Almost fully implemented text enginer

game/controller.asm

@@ -1 +1,66 @@
-controller.asm
+SECTION "ram_controller", WRAM0
+controller_curkeys: ds 1
+controller_newkeys: ds 1
+
+SECTION "Controller", ROM0
+
+InitController:
+  ld a, 0
+  ld [controller_curkeys], a
+  ld [controller_newkeys], a
+  ret
+
+; Controller reading ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+; This controller reading routine is optimized for size.
+; It stores currently pressed keys in controller_curkeys (1=pressed) and
+; keys newly pressed since last read in controller_newkeys, with the same
+; nibble ordering as the Game Boy Advance.
+; 76543210
+; |||||||+- A
+; ||||||+-- B
+; |||||+--- Select
+; ||||+---- Start
+; |||+----- Right
+; ||+------ Left
+; |+------- Up
+; +-------- Down
+;           R
+;           L (just kidding)
+
+UpdateController:
+  ; Poll half the controller
+  ld a,P1F_4
+  call .onenibble
+  ld b,a  ; B7-4 = 1; B3-0 = unpressed buttons
+
+  ; Poll the other half
+  ld a,P1F_5
+  call .onenibble
+  swap a   ; A3-0 = unpressed directions; A7-4 = 1
+  xor b    ; A = pressed buttons + directions
+  ld b,a   ; B = pressed buttons + directions
+
+  ; And release the controller
+  ld a,P1F_N
+  ld [rP1],a
+
+  ; Combine with previous controller_curkeys to make controller_newkeys
+  ld a, [controller_curkeys]
+  xor b    ; A = keys that changed state
+  and b    ; A = keys that changed to pressed
+  ld [controller_newkeys], a
+  ld a,b
+  ld [controller_curkeys], a
+  ret
+
+.onenibble:
+  ldh [rP1],a  ; switch the key matrix
+  ldh a,[rP1]  ; ignore value while waiting for the key matrix to settle
+  ldh a,[rP1]
+  ldh a,[rP1]
+  ldh a,[rP1]
+  ldh a,[rP1]
+  ldh a,[rP1]  ; the actual read
+  or $F0   ; A7-4 = 1; A3-0 = unpressed keys
+  ret

game/game.asm

@@ -1,4 +1,5 @@
 INCLUDE "game/text.asm"
+INCLUDE "game/controller.asm"
 
 SECTION "Game Loop", ROM0
 
@@ -7,6 +8,7 @@ GameLoop:
     call StartText
 .mainloop
     ; Start our game loop
+    call UpdateController
     call DrawActiveText
     call WaitVBlank
     jr .mainloop
@@ -16,4 +18,6 @@ Section "Hello wrold string", ROM0
 HelloWorldStr:
     ;  [                  ]
     db "...wake up...\n"
-    db "please wake up...", 0
+    db "please wake up...#"
+    db "...we don't have\n"
+    db "time, wake up...", 0

game/text.asm

@@ -1,19 +1,21 @@
 SECTION "ram_textwriter", WRAM0
 textwriter_curtext: ds 2
-textwriter_curletter: ds 1
 textwriter_posx: ds 1
 textwriter_posy: ds 1
 textwriter_curdelay: ds 1
 textwriter_active: ds 1
+textwriter_starting: ds 1
+textwriter_ending: ds 1
+textwriter_pausing: ds 1
 
 SECTION "rom_textmap", ROM0,ALIGN[8]
 textwriter_map:
     ;   00  01  02  03  04  05  06  07  08  09  0A  0B  0C  0D  0E  0F
-    db $50,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50 ; 0
+    db $44,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50 ; 0
     ;   10  11  12  13  14  15  16  17  18  19  1A  1B  1C  1D  1E  1F
     db $50,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50,$50 ; 16
     ;   20  21  22  23  24  25  26  27  28  29  2A  2B  2C  2D  2E  2F
-    db $50,$41,$50,$50,$50,$50,$50,$43,$50,$50,$50,$50,$42,$50,$3F,$50 ; 32
+    db $50,$41,$50,$45,$50,$50,$50,$43,$50,$50,$50,$50,$42,$50,$3F,$50 ; 32
     ;   30  31  32  33  34  35  36  37  38  39  3A  3B  3C  3D  3E  3F
     db $35,$36,$37,$38,$39,$3A,$3B,$3C,$3D,$3E,$50,$50,$50,$50,$50,$40 ; 48
     ;   40  41  42  43  44  45  46  47  48  49  4A  4B  4C  4D  4E  4F
@@ -29,16 +31,15 @@ SECTION "TextWriter", ROM0
 
