; vim:ts=4:sw=4:et:
; PRINT command routine
; Does not print attribute. Use PRINT_STR or PRINT_NUM for that

#include once <sposn.asm>
#include once <cls.asm>
#include once <in_screen.asm>
#include once <table_jump.asm>
#include once <ink.asm>
#include once <paper.asm>
#include once <flash.asm>
#include once <bright.asm>
#include once <over.asm>
#include once <inverse.asm>
#include once <bold.asm>
#include once <italic.asm>
#include once <const.asm>
#include once <attr.asm>

; Putting a comment starting with @INIT <address> 
; will make the compiler to add a CALL to <address>
; It is useful for initialization routines.
#init __PRINT_INIT

__PRINT_INIT: ; To be called before program starts (initializes library)
        PROC

        ld hl, __PRINT_START
        ld (PRINT_JUMP_STATE), hl

        ld hl, 1821h
        ld (MAXX), hl  ; Sets current maxX and maxY

        xor a
        ld (FLAGS2), a

        ret


__PRINTCHAR: ; Print character store in accumulator (A register)
             ; Modifies H'L', B'C', A'F', D'E', A

        LOCAL PO_GR_1

        LOCAL __PRCHAR
        LOCAL __PRINT_CONT
        LOCAL __PRINT_CONT2
        LOCAL __PRINT_JUMP
        LOCAL __SRCADDR
        LOCAL __PRINT_UDG
        LOCAL __PRGRAPH
        LOCAL __PRINT_START

PRINT_JUMP_STATE EQU __PRINT_JUMP + 1

__PRINT_JUMP:
        jp __PRINT_START    ; Where to jump. If we print 22 (AT), next two calls jumps to AT1 and AT2 respectively

__PRINT_START:
        cp ' '
        jp c, __PRINT_SPECIAL    ; Characters below ' ' are special ones

        exx            ; Switch to alternative registers
        ex af, af'        ; Saves a value (char to print) for later

        call __LOAD_S_POSN

; At this point we have the new coord
        ld hl, (SCREEN_ADDR)

        ld a, d
        ld c, a        ; Saves it for later
        
        and 0F8h    ; Masks 3 lower bit ; zy
        ld d, a

        ld a, c        ; Recovers it
        and 07h     ; MOD 7 ; y1
        rrca
        rrca
        rrca

        or e
        ld e, a
        add hl, de    ; HL = Screen address + DE
        ex de, hl     ; DE = Screen address
        
        ex af, af'

        cp 80h    ; Is it an UDG or a ? 
        jp c, __SRCADDR

        cp 90h
        jp nc, __PRINT_UDG

        ; Print a 8 bit pattern (80h to 8Fh)

        ld b, a
        call PO_GR_1 ; This ROM routine will generate the bit pattern at MEM0
        ld hl, MEM0
        jp __PRGRAPH

PO_GR_1 EQU 0B38h

__PRINT_UDG:
        sub 90h ; Sub ASC code
        ld bc, (UDG)
        jp __PRGRAPH0

__SOURCEADDR EQU (__SRCADDR + 1)    ; Address of the pointer to chars source
__SRCADDR:
        ld bc, (CHARS)

__PRGRAPH0:
        add a, a    ; A = a * 2 (since a < 80h) ; Thanks to Metalbrain at http://foro.speccy.org
        ld l, a
        ld h, 0        ; HL = a * 2 (accumulator)
        add hl, hl 
        add hl, hl ; HL = a * 8
        add hl, bc ; HL = CHARS address

__PRGRAPH:
        ex de, hl  ; HL = Write Address, DE = CHARS address
        bit 2, (iy + $47)
        call nz, __BOLD
        bit 4, (iy + $47)
        call nz, __ITALIC
        ld b, 8 ; 8 bytes per char
__PRCHAR:
        ld a, (de) ; DE *must* be ALWAYS source, and HL destiny

PRINT_MODE:        ; Which operation is used to write on the screen
                ; Set it with:
                ; LD A, <OPERATION>
                ; LD (PRINT_MODE), A
                ;
                ; Available opertions:
                ; NORMAL: 0h  --> NOP    ; OVER 0
                ; XOR    : AEh --> XOR (HL)        ; OVER 1
                ; OR    : B6h --> OR (HL)        ; PUTSPRITE
                ; AND   : A6h --> AND (HL)        ; PUTMASK
        nop        ;

