; Copyright 1996 Acorn Computers Ltd
;
; Licensed under the Apache License, Version 2.0 (the "License");
; you may not use this file except in compliance with the License.
; You may obtain a copy of the License at
;
; http://www.apache.org/licenses/LICENSE-2.0
;
; Unless required by applicable law or agreed to in writing, software
; distributed under the License is distributed on an "AS IS" BASIS,
; WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
; See the License for the specific language governing permissions and
; limitations under the License.
;
; > $.Source.Vdu5
; *****************************************************************************
;
; Print a character in VDU 5 mode
;
; *****This file has been extensively modified by DJS
; Alter these at your peril !
cxl RN 0
scr RN 0
ecfptr RN 1
cword0 RN 1
cyb RN 2
cyt2 RN 2
scrend RN 2
cword1 RN 2
cxr RN 3
cyb2 RN 3
ormask RN 3
cxl2 RN 4
eormask RN 4
cyb3 RN 5
charmsk RN 5
cword2 RN 5
cyt RN 6
llength RN 6
chartmp RN 6
sizex RN 7
charptr RN 7
sizey RN 8
invcharshf RN 8
charbyte RN 9
cxr2 RN 10
charshf RN 10
lgBPC RN 11
Vdu5Wrch
Push R14
BL Vdu5DoChar
Pull R14
B PostCharMove
; Vdu23_18
; LDR R0, [WsPtr, #QQ+1]
Vdu5DoChar
ADD ecfptr, WsPtr, #FgEcfOraEor ;Base address of OR/EOR pairs
Vdu5DoChar10
Push "R14"
MOV charbyte, R0 ;Put character out of harm's
; way
ASSERT cxl < cyt
ASSERT GCsIY = GCsIX +4
ADD cxl, WsPtr, #GCsIX
LDMIA cxl, {cxl, cyt} ; cxl=where left pixel would be
; cyt=where top pixel would be
ASSERT sizex < sizey
ADD sizex, WsPtr, #GCharSizes
LDMIA sizex, {sizex, sizey}
CMP sizey, #16 ; if SizeY=8 or SizeY=16
TEQNE sizey, #8 ; (leaving CS <=> SizeY=16)
TEQEQ sizex, #8 ; and SizeX=8, then do it fast
BNE SlowVdu5 ; else do by scaled char
TEQ charbyte, #127 ; Which font do we use?
ADDNE charptr, WsPtr, #(Font-32*8) ; Soft if character not DELETE
ADREQL charptr, HardFont-32*8 ; Hard if character is DELETE
ADD charptr, charptr, charbyte, LSL #3 ;Point at char def
MOVCS charptr, charptr, ASL #1 ; Double address if SizeY = 16
SUBCS charptr, charptr, #1 ; (tricky code, originally
; designed by TMD)
SUB cyb, cyt, sizey
ADD cyb, cyb, #1 ; where bottom pixel would be
ADD cxr, cxl, #7 ; where right pixel would be
ASSERT GWBRow = GWLCol+4
ASSERT GWRCol = GWLCol+8
ASSERT GWTRow = GWLCol+12
ASSERT cyb3 > cxl2
ASSERT cxr2 > cyb3
ASSERT R14 > cxr2
ADD cxl2, WsPtr, #GWLCol
LDMIA cxl2, {cxl2, cyb3, cxr2, R14}
Greatest cxl2, cxl2, cxl ; cxl2 := windowed left
; (2 instructions)
Least cxr2, cxr2, cxr ; cxr2 := windowed right
; (2 instructions)
Greatest cyb2, cyb3, cyb ; cyb2 := windowed bottom
; (3 instructions)
Least cyt2, R14, cyt ; cyt2 := windowed top
; (3 instructions)
SUBS cyb2, cyt2, cyb2 ; top >= bottom ?
CMPGE cxr2, cxl2 ; and right >= left ?