 InitWindow:
     ; Fill first line in window with straight line
-    ld hl, _SCRN1
-    ld b, $20
+    ld hl, (_SCRN1 + 1)
+    ld b, 19
     ld a, $52
     call Memfill
     ; Fill rest of the area with dark bg
-    ld b, $40
-    ld a, $50
-    call Memfill
+    call ClearWindow
     ; Fill last line in window with straight line
-    ld b, $20
+    ld hl, (_SCRN1 + $61)
+    ld b, 19
     ld a, $57
     call Memfill
     ; Top left corner
@@ -63,16 +64,26 @@ InitWindow:
     ld [hl], $55
     ld hl, _SCRN1 + $40 + 19
     ld [hl], $55
+    ; Some other common memory addresses that should be filled
+    ld a, 0
+    ld [textwriter_posx], a
+    ld [textwriter_posy], a
+    ld [textwriter_ending], a
+    ld [textwriter_pausing], a
+    ld [textwriter_active], a
+    ld [textwriter_curdelay], a
+    ld [textwriter_starting], a
     ret ; Return
 
 ClearWindow:
     ld hl, (_SCRN1 + $21)
     ld a, $50 
-    ld b, $1E
+    ld b, 18
     call Memfill
     ld hl, (_SCRN1 + $41)
-    ld b, $1E
+    ld b, 18
     call Memfill
+    ret
 
 ; Start to print a string on screen
 ; @param de - Address source string
@@ -85,9 +96,10 @@ StartText:
     ld a, 10
     ld [textwriter_curdelay], a
     ld a, 0
-    ld [textwriter_curletter], a
     ld [textwriter_posx], a
     ld [textwriter_posy], a
+    ld [textwriter_ending], a
+    ld [textwriter_pausing], a
     ld a, 1
     ld [textwriter_active], a
     ld hl, textwriter_curtext
@@ -96,6 +108,9 @@ StartText:
     ld a, e
     ld [hl], a
     dec hl
+    ld a, 16
+    ld [textwriter_starting], a
+    call ClearWindow ; Clear it just in case
     ret
 
 ; Draw text if one is currently active
@@ -103,14 +118,83 @@ StartText:
 DrawActiveText:
     ld a, [textwriter_active] ; Check if text is currently active
     and a
-    ret z
+    ret z ; If no text is active, just exit immediately
+
+    ld a, [textwriter_starting] ; Check if we're booting up the window
+    and a
+    jr z, .afterLoading ; Jump to after loading if we're not loading
+
+    ; We are loading the window
+    ld a, [rWY] ; Get current window position
+    dec a ; Decrement twice (moves it slowly up)
+    dec a
+    ld [rWY], a ; Set the position back into window
+    ld a, [textwriter_starting]
+    dec a
+    ld [textwriter_starting], a
+    jr z, .afterLoading
+    ret
+
+.afterLoading
+    ld a, [textwriter_ending] ; Check if we are ending
+    and a
+    jr z, .checkPausing ; If we are not ending, jump to check pause
+
+    ; We are ending, animate the window back down
+    ld a, [rWY] ; Get current window position
+    inc a ; Increment twice
+    inc a
+    ld [rWY], a ; Set the position back into window
+    ld a, [textwriter_ending] ; Grab the ending guy
+    dec a ; Decrement it
+    ld [textwriter_ending], a ; Set it back
+    jr z, .closingAll ; If we reach zero, we can disable text renderer
+    ret
+
+.closingAll
+    ld [textwriter_active], a
+    ret
+
+.checkPausing
+    ld a, [textwriter_pausing] ; Check if we're in a paused state
+    and a
+    jr z, .checkDelay ; Jump to Delayer if we're not in paused state
+
+    ld b, a ; We are in pause state so store pause state in register b
+    ld a, [controller_newkeys] ; Check our controller
+    and a, PAD_A|PAD_B ; Check if we pressed either A or B
+    ret z ; Exit if he didn't
+
+    dec b ; Decrement B, our paused state
+    jr z, .continuingNextLine ; If paused state was 1 then we continue
+                              ;to render next line
+
+    ; If we reach here, paused state was 2 which means we should
+    ; end text reader
+    ld a, 16 ; Set a to 1
+    ld [textwriter_ending], a ; Mark it as we are ending
+    ret
+
+.continuingNextLine
+    call ClearWindow
+    ld a, 0
+    ld [textwriter_pausing], a
+    ld [textwriter_posx], a
+    ld [textwriter_posy], a
+    jr .delayFinished
 
