Making some progress splitting the raycasting expander.

Platform/Apple/virtual/src/plasma/gameloop.pla

@@ -12,7 +12,7 @@
 // Fixed memory locations
 const seed          = $4E     // Incremented continuously by keyboard read routine
 const displayEngine = $6000   // main mem (raycaster and tile engine at same location)
-const expandVec     = $2000   // aux mem (only for raycaster)
+const expandVec     = $3000   // aux mem (only for raycaster)
 const fontEngine    = $E000   // main mem
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////

Platform/Apple/virtual/src/raycast/expand.s

@@ -8,11 +8,11 @@
 ; governing permissions and limitations under the License.
 ;****************************************************************************************
 
-* = $2000
+* = $3000
 !source "render.i"
 
 expand_vec:
-	!word expand_0
+	!word expand_split	; gets replaced by expand_0
 	!word expand_2
 	!word expand_4
 	!word expand_6
@@ -5776,6 +5776,8 @@ expand_102:
 +
 	rts
 
+!source "expand_split.i"
+!pseudopc $D000 {
 ; Produce 104 rows from 64 rows
 expand_104:
 	jsr selectMip0
@@ -7372,4 +7374,5 @@ e_t64oroo:
 	sta 66*BLIT_STRIDE + blitRoll,x
 	sta 67*BLIT_STRIDE + blitRoll,x
 +	rts
-
+} ; end of pseudopc
+expand_end = *

Platform/Apple/virtual/src/raycast/render.i

@@ -97,7 +97,7 @@ wSpriteLeft	= $B4
 
 ;---------------------------------
 ; The following are in aux mem...
-expandVec	= $2000
+expandVec	= $3000
 ; back to main mem
 ;---------------------------------
 

Platform/Apple/virtual/src/raycast/render.s

@@ -77,6 +77,7 @@ nextLink:	!byte 0		; next link to allocate
 plasmaStk:      !byte 0
 nTextures:	!byte 0
 scripts:	!word 0		; pointer to loaded scripts module
+expanderRelocd:	!byte 0		; flag so we only reloc expander once
 
 skyColorEven:   !byte $20
 skyColorOdd:    !byte $22
@@ -1254,14 +1255,17 @@ drawRay: !zone
 	lda texAddrHi,x
 	sta pTex+1
 	; jump to the unrolled expansion code for the selected height
+	!if DEBUG >= 2 { +prStr : !text "Calling expansion code.",0 }
 	lda lineCt
+	sei			; prevent interrupts while in aux mem
+	sta setAuxZP
 	asl
 	bcc +
 	lda #254		; clamp max height
 +	sta expanderJmp+1	; set vector offset
-	!if DEBUG >= 2 { +prStr : !text "Calling expansion code.",0 }
-	sei			; prevent interrupts while in aux mem
+	lda setLcRW+lcBank2	; part of expander split and relocated to LC bank 2
 	jsr callExpander	; was copied from .callIt to $100 at init time
+	sta clrAuxZP
 	cli			; interrupts ok after we get back from aux
 .skip	pla			; retrieve link to next in stack
 	tax			; put in X for indexing
@@ -1542,10 +1546,14 @@ setBackBuf: !zone
 setExpansionCaller:
 	; Copy the expansion caller to low stack.
 	ldx #.callEnd - .callIt - 1
+	sei
+	sta setAuxZP
 -	lda .callIt,x
 	sta callExpander,x
 	dex
 	bpl -
+	sta clrAuxZP
+	cli
 	rts
 .callIt:
 !pseudopc $100 {
@@ -2093,6 +2101,8 @@ pl_initMap: !zone
 	ldx #<(tableEnd-tableStart)
 	ldy #>(tableEnd-tableStart)
 	jsr mainLoader
+	; If expander hasn't been split and relocated yet, do so now
+	jsr splitExpander
 	; Proceed with loading
 	lda #1			; non-zero to init scripts also
 	jsr loadTextures
@@ -2107,6 +2117,42 @@ pl_initMap: !zone
 	jsr graphInit
 	jmp renderFrame
 
+splitExpander:
+	lda expanderRelocd
+	bne .done		; only relocate once
+	jsr setExpansionCaller
+	sei			; prevent interrupts while in aux mem
+	sta setAuxZP
+	sta setAuxWr
+	lda setLcRW+lcBank2	; reloc to bank 2 in aux mem (unused by anything else)
+	lda setLcRW+lcBank2	; second access to make it read/write
+	jsr callExpander	; was copied from .callIt to $100 at init time
+	sta clrAuxWr
+	sta clrAuxZP
+	cli			; interrupts ok after we get back from aux
+	pha			; save new seg length
+	txa
+	pha
+	; Now truncate the main segment of the expander, freeing up the
+	; split space for textures and other resources.
+	lda #FREE_MEMORY
+	jsr .memexp
+	lda #SET_MEM_TARGET
+	jsr .memexp
+	pla
+	tay
+	pla
+	tax
+	lda #REQUEST_MEMORY
+	jsr auxLoader
+	lda #LOCK_MEMORY
+	jsr .memexp
+	inc expanderRelocd
+.done	rts
+.memexp	ldx #<expandVec
+	ldy #>expandVec
+	jmp auxLoader
+
 ; Following are log/pow lookup tables. For speed, align them on a page boundary.
 	!align 255,0