feat(png): Validate signiture header

1 files changed, 37 insertions, 0 deletions

diff --git a/src/format/image/png.c b/src/format/image/png.c
new file mode 100644
index 0000000..b29e271
--- /dev/null
+++ b/src/format/image/png.c
@@ -0,0 +1,37 @@
+#include "tinyff/image/png.h"
+#include "png.h"
+
+ff_result ff_png_isvalid(FILE *file)
+{
+    char raw_sig[8];
+    if (fread(raw_sig, sizeof(char), 8, file) != 8) {
+        // Inable to read first 8 bytes
+        fclose(file);
+        return FF_RESULT_ERROR_INVALID_FILE;
+    }
+
+    if (memcmp(raw_sig, PNG_SIGNATURE, 8) != 0) {
+        // Signiture did not match
+        fclose(file);
+        return FF_RESULT_ERROR_INVALID_FILE_SIGNITURE;
+    }
+
+    return FF_RESULT_OK;
+}
+
+ff_png_ctx *ff_open_png(const char *filepath) {
+    // Validate
+    
+    ff_png_ctx ctx;
+    ctx.raw = fopen(filepath, "rb");
+
+    if (!ctx.raw) {
+        return NULL;
+    }
+
+    if (ff_png_isvalid(ctx.raw) != FF_RESULT_OK) {
+        return NULL;
+    }
+
+    // TODO: Parse
+}
\ No newline at end of file