-    ; Delay writing a letter by 10 frames
+.checkDelay
+    ; Delay writing a letter by 10 frames if no button is down
     ld a, [textwriter_curdelay]
     dec a
     ld [textwriter_curdelay], a
-    ret nz
+    jr z, .delayFinished
 
+    ld a, [controller_curkeys] ; Check our controller
+    and a, PAD_B
+    ret z ; If B button is being held, we skip any delay
+
+.delayFinished
     ; Reset the curdelay
     ld a, 10
     ld [textwriter_curdelay], a
@@ -148,19 +232,28 @@ DrawActiveText:
     ld a, [bc] ; Get the tile byte for the ASCII from the map
     ld [hl], a ; Print the byte to the map
 
+.checkIsEnding
     ld a, [de]
     and a ; Check if we reached the end
-    jr nz, .checkNewline
+    jr nz, .checkContinuing
 
-    ; We have reached the end of the string, disable textwriter
-    ld b, 0 ; Disable repeater
-    ld a, 0
-    ld [textwriter_active], a
+    ; We have reached the end of the string, mark it
+    ld a, 2
+    ld [textwriter_pausing], a
     jr .continue ; Jump straight to continue. No need to check anything
 
+.checkContinuing
+    ld a, [de] ; Regrab the ascii byte we printed
+    cp a, $23 ; Check if it's '#'
+    jr nz, .checkNewline ; Jump to next check if it wasn't
+
+    ld a, 1
+    ld [textwriter_pausing], a
+    jr .continue
+
 .checkNewline
     ld a, [de] ; Regrab the ascii byte we printed
-    cp a, $0A ; Check if it was a new line
+    cp a, $0A ; Check if it was a new line '\n'
     jr nz, .checkRepeatOnce ; Jump to checkRepeatOnce if it wasn't a new line
 
     ; The byte we printed was a new line so we increment Y position
@@ -171,15 +264,10 @@ DrawActiveText:
     ld a, 1
     ld [textwriter_posy], a ; Set our Y position to 1
     ld [textwriter_curdelay], a ; Also set curdelay to 1 as well
-
-    ; We already know we printed empty character so we can skip checking
-    ; if we need to repeat once again and just set the b flag
-    ld b, 1
     jr .continue
 
 .checkRepeatOnce
     ld a, [bc] ; Regrab the tile we printer
-    ld b, 0 ; Use b as our marker if we should repeat once
 
     ; Check if we printed an empty letter
     cp a, $50
@@ -200,10 +288,6 @@ DrawActiveText:
     ld a, [textwriter_posx]
     inc a
     ld [textwriter_posx], a
-    ; Update the current letter being drawn in ram
-    ld a, [textwriter_curletter]
-    inc a
-    ld [textwriter_curletter], a
 
 .exit
     ld a, [textwriter_active]

hardware.inc

@@ -89,6 +89,7 @@ OAMB_BANK1      EQU 3 ; Bank number; 0,1 (GBC)
 ; --
 rP1 EQU $FF00
 
+P1F_N EQU %00110000 ; P14-15 out port
 P1F_5 EQU %00100000 ; P15 out port
 P1F_4 EQU %00010000 ; P14 out port
 P1F_3 EQU %00001000 ; P13 in port
@@ -800,6 +801,15 @@ PADF_SELECT EQU $04
 PADF_B      EQU $02
 PADF_A      EQU $01
 
+PAD_DOWN   EQU $80
+PAD_UP     EQU $40
+PAD_LEFT   EQU $20
+PAD_RIGHT  EQU $10
+PAD_START  EQU $08
+PAD_SELECT EQU $04
+PAD_B      EQU $02
+PAD_A      EQU $01
+
 PADB_DOWN   EQU $7
 PADB_UP     EQU $6
 PADB_LEFT   EQU $5

main.asm

@@ -61,7 +61,7 @@ Start:
 
     ld a, 7
     ld [rWX], a
-    ld a, (SCRN_Y - 32)
+    ld a, SCRN_Y
     ld [rWY], a
 
