PropPrint.bas
This proportional printing routine is ideal for making text more readable. Do NOT use it for tables - letter positions move around within the lines depending what the text is. For tables, use a fixed width routine - either the system 32 chars per line, or the 42 chars per line version listed in the library.
usage
propPrint(xPosition, yPosition, SizeOfSpaceCharacter, GapBetweenLetters, "Text")
Note: X and Y are pixel positions. Note that unlike Print and Print42, this routine in in the form (x,y), not (y,x). That can easily be changed in the declaration below. [Just swap x and y].
SizeOfSpaceCharacter is the width of a space.
GapBetweenLetters can be as small as zero - though the letters crash into each other,
so it doesn't look wonderful. 1 pixel is probably the most common setting for this.
Text is anything that's valid as a string - either a String literal, or a variable.
' Proportional printing anywhere on screen.
' Original routine by Christoph Odenthal (Odin)
' ZXBC modification by Leszek Chmielewski (LCD)
' Thanks to Boriel and Britlion for help and hints
sub propPrint(x as ubyte,y as ubyte,spacesize as ubyte, xgap as ubyte,txt$ as string)
dim b$ as string '
b$=txt$+chr(0)
poke Uinteger @PropPrintTxtadr,PEEK(Uinteger, @b$)+2 'textadr
poke @PropPrintTxtadr+2,x
poke @PropPrintTxtadr+3,y
poke @PropPrintTxtadr+4,spacesize
poke @PropPrintTxtadr+5,xgap
PropPrint:
Asm
;' --------------------------------
;' Free Size N Place Text Print
;' --------------------------------
;' (c) 14.09.2002 C.Odenthal
;'
;' Last Modifications: 15.10.2002
;' Modification for Boriels ZXBC
;' By Leszek Chmielewski 02.06.2010
;' --------------------------------
;' ORG 32000
;' DUMP 45000
;' --------------------------------
;' Entry point
;' --------------------------------
Start:
JR Start2
;' --------------------------------
;' Parameter
;' --------------------------------
end asm
PropPrintTxtadr:
asm
text_addr:
DEFW 0 ;' Addr of text
x_pos:
DEFB 4 ;' Pos of text
y_pos:
DEFB 4
spc_size:
DEFB 3 ;' Width of space char
x_gap:
DEFB 1 ;' Gap between chars
y_gap:
DEFB 1 ;' Gap between lines
end_symb:
DEFB 0 ;' End of line char code
x_start:
DEFB 0 ;' Start of window
y_start:
DEFB 0
x_end:
DEFB 255 ;' End of window
y_end:
DEFB 191
x_zoom:
DEFB 1 ;' Zooming factor
y_zoom:
DEFB 1
;' --------------------------------
;' Main routine
;' --------------------------------
Start2:
LD A,(x_pos) ;' Calc. scr addr.
LD B,A
LD A,(y_pos)
LD C,A
CALL PosToScr
LD (scr_ad),DE ;' Store scr addr.
LD A,L
LD (pix_pos),A
LD A,(end_symb) ;' Get line ending char
LD (poke_here+1),A ;' Poke it into memory below
LD HL,(text_addr)
Main_Loop:
LD A,(HL);' Get char
poke_here:
CP 0 ;' End of text? (poked!)
JP Z,Exit1
INC HL
PUSH HL
CP 32 ;' Replace ctrl chars
JP NC,No_Ctrl
LD A,32
No_Ctrl:
CALL Copy_Chr ;' Copy char-gfx to work-buffer
CALL Measure ;' Measure left rim + width
PUSH BC ;' (Save results)
LD A,C ;' No pixel set in char?
AND A
JP Z,Space_Chr
LD A,(pix_pos);' size+bitpos (=1..15)
ADD A,C
CP 9 ;' > 8 ?
JP NC,Overlap ;' Char overlaps
;' Calculate 8 bit rotation
LD A,(pix_pos) ;' bitpos-l_rim (=-7..7)
SUB B
AND A ;' = 0 ?
JP Z,PrintIt8
JP C,Neg_8 ;' < 0 ?
;' --------------------------------
CP 5 ;' Not in 1..4 ?
