feat(png): Implement chunk handlers for IHDR and IDAT

2 files changed, 27 insertions, 5 deletions

diff --git a/include/tinyff/image/png.h b/include/tinyff/image/png.h
index 80e8fe6..9348dce 100644
--- a/include/tinyff/image/png.h
+++ b/include/tinyff/image/png.h
@@ -46,9 +46,9 @@ typedef struct {
 } ff_png_chunk_handler;
 
 const ff_png_chunk_handler ff_png_chunk_handlers[] = {
-    {"IHDR", NULL},
-    {"IDAT", NULL},
-    {"IEND", NULL},
+    {"IHDR", ff_png_header_handler},
+    {"IDAT", ff_png_data_handler},
+    {"IEND", ff_png_end_handler},
 
 
     {NULL, NULL} // Terminator
diff --git a/src/format/image/png.c b/src/format/image/png.c
index d177819..8662fa2 100644
--- a/src/format/image/png.c
+++ b/src/format/image/png.c
@@ -55,13 +55,15 @@ ff_result ff_open_png(const char *filepath, ff_png_ctx **out_ctx)
     return FF_RESULT_OK;
 }
 
-void ff_png_header_handler(uint8_t *buf, size_t len, ff_png_ctx *ctx)
+// Handlers
+
+ff_result ff_png_header_handler(uint8_t *buf, size_t len, ff_png_ctx *ctx)
 {
     ff_dprintf("png: IHDR chunk received (len=%zu)\n", len);
 
     if (len != 13) {
         ff_dprintf("png: invalid IHDR length\n");
-        return;
+        return FF_RESULT_ERROR_INVALID_FILE;
     }
 
     uint32_t w = get_big_endian(buf);
@@ -81,4 +83,24 @@ void ff_png_header_handler(uint8_t *buf, size_t len, ff_png_ctx *ctx)
     ctx->color_type = buf[9];
 
     ff_dprintf("png: IHDR stored in context\n");
+
+    return FF_RESULT_OK;
+}
+
+ff_result ff_png_data_handler(uint8_t *buf, size_t len, ff_png_ctx *ctx)
+{
+    ff_dprintf("png: IDAT chunk received (len=%zu)\n", len);
+    
+    // For now, compression handling is not implemented
+    // and instead will assume data is uncompressed
+
+    ff_dprintf("png: IDAT handler WIP - data is assumed uncompressed\n");
+    ff_dprintf("png: IDAT handler WIP - expect undefined behavior\n");
+
+    // We will need to loop over all the scanlines and apply filters
+    // But im too lazy to do that right now
+    // TODO implement
+    
+
+    return FF_RESULT_WARN_NO_IMPL;
 }
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