Improved support for clipping on EMF/WMF import, see bug 1302857

(bzr r13322)

7 files changed, 337 insertions, 86 deletions

diff --git a/src/extension/internal/emf-inout.cpp b/src/extension/internal/emf-inout.cpp
index 6455e7555..863d1e006 100644
--- a/src/extension/internal/emf-inout.cpp
+++ b/src/extension/internal/emf-inout.cpp
@@ -44,6 +44,7 @@
 #include "display/drawing.h"
 #include "display/drawing-item.h"
 #include "clear-n_.h"
+#include "svg/svg.h"
 #include "util/units.h" // even though it is included indirectly by wmf-inout.h
 #include "inkscape.h" // even though it is included indirectly by wmf-inout.h
 
@@ -60,8 +61,6 @@ namespace Inkscape {
 namespace Extension {
 namespace Internal {
 
-static U_RECTL  rc_old  = rectl_set(pointl_set(-1,-1),pointl_set(-1,-1));
-static bool     clipset = false;
 static uint32_t ICMmode = 0;  // not used yet, but code to read it from EMF implemented
 static uint32_t BLTmode = 0;
 
@@ -447,7 +446,7 @@ void Emf::enlarge_images(PEMF_CALLBACK_DATA d){
 
 /*  See if the image string is already in the list.  If it is return its position (1->n, not 1-n-1)
 */
-int Emf::in_images(PEMF_CALLBACK_DATA d, char *test){
+int Emf::in_images(PEMF_CALLBACK_DATA d, const char *test){
     int i;
     for(i=0; i<d->images.count; i++){
         if(strcmp(test,d->images.strings[i])==0)return(i+1);
@@ -618,7 +617,7 @@ void Emf::enlarge_gradients(PEMF_CALLBACK_DATA d){
 
 /*  See if the gradient name is already in the list.  If it is return its position (1->n, not 1-n-1)
 */
-int Emf::in_gradients(PEMF_CALLBACK_DATA d, char *test){
+int Emf::in_gradients(PEMF_CALLBACK_DATA d, const char *test){
     int i;
     for(i=0; i<d->gradients.count; i++){
         if(strcmp(test,d->gradients.strings[i])==0)return(i+1);
@@ -717,6 +716,65 @@ uint32_t Emf::add_gradient(PEMF_CALLBACK_DATA d, uint32_t gradientType, U_TRIVER
     return(idx-1);
 }
 
+/*  Add another 100 blank slots to the clips array.
+*/
+void Emf::enlarge_clips(PEMF_CALLBACK_DATA d){
+    d->clips.size += 100;
+    d->clips.strings = (char **) realloc(d->clips.strings,d->clips.size * sizeof(char *));
+}
+
+/*  See if the pattern name is already in the list.  If it is return its position (1->n, not 1-n-1)
+*/
+int Emf::in_clips(PEMF_CALLBACK_DATA d, const char *test){
+    int i;
+    for(i=0; i<d->clips.count; i++){
+        if(strcmp(test,d->clips.strings[i])==0)return(i+1);
+    }
+    return(0);
+}
+
+/*  (Conditionally) add a clip.  
+    If a matching clip already exists nothing happens  
+    If one does exist it is added to the clips list, entered into <defs>.
+*/
+void Emf::add_clips(PEMF_CALLBACK_DATA d, const char *clippath, unsigned int logic){
+    int op = combine_ops_to_livarot(logic);
+    Geom::PathVector combined_vect;
+    char *combined = NULL;
+    if (op >= 0 && d->dc[d->level].clip_id) {
+        unsigned int real_idx = d->dc[d->level].clip_id - 1;
+        Geom::PathVector old_vect = sp_svg_read_pathv(d->clips.strings[real_idx]);
+        Geom::PathVector new_vect = sp_svg_read_pathv(clippath);
+        combined_vect = sp_pathvector_boolop(new_vect, old_vect, (bool_op) op , (FillRule) fill_oddEven, (FillRule) fill_oddEven);
+        combined = sp_svg_write_path(combined_vect);
+    }
+    else {
+        combined = strdup(clippath);  // COPY operation, erases everything and starts a new one
+    }
+
+    uint32_t  idx = in_clips(d, combined);
+    if(!idx){  // add clip if not already present
+        if(d->clips.count == d->clips.size){  enlarge_clips(d); }
+        d->clips.strings[d->clips.count++]=strdup(combined);
+        d->dc[d->level].clip_id = d->clips.count;  // one more than the slot where it is actually stored
+        SVGOStringStream tmp_clippath;
+        tmp_clippath << "\n<clipPath";
+        tmp_clippath << "\n\tclipPathUnits=\"userSpaceOnUse\" ";
+        tmp_clippath << "\n\tid=\"clipEmfPath" << d->dc[d->level].clip_id << "\"";
+        tmp_clippath << " >";
+        tmp_clippath << "\n\t<path d=\"";
+        tmp_clippath << combined;
+        tmp_clippath << "\"";
+        tmp_clippath << "\n\t/>";
+        tmp_clippath << "\n</clipPath>";
+        d->outdef += tmp_clippath.str().c_str();
+    }
+    else {
+        d->dc[d->level].clip_id = idx;
+    }
+    free(combined);
+}
+
 
