From 912f9f436b1163c2235426eca4d8830eebcd4966 Mon Sep 17 00:00:00 2001
From: Alberto Griggio <agriggio@users.noreply.github.com>
Date: Mon, 20 Nov 2017 00:11:18 +0100
Subject: [PATCH] added support for 32-bit floating-point TIFF output

---
 rtengine/imageio.cc      | 23 ++++++++++++++++-------
 rtexif/rtexif.cc         |  2 ++
 rtgui/saveformatpanel.cc | 12 +++++++++---
 rtgui/saveformatpanel.h  |  2 +-
 4 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/rtengine/imageio.cc b/rtengine/imageio.cc
index ff9c9b559..e7a45ecf6 100644
--- a/rtengine/imageio.cc
+++ b/rtengine/imageio.cc
@@ -1250,20 +1250,28 @@ int ImageIO::saveTIFF (Glib::ustring fname, int bps, bool uncompressed)
         }
 
 #if __BYTE_ORDER__==__ORDER_LITTLE_ENDIAN__
-        bool needsReverse = bps == 16 && exifRoot->getOrder() == rtexif::MOTOROLA;
+        bool needsReverse = (bps == 16 || bps == 32) && exifRoot->getOrder() == rtexif::MOTOROLA;
 #else
-        bool needsReverse = bps == 16 && exifRoot->getOrder() == rtexif::INTEL;
+        bool needsReverse = (bps == 16 || bps == 32) && exifRoot->getOrder() == rtexif::INTEL;
 #endif
 
         for (int i = 0; i < height; i++) {
             getScanline (i, linebuffer, bps);
 
-            if (needsReverse)
-                for (int i = 0; i < lineWidth; i += 2) {
-                    char c = linebuffer[i];
-                    linebuffer[i] = linebuffer[i + 1];
-                    linebuffer[i + 1] = c;
+            if (needsReverse) {
+                if (bps == 16) {
+                    for (int i = 0; i < lineWidth; i += 2) {
+                        char c = linebuffer[i];
+                        linebuffer[i] = linebuffer[i + 1];
+                        linebuffer[i + 1] = c;
+                    }
+                } else {
+                    for (int i = 0; i < lineWidth; i += 4) {
+                        std::swap(linebuffer[i], linebuffer[i+3]);
+                        std::swap(linebuffer[i+1], linebuffer[i+2]);
+                    }
                 }
+            }
 
             fwrite (linebuffer, lineWidth, 1, file);
 
@@ -1362,6 +1370,7 @@ int ImageIO::saveTIFF (Glib::ustring fname, int bps, bool uncompressed)
         TIFFSetField (out, TIFFTAG_SAMPLEFORMAT, SAMPLEFORMAT_UINT);
         TIFFSetField (out, TIFFTAG_PHOTOMETRIC, PHOTOMETRIC_RGB);
         TIFFSetField (out, TIFFTAG_COMPRESSION, uncompressed ? COMPRESSION_NONE : COMPRESSION_DEFLATE);
+        TIFFSetField (out, TIFFTAG_SAMPLEFORMAT, bps == 32 ? SAMPLEFORMAT_IEEEFP : SAMPLEFORMAT_UINT);
 
         if (!uncompressed) {
             TIFFSetField (out, TIFFTAG_PREDICTOR, PREDICTOR_NONE);
diff --git a/rtexif/rtexif.cc b/rtexif/rtexif.cc
index bc0e2002f..1701b3058 100644
--- a/rtexif/rtexif.cc
+++ b/rtexif/rtexif.cc
@@ -3240,6 +3240,8 @@ int ExifManager::createTIFFHeader (const TagDirectory* root, const rtengine::pro
     Tag* stripOffs = new Tag (cl, lookupAttrib (ifdAttribs, "StripOffsets"));
     stripOffs->initInt (0, LONG, strips);
     cl->replaceTag (stripOffs);
+    Tag *sampleFormat = new Tag (cl, lookupAttrib (ifdAttribs, "SampleFormat"), bps == 32 ? 3 : 1, SHORT);
+    cl->replaceTag (sampleFormat);
 
     for (int i = 0; i < strips - 1; i++) {
         stripBC->setInt (rps * W * 3 * bps / 8, i * 4);
diff --git a/rtgui/saveformatpanel.cc b/rtgui/saveformatpanel.cc
index 13e687595..fef05de23 100644
--- a/rtgui/saveformatpanel.cc
+++ b/rtgui/saveformatpanel.cc
@@ -40,14 +40,16 @@ SaveFormatPanel::SaveFormatPanel () : listener (nullptr)
     format->append ("JPEG (8 bit)");
     format->append ("TIFF (8 bit)");
     format->append ("TIFF (16 bit)");
+    format->append ("TIFF (32 bit float)");
     format->append ("PNG (8 bit)");
     format->append ("PNG (16 bit)");
 
     fstr[0] = "jpg";
     fstr[1] = "tif";
     fstr[2] = "tif";
-    fstr[3] = "png";
+    fstr[3] = "tif";
     fstr[4] = "png";
+    fstr[5] = "png";
 
     hb1->attach (*flab, 0, 0, 1, 1);
     hb1->attach (*format, 1, 0, 1, 1);
@@ -121,8 +123,10 @@ void SaveFormatPanel::init (SaveFormat &sf)
     if (sf.format == "jpg") {
         format->set_active (0);
     } else if (sf.format == "png" && sf.pngBits == 16) {
-        format->set_active (4);
+        format->set_active (5);
     } else if (sf.format == "png" && sf.pngBits == 8) {
+        format->set_active (4);
+    } else if (sf.format == "tif" && sf.tiffBits == 32) {
         format->set_active (3);
     } else if (sf.format == "tif" && sf.tiffBits == 16) {
         format->set_active (2);
@@ -146,7 +150,7 @@ SaveFormat SaveFormatPanel::getFormat ()
     int sel = format->get_active_row_number();
     sf.format = fstr[sel];
 
-    if (sel == 4) {
+    if (sel == 5) {
         sf.pngBits = 16;
     } else {
         sf.pngBits = 8;
@@ -154,6 +158,8 @@ SaveFormat SaveFormatPanel::getFormat ()
 
     if (sel == 2) {
         sf.tiffBits = 16;
+    } else if (sel == 3) {
+        sf.tiffBits = 32;
     } else {
         sf.tiffBits = 8;
     }
diff --git a/rtgui/saveformatpanel.h b/rtgui/saveformatpanel.h
index 76ae7055d..8dc493051 100644
--- a/rtgui/saveformatpanel.h
+++ b/rtgui/saveformatpanel.h
@@ -44,7 +44,7 @@ protected:
     Gtk::Grid*          jpegOpts;
     Gtk::Label*         jpegSubSampLabel;
     FormatChangeListener* listener;
-    Glib::ustring       fstr[5];
+    Glib::ustring       fstr[6];
     Gtk::CheckButton*   savesPP;