Add metadata header to media files

The following properties are supported:

- Sound: "loop". Must be either 0 or 1
- Images: "transparent". Must be either 0 or 1

These headers are only used for non-PS1 builds, since .TIM and .VAG
files do already implement such information.

3 files changed, 88 insertions, 0 deletions

diff --git a/src/header/CMakeLists.txt b/src/header/CMakeLists.txt
new file mode 100644
index 0000000..e23d4fd
--- /dev/null
+++ b/src/header/CMakeLists.txt
@@ -0,0 +1,5 @@
+set(src "src/header.c")
+set(inc "inc")
+
+add_library(header ${src})
+target_include_directories(header PUBLIC ${inc})
diff --git a/src/header/inc/header.h b/src/header/inc/header.h
new file mode 100644
index 0000000..7514132
--- /dev/null
+++ b/src/header/inc/header.h
@@ -0,0 +1,18 @@
+#ifndef HEADER_H
+#define HEADER_H
+
+#include <stdbool.h>
+#include <stdio.h>
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+int header_load_bool(FILE *f, const char *key, bool *value);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* HEADER_H */
diff --git a/src/header/src/header.c b/src/header/src/header.c
new file mode 100644
index 0000000..bfc6534
--- /dev/null
+++ b/src/header/src/header.c
@@ -0,0 +1,65 @@
+#include <header.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int header_load_bool(FILE *const f, const char *const key, bool *const value)
+{
+    for (size_t i = 0; i < strlen(key); i++)
+    {
+        const int ci = fgetc(f);
+
+        if (ferror(f) || ci != key[i])
+        {
+            fprintf(stderr, "%s: failed to read property %s\n",
+                __func__, key);
+            return -1;
+        }
+    }
+
+    {
+        const int ci = fgetc(f);
+
+        if (ferror(f) || ci != '=')
+        {
+            fprintf(stderr, "%s: expected '=' on property %s\n",
+                __func__, key);
+            return -1;
+        }
+    }
+
+    {
+        static const char exp[] = "1";
+        char str[sizeof exp];
+
+        for (char *c = str; c - str < sizeof str; c++)
+        {
+            const int ci = fgetc(f);
+
+            if (ferror(f) || ci == EOF)
+            {
+                fprintf(stderr, "%s: could not read value for property %s\n",
+                    __func__, key);
+                return -1;
+            }
+
+            *c = ci;
+        }
+
+        errno = 0;
+        const unsigned long out = strtoul(str, NULL, 10);
+
+        if (errno || (out != 0 && out != 1))
+        {
+            fprintf(stderr, "%s: unexpected value for property %s: %lu\n",
+                __func__, key, out);
+            return -1;
+        }
+
+        *value = out;
+    }
+
+    return 0;
+}