 
 void
@@ -927,9 +985,8 @@ Emf::output_style(PEMF_CALLBACK_DATA d, int iType)
         tmp_style << "stroke-opacity:1;";
     }
     tmp_style << "\" ";
-    if (clipset)
-        tmp_style << "\n\tclip-path=\"url(#clipEmfPath" << d->id << ")\" ";
-    clipset = false;
+    if (d->dc[d->level].clip_id)
+        tmp_style << "\n\tclip-path=\"url(#clipEmfPath" << d->dc[d->level].clip_id << ")\" ";
 
     d->outsvg += tmp_style.str().c_str();
 }
@@ -1565,7 +1622,7 @@ int Emf::myEnhMetaFileProc(char *contents, unsigned int length, PEMF_CALLBACK_DA
 
     lpEMFR = (PU_ENHMETARECORD)(contents + off);
 //  Uncomment the following to track down toxic records
-//std::cout << "record type: " << lpEMFR->iType << " length: " << lpEMFR->nSize << " offset: " << off <<std::endl;
+// std::cout << "record type: " << lpEMFR->iType  << " name " << U_emr_names(lpEMFR->iType) << " length: " << lpEMFR->nSize << " offset: " << off <<std::endl;
     off += lpEMFR->nSize;
 
     SVGOStringStream tmp_outsvg;
@@ -1616,7 +1673,7 @@ int Emf::myEnhMetaFileProc(char *contents, unsigned int length, PEMF_CALLBACK_DA
         d->dc[d->level].dirty = 0;
     }
 
