Prevent removing main camera pointer by Play_ClearCamera

ASM/src/build.asm

@@ -134,6 +134,7 @@ RANDO_CONTEXT:
 .include "bg_gate_shutter.asm"
 .include "big_poe.asm"
 .include "player_ladder_cutscene.asm"
+.include "play_clearcamera.asm"
 
 .align 0x10
 .importobj "../build/bundle.o"

ASM/src/hacks.asm

@@ -4162,3 +4162,4 @@ DemoEffect_DrawJewel_AfterHook:
 .include "hacks/ovl_en_okarina_tag.asm"
 .include "hacks/sound.asm"
 .include "hacks/z_player.asm"
+.include "hacks/z_play.asm"

ASM/src/hacks/z_play.asm

@@ -0,0 +1,22 @@
+.headersize (0x80114dd0 - 0x00b8ad30)
+
+;================================================================================
+; Fixes crashing when too many subcameras spawn, because the main camera pointer
+; gets set to NULL (Spirit Temple mirror room etc)
+;================================================================================
+; Replaces  sll     a1,a1,0x10
+;           sra     a1,a1,0x10
+;           sw      ra,20(sp)
+;           move    a2,a0
+;           li      at,-1
+;           bne     a1,at,8009d248  (branch if camId not -1/NONE)
+;           sll     v0,a1,0x10
+
+.org 0x8009d238                    ; in Play_ClearCamera
+    sw      ra,20(sp)
+    jal     Play_ClearCameraAvoidMain
+    move    a2,a0                   ; displaced
+    beq     t0,at,0x8009d274        ; camId MAIN, skip to end function
+    nop
+    beq     t0,at,0x8009d248        ; not MAIN/NONE, remove pointer
+    nop

ASM/src/play_clearcamera.asm

@@ -0,0 +1,17 @@
+Play_ClearCameraAvoidMain:             ; camId a1 (-1 = NONE, 0 = MAIN)
+    sll     a1,a1,0x10                 ; displaced
+    sra     a1,a1,0x10                 ; displaced
+    li      at,-1                      ; displaced
+    li      t0,0                       ; return value because v0 is in use
+
+    beq     a1,at,@@Return             ; If camId = NONE, just continue as usual
+    sll     v0,a1,0x10                 ; displaced
+    li      at,1                       ; for beq in caller
+    beqzl   a1,@@Return                ; If camId = MAIN, skip to end and don't set pointer null
+    li      t0,1
+    li      at,2                       ; for beq in caller
+    b       @@Return                   ; If not MAIN/NONE, remove pointer
+    li      t0,2
+@@Return:
+    jr      ra
+    nop