Pull "PC", LT ; Exit if not. Otherwise cyb2
; has become clipped height
LDR R14, [WsPtr, #CursorFlags] ; update changed box, if wanted
TST R14, #ClipBoxEnableBit
BLNE ClipVdu5
ADD charptr, charptr, cyt ; adjust charptr to point at
SUB charptr, charptr, cyt2 ; first used row of character
MOV charmsk, #&FF ; Produce mask to do left/right
SUB R14, cxl2, cxl ; clipping
MOV charmsk, charmsk, LSR R14
SUB R14, cxr2, cxl2
ADD R14, R14, #1
BIC charmsk, charmsk, charmsk, LSR R14
TEQ sizey, #16 ; If double height, signal this
ORREQ charmsk, charmsk, #1:SHL:31 ; by making charmsk negative
ASSERT llength > scr
ASSERT LineLength = YWindLimit+4
LDR lgBPC, [WsPtr, #Log2BPC] ; Address point at (cxl, cyt2),
MOV charshf, cxl, LSL lgBPC ; putting address in scr, bit
ADD scr, WsPtr, #YWindLimit ; offset in charshf and
LDMIA scr, {scr, llength} ; adjusting ecfptr
SUB scr, scr, cyt2
AND R14, scr, #7
ADD ecfptr, ecfptr, R14, LSL #3
LDR R14, [WsPtr, #ScreenStart]
MLA scr, llength, scr, R14
MOV R14, charshf, ASR #5
ADD scr, scr, R14, LSL #2
AND charshf, charshf, #31
MLA scrend, llength, cyb2, scr ;Calculate terminating address
RSB invcharshf, charshf, #32 ;And inverse shift
Vdu5NextLine
ASSERT eormask > ormask
LDMIA ecfptr!, {ormask, eormask} ;Pick up ecf info and advance
TST ecfptr, #63 ; ecf pointer, wrapping if
SUBEQ ecfptr, ecfptr, #64 ; necessary
ASSERT HardFont < &40000000 :LOR: HardFont >= &C0000000
ASSERT WsPtr < &40000000 :LOR: WsPtr >= &C0000000
TEQ charmsk, #0 ; Double height? (MI=yes)
LDRMIB charbyte, [charptr, -charptr, ASR #1] ; Use ASR, as font will be at
LDRPLB charbyte, [charptr] ; top or bottom of memory (zero page,
ADD charptr, charptr, #1 ; system heap or ROM)
ANDS charbyte, charbyte, charmsk ;Clip left & right; skip loop
BEQ Vdu5TryNextLine ; body if nothing to plot
Push "ecfptr,scrend,charmsk,llength,charptr"
LDR R14, [WsPtr, #TextExpandArea] ;Address correct expansion
ADD charptr, charbyte, #&100 ; table entry, assuming that
ADD charptr, R14, charptr, LSL lgBPC ; this is not mode 10 or greater
CMP lgBPC, #1 ;Pick up this entry:
LDRLSB cword0, [charptr, #0] ; 1 byte if lgBPC = 0
LDREQB R14, [charptr, #1] ; 2 bytes if lgBPC = 1
ORREQ cword0, cword0, R14, LSL #8
MOV cword1, #0
BLS Vdu5DoOneWord
CMP lgBPC, #3
LDRLO cword0, [charptr, #0] ; 1 word if lgBPC = 2
BLO Vdu5DoOneWord
BHI Vdu5Mode10 ; 4 words if lgBPC = 4
LDMIA charptr, {cword0, cword1} ; 2 words if lgBPC = 3
MOVS cword2, cword1, LSR invcharshf
MACRO
$l DoVdu5Word $c, $reg, $off
$l
LDR$c chartmp, [scr, #$off]
AND$c R14, ormask, $reg
ORR$c chartmp, chartmp, R14
AND$c R14, eormask, $reg
EOR$c chartmp, chartmp, R14
STR$c chartmp, [scr, #$off]
MEND
Vdu5DoTwoWords
DoVdu5Word NE, cword2, 8
MOV cword1, cword1, LSL charshf
Vdu5DoOneWord
ORRS cword1, cword1, cword0, LSR invcharshf
DoVdu5Word NE, cword1, 4
MOVS cword0, cword0, LSL charshf
DoVdu5Word NE, cword0, 0
Vdu5LinePainted
Pull "ecfptr,scrend,charmsk,llength,charptr"
Vdu5TryNextLine
TEQ scr, scrend
ADDNE scr, scr, llength
BNE Vdu5NextLine
Pull "PC"
; This is mode 10 (or similar) - we must do bit expansion on the fly
Vdu5Mode10
CMP lgBPC, #5 ; is this a 32 bit per pixel mode, if so then ignore the
BEQ Vdu5Mode32 ; existing code and use a newer function
ADRL charptr, C16BTab
AND R14, charbyte, #&0F
ADD R14, charptr, R14, LSL #3
LDMIA R14, {cword0, cword1}
MOVS cword2, cword1, LSR invcharshf
DoVdu5Word NE, cword2, 16
MOV cword1, cword1, LSL charshf
ORRS cword1, cword1, cword0, LSR invcharshf
DoVdu5Word NE, cword1, 12
MOVS cword2, cword0, LSL charshf
AND R14, charbyte, #&F0
ADD R14, charptr, R14, LSR #1
LDMIA R14, {cword0, cword1}
ORRS cword2, cword2, cword1, LSR invcharshf
B Vdu5DoTwoWords
; Expand the character data out to 32 bit per pixel (mode 48 or similar)
MACRO
$l PixMunge32 $reg, $mask, $offset
$l
TST $reg, #$mask
LDRNE chartmp, [scr, #$offset]
ORRNE chartmp, chartmp, ormask
EORNE chartmp, chartmp, eormask
STRNE chartmp, [scr, #$offset]
MEND
MACRO
$l PixSolid32 $reg, $mask, $offset
$l
TST $reg, #$mask
STRNE chartmp, [scr, #$offset]
MEND
; Perform bit expansion on the fly, this is a word based operation, no need to
; extract sub-pixels from the ORR / EOR masks, simply perform the bit test and
; then write the character data to the screen!
