From 057c461e7d259a29298fc529cc673cc67775a84f Mon Sep 17 00:00:00 2001
From: Tigran Aivazian <tigran@bibles.org.uk>
Date: Thu, 4 Oct 2012 22:08:52 +0100
Subject: [PATCH] Display DjVu info in the status line. The DjVu info shown in
 the status line includes: 1. Physical page dimensions. 2. Current value of
 gamma and (in square brackets) the value of the display for which the page
 was designed. 3. Page resolution (in dpi). 4. Page type. For the end-user
 probably the most useful bit is the page type as it helps him decide which
 rendering mode to choose for this page (and also explains why he can't see
 anything on the page --- e.g. when rendering some COMPOUND or PHOTO pages in
 B&W mode). For the developer the physical page dimensions are also
 interesting as they allow to estimate the amount of time needed for page
 decoding and cache efficiency.

---
 djvu.c         | 56 ++++++++++++++++++++++++++++++++++++++++++++------
 djvureader.lua | 17 ++++-----------
 2 files changed, 54 insertions(+), 19 deletions(-)

diff --git a/djvu.c b/djvu.c
index f06eab25f..fae6c7ad4 100644
--- a/djvu.c
+++ b/djvu.c
@@ -85,11 +85,10 @@ static int openDocument(lua_State *L) {
 	ddjvu_cache_set_size(doc->context, (unsigned long)cache_size);
 
 	doc->doc_ref = ddjvu_document_create_by_filename_utf8(doc->context, filename, TRUE);
+	if (! doc->doc_ref)
+		return luaL_error(L, "cannot open DjVu file <%s>", filename);
 	while (! ddjvu_document_decoding_done(doc->doc_ref))
 		handle(L, doc->context, True);
-	if (! doc->doc_ref) {
-		return luaL_error(L, "cannot open DjVu file <%s>", filename);
-	}
 
 	doc->pixelformat = ddjvu_format_create(DDJVU_FORMAT_GREY8, 0, NULL);
 	if (! doc->pixelformat) {
@@ -254,20 +253,65 @@ static int getOriginalPageSize(lua_State *L) {
 
 	lua_pushnumber(L, info.width);
 	lua_pushnumber(L, info.height);
-	lua_pushnumber(L, info.dpi);
 
-	return 3;
+	return 2;
 }
 
 static int getPageInfo(lua_State *L) {
 	DjvuDocument *doc = (DjvuDocument*) luaL_checkudata(L, 1, "djvudocument");
 	int pageno = luaL_checkint(L, 2);
 	ddjvu_page_t *djvu_page;
+	int page_width, page_height, page_dpi;
+	double page_gamma;
+	ddjvu_page_type_t page_type;
+	char *page_type_str;
+
 	djvu_page = ddjvu_page_create_by_pageno(doc->doc_ref, pageno - 1);
-	if (!djvu_page)
+	if (! djvu_page)
 		return luaL_error(L, "cannot create djvu_page #%d", pageno);
+
 	while (! ddjvu_page_decoding_done(djvu_page))
 		handle(L, doc->context, TRUE);
+
+	page_width = ddjvu_page_get_width(djvu_page);
+	lua_pushnumber(L, page_width);
+
+	page_height = ddjvu_page_get_height(djvu_page);
+	lua_pushnumber(L, page_height);
+
+	page_dpi = ddjvu_page_get_resolution(djvu_page);
+	lua_pushnumber(L, page_dpi);
+
+	page_gamma = ddjvu_page_get_gamma(djvu_page);
+	lua_pushnumber(L, page_gamma);
+
+	page_type = ddjvu_page_get_type(djvu_page);
+	switch (page_type) {
+		case DDJVU_PAGETYPE_UNKNOWN:
+			page_type_str = "UNKNOWN";
+			break;
+
+		case DDJVU_PAGETYPE_BITONAL:
+			page_type_str = "BITONAL";
+			break;
+
+		case DDJVU_PAGETYPE_PHOTO:
+			page_type_str = "PHOTO";
+			break;
+
+		case DDJVU_PAGETYPE_COMPOUND:
+			page_type_str = "COMPOUND";
+			break;
+
+		default:
+			page_type_str = "INVALID";
+			break;
+	}
+	lua_pushstring(L, page_type_str);
+
+	ddjvu_page_release(djvu_page);
+
+	return 5;
 }
 
 /*
diff --git a/djvureader.lua b/djvureader.lua
index 01b39a04b..82b517686 100644
--- a/djvureader.lua
+++ b/djvureader.lua
@@ -70,19 +70,14 @@ function DJVUReader:invertTextYAxel(pageno, text_table)
 	return text_table
 end
 
--- used in UniReader:showMenu()
----[[
 function DJVUReader:_drawReadingInfo()
-	local secs, usecs = util.gettime()
 	local width, height = G_width, G_height
 	local numpages = self.doc:getPages()
 	local load_percent = self.pageno/numpages
-	-- changed to be the same font group as originaly intended
 	local face = Font:getFace("rifont", 20)
-	--local page_width, page_height, page_dpi = self.doc:getOriginalPageSize(self.pageno)
-	local page_width, page_height, page_dpi = self.doc:getPageInfo(self.pageno)
+	local page_width, page_height, page_dpi, page_gamma, page_type = self.doc:getPageInfo(self.pageno)
 
-	-- display memory on top of page
+	-- display memory, time, battery and DjVu info on top of page
 	fb.bb:paintRect(0, 0, width, 40+6*2, 0)
 	renderUtf8Text(fb.bb, 10, 15+6, face,
 		"M: "..
@@ -91,9 +86,9 @@ function DJVUReader:_drawReadingInfo()
 		os.date("%a %d %b %Y %T")..
 		" ["..BatteryLevel().."]", true)
 	renderUtf8Text(fb.bb, 10, 15+6+22, face,
-		"Gamma:"..tostring(self.globalgamma)..", "..
+		"Gm:"..string.format("%.1f",self.globalgamma).." ["..tostring(page_gamma).."], "..
 		tostring(page_width).."x"..tostring(page_height)..", "..
-		tostring(page_dpi).."dpi", true)
+		tostring(page_dpi).."dpi, "..page_type, true)
 
 	-- display reading progress on bottom of page
 	local ypos = height - 50
@@ -109,8 +104,4 @@ function DJVUReader:_drawReadingInfo()
 	ypos = ypos + 15
 	blitbuffer.progressBar(fb.bb, 10, ypos, width-20, 15,
 							5, 4, load_percent, 8)
-	local nsecs, nusecs = util.gettime()
-	local diff = (nsecs - secs)*1000000 + nusecs - usecs
-	print("DJVUReader:_drawReadingInfo(): "..tostring(diff).." us")
 end
---]]