     ; Reset OAM memory with zeros
@@ -70,7 +70,18 @@ Start:
     ld b, $FEA0 - _OAMRAM ; Get the full size of the fill
     call Memfill
 
+    ; Reset WRAM memory with zeros
+    ld hl, _RAM ; Set position of OAM Ram to hl
+    ld a, $01 ; Fill that memory space with zero
+    ld bc, $E000 - _RAM ; Get the full size of the fill
+    call Memfill16
+    ld hl, _RAM ; Set position of OAM Ram to hl
+    ld a, $00 ; Fill that memory space with zero
+    ld bc, $E000 - _RAM ; Get the full size of the fill
+    call Memfill16
+
     ; Initialize other stuff
+    call InitController
     call InitWindow
 
     ; Turn the screen on, display background

test.map

@@ -1,46 +1,65 @@
 ROM Bank #0 (HOME):
   SECTION: $0200-$027F ($0080 bytes) ["rom_textmap"]
            $0200 = textwriter_map
-  SECTION: $1280-$136C ($00ED bytes) ["TextWriter"]
-           $131D = DrawActiveText.drawletter
-           $1331 = DrawActiveText.checkNewline
-           $1353 = DrawActiveText.continue
-           $1347 = DrawActiveText.checkRepeatOnce
-           $12D3 = StartText
-           $12F1 = DrawActiveText
+  SECTION: $1280-$13EA ($016B bytes) ["TextWriter"]
+           $12D7 = ClearWindow
+           $132E = DrawActiveText.afterLoading
+           $1348 = DrawActiveText.checkPausing
+           $1344 = DrawActiveText.closingAll
+           $136E = DrawActiveText.checkDelay
+           $135E = DrawActiveText.continuingNextLine
+           $137D = DrawActiveText.delayFinished
+           $139C = DrawActiveText.drawletter
+           $13AE = DrawActiveText.checkContinuing
+           $13D8 = DrawActiveText.continue
+           $13BA = DrawActiveText.checkNewline
+           $13CE = DrawActiveText.checkRepeatOnce
+           $12EA = StartText
+           $1313 = DrawActiveText
            $1280 = InitWindow
-  SECTION: $0031-$003E ($000E bytes) ["Game Loop"]
-           $0037 = GameLoop.mainloop
-           $0031 = GameLoop
-  SECTION: $0000-$001F ($0020 bytes) ["Hello wrold string"]
-           $0000 = HelloWorldStr
-  SECTION: $0020-$0030 ($0011 bytes) ["Tools"]
-           $0029 = Memfill
-           $002E = WaitVBlank
-           $0020 = Memcpy
-           $0029 = Memfill.repeatFill
+  SECTION: $0000-$0039 ($003A bytes) ["Controller"]
+           $0029 = UpdateController.onenibble
+           $0009 = UpdateController
+           $0000 = InitController
+  SECTION: $0166-$0176 ($0011 bytes) ["Game Loop"]
+           $016C = GameLoop.mainloop
+           $0166 = GameLoop
+  SECTION: $00BB-$00FC ($0042 bytes) ["Hello wrold string"]
+           $00BB = HelloWorldStr
+  SECTION: $0150-$0165 ($0016 bytes) ["Tools"]
+           $0159 = Memfill
+           $0163 = WaitVBlank
+           $0150 = Memcpy
+           $0159 = Memfill.repeatFill
+           $015E = Memfill16.repeatFill
+           $015E = Memfill16
   SECTION: $0040-$0040 ($0001 bytes) ["InterruptVblank"]
   SECTION: $0048-$0048 ($0001 bytes) ["InterruptLCDC"]
   SECTION: $0050-$0050 ($0001 bytes) ["InterruptTimer_Overflow"]
   SECTION: $0058-$0058 ($0001 bytes) ["InterruptSerial"]
   SECTION: $0060-$0060 ($0001 bytes) ["Interruptp1thru4"]
   SECTION: $0100-$014F ($0050 bytes) ["Header"]
-  SECTION: $0061-$00A1 ($0041 bytes) ["Intro code"]
+  SECTION: $0061-$00BA ($005A bytes) ["Intro code"]
            $0061 = Start
   SECTION: $0280-$127F ($1000 bytes) ["Font"]
            $0280 = Page1
            $1280 = Page1End
-    SLACK: $2DBE bytes
+    SLACK: $2CC3 bytes
 
