From 2c258363ad3bc43c2d93761fe05898a10bf63151 Mon Sep 17 00:00:00 2001
From: Chad Brokaw <cbrokaw@gmail.com>
Date: Sat, 16 Jul 2022 16:48:04 -0400
Subject: [PATCH] restore tile.h to maintain sync with tile.rs

---
 piet-gpu/shader/tile.h | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/piet-gpu/shader/tile.h b/piet-gpu/shader/tile.h
index 500277b..45473f2 100644
--- a/piet-gpu/shader/tile.h
+++ b/piet-gpu/shader/tile.h
@@ -14,6 +14,10 @@ struct TileSegRef {
     uint offset;
 };
 
+struct TransformSegRef {
+    uint offset;
+};
+
 struct Path {
     uvec4 bbox;
     TileRef tiles;
@@ -49,6 +53,17 @@ TileSegRef TileSeg_index(TileSegRef ref, uint index) {
     return TileSegRef(ref.offset + index * TileSeg_size);
 }
 
+struct TransformSeg {
+    vec4 mat;
+    vec2 translate;
+};
+
+#define TransformSeg_size 24
+
+TransformSegRef TransformSeg_index(TransformSegRef ref, uint index) {
+    return TransformSegRef(ref.offset + index * TransformSeg_size);
+}
+
 Path Path_read(Alloc a, PathRef ref) {
     uint ix = ref.offset >> 2;
     uint raw0 = read_mem(a, ix + 0);
@@ -109,3 +124,26 @@ void TileSeg_write(Alloc a, TileSegRef ref, TileSeg s) {
     write_mem(a, ix + 5, s.next.offset);
 }
 
+TransformSeg TransformSeg_read(Alloc a, TransformSegRef ref) {
+    uint ix = ref.offset >> 2;
+    uint raw0 = read_mem(a, ix + 0);
+    uint raw1 = read_mem(a, ix + 1);
+    uint raw2 = read_mem(a, ix + 2);
+    uint raw3 = read_mem(a, ix + 3);
+    uint raw4 = read_mem(a, ix + 4);
+    uint raw5 = read_mem(a, ix + 5);
+    TransformSeg s;
+    s.mat = vec4(uintBitsToFloat(raw0), uintBitsToFloat(raw1), uintBitsToFloat(raw2), uintBitsToFloat(raw3));
+    s.translate = vec2(uintBitsToFloat(raw4), uintBitsToFloat(raw5));
+    return s;
+}
+
+void TransformSeg_write(Alloc a, TransformSegRef ref, TransformSeg s) {
+    uint ix = ref.offset >> 2;
+    write_mem(a, ix + 0, floatBitsToUint(s.mat.x));
+    write_mem(a, ix + 1, floatBitsToUint(s.mat.y));
+    write_mem(a, ix + 2, floatBitsToUint(s.mat.z));
+    write_mem(a, ix + 3, floatBitsToUint(s.mat.w));
+    write_mem(a, ix + 4, floatBitsToUint(s.translate.x));
+    write_mem(a, ix + 5, floatBitsToUint(s.translate.y));
+}