From cc83fef9b00e32ff9e3912938ae57df928a7f892 Mon Sep 17 00:00:00 2001
From: cassidoxa <cassidymoen@gmx.com>
Date: Sun, 13 Aug 2023 18:55:52 -0400
Subject: [PATCH] Shops VRAM transfer

---
 framehook.asm  | 20 ++++++++++++++++++++
 ram.asm        |  8 +++++---
 shopkeeper.asm | 28 +++++++++++++++++++---------
 3 files changed, 44 insertions(+), 12 deletions(-)

diff --git a/framehook.asm b/framehook.asm
index d889082..6f5b374 100644
--- a/framehook.asm
+++ b/framehook.asm
@@ -35,7 +35,27 @@ PostNMIHookAction:
                 .return
                 STZ.w NMIAux ; zero bank byte of NMI hook pointer
         +
+        JSR.w TransferItemGFX
         LDA.b INIDISPQ : STA.w INIDISP ; thing we wrote over, turn screen back on
 
 JML.l PostNMIHookReturn
 ;--------------------------------------------------------------------------------
+TransferItemGFX:
+; Only used for shops now but could be used for anything. We should look at how door rando does this
+; and try to unify one approach.
+        REP #$30
+        LDX.w ItemQueuePtr : BEQ .done
+                -
+                        LDA.w ItemGFXQueue,X : STA.w ItemGFXPtr
+                        LDA.w ItemTargetQueue,X : STA.w ItemGFXTarget
+                        PHX
+                        JSL.l TransferItemToVRAM
+                        REP #$10
+                        PLX
+                        DEX #2
+                BPL -
+
+        STZ.w ItemQueuePtr
+        .done
+        SEP #$30
+RTS
diff --git a/ram.asm b/ram.asm
index 9000afc..3a09259 100644
--- a/ram.asm
+++ b/ram.asm
@@ -189,9 +189,11 @@ RaceGameFlag = $7E021B            ;
 MessageJunk = $7E0223             ; Zeroed but never used (?)
                                   ;
 ShopPurchaseFlag = $7E0224        ; $01 = Shop purchase item receipt.
-;CoolScratch = $7E0226            ; 0x5A bytes of free ram
-SpriteID = $7E0230                ; 0x0A bytes
-                                  ;
+;CoolScratch = $7E0224            ; 0x5C bytes of free ram
+ItemQueuePtr = $7E0226            ; Pointer into Item GFX and VRAM target queues. Word length.
+SpriteID = $7E0230                ; 0x0A bytes. Receipt ID for main loop sprite we're handling.
+ItemGFXQueue = $7E0230            ; Pointers to decompressed item tiles deferred to NMI loading. $10 bytes
+ItemTargetQueue = $7E0240         ; Pointers to VRAM targets for ItemGFXQueue. $10 bytes
 AncillaVelocityZ = $7E0294        ; 0x0A bytes
 AncillaZCoord = $7E029E           ; 0x0A bytes
                                   ;
diff --git a/shopkeeper.asm b/shopkeeper.asm
index c85e873..b6cdd25 100644
--- a/shopkeeper.asm
+++ b/shopkeeper.asm
@@ -136,7 +136,7 @@ SpritePrep_ShopKeeper:
                                 TAY
                                 REP #$30
 				LDA.b 1,s : TAX : LDA.l .tile_offsets, X : TAX
-				JSR LoadTile
+				JSR.w SetupTileTransfer
 			PLY : PLX
 			INY #4
 		
@@ -144,11 +144,13 @@ SpritePrep_ShopKeeper:
 		INX #8
 	JMP -
 	.stop
+        REP #$20
+        LDA.w ItemQueuePtr
+        DEC #2
+        AND.w #$00E
+        STA.w ItemQueuePtr
+        SEP #$20
 	
-	;LDA.b #Shopkeeper_UploadVRAMTilesLong>>16 : STA.w NMIAux+2
-	;LDA.b #Shopkeeper_UploadVRAMTilesLong>>8 : STA.w NMIAux+1
-	;LDA.b #Shopkeeper_UploadVRAMTilesLong>>0 : STA.w NMIAux
-
 	.done
 	LDA.l ShopType : BIT.b #$20 : BEQ .notTakeAll ; Take-all
 	.takeAll
@@ -188,7 +190,7 @@ dw $0100, $0000
 ;--------------------------------------------------------------------------------
 ; X - Tile Buffer Offset
 ; Y - Item ID
-LoadTile:
+SetupTileTransfer:
         LDA.l ShopType : BIT.w #$0010 : BNE .alt_vram
 	        TXA : LSR #2
                 CLC : ADC.w #!FREE_TILE
@@ -197,10 +199,18 @@ LoadTile:
 	TXA : LSR #2
         CLC : ADC.w #!FREE_TILE_ALT
         .store_target
-        STA.w ItemGFXTarget
+        LDX.w ItemQueuePtr
+        STA.w ItemTargetQueue,X
+
 	TYA : ASL : TAX
-        LDA.l StandingItemGraphicsOffsets,X : STA.w ItemGFXPtr
-        JSL.l TransferItemToVRAM
+        LDA.l StandingItemGraphicsOffsets,X
+        LDX.w ItemQueuePtr
+        STA.w ItemGFXQueue,X
+
+        TXA
+        INC #2
+        AND.w #$000E
+        STA.w ItemQueuePtr
         TDC
 	REP #$10 ; set 16-bit index registers
         SEP #$20