 WRAM Bank #0:
-  SECTION: $C000-$C006 ($0007 bytes) ["ram_textwriter"]
-           $C005 = textwriter_curdelay
-           $C002 = textwriter_curletter
-           $C003 = textwriter_posx
-           $C004 = textwriter_posy
-           $C006 = textwriter_active
+  SECTION: $C000-$C008 ($0009 bytes) ["ram_textwriter"]
+           $C002 = textwriter_posx
+           $C003 = textwriter_posy
+           $C007 = textwriter_ending
+           $C008 = textwriter_pausing
+           $C005 = textwriter_active
+           $C004 = textwriter_curdelay
+           $C006 = textwriter_starting
            $C000 = textwriter_curtext
-    SLACK: $0FF9 bytes
+  SECTION: $C009-$C00A ($0002 bytes) ["ram_controller"]
+           $C00A = controller_newkeys
+           $C009 = controller_curkeys
+    SLACK: $0FF5 bytes
 
 WRAM Bank #1:
   EMPTY

test.sym

@@ -1,26 +1,43 @@
 ; File generated by rgblink
 
 00:0200 textwriter_map
-00:131D DrawActiveText.drawletter
-00:1331 DrawActiveText.checkNewline
-00:1353 DrawActiveText.continue
-00:1347 DrawActiveText.checkRepeatOnce
-00:12D3 StartText
-00:12F1 DrawActiveText
+00:12D7 ClearWindow
+00:132E DrawActiveText.afterLoading
+00:1348 DrawActiveText.checkPausing
+00:1344 DrawActiveText.closingAll
+00:136E DrawActiveText.checkDelay
+00:135E DrawActiveText.continuingNextLine
+00:137D DrawActiveText.delayFinished
+00:139C DrawActiveText.drawletter
+00:13AE DrawActiveText.checkContinuing
+00:13D8 DrawActiveText.continue
+00:13BA DrawActiveText.checkNewline
+00:13CE DrawActiveText.checkRepeatOnce
+00:12EA StartText
+00:1313 DrawActiveText
 00:1280 InitWindow
-00:0037 GameLoop.mainloop
-00:0031 GameLoop
-00:0000 HelloWorldStr
-00:0029 Memfill
-00:002E WaitVBlank
-00:0020 Memcpy
-00:0029 Memfill.repeatFill
+00:0029 UpdateController.onenibble
+00:0009 UpdateController
+00:0000 InitController
+00:016C GameLoop.mainloop
+00:0166 GameLoop
+00:00BB HelloWorldStr
+00:0159 Memfill
+00:0163 WaitVBlank
+00:0150 Memcpy
+00:0159 Memfill.repeatFill
+00:015E Memfill16.repeatFill
+00:015E Memfill16
 00:0061 Start
 00:0280 Page1
 00:1280 Page1End
-00:C005 textwriter_curdelay
-00:C002 textwriter_curletter
-00:C003 textwriter_posx
-00:C004 textwriter_posy
-00:C006 textwriter_active
+00:C002 textwriter_posx
+00:C003 textwriter_posy
+00:C007 textwriter_ending
+00:C008 textwriter_pausing
+00:C005 textwriter_active
+00:C004 textwriter_curdelay
+00:C006 textwriter_starting
 00:C000 textwriter_curtext
+00:C00A controller_newkeys
+00:C009 controller_curkeys

tools.asm

@@ -35,6 +35,23 @@ Memfill:
     jr nz, .repeatFill
     ret
 
+Memfill16:
+; Fill an area in memory at position hl with value a for bc amount of times
+; 
+; @param hl - Starting address in memory to fill
+; @param a - The value to fill said address space with
+; @param b - How many bytes we should fill starting from said address space
+; @return a - garbage
+; @return b - PosX on where to draw text
+; @return c - PosY on where to draw text
+; @return hl - Workram position for text pointer
+; @return de - Memory address to source string
+.repeatFill
+    ld [hli], a
+    dec bc
+    jr nz, .repeatFill
+    ret
+
 ;;
 ; Waits for the vblank ISR to increment the count of vertical blanks.
 ; Will lock up if DI, vblank IRQ off, or LCD off.