Define sources & backends

1 files changed, 30 insertions, 0 deletions

diff --git a/src/backend.h b/src/backend.h
new file mode 100644
index 0000000..0da2244
--- /dev/null
+++ b/src/backend.h
@@ -0,0 +1,30 @@
+#ifndef IMV_BACKEND_H
+#define IMV_BACKEND_H
+
+struct imv_source;
+
+enum backend_result {
+  BACKEND_SUCCESS = 0, /* successful load */
+  BACKEND_BAD_PATH = 1, /* no such file, bad permissions, etc. */
+  BACKEND_UNSUPPORTED = 2, /* unsupported file format */
+};
+
+/* A backend is responsible for taking a path, or a raw data pointer, and
+ * converting that into a source that imv can handle. Each backend
+ * may be powered by a different image library and support different
+ * image formats.
+ */
+struct imv_backend {
+  /* Name of the backend, for debug and user informational purposes */
+  const char *name;
+
+  /* Input: path to open
+   * Output: initialises the imv_source instance passed in
+   */
+  enum backend_result (*open_path)(const char *path, struct imv_source **src);
+
+  /* Clean up this backend */
+  void (*free)(struct imv_backend *backend);
+};
+
+#endif