[PdfToPpm] Add an option to scale before rotate

-scale-dimension-before-rotation

utils/pdftoppm.1

@@ -62,6 +62,9 @@ Scales each page vertically to fit in scale-to-y pixels. If scale-to-x
 is set to -1, the horizontal size will determined by the aspect ratio
 of the page.
 .TP
+.B \-scale-dimension-before-rotation
+Swaps horizontal and vertical size for a rotated (landscape) pdf before scaling instead of after.
+.TP
 .BI \-x " number"
 Specifies the x-coordinate of the crop area top left corner
 .TP

utils/pdftoppm.cc

@@ -74,6 +74,7 @@ static int lastPage = 0;
 static bool printOnlyOdd = false;
 static bool printOnlyEven = false;
 static bool singleFile = false;
+static bool scaleDimensionBeforeRotation = false;
 static double resolution = 0.0;
 static double x_resolution = 150.0;
 static double y_resolution = 150.0;
@@ -128,6 +129,8 @@ static const ArgDesc argDesc[] = {
    "print only even pages"},
   {"-singlefile", argFlag,  &singleFile,   0,
    "write only the first page and do not add digits"},
+  {"-scale-dimension-before-rotation", argFlag,  &scaleDimensionBeforeRotation,   0,
+   "for rotated pdf, resize dimensions before the rotation"},
 
   {"-r",      argFP,       &resolution,    0,
    "resolution, in DPI (default is 150)"},
@@ -218,6 +221,11 @@ static const ArgDesc argDesc[] = {
   {}
 };
 
+static bool needToRotate(int angle)
+{
+    return (angle == 90) || (angle == 270);
+}
+
 static bool parseJpegOptions()
 {
   //jpegOpt format is: <opt1>=<val1>,<opt2>=<val2>,...
@@ -395,7 +403,7 @@ int main(int argc, char *argv[]) {
   bool ok;
   int exitCode;
   int pg, pg_num_len;
-  double pg_w, pg_h, tmp;
+  double pg_w, pg_h;
 
   Win32Console win32Console(&argc, &argv);
   exitCode = 99;
@@ -558,6 +566,9 @@ int main(int argc, char *argv[]) {
       pg_h = doc->getPageMediaHeight(pg);
     }
 
+    if (scaleDimensionBeforeRotation && needToRotate(doc->getPageRotate(pg)))
+      std::swap(pg_w, pg_h);
+
     if (scaleTo != 0) {
       resolution = (72.0 * scaleTo) / (pg_w > pg_h ? pg_w : pg_h);
       x_resolution = y_resolution = resolution;
@@ -575,11 +586,10 @@ int main(int argc, char *argv[]) {
     }
     pg_w = pg_w * (x_resolution / 72.0);
     pg_h = pg_h * (y_resolution / 72.0);
-    if ((doc->getPageRotate(pg) == 90) || (doc->getPageRotate(pg) == 270)) {
-      tmp = pg_w;
-      pg_w = pg_h;
-      pg_h = tmp;
-    }
+
+    if (!scaleDimensionBeforeRotation && needToRotate(doc->getPageRotate(pg)))
+      std::swap(pg_w, pg_h);
+
     if (ppmRoot != nullptr) {
       const char *ext = png ? "png" : (jpeg || jpegcmyk) ? "jpg" : tiff ? "tif" : mono ? "pbm" : gray ? "pgm" : "ppm";
       if (singleFile && !forceNum ) {