Vdu5Mode32
[ AvoidScreenReads
CMP ormask, #&FFFFFFFF
BNE Vdu5Mode32_NotSolid
MVN chartmp, eormask
PixSolid32 charbyte, 1<<7, 0
PixSolid32 charbyte, 1<<6, 4
PixSolid32 charbyte, 1<<5, 8
PixSolid32 charbyte, 1<<4, 12
PixSolid32 charbyte, 1<<3, 16
PixSolid32 charbyte, 1<<2, 20
PixSolid32 charbyte, 1<<1, 24
PixSolid32 charbyte, 1<<0, 28
B Vdu5LinePainted
Vdu5Mode32_NotSolid
]
PixMunge32 charbyte, 1<<7, 0
PixMunge32 charbyte, 1<<6, 4
PixMunge32 charbyte, 1<<5, 8
PixMunge32 charbyte, 1<<4, 12
PixMunge32 charbyte, 1<<3, 16
PixMunge32 charbyte, 1<<2, 20
PixMunge32 charbyte, 1<<1, 24
PixMunge32 charbyte, 1<<0, 28
B Vdu5LinePainted ; flow down and try the next line
; *****************************************************************************
;
; Slow VDU 5 - Print char by scaled method (in SprExtend)
;
; in: R1 (ecfptr) = pointer to ecf pattern
; R7 (sizex) = SizeX
; R8 (sizey) = SizeY
; R9 (charbyte) = character to plot
;
; Stack: Return address
;
ASSERT ecfptr = R1
ASSERT sizex = R7
ASSERT sizey = R8
ASSERT charbyte = R9
SlowVdu5 ROUT
MOV R10, R1 ; R10 := ecfptr
; now save current GCOL on stack if necessary
ADD R11, WsPtr, #FgEcfOraEor
TEQ R10, R11 ; if going to use this one
BEQ %FT20 ; then skip
MOV R0, #64 ; 64 bytes
10
LDMIA R11, {R3-R6} ; copy old GCOL into stack
Push "R3-R6" ; frame, reversing order of
; 16 byte chunks
LDMIA R10!, {R3-R6} ; copy new colour
STMIA R11!, {R3-R6} ; into GCOL
SUBS R0, R0, #16
BNE %BT10
20
MOV R4, #8
MOV R5, #8
Push "R4,R5"
Push "R7,R8"
MOV R6, R13 ; R6 -> scaling block
SUB R1, R8, #1 ; SizeY-1
LDR R5, [WsPtr, #YEigFactor]
ADD R3, WsPtr, #GCsX
LDMIA R3, {R3, R4} ; R3 = ext X; R4 = ext Y (top)
SUB R4, R4, R1, LSL R5 ; R4 = ext Y (bottom)
MOV R1, R9 ; R1 = char
MOV R0, #SpriteReason_PaintCharScaled
SWI XOS_SpriteOp
ADD R13, R13, #4*4 ; junk scaling block
TEQ R10, R11 ; if we didn't copy GCOLs
Pull "PC", EQ ; then return, else copy back
MOV R0, #64
30
Pull "R3-R6" ; Reverse order of 16 byte
STMDB R11!, {R3-R6} ; chunks during copy again
SUBS R0, R0, #16
BNE %BT30
Pull PC
; *****************************************************************************
;
; VDU 5 - Start printing text at graphics cursor
ENQ
GraphicsMode R0
MOVNE PC, R14
MOV R1, #0
BSR CursorOnOff ; turn cursor off without
; saving to copy
LDR R6, [WsPtr, #CursorFlags]
ORR R6, R6, #Vdu5Bit
B R6toCursorFlags
; *****************************************************************************
;
; VDU 4 - Return to printing text at text cursor
EOT
GraphicsMode R0
MOVNE PC,LR
MOV R1, #1
BSR CursorOnOff ; restore cursor from copy
LDR R6, [WsPtr, #CursorFlags]
BIC R6, R6, #Vdu5Bit
B R6toCursorFlags
; *****************************************************************************
;