JP NC,Left_8
;' --------------------------------
LD B,A
CALL Chr_Rgt8 ;' Rotate right 8 bit
JP PrintIt8
;' --------------------------------
Left_8:
NEG ;' = 8 - A
ADD A,8
LD B,A
CALL Chr_Left8 ;' Rotate left 8 bit
JP PrintIt8
;' --------------------------------
Neg_8:
NEG
CP 5 ;' Not in 1..4 ?
JP NC,Right_8
;' --------------------------------
LD B,A
CALL Chr_Left8 ;' Rotate left 8 bit
JP PrintIt8
;' --------------------------------
Right_8:
NEG ;' = 8 - A
ADD A,8
LD B,A
CALL Chr_Rgt8 ;' Rotate right 8 bit
JP PrintIt8
;' --------------------------------
;' Calculate 16 bit rotation
;' --------------------------------
Overlap:
LD A,(pix_pos);' bitpos-l_rim (=-7..7)
SUB B
AND A ;' = 0 ?
JP Z,PrintIt8
;' --------------------------------
LD B,A
CALL Chr_Rgt16 ;' Rotate right 16 bit
PrintIt16:
LD DE,(scr_ad);' Check for screen end
LD A,E
AND 31
CP 31 ;' (2nd byte outside ?)
JP Z,Outside
CALL Print16 ;' Display char (16 bit)
JP Next_Loc
;' --------------------------------
PrintIt8:
LD DE,(scr_ad);' Display char (8 bit)
CALL Print8
JP Next_Loc
;' --------------------------------
Space_Chr:
LD A,(spc_size);' Skip pixels
LD DE,(scr_ad);' Get screen addr.
POP BC ;' Throw away values
LD B,0
LD C,A
JP Next_Loc2
;' --------------------------------
Next_Loc:
POP BC ;' Move to next char location
Next_Loc2:
LD A,(pix_pos);' =bitpos+x_gap+size
LD L,A
LD A,(x_gap)
ADD A,L
ADD A ,C
LD L ,A
AND 7 ;' New pix_pos
LD (pix_pos),A
LD H,0 ;' =result/8
SRL L
SRL L
SRL L
ADD HL,DE ;' New byte pos
LD A ,E ;' Check for screen end
AND 31
LD E,A
LD A,L
AND 31
CP E ;' New pos smaller than old ?
JP C ,Exit2 ;' -> End of printing
LD (scr_ad),HL ;' Store new scr ad.
POP HL ;' Restore text pointer
JP Main_Loop
;' --------------------------------
Outside:
POP BC ;' Stop printing
POP HL ;' Char not printed!
DEC HL
JP Exit1
;' --------------------------------
Exit2:
POP HL ;' Return nr of printed chars
Exit1:
LD DE,(text_addr)
XOR A
SBC HL,DE
LD B,H ;' Return value in BC to Basic
LD C,L
jp PropPrintTxtadr2
;' --------------------------------
;' Calc. scr adr from x,y
;' --------------------------------
;' In : B = x / C = y (preserved)
;' Out: DE = scr adr / L = pixpos
;' Usd: A, BC, DE, L
;' --------------------------------
PosToScr:
LD A,C ;' Range check
CP 185
JP C,ValOk
LD C,184
ValOk:
LD A,B ;' Pix pos
AND 7
LD L,A
LD E,B
SRL E
SRL E
SRL E
LD A,C ;' Scr pos
AND 7
LD D,A
LD A,C
AND 56
RLA
RLA
OR E
LD E,A
LD A,C
AND 192
RRA
RRA
RRA
OR D
OR 64
LD D,A
RET
;' --------------------------------
;' Copy char into buffer
;' --------------------------------
;' In : A = Char
;' Out: -
;' Usd: A, HL, DE, BC
;' --------------------------------
Copy_Chr:
LD DE,(23606);' SysVar CHARS
LD H,0
LD L,A
ADD HL,HL ;' * 8
ADD HL,HL
ADD HL,HL
ADD HL,DE ;' + Chartable
EX DE,HL
LD HL,Chr_Buf
LD B,8
Copy_Loop:
LD A,(DE);' Double to 16 pixel/row
INC DE
LD (HL),A ;' Low-byte in memory!
INC HL
LD (HL),0 ;' High-byte in memory!
