From 8ee021416428da440656e52f3dc0cb021ccb379a Mon Sep 17 00:00:00 2001
From: Ry <ryanst755@gmail.com>
Date: Tue, 26 Jul 2022 16:58:20 -0700
Subject: [PATCH] Add some convenience routines for moving and resizing
 overlays

---
 fox32rom.def |  5 ++++
 main.asm     |  5 ++++
 overlay.asm  | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 84 insertions(+)

diff --git a/fox32rom.def b/fox32rom.def
index 1fbe406..a480be9 100644
--- a/fox32rom.def
+++ b/fox32rom.def
@@ -43,6 +43,11 @@ draw_pixel_to_overlay:                    jmp [0xF004301C]
 draw_filled_rectangle_to_overlay:         jmp [0xF0043020]
 check_if_overlay_covers_position:         jmp [0xF0043024]
 check_if_enabled_overlay_covers_position: jmp [0xF0043028]
+enable_overlay:                           jmp [0xF004302C]
+disable_overlay:                          jmp [0xF0043030]
+move_overlay:                             jmp [0xF0043034]
+resize_overlay:                           jmp [0xF0043038]
+set_overlay_framebuffer_pointer:          jmp [0xF004303C]
 
 ; menu bar jump table
 enable_menu_bar:                          jmp [0xF0044000]
diff --git a/main.asm b/main.asm
index d2771ed..d537521 100644
--- a/main.asm
+++ b/main.asm
@@ -189,6 +189,11 @@ get_rom_version:
     data.32 draw_filled_rectangle_to_overlay
     data.32 check_if_overlay_covers_position
     data.32 check_if_enabled_overlay_covers_position
+    data.32 enable_overlay
+    data.32 disable_overlay
+    data.32 move_overlay
+    data.32 resize_overlay
+    data.32 set_overlay_framebuffer_pointer
 
     ; menu bar jump table
     org.pad 0xF0044000
diff --git a/overlay.asm b/overlay.asm
index 9576883..a70ee35 100644
--- a/overlay.asm
+++ b/overlay.asm
@@ -1,5 +1,79 @@
 ; overlay routines
 
+; enable an overlay
+; inputs:
+; r0: overlay number
+; outputs:
+; none
+enable_overlay:
+    push r0
+
+    or r0, 0x80000300
+    out r0, 1
+
+    pop r0
+    ret
+
+; disable an overlay
+; inputs:
+; r0: overlay number
+; outputs:
+; none
+disable_overlay:
+    push r0
+
+    or r0, 0x80000300
+    out r0, 0
+
+    pop r0
+    ret
+
+; move an overlay
+; r0: X position
+; r1: Y position
+; r2: overlay number
+move_overlay:
+    push r1
+    push r2
+
+    or r2, 0x80000000
+    sla r1, 16
+    mov.16 r1, r0
+    out r2, r1
+
+    pop r2
+    pop r1
+    ret
+
+; resize an overlay
+; r0: width
+; r1: height
+; r2: overlay number
+resize_overlay:
+    push r1
+    push r2
+
+    or r2, 0x80000100
+    sla r1, 16
+    mov.16 r1, r0
+    out r2, r1
+
+    pop r2
+    pop r1
+    ret
+
+; set an overlay's framebuffer pointer
+; r0: framebuffer pointer
+; r1: overlay number
+set_overlay_framebuffer_pointer:
+    push r1
+
+    or r1, 0x80000200
+    out r1, r0
+
+    pop r1
+    ret
+
 ; fill a whole overlay with a color
 ; inputs:
 ; r0: color