apply patch 1498946 by zbsz (fixes #1492545 "PNG resolution value export")

(bzr r1262)

7 files changed, 13 insertions, 12 deletions

diff --git a/src/dialogs/export.cpp b/src/dialogs/export.cpp
index 3b1943c4f..a141053dc 100644
--- a/src/dialogs/export.cpp
+++ b/src/dialogs/export.cpp
@@ -1070,7 +1070,7 @@ sp_export_export_clicked (GtkButton *button, GtkObject *base)
     
     /* Do export */
     if (!sp_export_png_file (sp_desktop_document (SP_ACTIVE_DESKTOP), filename, 
-                             x0, y0, x1, y1, width, height, 
+                             x0, y0, x1, y1, width, height, xdpi, ydpi, 
                              nv->pagecolor, 
                              sp_export_progress_callback, base)) {
         gchar * error;
diff --git a/src/file.cpp b/src/file.cpp
index de9b615aa..5c236da82 100644
--- a/src/file.cpp
+++ b/src/file.cpp
@@ -1091,7 +1091,7 @@ hide_other_items_recursively(SPObject *o, GSList *list, unsigned dkey)
 int
 sp_export_png_file(SPDocument *doc, gchar const *filename,
                    double x0, double y0, double x1, double y1,
-                   unsigned width, unsigned height,
+                   unsigned width, unsigned height, double xdpi, double ydpi,
                    unsigned long bgcolor,
                    unsigned (*status)(float, void *),
                    void *data, bool force_overwrite,
@@ -1168,12 +1168,12 @@ sp_export_png_file(SPDocument *doc, gchar const *filename,
     if ((width < 256) || ((width * height) < 32768)) {
         ebp.px = nr_pixelstore_64K_new(FALSE, 0);
         ebp.sheight = 65536 / (4 * width);
-        write_status = sp_png_write_rgba_striped(filename, width, height, sp_export_get_rows, &ebp);
+        write_status = sp_png_write_rgba_striped(filename, width, height, xdpi, ydpi, sp_export_get_rows, &ebp);
         nr_pixelstore_64K_free(ebp.px);
     } else {
         ebp.px = g_new(guchar, 4 * 64 * width);
         ebp.sheight = 64;
-        write_status = sp_png_write_rgba_striped(filename, width, height, sp_export_get_rows, &ebp);
+        write_status = sp_png_write_rgba_striped(filename, width, height, xdpi, ydpi, sp_export_get_rows, &ebp);
         g_free(ebp.px);
     }
 
diff --git a/src/file.h b/src/file.h
index f18f757f6..be4927395 100644
--- a/src/file.h
+++ b/src/file.h
@@ -129,7 +129,7 @@ void sp_file_export_dialog (void *widget);
  */
 int sp_export_png_file (SPDocument *doc, const gchar *filename,
 			 double x0, double y0, double x1, double y1,
-			 unsigned int width, unsigned int height,
+			 unsigned int width, unsigned int height, double xdpi, double ydpi,
 			 unsigned long bgcolor,
 			 unsigned int (*status) (float, void *), void *data, bool force_overwrite = false, GSList *items_only = NULL);
 
diff --git a/src/helper/png-write.cpp b/src/helper/png-write.cpp
index 21eca1efa..c90121860 100644
--- a/src/helper/png-write.cpp
+++ b/src/helper/png-write.cpp
@@ -53,18 +53,18 @@ sp_png_get_block_stripe (const guchar **rows, int row, int num_rows, void *data)
 }
 
 int
-sp_png_write_rgba (const gchar *filename, const guchar *px, int width, int height, int rowstride)
+sp_png_write_rgba (const gchar *filename, const guchar *px, int width, int height, double xdpi, double ydpi, int rowstride)
 {
 	SPPNGBD bd;
 
 	bd.px = px;
 	bd.rowstride = rowstride;
 
-	return sp_png_write_rgba_striped (filename, width, height, sp_png_get_block_stripe, &bd);
+	return sp_png_write_rgba_striped (filename, width, height, xdpi, ydpi, sp_png_get_block_stripe, &bd);
 }
 
 int
-sp_png_write_rgba_striped (const gchar *filename, int width, int height,
+sp_png_write_rgba_striped (const gchar *filename, int width, int height, double xdpi, double ydpi,
 			   int (* get_rows) (const guchar **rows, int row, int num_rows, void *data),
 			   void *data)
 {
@@ -151,6 +151,7 @@ sp_png_write_rgba_striped (const gchar *filename, int width, int height,
 	/* other optional chunks like cHRM, bKGD, tRNS, tIME, oFFs, pHYs, */
 	/* note that if sRGB is present the cHRM chunk must be ignored
 	 * on read and must be written in accordance with the sRGB profile */
+        png_set_pHYs(png_ptr, info_ptr, unsigned(xdpi / 0.0254 + 0.5), unsigned(ydpi / 0.0254 + 0.5), PNG_RESOLUTION_METER); 
 
 	/* Write the file header information.  REQUIRED */
 	png_write_info(png_ptr, info_ptr);
diff --git a/src/helper/png-write.h b/src/helper/png-write.h
index 2d2c16544..f8011f53e 100644
--- a/src/helper/png-write.h
+++ b/src/helper/png-write.h
@@ -14,9 +14,9 @@
 
 #include <glib/gtypes.h>
 
-int sp_png_write_rgba(gchar const *filename, guchar const *px, int width, int height, int rowstride);
+int sp_png_write_rgba(gchar const *filename, guchar const *px, int width, int height, double xdpi, double ydpi, int rowstride);
 
-int sp_png_write_rgba_striped(gchar const *filename, int width, int height,
+int sp_png_write_rgba_striped(gchar const *filename, int width, int height, double xdpi, double ydpi,
 			      int (* get_rows) (guchar const **rows, int row, int num_rows, void *data),
 			      void *data);
 
diff --git a/src/main.cpp b/src/main.cpp
index 3c3655175..aa97f3aec 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -955,7 +955,7 @@ sp_do_export_png(SPDocument *doc)
     g_print("Bitmap saved as: %s\n", filename);
 
     if ((width >= 1) && (height >= 1) && (width < 65536) && (height < 65536)) {
-        sp_export_png_file(doc, filename, area.x0, area.y0, area.x1, area.y1, width, height, bgcolor, NULL, NULL, true, sp_export_id_only ? items : NULL);
+        sp_export_png_file(doc, filename, area.x0, area.y0, area.x1, area.y1, width, height, dpi, dpi, bgcolor, NULL, NULL, true, sp_export_id_only ? items : NULL);
     } else {
         g_warning("Calculated bitmap dimensions %d %d are out of range (1 - 65535). Nothing exported.", width, height);
     }
diff --git a/src/selection-chemistry.cpp b/src/selection-chemistry.cpp
index 1225a66f3..352a0b6ad 100644
--- a/src/selection-chemistry.cpp
+++ b/src/selection-chemistry.cpp
@@ -2332,7 +2332,7 @@ sp_selection_create_bitmap_copy ()
     // Do the export
     sp_export_png_file(document, filepath,
                    bbox.x0, bbox.y0, bbox.x1, bbox.y1,
-                   width, height,
+                   width, height, res, res,
                    (guint32) 0xffffff00,
                    NULL, NULL,
                    true,  /*bool force_overwrite,*/