add set dd addr from charcount

system/lcd.h65

@@ -20,7 +20,32 @@ INCLUDE_LCD = 1
 .scope lcd
 LCD_IO = IO1
 Import lcd,init,clear,print,print_char,set_position,set_custom_char
-Import lcd,_cmd,_wait_nbusy,_write_ram,_read_ram
+Import lcd,_cmd,_wait_nbusy,_write_ram,_read_ram,_charcount
+; PIN MASKS
+E       = %10000000
+RW      = %01000000
+RS      = %00100000
+
+RA_MASK = %11100000
+
+; LCD Instructions (see datasheet for more)
+CMD_CLEAR           = %00000001  ; clear display
+CMD_ENTRY_MODE      = %00000110  ; auto-shift cursor
+CMD_DISPLAY_ON      = %00001111  ; everything on, with blinking cursor
+CMD_SHIFT_CUR_LEFT  = %00101000  ; shift the display to the left
+CMD_SHIFT_DIS_LEFT  = %00111000  ; shift the display to the left
+CMD_SHIFT_DIS_RIGHT = %00110000  ; shift the display to the right
+CMD_SHIFT_CUR_RIGHT = %00100000  ; shift the display to the right
+CMD_FUNCTION_SET    = %00111000  ; 8-bit, 4 lines, 5x7 font
+CMD_SET_CG_ADDRESS  = %01000000  ; or with the address
+CMD_SET_ADDRESS     = %10000000  ; or with the address
+; LCD Constants
+LINE1      = $00
+LINE2      = $40
+LINE3      = $10
+LINE4      = $50
+
+.endscope
 
 ;;********************************************************************************
 ;; @macro Clear the screen and print a null-terminated string
@@ -73,29 +98,38 @@ Import lcd,_cmd,_wait_nbusy,_write_ram,_read_ram
     jsr lcd::print
 .endmacro
 
-; PIN MASKS
-E       = %10000000
-RW      = %01000000
-RS      = %00100000
 
-RA_MASK = %11100000
+;;********************************************************************************
+;; @macro Print a null-terminated string
+;; @param message: Address of the message or string literal
+;;********************************************************************************
+.macro lcd_SetCursor pos
+    .if .match (pos, a)
+    .elseif .match (pos, x)
+    txa
+    .elseif .match (pos, y)
+    tya
+    .else
+    lda #pos
+    .endif
+    sta lcd::_charcount
+    jsr lcd::_set_dd_ram_addr_from__charcount
+.endmacro
+
+;;********************************************************************************
+;; @macro Print a null-terminated string
+;; @param message: Address of the message or string literal
+;;********************************************************************************
+.macro lcd_AdvanceCursor n
+    .ifblank n
+    inc lcd::_charcount
+    .else
+    lda lcd::_charcount
+    add n
+    sta lcd::_charcount
+    .endif
+    jsr lcd::_set_dd_ram_addr_from__charcount
+.endmacro
 
-; LCD Instructions (see datasheet for more)
-CMD_CLEAR           = %00000001  ; clear display
-CMD_ENTRY_MODE      = %00000110  ; auto-shift cursor
-CMD_DISPLAY_ON      = %00001111  ; everything on, with blinking cursor
-CMD_SHIFT_CUR_LEFT  = %00101000  ; shift the display to the left
-CMD_SHIFT_DIS_LEFT  = %00111000  ; shift the display to the left
-CMD_SHIFT_DIS_RIGHT = %00110000  ; shift the display to the right
-CMD_SHIFT_CUR_RIGHT = %00100000  ; shift the display to the right
-CMD_FUNCTION_SET    = %00111000  ; 8-bit, 4 lines, 5x7 font
-CMD_SET_CG_ADDRESS  = %01000000  ; or with the address
-CMD_SET_ADDRESS     = %10000000  ; or with the address
-; LCD Constants
-LINE1      = $00
-LINE2      = $40
-LINE3      = $10
-LINE4      = $50
 
-.endscope
 .endif  ; guard

system/lcd.s65

@@ -5,10 +5,10 @@
 .endif
 
 Export lcd,init,clear,print,print_char,set_position,set_custom_char
-Export lcd,_cmd,_wait_nbusy,_write_ram,_read_ram
+Export lcd,_cmd,_wait_nbusy,_write_ram,_read_ram,_charcount
 ; RAM VARIABLES
 .bss
-charcount:  .res 1
+_charcount:  .res 1
 
