From cd04860b16d26acd5805ca3e0051e198c83fdb63 Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Sat, 20 Aug 2022 13:13:39 +0200
Subject: [PATCH] Page rotation is now a part of pdf-tools

---
 cmds.cc      | 22 +---------------------
 pdf-tools.cc | 28 +++++++++++++++++++++++++++-
 pdf-tools.h  |  1 +
 3 files changed, 29 insertions(+), 22 deletions(-)

diff --git a/cmds.cc b/cmds.cc
index 7fad302..719058a 100644
--- a/cmds.cc
+++ b/cmds.cc
@@ -483,27 +483,7 @@ public:
     }
   page *process_page(page *p) override
     {
-      pdf_matrix m;
-      switch (deg)
-	{
-	case 0:
-	  break;
-	case 90:
-	  m.rotate_deg(-90);
-	  m.shift(0, p->width);
-	  break;
-	case 180:
-	  m.rotate_deg(180);
-	  m.shift(p->width, p->height);
-	  break;
-	case 270:
-	  m.rotate_deg(90);
-	  m.shift(p->height, 0);
-	  break;
-	default:
-	  abort();
-	}
-      return new xform_page(p, m);
+      return new xform_page(p, pdf_rotation_matrix(deg, p->width, p->height));
     }
 };
 
diff --git a/pdf-tools.cc b/pdf-tools.cc
index 0871637..0d74ca3 100644
--- a/pdf-tools.cc
+++ b/pdf-tools.cc
@@ -1,7 +1,7 @@
 /*
  *	Auxiliary functions for processing PDF files
  *
- *	(c) 2018 Martin Mares <mj@ucw.cz>
+ *	(c) 2018--2022 Martin Mares <mj@ucw.cz>
  */
 
 #include <cstdio>
@@ -247,3 +247,29 @@ string pdf_coord(double x, uint digits)
 		buf[--n] = 0;
 	return buf;
 }
+
+/*** Rotation matrix construction ***/
+
+pdf_matrix pdf_rotation_matrix(int deg, double width, double height)
+{
+      pdf_matrix m;
+      switch (deg) {
+	      case 0:
+		      break;
+	      case 90:
+		      m.rotate_deg(-90);
+		      m.shift(0, width);
+		      break;
+	      case 180:
+		      m.rotate_deg(180);
+		      m.shift(width, height);
+		      break;
+	      case 270:
+		      m.rotate_deg(90);
+		      m.shift(height, 0);
+		      break;
+	      default:
+		      abort();
+      }
+      return m;
+}
diff --git a/pdf-tools.h b/pdf-tools.h
index 46430f4..ea7b920 100644
--- a/pdf-tools.h
+++ b/pdf-tools.h
@@ -143,5 +143,6 @@ private:
 QPDFObjectHandle unicode_string(std::string s);
 QPDFObjectHandle page_to_xobject(QPDF *out, QPDFObjectHandle page);
 string pdf_coord(double x, uint digits=1);
+pdf_matrix pdf_rotation_matrix(int deg, double width, double height);
 
 #endif
-- 
2.39.5