From 3c84f5266cdde2c7fa0849ff118d1ecc173b7990 Mon Sep 17 00:00:00 2001
From: Nick Bowler <nbowler@draconx.ca>
Date: Sat, 19 May 2012 13:40:03 -0400
Subject: [PATCH] uobject: Initial support for object imports.

This is missing a lot of features currently; in particular, imports will
get loaded multiple times, but we can at least resolve them and create
the relevant objects.

Add a DetailTexture property to Engine.Texture to demonstrate.
---
 src/engine/texture.gob |  8 ++++
 src/uobject/uobject.c  | 90 +++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 96 insertions(+), 2 deletions(-)

diff --git a/src/engine/texture.gob b/src/engine/texture.gob
index 8e7bb4a..ea5e266 100644
--- a/src/engine/texture.gob
+++ b/src/engine/texture.gob
@@ -118,6 +118,7 @@ class Engine:Texture from U:Object (dynamic)
 	private unsigned VBits;
 
 	private Engine:Palette *Palette;
+	private Engine:Texture *DetailTexture;
 
 	private struct engine_texture_data **mipmap_data;
 	private unsigned char mipmap_count;
@@ -275,4 +276,11 @@ class Engine:Texture from U:Object (dynamic)
 		, object_type = Engine:Palette
 		, link
 		);
+
+	property OBJECT DetailTexture
+		( nick = "Detail Texture"
+		, blurb = "Reference to the corresponding detail texture."
+		, object_type = Engine:Texture
+		, link
+		);
 }
diff --git a/src/uobject/uobject.c b/src/uobject/uobject.c
index b8c2479..74734dd 100644
--- a/src/uobject/uobject.c
+++ b/src/uobject/uobject.c
@@ -190,6 +190,93 @@ decode_prop_header(struct upkg *upkg, struct prop_head *head,
 	return len;
 }
 
+/*
+ * TODO: Make this use the uobject_module stuff so packages are not loaded
+ * more than once.
+ */
+static GTypeModule *
+open_import_package(UObject *uo, const struct upkg_import *i)
+{
+	GTypeModule *pkg;
+
+	assert(i->parent == NULL);
+
+	if (strcmp(i->class_package, "Core") != 0
+	    || strcmp(i->class_name, "Package") != 0) {
+		u_err(uo, "import root must be Core.Package");
+		return NULL;
+	}
+
+	pkg = u_pkg_open(i->name);
+	if (!pkg || !g_type_module_use(pkg)) {
+		u_err(uo, "failed to open package: %s", i->name);
+		return NULL;
+	}
+
+	if (!U_PKG(pkg)->pkg) {
+		g_type_module_unuse(pkg);
+		u_err(uo, "failed to open package: %s", pkg->name);
+		return NULL;
+	}
+
+	return pkg;
+}
+
+/* Find the export index of a package based on the import chain from another
+ * package.  Returns the (non-negative) offset on success, or a negative value
+ * on failure. */
+static long resolve_import(struct upkg *pkg, const struct upkg_import *import)
+{
+	long current, index;
+
+	if (!import->parent)
+		return -1;
+
+	current = resolve_import(pkg, import->parent);
+	if (current != -1 && current >= 0)
+		return -42;
+
+	index = upkg_export_find(pkg, current, import->name);
+	if (index < 0)
+		return -42;
+
+	return index;
+}
+
+static GObject *get_import_object(UObject *uo, unsigned long index)
+{
+	const struct upkg_import *import;
+	GObject *obj = NULL;
+	GTypeModule *pkg;
+	long obj_index;
+
+	import = upkg_get_import(uo->pkg_file->pkg, index);
+	if (!import) {
+		u_err(uo, "invalid package import: %ld", index);
+		return NULL;
+	}
+
+	/* Get the package name at the top of the hierarchy. */
+	for (const struct upkg_import *i = import; i; i = i->parent) {
+		if (i->parent == NULL) {
+			pkg = open_import_package(uo, i);
+			if (!pkg)
+				return NULL;
+		}
+	}
+
+	obj_index = resolve_import(U_PKG(pkg)->pkg, import);
+	if (obj_index < 0) {
+		u_err(uo, "could not find import in package: %s", pkg->name);
+		goto out;
+	}
+
+	obj = u_object_new_from_package(pkg, obj_index);
+out:
+	g_type_module_unuse(pkg);
+	return obj;
+}
+
 static int decode_object_property(UObject *uo, GValue *val, unsigned long len)
 {
 	struct u_object_priv *priv = U_OBJECT_GET_PRIV(uo);
@@ -202,7 +289,7 @@ static int decode_object_property(UObject *uo, GValue *val, unsigned long len)
 		return -1;
 
 	if (index < 0) {
-		fprintf(stderr, "Imports not supported yet.\n");
+		obj = get_import_object(uo, -(index+1));
 	} else {
 		obj = u_object_new_from_package(uo->pkg, index-1);
 	}
@@ -392,7 +479,6 @@ GObject *u_object_new_from_package(GTypeModule *pkg, unsigned long idx)
 {
 	g_return_val_if_fail(IS_U_PKG(pkg), NULL);
 
-	const struct upkg_export *export;
 	const char *class, *package;
 	GObject *obj = NULL;
 	GType type;
-- 
2.43.0