Implement partial text drawing

Text can now be drawn while the PPU is turned on.  One tile is written
to the PPU per frame.  No new commands are added for this specifically.

Added the ClearText scene command to clear two whole rows of tiles.
This includes the ClearTileRow function in the text engine to implement
clearing the CHR RAM in an unrolled loop.

main.asm

@@ -125,6 +125,10 @@ CHUNK_DONE = 0 ; no more chunks
     ; Arguments: [start PPU address] [text] $00
     DrawTextFromTable
 
+    ; Clears out two full rows of tiles.  Takes two
+    ; arguments, one for each tile ID to start from.
+    ClearText
+
     ; Turn off the PPU and enable commands to draw
     ; to the screen outside of NMI
     TurnOffPPU
@@ -149,8 +153,8 @@ CHUNK_DONE = 0 ; no more chunks
     SetPalette
 
     ; TODO: rewrite these functions
-    TvAttr
-    StaticAttr
+    ;TvAttr
+    ;StaticAttr
 
     ; Clear an attribute table to $00
     ClearAttr0
@@ -219,6 +223,7 @@ sf_ExitRoutine: .res 1
 sf_TextStartTiles: .res 2 ; Tile IDs where the two text areas start
 sf_DialogueTable: .res 2
 sf_DialogueSwitch: .res 1 ; used in sf_DrawText and sf_DrawTextFromTable
+sf_LiveSwitch: .res 1 ; Only draw text in NMI
 
 Sleeping: .res 1
 

maps/main-boards.tmx

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<map version="1.2" tiledversion="1.3.1" orientation="orthogonal" renderorder="right-down" compressionlevel="0" width="24" height="12" tilewidth="8" tileheight="8" infinite="0" nextlayerid="17" nextobjectid="1">
+<map version="1.9" tiledversion="1.9.0" orientation="orthogonal" renderorder="right-down" compressionlevel="0" width="24" height="12" tilewidth="8" tileheight="8" infinite="0" nextlayerid="17" nextobjectid="1">
  <tileset firstgid="1" source="MetaTiles.tsx"/>
- <layer id="3" name="board-00" width="24" height="12" visible="0">
+ <layer id="3" name="board-00" width="24" height="12">
   <properties>
    <property name="gravity" type="bool" value="false"/>
    <property name="health" type="int" value="0"/>
@@ -20,7 +20,7 @@
 23,0,23,0,23,0,23,0,23,0,0,0,23,0,23,0,23,0,23,0,23,0,23,0,
 23,0,23,0,23,0,23,0,23,0,0,0,23,0,23,0,23,0,23,0,23,0,23,0,
 23,0,23,0,23,0,23,0,23,0,0,0,23,0,23,0,23,0,23,0,23,0,23,0,
-23,0,23,0,23,0,23,0,23,0,0,0,23,0,23,0,23,0,23,0,23,0,23,0
+23,0,23,0,23,0,23,0,3,0,0,0,4,0,23,0,23,0,23,0,23,0,23,0
 </data>
  </layer>
  <layer id="2" name="board-01" width="24" height="12" visible="0">
@@ -275,7 +275,7 @@
 38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38
 </data>
  </layer>
- <layer id="9" name="board-15" width="24" height="12">
+ <layer id="9" name="board-15" width="24" height="12" visible="0">
   <properties>
    <property name="gravity" type="bool" value="true"/>
   </properties>

scene-data.asm

@@ -199,6 +199,12 @@ Scene_Intro:
         .byte 2
 
     .byte SceneCmd::TurnOffPPU
+
+    ; Clear out the text from before
+    .byte SceneCmd::ClearText
+        .byte $90 ; start tile ID
+        .byte $A0 ; start tile ID
+
     .byte SceneCmd::SetNametable0
 
     .byte SceneCmd::DrawFullScene
@@ -233,8 +239,37 @@ Scene_Intro:
     .byte SceneCmd::SetFramePointer
         .word $0000
 
