From e7ea6fd77f9cc102ba49d119e6e0cf0dcb5d1bd2 Mon Sep 17 00:00:00 2001
From: Fredrick Brennan <copypaste@kittens.ph>
Date: Thu, 10 Nov 2022 04:36:46 -0500
Subject: [PATCH] patterns: Added APNG support to PNG pattern (#53)

---
 patterns/png.hexpat | 46 +++++++++++++++++++++++++++++++++++----------
 1 file changed, 36 insertions(+), 10 deletions(-)

diff --git a/patterns/png.hexpat b/patterns/png.hexpat
index ff55e03..f88c675 100644
--- a/patterns/png.hexpat
+++ b/patterns/png.hexpat
@@ -1,6 +1,5 @@
 #pragma MIME image/png
 #pragma endian big
-#pragma pattern_limit 0
 
 struct header_t {
     u8 highBitByte;
@@ -88,6 +87,33 @@ fn text_len() {
    return len;
 };
 
+enum BlendOp: u8 {
+	Source = 0x0,
+	Over
+};
+
+enum DisposeOp: u8 {
+    None = 0x0,
+    Background,
+    Previous
+};
+
+struct fctl_t {
+	u32 sequence_no [[comment("Sequence №")]];
+	u32 width [[comment("Frame width")]];
+	u32 height [[comment("Frame height")]];
+	u32 xoff;
+	u32 yoff;
+	u16 delay_num [[comment("Frame delay fraction numerator")]];
+	u16 delay_den [[comment("Frame delay fraction denominator")]];
+	DisposeOp dispose_op;
+	BlendOp blend_op;
+};
+
+struct fdat_t {
+    u32 sequence_no;
+};
+
 struct itxt_t {
     char keyword[];
     u8 compression_flag;
@@ -145,18 +171,20 @@ struct chunk_t {
         sRGB srgb;
     } else if (name == pHYs_k) {
         phys_t phys;
-    } else if (name == acTL_k) {
-        actl_t  actl;
-    } else if (name == fcTL_k) {
+    } else if (type == acTL_k) {
+        actl_t  actl [[comment("Animation control chunk")]];
+    } else if (type == fcTL_k) {
         fctl_t fctl [[comment("Frame control chunk")]];
-    } else if (name == iTXt_k) {
+    } else if (type == iTXt_k) {
         itxt_t text;
+    } else if (type == gAMA_k) {
+    	u32 gamma [[name("image gamma"), comment("4 byte unsigned integer representing gamma times 100000")]];
+    } else if (type == iCCP_k) {
+    	iccp_t iccp;
     } else if (name == tEXt_k) {
         text_t text;
     } else if (name == zTXt_k) {
         ztxt_t text;
-    } else if (name == gAMA_k) {
-        u32 gamma [[name("image gamma"), comment("4 byte unsigned integer representing gamma times 100000")]];
     } else if (name == iCCP_k) {
         iccp_t iccp;
     } else if (name == fdAT_k) {
@@ -180,6 +208,4 @@ struct chunk_set {
 header_t header @ 0x00 [[comment("PNG file signature"), name("Signature")]];
 chunk_t ihdr_chunk @ 0x08 [[comment("PNG Header chunk"), name("IHDR")]];
 chunk_set set @ $ [[comment("PNG Chunks"), name("Chunks"), inline]];
-chunk_t iend_chunk @ $ [[comment("Image End Chunk"), name("IEND")]];
-
-// vim: syntax=rust
+chunk_t iend_chunk @ $ [[comment("Image End Chunk"), name("IEND")]];
\ No newline at end of file