-//std::cout << "BEFORE DRAW logic d->mask: " << std::hex << d->mask << " emr_mask: " << emr_mask << std::dec << std::endl;
+// std::cout << "BEFORE DRAW logic d->mask: " << std::hex << d->mask << " emr_mask: " << emr_mask << std::dec << std::endl;
 /*
 std::cout << "BEFORE DRAW"
  << " test0 " << ( d->mask & U_DRAW_VISIBLE)
@@ -1643,7 +1700,7 @@ std::cout << "BEFORE DRAW"
             )
         )
     ){
-// std::cout << "PATH DRAW at TOP" << std::endl;
+// std::cout << "PATH DRAW at TOP path" << *(d->path) << std::endl;
         d->outsvg += "   <path ";     // this is the ONLY place <path should be used!!!  One exception, gradientfill.
         if(d->drawtype){                 // explicit draw type EMR record
             output_style(d, d->drawtype);
@@ -2115,7 +2172,24 @@ std::cout << "BEFORE DRAW"
             }
             break;
         }
-        case U_EMR_OFFSETCLIPRGN:        dbg_str << "<!-- U_EMR_OFFSETCLIPRGN -->\n";      break;
+        case U_EMR_OFFSETCLIPRGN:
+        {
+            dbg_str << "<!-- U_EMR_OFFSETCLIPRGN -->\n"; 
+            if (d->dc[d->level].clip_id) { // can only offsetan existing clipping path
+                PU_EMROFFSETCLIPRGN pEmr = (PU_EMROFFSETCLIPRGN) lpEMFR;
+                U_POINTL off = pEmr->ptlOffset;
+                unsigned int real_idx = d->dc[d->level].clip_id - 1;
+                Geom::PathVector tmp_vect = sp_svg_read_pathv(d->clips.strings[real_idx]);
+                double ox = pix_to_x_point(d, off.x, off.y) - pix_to_x_point(d, 0, 0); // take into account all active transforms
+                double oy = pix_to_y_point(d, off.x, off.y) - pix_to_y_point(d, 0, 0);
+                Geom::Affine tf = Geom::Translate(ox,oy);
+                tmp_vect *= tf;
+                char *tmp_path = sp_svg_write_path(tmp_vect);
+                add_clips(d, tmp_path, U_RGN_COPY);
+                free(tmp_path);
+            }
+            break;
+        }
         case U_EMR_MOVETOEX:
         {
             dbg_str << "<!-- U_EMR_MOVETOEX -->\n";
@@ -2131,36 +2205,52 @@ std::cout << "BEFORE DRAW"
             break;
         }
         case U_EMR_SETMETARGN:           dbg_str << "<!-- U_EMR_SETMETARGN -->\n";         break;
-        case U_EMR_EXCLUDECLIPRECT:      dbg_str << "<!-- U_EMR_EXCLUDECLIPRECT -->\n";    break;
+        case U_EMR_EXCLUDECLIPRECT:
+        {
+            dbg_str << "<!-- U_EMR_EXCLUDECLIPRECT -->\n";
+
+            PU_EMREXCLUDECLIPRECT pEmr = (PU_EMREXCLUDECLIPRECT) lpEMFR;
+            U_RECTL rc = pEmr->rclClip;
+
+            SVGOStringStream tmp_path;
+            float faraway = 10000000; // hopefully well outside any real drawing!
+            //outer rect, clockwise 
+            tmp_path << "M " <<  faraway << "," <<  faraway << " ";
+            tmp_path << "L " <<  faraway << "," << -faraway << " ";
+            tmp_path << "L " << -faraway << "," << -faraway << " ";
+            tmp_path << "L " << -faraway << "," <<  faraway << " ";
+            tmp_path << "z ";
+            //inner rect, counterclockwise (sign of Y is reversed)
+            tmp_path << "M " << pix_to_xy( d, rc.left , rc.top )     << " ";
+            tmp_path << "L " << pix_to_xy( d, rc.right, rc.top )     << " ";
+            tmp_path << "L " << pix_to_xy( d, rc.right, rc.bottom )  << " ";
+            tmp_path << "L " << pix_to_xy( d, rc.left,  rc.bottom )  << " ";
+            tmp_path << "z";
+            
+            add_clips(d, tmp_path.str().c_str(), U_RGN_AND);
+
+            d->path = "";
+            d->drawtype = 0;
+            break;
+        }
         case U_EMR_INTERSECTCLIPRECT:
         {
             dbg_str << "<!-- U_EMR_INTERSECTCLIPRECT -->\n";
 
             PU_EMRINTERSECTCLIPRECT pEmr = (PU_EMRINTERSECTCLIPRECT) lpEMFR;
             U_RECTL rc = pEmr->rclClip;
-            clipset = true;
-            if ((rc.left == rc_old.left) && (rc.top == rc_old.top) && (rc.right == rc_old.right) && (rc.bottom == rc_old.bottom))
-                break;
-            rc_old = rc;
 