INC HL
DJNZ Copy_Loop
RET
;' --------------------------------
;' Measure left border and width
;' --------------------------------
;' In : -
;' Out: B = left rim / C = width
;' Usd: A, HL, BC
;' --------------------------------
Measure:
LD HL,Chr_Buf ;' "OR" together all 8 bytes
LD B,8
XOR A
Msr_Loop:
OR (HL)
INC HL
INC HL
DJNZ Msr_Loop
LD BC,0
AND A ;' Check if zero
RET Z
Msr_Loop2:
INC B ;' Measure left border
RLCA
JP NC,Msr_Loop2
RRCA
DEC B
LD C,9 ;' Measure width
Msr_Loop3:
DEC C
RRCA
JP NC,Msr_Loop3
RET
;' --------------------------------
;' Move char to left, 8 bit
;' --------------------------------
;' In : B = Nr of bits to shift
;' Out: -
;' Usd: A, B, HL
;' --------------------------------
Chr_Left8:
PUSH BC
LD HL,Chr_Buf ;' Rotate char left 8 bit
LD C,B ;' 1st row
LD A,(HL )
Chr_LLp1:
RLCA
DJNZ Chr_LLp1
LD (HL),A
LD B,C
INC HL
INC HL
LD C,B ;' 2nd row
LD A,(HL)
Chr_LLp2:
RLCA
DJNZ Chr_LLp2
LD (HL),A
LD B,C
INC HL
INC HL
LD C,B ;' 3rd row
LD A ,(HL)
Chr_LLp3:
RLCA
DJNZ Chr_LLp3
LD (HL),A
LD B,C
INC HL
INC HL
LD C,B ;' 4th row
LD A,(HL)
Chr_LLp4:
RLCA
DJNZ Chr_LLp4
LD (HL),A
LD B,C
INC HL
INC HL
LD C,B ;' 5th row
LD A,(HL)
Chr_LLp5:
RLCA
DJNZ Chr_LLp5
LD (HL),A
LD B,C
INC HL
INC HL
LD C,B ;' 6th row
LD A,(HL)
Chr_LLp6:
RLCA
DJNZ Chr_LLp6
LD (HL),A
LD B,C
INC HL
INC HL
LD C,B ;' 7th row
LD A,(HL)
Chr_LLp7:
RLCA
DJNZ Chr_LLp7
LD (HL),A
LD B,C
INC HL
INC HL
LD C,B ;' 8th row
LD A,(HL)
Chr_LLp8:
RLCA
DJNZ Chr_LLp8
LD (HL),A
LD B,C
POP BC
RET
;' --------------------------------
;' Move char to right, 8 bit
;' --------------------------------
;' In : B = Nr of bits to shift
;' Out: -
;' Usd: A, B, HL
;' --------------------------------
Chr_Rgt8:
PUSH BC
LD HL,Chr_Buf ;' Rotate char right 8 bit
LD C,B ;' 1st row
LD A,(HL)
Chr_RLp1:
RRCA
DJNZ Chr_RLp1
LD (HL),A
LD B,C
INC HL
INC HL
LD C,B ;' 2nd row
LD A,(HL)
Chr_RLp2:
RRCA
DJNZ Chr_RLp2
LD (HL),A
LD B,C
INC HL
INC HL
LD C,B ;' 3rd row
LD A,(HL)
Chr_RLp3:
RRCA
DJNZ Chr_RLp3
LD (HL),A
LD B,C
INC HL
INC HL
LD C,B ;' 4th row
LD A,(HL)
Chr_RLp4:
RRCA
DJNZ Chr_RLp4
LD (HL),A
LD B,C
INC HL
INC HL
LD C,B ;' 5th row
LD A,(HL)
Chr_RLp5:
RRCA
DJNZ Chr_RLp5
LD (HL),A
LD B,C
INC HL
INC HL
LD C,B ;' 6th row
LD A ,(HL )
Chr_RLp6:
RRCA
DJNZ Chr_RLp6
LD (HL),A
LD B,C
INC HL
INC HL
LD C,B ;' 7th row
LD A,(HL)
Chr_RLp7:
RRCA
DJNZ Chr_RLp7
LD (HL),A
LD B,C
INC HL
INC HL
LD C,B ;' 8th row
LD A,(HL)
Chr_RLp8:
RRCA
DJNZ Chr_RLp8
LD (HL),A
LD B,C
POP BC
RET
;' --------------------------------
;' Move char to right 16 bit
;' --------------------------------
;' In : B = Nr of bits to shift
;' Out:
;' Usd: A, B, HL
;' --------------------------------
Chr_Rgt16:
LD HL,(Chr_Buf);' Rotate char right 16 bit
LD A,B ;' 1st row
Chr_R2Lp1:
SRL L
RR H ;' Insert carry
DJNZ Chr_R2Lp1
LD B,A
LD (Chr_Buf),HL
LD HL,(Chr_Buf+2);' 2nd row
LD A,B
Chr_R2Lp2:
SRL L
RR H ;' Insert carry
DJNZ Chr_R2Lp2
LD B,A
LD (Chr_Buf+2),HL
LD HL,(Chr_Buf+4);' 3rd row
LD A,B
Chr_R2Lp3:
SRL L
RR H ;' Insert carry
DJNZ Chr_R2Lp3
LD B,A
LD (Chr_Buf+4),HL
LD HL,(Chr_Buf+6);' 4th row
LD A,B
Chr_R2Lp4:
SRL L
RR H ;' Insert carry
DJNZ Chr_R2Lp4
LD B,A
LD (Chr_Buf+6),HL
LD HL,(Chr_Buf+8);' 5th row
LD A,B
Chr_R2Lp5:
SRL L
RR H ;' Insert carry
DJNZ Chr_R2Lp5
LD B,A
LD (Chr_Buf+8),HL
LD HL,(Chr_Buf+10);' 6th row
LD A,B
Chr_R2Lp6:
SRL L
RR H ;' Insert carry
DJNZ Chr_R2Lp6
LD B,A
LD (Chr_Buf+10),HL
LD HL,(Chr_Buf+12);' 7th row
LD A,B
Chr_R2Lp7:
SRL L
RR H ;' Insert carry
DJNZ Chr_R2Lp7
LD B,A
LD (Chr_Buf+12),HL
LD HL,(Chr_Buf+14);' 8th row
LD A,B
Chr_R2Lp8:
SRL L
RR H ;'Insert carry
DJNZ Chr_R2Lp8
LD B,A
LD (Chr_Buf+14),HL
RET
;' --------------------------------
;' Print 8 bit wide char on screen
;' --------------------------------
;' In : DE = screen adr.
;' Out: -
;' Usd: A, HL, DE, B
;' --------------------------------
Print8:
LD HL,Chr_Buf
PUSH DE ;' save scr ad.
EX DE,HL
LD B,8 ;' 8 lines
Prt8_L:
LD A,(DE);' set 1 byte
XOR (HL)
LD (HL),A
INC DE ;' skip 1 byte
INC DE ;' next byte
INC H ;' calc. next line
LD A,H
AND 7
JP NZ,Prt8_C
LD A,L
ADD A,32
LD L,A
JR C,Prt8_C
LD A,H
SUB 8
LD H,A
Prt8_C:
DJNZ Prt8_L ;' next round
POP DE ;' restore scr ad.
RET
;'--------------------------------
;' Print 16 bit wide char on screen
;' --------------------------------
;' In : DE = screen adr.
;' Out: -
;' Usd: A, HL, DE, B
;' --------------------------------
Print16:
LD HL,Chr_Buf
PUSH DE ;' save scr ad.
EX DE,HL
LD B,8 ;' 8 lines
Prt16_L:
LD A,(DE);' set 1 byte
XOR (HL)
LD (HL),A
INC HL ;' next scr pos
INC DE ;' next byte
LD A,(DE);' set 1 byte
XOR (HL)
LD (HL),A
DEC HL ;' prev scr pos
INC DE ;' next byte
INC H ;' calc. next line
LD A,H
AND 7
JP NZ,Prt16_C
LD A,L
ADD A,32
LD L,A
JR C,Prt16_C
LD A,H
SUB 8
LD H,A
Prt16_C:
DJNZ Prt16_L ;' next round
POP DE ;' restore scr ad.
RET
;' --------------------------------
;' Variables
;' --------------------------------
Chr_Buf:
DEFS 16
scr_ad:
DEFW 0
pix_pos:
DEFB 0
;' -----------------
PropPrintTxtadr2:
end asm
end sub