INVERSE_MODE:    ; 00 -> NOP -> INVERSE 0
        nop        ; 2F -> CPL -> INVERSE 1

        ld (hl), a

        inc de 
        inc h     ; Next line
        djnz __PRCHAR    

        call __LOAD_S_POSN
        push de
        call __SET_ATTR
        pop de
        inc e            ; COL = COL + 1
        ld hl, (MAXX)
        ld a, e
        dec l            ; l = MAXX
        cp l            ; Lower than max?
        jp c, __PRINT_CONT; Nothing to do
        call __PRINT_EOL1
        exx            ; counteracts __PRINT_EOL1 exx
        jp __PRINT_CONT2

__PRINT_CONT:
        call __SAVE_S_POSN

__PRINT_CONT2:
        exx
        ret

; ------------- SPECIAL CHARS (< 32) -----------------

__PRINT_SPECIAL:    ; Jumps here if it is a special char
        exx
        ld hl, __PRINT_TABLE
        jp JUMP_HL_PLUS_2A


PRINT_EOL:        ; Called WHENEVER there is no ";" at end of PRINT sentence
        exx

__PRINT_0Dh:        ; Called WHEN printing CHR$(13)
        call __LOAD_S_POSN

__PRINT_EOL1:        ; Another entry called from PRINT when next line required
        ld e, 0

__PRINT_EOL2:
        ld a, d
        inc a

__PRINT_AT1_END:
        ld hl, (MAXY)
        cp l
        jr c, __PRINT_EOL_END    ; Carry if (MAXY) < d
        xor a

__PRINT_EOL_END:
        ld d, a    

__PRINT_AT2_END:
        call __SAVE_S_POSN
        exx
        ret

__PRINT_COM:
        exx
        push hl
        push de
        push bc
        call PRINT_COMMA
        pop bc
        pop de
        pop hl
        ret

__PRINT_TAB:
        ld hl, __PRINT_TAB1
        jp __PRINT_SET_STATE

__PRINT_TAB1:
        ld (MEM0), a         
        ld hl, __PRINT_TAB2
        ld (PRINT_JUMP_STATE), hl
        ret

__PRINT_TAB2:
        ld a, (MEM0)        ; Load tab code (ignore the current one)
        push hl
        push de
        push bc
        ld hl, __PRINT_START
        ld (PRINT_JUMP_STATE), hl
        call PRINT_TAB
        pop bc
        pop de
        pop hl
        ret

__PRINT_NOP:
__PRINT_RESTART:
        ld hl, __PRINT_START
        jp __PRINT_SET_STATE

__PRINT_AT:
        ld hl, __PRINT_AT1

__PRINT_SET_STATE:
        ld (PRINT_JUMP_STATE), hl    ; Saves next entry call
        exx
        ret

__PRINT_AT1:    ; Jumps here if waiting for 1st parameter
        exx
        ld hl, __PRINT_AT2
        ld (PRINT_JUMP_STATE), hl    ; Saves next entry call
        call __LOAD_S_POSN
        jp __PRINT_AT1_END

__PRINT_AT2:
        exx
        ld hl, __PRINT_START
        ld (PRINT_JUMP_STATE), hl    ; Saves next entry call
        call __LOAD_S_POSN
        ld e, a
        ld hl, (MAXX)
        cp e
        jr c, __PRINT_AT2_END
        ld e, 0
        jp __PRINT_AT2_END

__PRINT_DEL:
        call __LOAD_S_POSN        ; Gets current screen position
        dec e
        ld a, -1
        cp e
        jp nz, __PRINT_AT2_END
        ld hl, (MAXX)
        ld e, l
        dec e
        dec e
        dec d
        cp d
        jp nz, __PRINT_AT2_END
        ld d, h
        dec d
        jp __PRINT_AT2_END