 ; TODO when clockspeeds are more than 1MHz, _cmd, _write_ram and _read_ram might need to be adjusted
 .code
@@ -36,7 +36,7 @@ charcount:  .res 1
     lda #lcd::CMD_ENTRY_MODE
     jsr _cmd
 
-    stz charcount
+    stz _charcount
     rts
 .endproc
 
@@ -61,17 +61,17 @@ charcount:  .res 1
     cmp #$10
     bge @line3
     bra @set
-; @line1:  ; starts at $00, charcount at $00
+; @line1:  ; starts at $00, _charcount at $00
-@line2:  ; starts at $40, charcount at $10
+@line2:  ; starts at $40, _charcount at $10
     sbc #$30  ; carry is already set
     bra @set
-@line3:  ; starts at $10, charcount at $20
+@line3:  ; starts at $10, _charcount at $20
     add #$10
     bra @set
-@line4:  ; starts at $50, charcount at $30
+@line4:  ; starts at $50, _charcount at $30
     sbc #$20
 @set:
-    sta charcount
+    sta _charcount
     pla
     pha
     ora #lcd::CMD_SET_ADDRESS
@@ -82,7 +82,7 @@ charcount:  .res 1
 @invalid:
     pla  ; otherwise stack corruption
     lda #$13
-    sta charcount
+    sta _charcount
     lda #(lcd::CMD_SET_ADDRESS | (lcd::LINE2 + 3))
     jsr _cmd
     lda #(lcd::LINE2 + 3)
@@ -99,7 +99,7 @@ charcount:  .res 1
 ;; @modifies A
 ;;********************************************************************************
 .proc clear
-    stz charcount
+    stz _charcount
     lda #lcd::CMD_CLEAR
     jsr _cmd
     rts
@@ -131,7 +131,7 @@ charcount:  .res 1
 .proc print_char
     pha
     jsr _write_ram
-    inc charcount
+    inc _charcount
     jsr _break_line
     pla ; put char back in a
 .endproc
@@ -286,11 +286,53 @@ charcount:  .res 1
 
 
 ;;********************************************************************************
-;; @function Set the LCD DD-RAM Address so that text linebreaks after 16 chars
+;; @function Set the LCD DD-RAM Address from the character count
+;; @details
+;;  Sets the DD-RAM Address so that a line break occurs after 16 characters
+;;  If _charcount is more than $40, the position will be set to line 1.
+;;********************************************************************************
+.proc _set_dd_ram_addr_from__charcount
+    cmp #$40  ; set to line1 when full
+    bcs @wrap_to_line1 
+    cmp #$10
+    bcc @line1
+    cmp #$20
+    bcc @line3
+    ; bra @line4
+@line4:
+    clc
+    adc #$20        ; _charcount $30-$3f -> $50 - $5f
+    bra @set_address
+@wrap_to_line1:
+    sbc #$40
+    and #%00001111
+    ; now every _charcount is mapped between 0 and $3f
+    bra @set_address
+@line2:
+    adc #$30        ; _charcount $10-$1f -> $40 - $4f
+    bra @set_address
+@line3:
+    sec
+    sbc #$10        ; _charcount $20-$2f -> $10 - $1f
+    bra @set_address
+@line1:             ; _charcount $00-$1f -> $00 - $0f - nothing to do
+@set_address:
+    ora #lcd::CMD_SET_ADDRESS
+    jsr _cmd
+    rts
+.endproc
+
+;;********************************************************************************
+;; @function Set the LCD DD-RAM Address to te next line if the end of the line was reached
+;; @details
+;;  If the cursor is past the end of a line, the DD-RAM Address is set to the next line.
+;;  If _charcount is more than $40, the position will be set to line 1.
+;;  This function is intended to be used with to set the correct address when
+;;  auto-shift is enabled
 ;;********************************************************************************
 .proc _break_line
     ; check if checks are necessary
-    lda charcount
+    lda _charcount
     beq @line1
     bit #%10001111  ; ($10 | $20 | $30 | $40) = %01110000
     beq @check
@@ -307,7 +349,7 @@ charcount:  .res 1
     bge @line1 
     rts
 @line1:
-    stz charcount
+    stz _charcount
     lda #(lcd::CMD_SET_ADDRESS | lcd::LINE1)
     jsr _cmd
     rts