unified coordinates system in djvrereader

fix bug in showing manual corp area.
this also fixes #132.

djvu.c

@@ -255,6 +255,17 @@ static int getPageText(lua_State *L) {
 	DjvuDocument *doc = (DjvuDocument*) luaL_checkudata(L, 1, "djvudocument");
 	int pageno = luaL_checkint(L, 2);
 
+	/* get page height for coordinates transform */
+	ddjvu_pageinfo_t info;
+	ddjvu_status_t r;
+	while ((r=ddjvu_document_get_pageinfo(
+				   doc->doc_ref, pageno-1, &info))<DDJVU_JOB_OK) {
+		handle(L, doc->context, TRUE);
+	}
+	if (r>=DDJVU_JOB_FAILED)
+		return luaL_error(L, "cannot get page #%d information", pageno);
+
+	/* start retrieving page text */
 	miniexp_t sexp, se_line, se_word;
 	int i = 1, j = 1, counter_l = 1, counter_w=1,
 		nr_line = 0, nr_word = 0;
@@ -292,16 +303,18 @@ static int getPageText(lua_State *L) {
 		lua_pushnumber(L, miniexp_to_int(miniexp_nth(1, se_line)));
 		lua_settable(L, -3);
 
-		lua_pushstring(L, "y0");
-		lua_pushnumber(L, miniexp_to_int(miniexp_nth(2, se_line)));
+		lua_pushstring(L, "y1");
+		lua_pushnumber(L, 
+				info.height - miniexp_to_int(miniexp_nth(2, se_line)));
 		lua_settable(L, -3);
 
 		lua_pushstring(L, "x1");
 		lua_pushnumber(L, miniexp_to_int(miniexp_nth(3, se_line)));
 		lua_settable(L, -3);
 
-		lua_pushstring(L, "y1");
-		lua_pushnumber(L, miniexp_to_int(miniexp_nth(4, se_line)));
+		lua_pushstring(L, "y0");
+		lua_pushnumber(L, 
+				info.height - miniexp_to_int(miniexp_nth(4, se_line)));
 		lua_settable(L, -3);
 
 		/* now loop through each word in the line */
@@ -325,16 +338,18 @@ static int getPageText(lua_State *L) {
 			lua_pushnumber(L, miniexp_to_int(miniexp_nth(1, se_word)));
 			lua_settable(L, -3);
 
-			lua_pushstring(L, "y0");
-			lua_pushnumber(L, miniexp_to_int(miniexp_nth(2, se_word)));
+			lua_pushstring(L, "y1");
+			lua_pushnumber(L, 
+					info.height - miniexp_to_int(miniexp_nth(2, se_word)));
 			lua_settable(L, -3);
 
 			lua_pushstring(L, "x1");
 			lua_pushnumber(L, miniexp_to_int(miniexp_nth(3, se_word)));
 			lua_settable(L, -3);
 
-			lua_pushstring(L, "y1");
-			lua_pushnumber(L, miniexp_to_int(miniexp_nth(4, se_word)));
+			lua_pushstring(L, "y0");
+			lua_pushnumber(L, 
+					info.height - miniexp_to_int(miniexp_nth(4, se_word)));
 			lua_settable(L, -3);
 
 			lua_pushstring(L, "word");

djvureader.lua

@@ -31,68 +31,3 @@ function DJVUReader:getText(pageno)
 	return self.doc:getPageText(pageno)
 end
 
-----------------------------------------------------
--- In djvulibre library, some coordinates starts from
--- lower left conner, i.e. y is upside down in kpv's
--- coordinate. So y0 should be taken with special care.
-----------------------------------------------------
-function DJVUReader:zoomedRectCoordTransform(x0, y0, x1, y1)
-	local x,y = self:screenOffset()
-	return 
-		x0 * self.globalzoom + x,
-		self.cur_full_height - (y1 * self.globalzoom) + y,
-		(x1 - x0) * self.globalzoom,
-		(y1 - y0) * self.globalzoom
-end
-
--- make sure at least part of the box can be seen in next/previous view
--- @FIXME only works in FIT_TO_CONTENT_WIDTH mode  21.04 2012 (houqp)
--- @TODO use zoomedRectCoordTransform in unireader, no need to overwrite
---       it in here.
-function DJVUReader:_isBoxInNextView(box)
-	return self.cur_full_height - (box.y0 * self.globalzoom) > -self.offset_y + G_height
-end
-
-function DJVUReader:_isBoxInPrevView(box)
-	return self.cur_full_height - (box.y1 * self.globalzoom) < -self.offset_y
-end
-
--- y axel in djvulibre starts from bottom
-function DJVUReader:_isEntireWordInScreenHeightRange(w)
-	return	(w ~= nil) and
-			(self.cur_full_height - (w.y1 * self.globalzoom) >=
-				-self.offset_y) and
-			(self.cur_full_height - (w.y0 * self.globalzoom) <= 
-				-self.offset_y + G_height)
-end
-
--- y axel in djvulibre starts from bottom
-function DJVUReader:_isEntireLineInScreenHeightRange(l)
-	return	(l ~= nil) and
-			(self.cur_full_height - (l.y1 * self.globalzoom) >=
-				-self.offset_y) and
-			(self.cur_full_height - (l.y0 * self.globalzoom) <= 
-				-self.offset_y + G_height)
-end
-
--- y axel in djvulibre starts from bottom
-function DJVUReader:_isWordInScreenRange(w)
-	if not w then
-		return false
-	end
-
-	is_entire_word_out_of_screen_height = 
-		(self.cur_full_height - (w.y0 * self.globalzoom) <=
-											-self.offset_y)
-		or (self.cur_full_height - (w.y1 * self.globalzoom) >=
-											-self.offset_y + G_height)
-
-	is_entire_word_out_of_screen_width = 
-			(w.x0 * self.globalzoom >= -self.offset_x + G_width
-			or w.x1 * self.globalzoom <= -self.offset_x)
-
-	return	(not is_entire_word_out_of_screen_height) and
-			(not is_entire_word_out_of_screen_width)
-end
-
-