordinates.
SUB putChars(x as uByte,y as uByte, width as uByte, height as uByte, dataAddress as uInteger)
' Copyleft Britlion. Feel free to use as you will. Please attribute me if you use this, however!
Asm
BLPutChar:
LD a,(IX+5)
;AND 31
ld l,a
ld a,(IX+7) ; Y value
ld d,a
AND 24
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.
ld h,a
ld a,d
AND 7
rrca
rrca
rrca
OR l
ld l,a
PUSH HL ; save our address
LD E,(IX+12) ; data address
LD D,(IX+13)
LD B,(IX+9) ; width
PUSH BC ; save our column count
BLPutCharColumnLoop:
LD B,(IX+11) ; height
BLPutCharInColumnLoop:
; gets screen address in HL, and bytes address in DE. Copies the 8 bytes to the screen
ld a,(DE) ; First Row
LD (HL),a
INC DE
INC H
ld a,(DE)
LD (HL),a ; second Row
INC DE
INC H
ld a,(DE)
LD (HL),a ; Third Row
INC DE
INC H
ld a,(DE)
LD (HL),a ; Fourth Row
INC DE
INC H
ld a,(DE)
LD (HL),a ; Fifth Row
INC DE
INC H
ld a,(DE)
LD (HL),a ; Sixth Row
INC DE
INC H
ld a,(DE)
LD (HL),a ; Seventh Row
INC DE
INC H
ld a,(DE)
LD (HL),a ; Eigth Row
INC DE ; Move to next data item.
DEC B
JR Z,BLPutCharNextColumn
;The following code calculates the address of the next line down below current HL address.
PUSH DE ; save DE
ld a,l
and 224
cp 224
jp z,BLPutCharNextThird
BLPutCharSameThird:
ld de,-1760
;and a
add hl,de
POP DE ; get our data point back.
jp BLPutCharInColumnLoop
BLPutCharNextThird:
ld de,32
;and a
add hl,de
POP DE ; get our data point back.
JP BLPutCharInColumnLoop
BLPutCharNextColumn:
POP BC
POP HL
DEC B
JP Z, BLPutCharsEnd
INC L ; Note this would normally be Increase HL - but block painting should never need to increase H, since that would wrap around.
PUSH HL
PUSH BC
JP BLPutCharColumnLoop
BLPutCharsEnd:
End Asm
END SUB
Paint
Prints the colour data to the screen at the given character co-ordinates.
Syntax
paint (x as uByte,y as uByte, width as uByte, height as uByte, attribute as ubyte)
Where * x is the x value in character co-ordinates * y is the y value in character co-ordinates * width is the width in characters * height is the height in characters * attribute is the byte value of the attribute to paint to the given co-ordinates. (As one would get from the ATTR function)
Usage
There is a an example program after the source code.
SUB paint (x as uByte,y as uByte, width as uByte, height as uByte, attribute as ubyte)
REM Copyleft Britlion. Feel free to use as you will. Please attribute me if you use this, however!
Asm
ld a,(IX+7) ;ypos
rrca
rrca
rrca ; Multiply by 32
ld l,a ; Pass to L
and 3 ; Mask with 00000011
add a,88 ; 88 * 256 = 22528 - start of attributes. Change this if you are working with a buffer or somesuch.
ld h,a ; Put it in the High Byte
ld a,l ; We get y value *32
and 224 ; Mask with 11100000
ld l,a ; Put it in L
ld a,(IX+5) ; xpos
add a,l ; Add it to the Low byte
ld l,a ; Put it back in L, and we're done. HL=Address.
push HL ; save address
LD A, (IX+13) ; attribute
LD DE,32
LD c,(IX+11) ; height
BLPaintHeightLoop:
LD b,(IX+9) ; width
BLPaintWidthLoop:
LD (HL),a ; paint a character
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)
DJNZ BLPaintWidthLoop
BLPaintWidthExitLoop:
POP HL ; recover our left edge
DEC C
JR Z, BLPaintHeightExitLoop
ADD HL,DE ; move 32 down
PUSH HL ; save it again
JP BLPaintHeightLoop
BLPaintHeightExitLoop:
end asm
END SUB
PaintData
Copies the colour data to the screen at the given character co-ordinates. The order here is Rows and then Columns; so first row, then second row and so on. While this may be awkward, being the other way around to the pixel data, these orders are the most efficient speedwise.
Where * x is the x value in character co-ordinates * y is the y value in character co-ordinates * width is the width in characters * height is the height in characters * address is the address of the data to copy to the screen's attribute area.
Usage
There is a an example program that uses this at the end of the page.
paintData (x as uByte,y as uByte, width as uByte, height as uByte, address as uInteger)
SUB paintData (x as uByte,y as uByte, width as uByte, height as uByte, address as uInteger)
REM Copyleft Britlion. Feel free to use as you will. Please attribute me if you use this, however!
Asm
ld a,(IX+7) ;ypos
rrca
rrca
rrca ; Multiply by 32
ld l,a ; Pass to L
and 3 ; Mask with 00000011
add a,88 ; 88 * 256 = 22528 - start of attributes. Change this if you are working with a buffer or somesuch.
ld h,a ; Put it in the High Byte
ld a,l ; We get y value *32
and 224 ; Mask with 11100000
ld l,a ; Put it in L
ld a,(IX+5) ; xpos
add a,l ; Add it to the Low byte
ld l,a ; Put it back in L, and we're done. HL=Address.
push HL ; save address
LD D, (IX+13)
LD E, (IX+12)
LD c,(IX+11) ; height
BLPaintDataHeightLoop:
LD b,(IX+9) ; width
BLPaintDataWidthLoop:
LD a,(DE)
LD (HL),a ; paint a character
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)
INC DE
DJNZ BLPaintDataWidthLoop
BLPaintDataWidthExitLoop:
POP HL ; recover our left edge
DEC C
JR Z, BLPaintDataHeightExitLoop
PUSH DE
LD DE,32
ADD HL,DE ; move 32 down
POP DE
PUSH HL ; save it again
JP BLPaintDataHeightLoop
BLPaintDataHeightExitLoop:
End Asm
END SUB
Example Program
goto start
datapoint:
Asm
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
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
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
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
End Asm
start:
cls
putChars(10,10,3,3,@datapoint)
paint(10,10,3,3,79)