+    .byte SceneCmd::PrepareText
+        .word $22A8 ; NT address
+        .byte 0     ; ID
+        .byte $90 ; start tile ID
+
+    .byte SceneCmd::PrepareText
+        .word $22C8 ; NT address
+        .byte 1     ; ID
+        .byte $A0 ; start tile ID
+
+    .byte SceneCmd::DrawTextFromTable
+        .byte 0 | $80
+        .byte Dialogue::CyberPiss_1
+
+    .byte SceneCmd::DrawTextFromTable
+        .byte 1 | $80
+        .byte Dialogue::CyberPiss_2
+
+    .byte SceneCmd::WaitSeconds
+        .byte 3
+
+    .byte SceneCmd::DrawTextFromTable
+        .byte 0 | $80
+        .byte Dialogue::CyberPiss_3
+
+    .byte SceneCmd::DrawTextFromTable
+        .byte 1 | $80
+        .byte Dialogue::CyberPiss_4
+
     .byte SceneCmd::WaitSeconds
-        .byte 10
+        .byte 5
 
     .byte SceneCmd::GotoInit
 

scene-engine.asm

@@ -63,14 +63,15 @@ scene_Functions:
     .word sf_SetUnskippable-1
     .word sf_DrawText-1
     .word sf_DrawTextFromTable-1
+    .word sf_ClearText-1
     .word sf_TurnOffPPU-1
     .word sf_TurnOnPPU-1
     .word sf_FillNametable-1
     .word sf_LoadChr-1
     .word sf_PadSprites-1
     .word sf_SetPalette-1
-    .word WriteNewsAttr-1
-    .word WriteStaticAttributes-1
+    ;.word WriteNewsAttr-1
+    ;.word WriteStaticAttributes-1
     .word ClearAttrTable0-1
     .word ClearAttrTable1-1
     .word ClearAttrTable2-1
@@ -243,7 +244,10 @@ sf_SetUnskippable:
     rts
 
 sf_TurnOffPPU:
-    .Disable_Drawing
+    ;.Disable_Drawing
+    lda #0
+    sta sf_PpuOn
+    jsr WaitForNMI
     rts
 
 sf_TurnOnPPU:
@@ -409,6 +413,48 @@ sf_SetExitRoutine:
     sta sf_ExitRoutine
     rts
 
+sf_ClearText:
+    ; Get the CHR start tile ID
+    lda (AddressPointer3), y
+    iny
+    tax
+
+    ; TileID -> CHR Address
+    lda data_Mult16_A, x
+    sta AddressPointer0+0
+    lda data_Mult16_B, x
+    sta AddressPointer0+1
+
+    ; Clear all the CHR tiles in PPU RAM
+    ;jsr WriteBufferUnrolled
+    ldx #$FF
+    lda #$00
+    jsr ClearTileRow
+
+    ; Do it again, lmao
+
+    ; Get the CHR start tile ID
+    lda (AddressPointer3), y
+    iny
+    tax
+
+    ; TileID -> CHR Address
+    lda data_Mult16_A, x
+    sta AddressPointer0+0
+    lda data_Mult16_B, x
+    sta AddressPointer0+1
+
+    ; Clear all the CHR tiles in PPU RAM
+    ;jsr WriteBufferUnrolled
+    ldx #$FF
+    lda #$00
+    jsr ClearTileRow
+
+    jsr TextClearStringBuffer
+    jsr TextClearBuffer
+
+    rts
+
 sf_DrawText:
     ;bit $2002
     lda #$00
@@ -440,25 +486,26 @@ sf_DrawText:
     lda sf_DialogueSwitch
     beq :+
 
-    ; Backup pointer
-    lda AddressPointer3+0
-    pha
-    lda AddressPointer3+1
-    pha
-
     ; Lookup pointer to text
+    iny
     lda (AddressPointer3), y
+    asl a
     tax
     lda DialogueIndex+0, x
     sta AddressPointer4+0
     lda DialogueIndex+1, x
     sta AddressPointer4+1
 
+    ; Backup pointer
+    lda AddressPointer3+0
+    pha
+    lda AddressPointer3+1
+    pha
+
     ; Backup Y
-    iny
     tya
     pha
-    ldy #0
+    ldy #$FF
 
     ; Grab pointer to text
     lda AddressPointer4+0
@@ -501,16 +548,33 @@ sf_DrawText:
     ;jsr TextPrepare_v2
     jsr TextPrepare_v3
 
