Started re-adding the uiInit functions, with a new method of returning errors.

doc/00_index.md

@@ -1,3 +1,4 @@
 <!-- 8 april 2019 -->
 
 * [Using libui](using-libui.md)
+* [Initialization and the Main Loop](init-main.md)

doc/init-main.md

@@ -0,0 +1,27 @@
+<!-- 12 april 2019 -->
+
+# Initialization and the Main Loop
+
+## Reference
+
+### `uiInit()`
+
+```c
+int uiInit(void *options, uiInitError *err);
+```
+
+### `uiUninit()`
+
+```c
+void uiUninit(void);
+```
+
+### `uiInitError`
+
+```c
+typedef struct uiInitError uiInitError;
+struct uiInitError {
+	size_t Size;
+	char Message[256];
+};
+```

ui.h

@@ -30,6 +30,16 @@ extern "C" {
 // This has the advantage of being ABI-able should we ever need an ABI...
 #define uiprivEnum(s) typedef unsigned int s; enum
 
+typedef struct uiInitError uiInitError;
+
+struct uiInitError {
+	size_t Size;
+	char Message[256];
+};
+
+uiprivExtern int uiInit(void *options, uiInitError *err);
+uiprivExtern void uiUninit(void);
+
 #ifdef __cplusplus
 }
 #endif

zOLD_ui.h

@@ -23,8 +23,6 @@ struct uiInitOptions {
 	size_t Size;
 };
 
-uiprivExtern const char *uiInit(uiInitOptions *options);
-uiprivExtern void uiUninit(void);
 uiprivExtern void uiFreeInitError(const char *err);
 
 uiprivExtern void uiMain(void);