move font drawing routines to LC RAM 2

src/4cade.a

@@ -80,7 +80,7 @@ RestoreStackNextTime
          !source "src/textrank.a"
          !source "src/parse.common.a"
          !source "src/parse.prefs.a"
-         !source "src/ui.font.a"
+         !source "src/glue.font.a"
          ; add new files above here so ui.common stays last
          !source "src/ui.common.a"
 MachineStatus
@@ -104,9 +104,12 @@ gGamesListStore
 LastMover
 !pseudopc $D600 {
          !source "src/ui.font.data.a"
+         !source "src/ui.font.a"
          !source "src/prodos.impl.a"
   !if * > $DEFF {
     !error "code is too large: ends at ", *
+;  } else {
+;    !warn "LCRAM2 ends at ", *
   }
 }
 EvenLasterMover

src/constants.a

@@ -16,8 +16,8 @@
 ; D000..D3FF - ProRWTS data
 ; D400..D5FF - ProRWTS code
 ; D600..D9FF - HGR font data
-; DA00..DD5C - ProRWTS glue code
-; DD5D..DFEF - unused
+; DA00..DEE6 - ProRWTS glue code
+; DEE7..DFEF - unused
 ; DFF0..DFFF - backup of stack (during gameplay and self-running demos)
 ;------------------------------------------------------------------------------
 

src/glue.font.a

@@ -0,0 +1,38 @@
+;license:MIT
+;(c) 2018-9 by 4am
+;
+; hi-res font drawing routines
+;
+; Glue functions that handle bank switching and calling the real font drawing routines
+; that live in LC RAM 2 now.
+;
+; Public functions
+; - DrawPage
+; - Draw40Chars
+; - DrawString
+; - DrawBuffer
+;
+
+DrawPage
+         +READ_RAM2_WRITE_RAM2
+         jsr   DrawPageInternal
+         +READ_RAM1_WRITE_RAM1
+         rts
+
+Draw40Chars
+         +READ_RAM2_WRITE_RAM2
+         jsr   Draw40CharsInternal
+         +READ_RAM1_WRITE_RAM1
+         rts
+
+DrawString
+         +READ_RAM2_WRITE_RAM2
+         jsr   DrawStringInternal
+         +READ_RAM1_WRITE_RAM1
+         rts
+
+DrawBuffer
+         +READ_RAM2_WRITE_RAM2
+         jsr   DrawBufferInternal
+         +READ_RAM1_WRITE_RAM1
+         rts

src/ui.font.a

@@ -3,14 +3,18 @@
 ;
 ; hi-res font drawing routines
 ;
+; /!\ These live in LC RAM 2 and rely on the font data which is also in LC RAM 2. /!\
+; Code in LC RAM 1 (which is most program code) should call the functions in glue.font
+; which handle bank switching for you.
+;
 ; Public functions
-; - DrawPage
-; - Draw40Chars
-; - DrawString
-; - DrawBuffer
+; - DrawPageInternal
+; - Draw40CharsInternal
+; - DrawStringInternal
+; - DrawBufferInternal
 ;
 
-DrawPage
+DrawPageInternal
 ; A/Y contains address of character buffer
 ; carry bit clear -> draw on page 1
 ; carry bit set   -> draw on page 2
@@ -51,7 +55,7 @@ DrawPage
          +LDAY PTR
          plp
          php
-         jsr   DrawBuffer
+         jsr   DrawBufferInternal
 @skip    inc   SAVE                  ; skip carriage return
          lda   SAVE                  ; advance PTR to start of next line
          clc
@@ -65,7 +69,7 @@ DrawPage
          plp
          rts
 
-Draw40Chars
+Draw40CharsInternal
 ; A/Y contains address of character buffer
 ; carry bit clear -> draw on page 1
 ; carry bit set   -> draw on page 2
@@ -76,13 +80,13 @@ Draw40Chars
 ; clobbers A/X/Y
          jsr   +
          ldx   #40
-         jsr   DrawBuffer
+         jsr   DrawBufferInternal
          inc   VTAB
 +        ldx   #0
          stx   HTAB
          rts
 
-DrawString
+DrawStringInternal
 ; A/Y contains address of length-prefixed string
 ; carry bit clear -> draw on page 1
 ; carry bit set   -> draw on page 2
@@ -102,7 +106,7 @@ DrawString
          +LDAY PTR
 ; note: execution falls through here
 
-DrawBuffer
+DrawBufferInternal
 ; A/Y contains address of character buffer
 ; X contains buffer length (1..40)
 ; carry bit clear -> draw on page 1
@@ -174,7 +178,6 @@ DrawBuffer
          sta   @row5+1
          sta   @row6+1
          sta   @row7+1
-         +READ_RAM2_WRITE_RAM2
 @loop
 @src     ldy   $FDFD,x
          lda   FontDataRow0,y
@@ -196,5 +199,4 @@ DrawBuffer
          inc   HTAB
          dex
          bpl   @loop
-         +READ_RAM1_WRITE_RAM1
          rts