-            double dx = pix_to_x_point( d, rc.left, rc.top );
-            double dy = pix_to_y_point( d, rc.left, rc.top );
-            double dw = pix_to_abs_size( d, rc.right  - rc.left + 1);
-            double dh = pix_to_abs_size( d, rc.bottom - rc.top  + 1);
+            SVGOStringStream tmp_path;
+            tmp_path << "M " << pix_to_xy( d, rc.left , rc.top )     << " ";
+            tmp_path << "L " << pix_to_xy( d, rc.right, rc.top )     << " ";
+            tmp_path << "L " << pix_to_xy( d, rc.right, rc.bottom )  << " ";
+            tmp_path << "L " << pix_to_xy( d, rc.left,  rc.bottom )  << " ";
+            tmp_path << "z";
+            
+            add_clips(d, tmp_path.str().c_str(), U_RGN_AND);
 
-            SVGOStringStream tmp_rectangle;
-            tmp_rectangle << "\n<clipPath\n\tclipPathUnits=\"userSpaceOnUse\" ";
-            tmp_rectangle << "\nid=\"clipEmfPath" << ++(d->id) << "\" >";
-            tmp_rectangle << "\n<rect ";
-            tmp_rectangle << "\n   x=\""      << dx << "\" ";
-            tmp_rectangle << "\n   y=\""      << dy << "\" ";
-            tmp_rectangle << "\n   width=\""  << dw << "\" ";
-            tmp_rectangle << "\n   height=\"" << dh << "\" ";
-            tmp_rectangle << "\n   transform=" << current_matrix(d, dx, dy, 1); // calculate appropriate offset
-            tmp_rectangle << "/>\n</clipPath>";
-
-            d->outdef += tmp_rectangle.str().c_str();
             d->path = "";
+            d->drawtype = 0;
             break;
         }
         case U_EMR_SCALEVIEWPORTEXTEX:   dbg_str << "<!-- U_EMR_SCALEVIEWPORTEXTEX -->\n"; break;
@@ -2171,7 +2261,7 @@ std::cout << "BEFORE DRAW"
             if (d->level < EMF_MAX_DC) {
                 d->dc[d->level + 1] = d->dc[d->level];
                 if(d->dc[d->level].font_name){
-                  d->dc[d->level + 1].font_name = strdup(d->dc[d->level].font_name); // or memory access problems because font name pointer duplicated
+                    d->dc[d->level + 1].font_name = strdup(d->dc[d->level].font_name); // or memory access problems because font name pointer duplicated
                 }
                 d->level = d->level + 1;
             }
@@ -2727,7 +2817,18 @@ std::cout << "BEFORE DRAW"
         }
         case U_EMR_FLATTENPATH:          dbg_str << "<!-- U_EMR_FLATTENPATH -->\n";          break;
         case U_EMR_WIDENPATH:            dbg_str << "<!-- U_EMR_WIDENPATH -->\n";            break;
-        case U_EMR_SELECTCLIPPATH:       dbg_str << "<!-- U_EMR_SELECTCLIPPATH -->\n";       break;
+        case U_EMR_SELECTCLIPPATH:
+        {
+            dbg_str << "<!-- U_EMR_SELECTCLIPPATH -->\n";
+            PU_EMRSELECTCLIPPATH pEmr = (PU_EMRSELECTCLIPPATH) lpEMFR;
+            int logic = pEmr->iMode;
+
+            if ((logic < U_RGN_MIN) || (logic > U_RGN_MAX)){ break; }
+            add_clips(d, d->path.c_str(), logic); // finds an existing one or stores this, sets clip_id
+            d->path = "";
+            d->drawtype = 0;
+            break;
+        }
         case U_EMR_ABORTPATH:
         {
             dbg_str << "<!-- U_EMR_ABORTPATH -->\n";
@@ -2770,8 +2871,10 @@ std::cout << "BEFORE DRAW"
             dbg_str << "<!-- U_EMR_EXTSELECTCLIPRGN -->\n";
 