; Vdu5HT - Move cursor "right" when in VDU 5 mode
;
; in: R6 = CursorFlags
Vdu5HT
Push R14
BL GCursorMove ; try to move in +ve X direction
BCC EndVdu5HT ; if successful, finish
BL GCursorB0 ; else move cursor to -ve X boundary
Vdu5HT10
EOR R6, R6, #8 ; change to +ve Y direction
BL GCursorMove ; try to move in that direction
BLCS GCursorB0 ; if unsuccessful, move to -ve Y bdy
EndVdu5HT
Pull R14
B IEG
; *****************************************************************************
;
; Vdu5BS - Move cursor "left" when in VDU 5 mode
;
; in: R6 = CursorFlags
Vdu5BS
EOR R6, R6, #6 ; go to -ve X direction
B Vdu5HT ; dead easy, huh ?
; *****************************************************************************
;
; Vdu5LF - Move cursor "down" when in VDU 5 mode
;
; in: R6 = CursorFlags
Vdu5LF
Push R14
B Vdu5HT10
; *****************************************************************************
;
; Vdu5VT - Move cursor "up" when in VDU 5 mode
;
; in: R6 = CursorFlags
Vdu5VT
EOR R6, R6, #6 ; go to -ve Y direction (eventually)
B Vdu5LF
; *****************************************************************************
;
; Vdu5CR - Carriage return in VDU 5 mode
;
; in: R6 = CursorFlags
Vdu5CR
BSR GCursorB0
B IEG
; *****************************************************************************
;
; Vdu5FF - Clear screen in VDU 5 mode
;
; in: R6 = CursorFlags
Vdu5FF
BSR Home
B CLG
; *****************************************************************************
;
; Vdu5TAB - TAB(X,Y) in VDU 5 mode
;
; in: R0 = X, R1 = Y, R6 = CursorFlags
Vdu5TAB
BSR GCursorBdy
EOR R6, R6, #8
MOV R0, R1
BSR GCursorBdy
B IEG
; *****************************************************************************
;
; Vdu5Delete - Delete in VDU 5 mode (already done backspace)
;
; in: R6 = CursorFlags
Vdu5Delete
ADD ecfptr, WsPtr, #BgEcfStore ; STORE background colour/ecf
MOV R0, #127 ; uses hard font for this char
B Vdu5DoChar10
; *****************************************************************************
;
; GCursorMove - Move graphics cursor in direction specified by R6
; (0,4 = right; 2,6 = left; 8,10 = down; 12,14 = up)
; R6 is preserved
GCursorMove
ADD R0, WsPtr, #GCsIX
LDMIA R0, {R0, R1} ; R0 = GCsIX; R1 = GCsIY
ADD R2, WsPtr, #GCharSpacing+8 ; +8 needed to address it
LDMDB R2, {R2, R3} ; R2=GCharSpaceX;R3=GCharSpaceY
WINDow R0, R1, R8,R9,R10,R11 ; return LT if outside window
ADR R7, GCMVTab
B DoJumpTable
GCMVTab
& GMoveRight-GCMVTab
& GMoveLeft-GCMVTab
& GMoveRight-GCMVTab
& GMoveLeft-GCMVTab
& GMoveDown-GCMVTab
& GMoveDown-GCMVTab
& GMoveUp-GCMVTab
& GMoveUp-GCMVTab
; Move graphics cursor right if possible - on exit C=0 iff OK to move
GMoveRight
ADD R0, R0, R2 ; add on GCharSpaceX
GMove10
STR R0, [WsPtr, #GCsIX]
GMove15