__PRINT_INK:
        ld hl, __PRINT_INK2
        jp __PRINT_SET_STATE

__PRINT_INK2:
        exx
        call INK_TMP
        jp __PRINT_RESTART

__PRINT_PAP:
        ld hl, __PRINT_PAP2
        jp __PRINT_SET_STATE
        
__PRINT_PAP2:
        exx
        call PAPER_TMP
        jp __PRINT_RESTART

__PRINT_FLA:
        ld hl, __PRINT_FLA2
        jp __PRINT_SET_STATE

__PRINT_FLA2:
        exx
        call FLASH_TMP
        jp __PRINT_RESTART

__PRINT_BRI:
        ld hl, __PRINT_BRI2
        jp __PRINT_SET_STATE

__PRINT_BRI2:
        exx
        call BRIGHT_TMP
        jp __PRINT_RESTART

__PRINT_INV:
        ld hl, __PRINT_INV2
        jp __PRINT_SET_STATE

__PRINT_INV2:
        exx
        call INVERSE_TMP
        jp __PRINT_RESTART

__PRINT_OVR:
        ld hl, __PRINT_OVR2
        jp __PRINT_SET_STATE

__PRINT_OVR2:
        exx
        call OVER_TMP
        jp __PRINT_RESTART

__PRINT_BOLD:
        ld hl, __PRINT_BOLD2
        jp __PRINT_SET_STATE

__PRINT_BOLD2:
        exx
        call BOLD_TMP
        jp __PRINT_RESTART

__PRINT_ITA:
        ld hl, __PRINT_ITA2
        jp __PRINT_SET_STATE

__PRINT_ITA2:
        exx
        call ITALIC_TMP
        jp __PRINT_RESTART


__BOLD:
        push hl
        ld hl, MEM0
        ld b, 8
__BOLD_LOOP:
        ld a, (de)
        ld c, a
        rlca
        or c
        ld (hl), a
        inc hl
        inc de
        djnz __BOLD_LOOP
        pop hl
        ld de, MEM0
        ret
            

__ITALIC:
        push hl
        ld hl, MEM0
        ex de, hl
        ld bc, 8
        ldir
        ld hl, MEM0
        srl (hl)
        inc hl
        srl (hl)
        inc hl
        srl (hl)
        inc hl
        inc hl
        inc hl
        sla (hl)
        inc hl
        sla (hl)
        inc hl
        sla (hl)
        pop hl
        ld de, MEM0
        ret

PRINT_COMMA:
        call __LOAD_S_POSN
        ld a, e
        inc a
        and 16
        add a, 16

PRINT_TAB:
        PROC
        LOCAL LOOP, CONTINUE

        call __LOAD_S_POSN ; e = current row
        ld d, a
        ld a, e
        cp 21h
        jr nz, CONTINUE
        ld e, -1
CONTINUE:
        ld a, d
        inc e
        sub e  ; A = A - E 
        and 31 ;
        ret z  ; Already at position E
        ld b, a
LOOP:
        ld a, ' '
        call __PRINTCHAR
        djnz LOOP
        ret
        ENDP

PRINT_AT: ; CHanges cursor to ROW, COL
         ; COL in A register
         ; ROW in stack 

        pop hl    ; Ret address
        ex (sp), hl ; callee H = ROW
        ld l, a
        ex de, hl

        call __IN_SCREEN
        ret nc    ; Return if out of screen

        jp __SAVE_S_POSN

        LOCAL __PRINT_COM
        LOCAL __BOLD
        LOCAL __BOLD_LOOP
        LOCAL __ITALIC
        LOCAL __PRINT_EOL1
        LOCAL __PRINT_EOL2
        LOCAL __PRINT_AT1
        LOCAL __PRINT_AT2
        LOCAL __PRINT_AT2_END
        LOCAL __PRINT_BOLD
        LOCAL __PRINT_BOLD2
        LOCAL __PRINT_ITA
        LOCAL __PRINT_ITA2
        LOCAL __PRINT_INK
        LOCAL __PRINT_PAP
        LOCAL __PRINT_SET_STATE
        LOCAL __PRINT_TABLE
        LOCAL __PRINT_TAB, __PRINT_TAB1, __PRINT_TAB2
            
__PRINT_TABLE:    ; Jump table for 0 .. 22 codes
        
        DW __PRINT_NOP    ;  0
        DW __PRINT_NOP    ;  1
        DW __PRINT_NOP    ;  2
        DW __PRINT_NOP    ;  3
        DW __PRINT_NOP    ;  4
        DW __PRINT_NOP    ;  5
        DW __PRINT_COM    ;  6 COMMA
        DW __PRINT_NOP    ;  7
        DW __PRINT_DEL    ;  8 DEL
        DW __PRINT_NOP    ;  9
        DW __PRINT_NOP    ; 10
        DW __PRINT_NOP    ; 11
        DW __PRINT_NOP    ; 12
        DW __PRINT_0Dh    ; 13
        DW __PRINT_BOLD    ; 14
        DW __PRINT_ITA    ; 15
        DW __PRINT_INK    ; 16
        DW __PRINT_PAP    ; 17
        DW __PRINT_FLA    ; 18
        DW __PRINT_BRI    ; 19
        DW __PRINT_INV    ; 20
        DW __PRINT_OVR    ; 21
        DW __PRINT_AT    ; 22 AT
        DW __PRINT_TAB  ; 23 TAB

        ENDP
        