             PU_EMREXTSELECTCLIPRGN pEmr = (PU_EMREXTSELECTCLIPRGN) lpEMFR;
-            if (pEmr->iMode == U_RGN_COPY)
-                clipset = false;
+            // the only mode we implement - this clears the clipping region
+            if (pEmr->iMode == U_RGN_COPY) {
+                d->dc[d->level].clip_id = 0;
+            }
             break;
         }
         case U_EMR_BITBLT:
@@ -3334,6 +3437,8 @@ void Emf::free_emf_strings(EMF_STRINGS name){
         for(int i=0; i< name.count; i++){ free(name.strings[i]); }
         free(name.strings);
     }
+    name.count = 0;
+    name.size = 0;
 }
 
 SPDocument *
@@ -3381,6 +3486,7 @@ Emf::open( Inkscape::Extension::Input * /*mod*/, const gchar *uri )
     free_emf_strings(d.hatches);
     free_emf_strings(d.images);
     free_emf_strings(d.gradients);
+    free_emf_strings(d.clips);
 
     if (d.emf_obj) {
         int i;
diff --git a/src/extension/internal/emf-inout.h b/src/extension/internal/emf-inout.h
index f15db5518..302d5c474 100644
--- a/src/extension/internal/emf-inout.h
+++ b/src/extension/internal/emf-inout.h
@@ -53,6 +53,7 @@ typedef struct emf_device_context {
     emf_device_context() :
         // SPStyle: class with constructor
         font_name(NULL),
+        clip_id(0),
         stroke_set(false), stroke_mode(0), stroke_idx(0), stroke_recidx(0),
         fill_set(false),   fill_mode(0),   fill_idx(0),   fill_recidx(0),
         dirty(0),
@@ -81,6 +82,7 @@ typedef struct emf_device_context {
     };        
     SPStyle         style;
     char           *font_name;
+    int             clip_id;      // 0 if none, else 1 + index into clips
     bool            stroke_set;
     int             stroke_mode;  // enumeration from drawmode, not used if fill_set is not True
     int             stroke_idx;   // used with DRAW_PATTERN and DRAW_IMAGE to return the appropriate fill
@@ -122,7 +124,7 @@ typedef struct emf_callback_data {
         arcdir(U_AD_COUNTERCLOCKWISE),
         dwRop2(U_R2_COPYPEN), dwRop3(0),
         MMX(0),MMY(0),
-        id(0), drawtype(0),
+        drawtype(0),
         pDesc(NULL),
         // hatches, images, gradients,  struct w/ constructor
         tri(NULL),
@@ -154,13 +156,13 @@ typedef struct emf_callback_data {
     float MMX;
     float MMY;
 
-    unsigned int id;
     unsigned int drawtype;  // one of 0 or U_EMR_FILLPATH, U_EMR_STROKEPATH, U_EMR_STROKEANDFILLPATH
     char *pDesc;
                               // both of these end up in <defs> under the names shown here.  These structures allow duplicates to be avoided.
     EMF_STRINGS hatches;      // hold pattern names, all like EMFhatch#_$$$$$$ where # is the EMF hatch code and $$$$$$ is the color
     EMF_STRINGS images;       // hold images, all like Image#, where # is the slot the image lives.
     EMF_STRINGS gradients;    // hold gradient  names, all like EMF[HV]_$$$$$$_$$$$$$ where $$$$$$ are the colors
+    EMF_STRINGS clips;        // hold clipping paths, referred to be the slot where the clipping path lives
     TR_INFO    *tri;          // Text Reassembly data structure
 
