From 19468be9fb4222290813c11b9f4feea22959818b Mon Sep 17 00:00:00 2001
From: Tijn Kersjes <tijn@divbyzero.nl>
Date: Wed, 11 Sep 2019 23:31:50 +0300
Subject: [PATCH] Add struct

---
 examples/sprite-demo/sprite-demo.fs | 39 ++++++++++++++++++-----------
 lib/struct.fs                       |  6 +++++
 2 files changed, 31 insertions(+), 14 deletions(-)
 create mode 100644 lib/struct.fs

diff --git a/examples/sprite-demo/sprite-demo.fs b/examples/sprite-demo/sprite-demo.fs
index 9bcd3699..76f5b868 100644
--- a/examples/sprite-demo/sprite-demo.fs
+++ b/examples/sprite-demo/sprite-demo.fs
@@ -5,16 +5,27 @@ require gbhw.fs
 require input.fs
 require lcd.fs
 require ibm-font.fs
-
+require struct.fs
 ( program start )
 
-_OAM 0 + constant player.y
-_OAM 1 + constant player.x
-_OAM 2 + constant player.tile
-_OAM 3 + constant player.opts
+:m new CREATE allot ;
+:m sprite 4 * _OAM + CONSTANT ;
+
+ROM
+
+struct
+  1 chars field spr-y
+  1 chars field spr-x
+  1 chars field spr-tile
+  1 chars field spr-opts
+end-struct sprite%
+
+0 SPRITE player
+
+: v! lcd-wait-vblank c! ;
 
-: playerX+! player.x lcd-wait-vblank +! ;
-: playerY+! player.y lcd-wait-vblank +! ;
+: playerX+! player spr-x lcd-wait-vblank +! ;
+: playerY+! player spr-y lcd-wait-vblank +! ;
 
 : handle-input
   begin
@@ -23,8 +34,8 @@ _OAM 3 + constant player.opts
     dup k-left  and if -1 playerX+! then
     dup k-up    and if -1 playerY+! then
     dup k-down  and if  1 playerY+! then
-    dup k-a     and if  1 player.tile lcd-wait-vblank c! then
-    dup k-b     and if  2 player.tile lcd-wait-vblank c! then
+    dup k-a     and if  1 player spr-tile v! then
+    dup k-b     and if  2 player spr-tile v! then
     \ If there no key pressed, wait for one
     0= if halt then
   again ;
@@ -32,7 +43,7 @@ _OAM 3 + constant player.opts
 : enable-sprites
   [ LCDCF_ON
     LCDCF_BG8000 or
-    LCDCF_BGOFF or
+    LCDCF_BGON or
     LCDCF_OBJ8 or
     LCDCF_OBJON or ]L
   rLCDC c! ;
@@ -44,10 +55,10 @@ _OAM 3 + constant player.opts
   _OAM [ 40 4 * ]L erase ;
 
 : init-player-sprite
-  #1        player.tile c!
-  %00000000 player.opts c!
-  #80       player.y    c!
-  #50       player.x    c! ;
+  #1        player spr-tile c!
+  %00000000 player spr-opts c!
+  #80       player spr-y    c!
+  #50       player spr-x    c! ;
 
 : main
   init-input
diff --git a/lib/struct.fs b/lib/struct.fs
new file mode 100644
index 00000000..1e5a8aaf
--- /dev/null
+++ b/lib/struct.fs
@@ -0,0 +1,6 @@
+:m struct 0 ;
+:m field over + swap CREATE , DOES> @ + ;
+:m end-struct constant ;
+
+:m c-field 1 chars field ;
+:m a-field 1 cells field ;