BLT GMoveOK ; if we were outside already
TST R6, #&40 ; or we are in nowrap mode
BNE GMoveOK ; then we were OK to move
WINDow R0, R1, R8,R9,R10,R11
BGE GMoveOK ; if inside now, then OK
SEC
MOV PC, R14
GMoveOK
CLC
MOV PC, R14
; Move graphics cursor left if possible - on exit C=0 iff OK to move
GMoveLeft
SUB R0, R0, R2 ; subtract off GCharSpaceX
B GMove10
; Move graphics cursor down if possible - on exit C=0 iff OK to move
GMoveDown
SUB R1, R1, R3 ; subtract off GCharSpaceY
GMove20
STR R1, [WsPtr, #GCsIY]
B GMove15
; Move graphics cursor up if possible - on exit C=0 iff OK to move
GMoveUp
ADD R1, R1, R3 ; add on GCharSpaceY
B GMove20
; *****************************************************************************
;
; Move graphics cursor to boundary indicated by value of R6 in bits 1-3
; (0 or 4 = left, 2 or 6 = right, 8 or 10 = up, 12 or 14 = down)
; + R0 character positions in
;
GCursorB0
MOV R0, #0
GCursorBdy
ADR R7, GCBDYTab
B DoJumpTable
GCBDYTab
& GCursorLBdy-GCBDYTab
& GCursorRBdy-GCBDYTab
& GCursorLBdy-GCBDYTab
& GCursorRBdy-GCBDYTab
& GCursorUBdy-GCBDYTab
& GCursorUBdy-GCBDYTab
& GCursorDBdy-GCBDYTab
& GCursorDBdy-GCBDYTab
; Move graphics cursor to left boundary + R0 characters in
GCursorLBdy
LDR R7, [WsPtr, #GWLCol]
LDR R2, [WsPtr, #GCharSpaceX]
MLA R0, R2, R0, R7 ; GCsIX := GWLCol + (X*SpaceX)
STR R0, [WsPtr, #GCsIX]
MOV PC, R14
; Move graphics cursor to right boundary + R0 characters in
; (adjust for character size)
GCursorRBdy
LDR R7, [WsPtr, #GWRCol]
LDR R2, [WsPtr, #GCharSizeX]
SUB R7, R2, R7 ; R7 = SizeX-GWRCol
LDR R2, [WsPtr, #GCharSpaceX]
MLA R0, R2, R0, R7 ; R0 = SizeX-GWRCol+X*SpaceX
RSB R0, R0, #1 ; GWRCol-X*SpaceX-(SizeX-1)
STR R0, [WsPtr, #GCsIX]
MOV PC, R14
; Move graphics cursor to up boundary + R0 characters in
GCursorUBdy
LDR R7, [WsPtr, #GWTRow]
LDR R2, [WsPtr, #GCharSpaceY]
RSB R2, R2, #0 ; -SizeY
MLA R0, R2, R0, R7 ; GWTRow-Y*SizeY
STR R0, [WsPtr, #GCsIY]
MOV PC, R14
; Move graphics cursor to down boundary + R0 characters in
; (adjust for character size)
GCursorDBdy
LDR R7, [WsPtr, #GWBRow]
LDR R2, [WsPtr, #GCharSpaceY]
MLA R0, R2, R0, R7 ; GWBRow+Y*SpaceY
LDR R2, [WsPtr, #GCharSizeY]
ADD R0, R0, R2
SUB R0, R0, #1 ; GWBRow+Y*SpaceY+(SizeY-1)
STR R0, [WsPtr, #GCsIY]
MOV PC, R14
; *****************************************************************************
;
; ClipVdu5 - Add a VDU 5 char to clip box
;
; in: cxl2 = left
; cyb2 = top-bottom
; cxr2 = right
; cyt2 = top
;
; out: All registers preserved
;
ASSERT (cxl2=R4) :LAND: (cyb2=R3) :LAND: (cxr2=R10) :LAND: (cyt2=R2)
ClipVdu5 ROUT
Push "R0-R3, R4, R10, R14"
MOV R0, cxl2
SUB R1, cyt2, cyb2 ; top-(top-bottom) = bottom
MOV R3, cyt2
MOV R2, cxr2
BL MergeClipBox
Pull "R0-R3, R4, R10, PC"
END