 
@@ -199,12 +201,17 @@ protected:
     static int         in_hatches(PEMF_CALLBACK_DATA d, char *test);
     static uint32_t    add_hatch(PEMF_CALLBACK_DATA d, uint32_t hatchType, U_COLORREF hatchColor);
     static void        enlarge_images(PEMF_CALLBACK_DATA d);
-    static int         in_images(PEMF_CALLBACK_DATA d, char *test);
+    static int         in_images(PEMF_CALLBACK_DATA d, const char *test);
     static uint32_t    add_image(PEMF_CALLBACK_DATA d,  void *pEmr, uint32_t cbBits, uint32_t cbBmi, 
                             uint32_t iUsage, uint32_t offBits, uint32_t offBmi);
     static void        enlarge_gradients(PEMF_CALLBACK_DATA d);
-    static int         in_gradients(PEMF_CALLBACK_DATA d, char *test);
+    static int         in_gradients(PEMF_CALLBACK_DATA d, const char *test);
     static uint32_t    add_gradient(PEMF_CALLBACK_DATA d, uint32_t gradientType, U_TRIVERTEX tv1, U_TRIVERTEX tv2);
+
+    static void        enlarge_clips(PEMF_CALLBACK_DATA d);
+    static int         in_clips(PEMF_CALLBACK_DATA d, const char *test);
+    static void        add_clips(PEMF_CALLBACK_DATA d, const char *clippath, unsigned int logic);
+
     static void        output_style(PEMF_CALLBACK_DATA d, int iType);
     static double      _pix_x_to_point(PEMF_CALLBACK_DATA d, double px);
     static double      _pix_y_to_point(PEMF_CALLBACK_DATA d, double py);
diff --git a/src/extension/internal/emf-print.cpp b/src/extension/internal/emf-print.cpp
index 8b80fec1c..9c68e40a4 100644
--- a/src/extension/internal/emf-print.cpp
+++ b/src/extension/internal/emf-print.cpp
@@ -34,6 +34,7 @@
 #include <2geom/pathvector.h>
 #include <2geom/rect.h>
 #include <2geom/curves.h>
+#include <sp-clippath.h>
 
 #include "helper/geom.h"
 #include "helper/geom-curves.h"
@@ -975,6 +976,9 @@ unsigned int PrintEmf::fill(
 {
     using Geom::X;
     using Geom::Y;
+    
+    SPItem *item = SP_ITEM(style->object);
+    SPClipPath *scp = (item->clip_ref ? item->clip_ref->getObject() : NULL);
 
     Geom::Affine tf = m_tr_stack.top();
 
diff --git a/src/extension/internal/metafile-inout.cpp b/src/extension/internal/metafile-inout.cpp
index 53bb86d24..162ad8b7d 100644
--- a/src/extension/internal/metafile-inout.cpp
+++ b/src/extension/internal/metafile-inout.cpp
@@ -179,28 +179,6 @@ void Metafile::toPNG(PMEMPNG accum, int width, int height, const char *px){
 
 }
 
-
-/* convert an EMF RGB(A) color to 0RGB
-inverse of gethexcolor() in emf-print.cpp
-*/
-uint32_t Metafile::sethexcolor(U_COLORREF color){
-
-    uint32_t out;
-    out = (U_RGBAGetR(color) << 16) +
-          (U_RGBAGetG(color) << 8 ) +
-          (U_RGBAGetB(color)      );
-    return(out);
-}
-
-/* Return the base64 encoded png which is shown for all bad images.
-Currently a random 3x4 blotch.
-Caller must free.
-*/
-gchar *Metafile::bad_image_png(void){
-    gchar *gstring = g_strdup("iVBORw0KGgoAAAANSUhEUgAAAAQAAAADCAIAAAA7ljmRAAAAA3NCSVQICAjb4U/gAAAALElEQVQImQXBQQ2AMAAAsUJQMSWI2H8qME1yMshojwrvGB8XcHKvR1XtOTc/8HENumHCsOMAAAAASUVORK5CYII=");
-    return(gstring);
-}
-
 /*  If the viewBox is missing, set one 
 */
 void Metafile::setViewBoxIfMissing(SPDocument *doc) {
@@ -257,6 +235,55 @@ void Metafile::setViewBoxIfMissing(SPDocument *doc) {
     }
 }
 
