From a990b07cb580eb8847621b4f4b4ac9797b0b5c26 Mon Sep 17 00:00:00 2001
From: Treeki <treeki@gmail.com>
Date: Mon, 6 May 2013 09:30:59 +0200
Subject: optimised copying for animated tiles

---
 animtiles.yaml    |  6 ++++++
 src/animtiles.cpp | 17 +++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/animtiles.yaml b/animtiles.yaml
index 3f8f8ab..879693b 100644
--- a/animtiles.yaml
+++ b/animtiles.yaml
@@ -20,3 +20,9 @@ hooks:
     addr_ntsc: 0xdeadbeef
     addr_pal: 0x80087544
     data: '3880 1000' # 128 tiles should be enough for anyone
+
+  - name: AnimTileOptimisedCopy
+    type: branch_insn
+    branch_type: bl
+    src_addr_pal: 0x80087AD0
+    target_func: 'CopyAnimTile'
diff --git a/src/animtiles.cpp b/src/animtiles.cpp
index 4213e6a..53a204b 100644
--- a/src/animtiles.cpp
+++ b/src/animtiles.cpp
@@ -51,3 +51,20 @@ void DoTiles(void* self) {
 void DestroyTiles(void *self) {
 	FreeFile(&fh);
 }
+
+
+extern "C" void CopyAnimTile(u8 *target, int tileNum, u8 *source, int frameNum) {
+	int tileRow = tileNum >> 5; // divided by 32
+	int tileColumn = tileNum & 31; // modulus by 32
+
+	u8 *baseRow = target + (tileRow * 2 * 32 * 1024);
+	u8 *baseTile = baseRow + (tileColumn * 32 * 4 * 2);
+
+	u8 *sourceRow = source + (frameNum * 2 * 32 * 32);
+
+	for (int i = 0; i < 8; i++) {
+		memcpy(baseTile, sourceRow, 32*4*2);
+		baseTile += (2 * 4 * 1024);
+		sourceRow += (2 * 32 * 4);
+	}
+}
-- 
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