integrate djvu into PDFReader, alternative to #26

This code is based on current master but doesn't include unireader, but
leaves all names to old PDFReader to preserve compatilbity

djvu.c

@@ -238,34 +238,17 @@ static int getPageSize(lua_State *L) {
 	return 2;
 }
 
-/*static int getUsedBBox(lua_State *L) {*/
-	/*fz_bbox result;*/
-	/*fz_matrix ctm;*/
-	/*fz_device *dev;*/
-	/*DjvuPage *page = (DjvuPage*) luaL_checkudata(L, 1, "djvupage");*/
-
-	/*[> returned BBox is in centi-point (n * 0.01 pt) <]*/
-	/*ctm = fz_scale(100, 100);*/
-	/*ctm = fz_concat(ctm, fz_rotate(page->page->rotate));*/
-
-	/*fz_try(page->doc->context) {*/
-		/*dev = fz_new_bbox_device(page->doc->context, &result);*/
-		/*pdf_run_page(page->doc->xref, page->page, dev, ctm, NULL);*/
-	/*}*/
-	/*fz_always(page->doc->context) {*/
-		/*fz_free_device(dev);*/
-	/*}*/
-	/*fz_catch(page->doc->context) {*/
-		/*return luaL_error(L, "cannot calculate bbox for page");*/
-	/*}*/
-
-           /*lua_pushnumber(L, ((double)result.x0)/100);*/
-	/*lua_pushnumber(L, ((double)result.y0)/100);*/
-           /*lua_pushnumber(L, ((double)result.x1)/100);*/
-	/*lua_pushnumber(L, ((double)result.y1)/100);*/
-
-	/*return 4;*/
-/*}*/
+/* unsupported so fake it */
+static int getUsedBBox(lua_State *L) {
+	DjvuPage *page = (DjvuPage*) luaL_checkudata(L, 1, "djvupage");
+
+	lua_pushnumber(L, (double)0.01);
+	lua_pushnumber(L, (double)0.01);
+	lua_pushnumber(L, (double)-0.01);
+	lua_pushnumber(L, (double)-0.01);
+
+	return 4;
+}
 
 static int closePage(lua_State *L) {
 	DjvuPage *page = (DjvuPage*) luaL_checkudata(L, 1, "djvupage");
@@ -384,7 +367,7 @@ static const struct luaL_reg djvudocument_meth[] = {
 
 static const struct luaL_reg djvupage_meth[] = {
 	{"getSize", getPageSize},
-	/*{"getUsedBBox", getUsedBBox},*/
+	{"getUsedBBox", getUsedBBox},
 	{"close", closePage},
 	{"__gc", closePage},
 	{"draw", drawPage},

pdfreader.lua

@@ -51,7 +51,8 @@ PDFReader = {
 	settings = nil,
 
 	-- we will use this one often, so keep it "static":
-	nulldc = pdf.newDC(),
+	nulldc = nil,
+	newDC = nil,
 
 	-- tile cache configuration:
 	cache_max_memsize = 1024*1024*5, -- 5MB tile cache
@@ -125,7 +126,22 @@ end
 
 -- open a PDF file and its settings store
 function PDFReader:open(filename, password)
-	self.doc = pdf.openDocument(filename, password or "")
+	if string.match(filename, ".+%.[dD][jJ][vV][uU]$") then
+		self.doc = djvu.openDocument(filename)
+		self.newDC = function()
+			print("djvu.newDC")
+			return djvu.newDC()
+		end
+	else
+		self.doc = pdf.openDocument(filename, password or "")
+		self.newDC = function()
+			print("pdf.newDC")
+		 	return pdf.newDC()
+		end
+	end
+
+	self.nulldc = self.newDC();
+
 	if self.doc ~= nil then
 		self.settings = DocSettings:open(filename)
 		local gamma = self.settings:readsetting("gamma")
@@ -139,7 +155,7 @@ end
 
 -- set viewer state according to zoom state
 function PDFReader:setzoom(page)
-	local dc = pdf.newDC()
+	local dc = self.newDC()
 	local pwidth, pheight = page:getSize(self.nulldc)
 	print("# page::getSize "..pwidth.."*"..pheight);
 	local x0, y0, x1, y1 = page:getUsedBBox()