+    ;lda #16 ; number of chars
+    ldx #0
+    ;ldx #$FF
+
+    lda sf_PpuOn
+    beq @fulldraw
+    lda #16 ; CHR count
+
+    jsr PreparePartialTextWrite
+
+@partial:
+    jsr WaitForNMI
+    jsr WritePartialTextBuffer
+    dec ChrCount
+    bne @partial
+    jmp @drawdone
+
+@fulldraw:
     lda AddressPointer6+0
     sta AddressPointer0+0
     lda AddressPointer6+1
     sta AddressPointer0+1
 
-    lda #16 ; number of chars
-    ldx #0
-    ;ldx #$FF
+    lda #16 ; CHR count
     jsr WriteTextBuffer
 
+@drawdone:
     jsr TextClearBuffer
 
     pla
@@ -582,7 +646,7 @@ sf_GotoInit:
 NMI_Scene:
     pha
     lda sf_PpuOn
-    beq :+
+    beq @ppuoff
     ;lda #0
     ;sta sf_PpuOn
 
@@ -602,7 +666,13 @@ NMI_Scene:
     lda #0
     sta $2005
     sta $2005
-:
+    dec Sleeping
+    pla
+    rti
+
+@ppuoff:
+    lda #0
+    sta $2001
     dec Sleeping
     pla
     rti

screen-decode.asm

@@ -280,6 +280,7 @@ WriteTvAttr:
     sta $2007
     sta $2007
     rts
+
 WriteNewsAttr:
     ; 23CA
     lda #$23

text-engine-ram.asm

@@ -22,6 +22,8 @@ WorkingRuneB: .res 8
 
 .segment "MAINRAM"
 
+BgTextPal: .res 1
+
 ;ChrAddr:    .res 2
 ChrCount:   .res 1  ; Tile count, not byte count
 

text-engine.asm

@@ -8,14 +8,36 @@
 
     SPACE_WIDTH = 5
 
+; Clear a set of 16 tiles, starting at the address in AddressPointer0
+; X holds values for first bit plane
+; A holds values for second bit plane
+ClearTileRow:
+    pha
+    bit $2002
+    lda AddressPointer0+1
+    sta $2006
+    lda AddressPointer0+0
+    sta $2006
+    pla
+
+    .repeat 16
+        .repeat 8
+        stx $2007
+        .endrepeat
+        .repeat 8
+        sta $2007
+        .endrepeat
+    .endrepeat
+    rts
+
 WriteBufferUnrolled:
     bit $2002
     lda AddressPointer0+1
     sta $2006
     lda AddressPointer0+0
     sta $2006
 
-    .repeat 21, B
+    .repeat 16, B
         .repeat 8, C
         lda ChrBuffer + ((B*8) + C)
         sta $2007
@@ -250,6 +272,58 @@ WriteTextBuffer_LevelSelect:
     sta TextEor
     rts
 
+; A has count
+; X has the BG palette value thing in it
+PreparePartialTextWrite:
+    sta ChrCount
+    txa
+    sta BgTextPal
+    lda #0
+    sta TextIdx
+    lda #$FF
+    sta TextEor
+    rts
+
+; Similar to WriteTextBuffer, but only
+; writes a few tiles. (one for now)
+WritePartialTextBuffer:
+    bit $2002
+    lda AddressPointer6+1
+    sta $2006
+    lda AddressPointer6+0
+    sta $2006
+
+    ldx TextIdx
+
+    .repeat 8,i
+    lda ChrBuffer+i, x
+    eor TextEor
+    sta $2007
+    .endrepeat
+
+    txa
+    clc
+    adc #8
+    sta TextIdx
+
+    ; Second plane
+    lda BgTextPal
+    .repeat 8
+    sta $2007
+    .endrepeat
+
+    clc
+    lda #16
+    adc AddressPointer6+0
+    sta AddressPointer6+0
+    bcc :+
+    inc AddressPointer6+1
+:
+    lda #0
+    sta $2005
+    sta $2005
+    rts
+
 ; A has count
 ; X has the BG palette value thing in it
 WriteTextBuffer: