If the page being viewed is rotated 180° by selecting
"upside down" (B2 menu), "orig size" retains the angle.  But
if the page is rotated 180° by selecting "rotate 90" twice,
"orig size" doesn't retain the angle.

Arvindh

Notes:
Wed Jan 4 07:31:23 EST 2006 rsc
    Thanks! 
    


Reference: /n/sources/patch/applied/page-angle
Date: Tue Jan  3 21:18:22 CET 2006
Reviewed-by: rsc

--- /sys/src/cmd/page/page.h	Tue Jan  3 20:42:12 2006
+++ /sys/src/cmd/page/page.h	Tue Jan  3 20:41:59 2006
@@ -42,6 +42,7 @@
 
 void rot180(Image*);
 Image *rot90(Image*);
+Image *rot270(Image*);
 Image *resample(Image*, Image*);
 
 /* ghostscript interface shared by ps, pdf */
--- /sys/src/cmd/page/rotate.c	Tue Jan  3 20:43:06 2006
+++ /sys/src/cmd/page/rotate.c	Tue Jan  3 20:42:55 2006
@@ -245,6 +245,31 @@
 	return(tmp);
 }
 
+/* rotates an image 270 degrees clockwise */
+Image *
+rot270(Image *im)
+{
+	Image *tmp;
+	int i, j, dx, dy;
+
+	dx = Dx(im->r);
+	dy = Dy(im->r);
+	tmp = xallocimage(display, Rect(0, 0, dy, dx), im->chan, 0, DCyan);
+	if(tmp == nil) {
+		fprint(2, "out of memory during rot270: %r\n");
+		wexits("memory");
+	}
+
+	for(i = 0; i < dy; i++) {
+		for(j = 0; j < dx; j++) {
+			drawop(tmp, Rect(i, j, i+1, j+1), im, nil, Pt(dx-(j+1), i), S);
+		}
+	}
+	freeimage(im);
+
+	return(tmp);
+}
+
 /* from resample.c -- resize from → to using interpolation */
 
 
--- /sys/src/cmd/page/view.c	Tue Jan  3 20:44:08 2006
+++ /sys/src/cmd/page/view.c	Tue Jan  3 20:43:53 2006
@@ -16,7 +16,7 @@
 Document *doc;
 Image *im;
 int page;
-int upside = 0;
+int angle = 0;
 int showbottom = 0;		/* on the next showpage, move the image so the bottom is visible. */
 
 Rectangle ulrange;	/* the upper left corner of the image must be in this rectangle */
@@ -156,8 +156,17 @@
 		im = tmp;
 	}
 
-	if(upside)
+	switch(angle){
+	case 90:
+		im = rot90(im);
+		break;
+	case 180:
 		rot180(im);
+		break;
+	case 270:
+		im = rot270(im);
+		break;
+	}
 
 	esetcursor(nil);
 	if(showbottom){
@@ -390,7 +399,7 @@
 				esetcursor(&reading);
 				rot180(im);
 				esetcursor(nil);
-				upside = !upside;
+				angle = (angle+180) % 360;
 				redraw(screen);
 				flushimage(display, 1);
 				break;
@@ -589,6 +598,7 @@
 					esetcursor(&reading);
 					im = rot90(im);
 					esetcursor(nil);
+					angle = (angle+90) % 360;
 					redraw(screen);
 					flushimage(display, 1);
 					break;
@@ -598,7 +608,7 @@
 					esetcursor(&reading);
 					rot180(im);
 					esetcursor(nil);
-					upside = !upside;
+					angle = (angle+180) % 360;
 					redraw(screen);
 					flushimage(display, 1);
 					break;