feat(png): Implement IEND chunk support

2 files changed, 46 insertions, 5 deletions

diff --git a/include/tinyff/image/png.h b/include/tinyff/image/png.h
index 9348dce..a77092a 100644
--- a/include/tinyff/image/png.h
+++ b/include/tinyff/image/png.h
@@ -17,13 +17,29 @@ static const unsigned char PNG_SIGNATURE[8] = {
 
 
 typedef struct {
+    
+    // Raw file handle
     FILE *raw;
+
+    // Image dimensions
     uint32_t width;
     uint32_t height;
+
+    // Color information
     uint8_t bit_depth;
     uint8_t color_type;
-    uint8_t *pixels;
-    size_t count_pixels;
+
+    // Image data
+    //
+    // It's weird because theres actually multiple ways to store it
+    // we need to be able to have the same fields to hold the data
+    // or have two seperate fields and a flag pointing to which one is actually
+    // being used sorta because of palette vs direct color
+    // so until i find a better way than holding this crappy project together with duct tape
+    // im just gonna use two fields and a flag
+    // but again with bit depths and color types this can get really messy really fast
+    // and i have NO idea what what type direct color data should be stored as.
+    // god... i hate png
     bool valid;
 } ff_png_ctx;
 
@@ -49,6 +65,9 @@ const ff_png_chunk_handler ff_png_chunk_handlers[] = {
     {"IHDR", ff_png_header_handler},
     {"IDAT", ff_png_data_handler},
     {"IEND", ff_png_end_handler},
+    {"PLTE", ff_png_palette_handler},   
+
+    // From now on, the handlers will be for ancillary chunks
 
 
     {NULL, NULL} // Terminator
@@ -58,9 +77,10 @@ const ff_png_chunk_handler ff_png_chunk_handlers[] = {
 // Massive W.I.P
 
 // Required by definition
-void ff_png_header_handler(uint8_t *buf, size_t len, ff_png_ctx* ctx); // IHDR
-void ff_png_data_handler(uint8_t *buf, size_t len, ff_png_ctx* ctx); // IDAT
-void ff_png_end_handler(uint8_t *buf, size_t len, ff_png_ctx* ctx); // IEND
+ff_result ff_png_header_handler(uint8_t *buf, size_t len, ff_png_ctx* ctx); // IHDR
+ff_result ff_png_palette_handler(uint8_t *buf, size_t len, ff_png_ctx* ctx); // PLTE
+ff_result ff_png_data_handler(uint8_t *buf, size_t len, ff_png_ctx* ctx); // IDAT
+ff_result ff_png_end_handler(uint8_t *buf, size_t len, ff_png_ctx* ctx); // IEND
 
 // PLTE is a funny one
 // Its only required for indexed color types
diff --git a/src/format/image/png.c b/src/format/image/png.c
index 8662fa2..11f4093 100644
--- a/src/format/image/png.c
+++ b/src/format/image/png.c
@@ -1,5 +1,6 @@
 #include "tinyff/image/png.h"
 #include "tinyff/dbg.h"
+#include "png.h"
 
 ff_result ff_png_isvalid(FILE *file)
 {
@@ -87,6 +88,18 @@ ff_result ff_png_header_handler(uint8_t *buf, size_t len, ff_png_ctx *ctx)
     return FF_RESULT_OK;
 }
 
+ff_result ff_png_chunk_palette_handler(uint8_t *buf, size_t len, ff_png_ctx *ctx)
+{
+    ff_dprintf("png: PLTE chunk received (len=%zu)\n", len);
+    
+    uint16_t num_entries = len / 3;
+    ff_dprintf("png: PLTE contains %u palette entries\n", num_entries);
+
+    
+
+    return FF_RESULT_WARN_NO_IMPL;
+}   
+
 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);
@@ -103,4 +116,12 @@ ff_result ff_png_data_handler(uint8_t *buf, size_t len, ff_png_ctx *ctx)
     
 
     return FF_RESULT_WARN_NO_IMPL;
+}
+
+ff_result ff_png_end_handler(uint8_t *buf, size_t len, ff_png_ctx *ctx)
+{
+    ff_dprintf("png: IEND chunk received (len=%zu)\n", len);
+    ff_dprintf("png: all chunks received\n");
+
+    return FF_RESULT_OK;
 }
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