+/**
+    \fn Convert EMF/WMF region combining ops to livarot region combining ops
+    \return combination operators in livarot enumeration, or -1 on no match
+    \param  ops      (int) combination operator (Inkscape)
+*/
+int Metafile::combine_ops_to_livarot(const int op)
+{
+    int ret = -1; 
+    switch(op) {
+        case U_RGN_AND:
+           ret = bool_op_inters;
+           break;
+        case U_RGN_OR:
+           ret = bool_op_union;
+           break;
+        case U_RGN_XOR:
+           ret = bool_op_symdiff;
+           break;
+        case U_RGN_DIFF:
+           ret = bool_op_diff;
+           break;
+    }
+    return(ret);
+}
+
+
+
+/* convert an EMF RGB(A) color to 0RGB
+inverse of gethexcolor() in emf-print.cpp
+*/
+uint32_t Metafile::sethexcolor(U_COLORREF color){
+
+    uint32_t out;
+    out = (U_RGBAGetR(color) << 16) +
+          (U_RGBAGetG(color) << 8 ) +
+          (U_RGBAGetB(color)      );
+    return(out);
+}
+
+/* Return the base64 encoded png which is shown for all bad images.
+Currently a random 3x4 blotch.
+Caller must free.
+*/
+gchar *Metafile::bad_image_png(void){
+    gchar *gstring = g_strdup("iVBORw0KGgoAAAANSUhEUgAAAAQAAAADCAIAAAA7ljmRAAAAA3NCSVQICAjb4U/gAAAALElEQVQImQXBQQ2AMAAAsUJQMSWI2H8qME1yMshojwrvGB8XcHKvR1XtOTc/8HENumHCsOMAAAAASUVORK5CYII=");
+    return(gstring);
+}
+
+
 
 } // namespace Internal
 } // namespace Extension
diff --git a/src/extension/internal/metafile-inout.h b/src/extension/internal/metafile-inout.h
index 2f7001cf2..b3efee2a6 100644
--- a/src/extension/internal/metafile-inout.h
+++ b/src/extension/internal/metafile-inout.h
@@ -72,6 +72,7 @@ protected:
     static void        toPNG(PMEMPNG accum, int width, int height, const char *px);
     static gchar      *bad_image_png(void);
     static void        setViewBoxIfMissing(SPDocument *doc);
+    static int         combine_ops_to_livarot(const int op);
 
 
 private:
diff --git a/src/extension/internal/wmf-inout.cpp b/src/extension/internal/wmf-inout.cpp
index 5d7fc29d0..85060470b 100644
--- a/src/extension/internal/wmf-inout.cpp
+++ b/src/extension/internal/wmf-inout.cpp
@@ -44,6 +44,7 @@
 #include "display/drawing.h"
 #include "display/drawing-item.h"
 #include "clear-n_.h"
+#include "svg/svg.h"
 #include "util/units.h" // even though it is included indirectly by wmf-inout.h
 #include "inkscape.h" // even though it is included indirectly by wmf-inout.h
 
@@ -626,6 +627,67 @@ uint32_t Wmf::add_bm16_image(PWMF_CALLBACK_DATA d, U_BITMAP16 Bm16, const char *
     return(idx-1);
 }
 
+/*  Add another 100 blank slots to the clips array.
+*/
+void Wmf::enlarge_clips(PWMF_CALLBACK_DATA d){
+    d->clips.size += 100;
+    d->clips.strings = (char **) realloc(d->clips.strings,d->clips.size * sizeof(char *));
+}
+
+/*  See if the pattern name is already in the list.  If it is return its position (1->n, not 1-n-1)
+*/
+int Wmf::in_clips(PWMF_CALLBACK_DATA d, const char *test){
+    int i;
+    for(i=0; i<d->clips.count; i++){
+        if(strcmp(test,d->clips.strings[i])==0)return(i+1);
+    }
+    return(0);
+}
+
+/*  (Conditionally) add a clip.  
+    If a matching clip already exists nothing happens  
+    If one does exist it is added to the clips list, entered into <defs>.
+*/
+void Wmf::add_clips(PWMF_CALLBACK_DATA d, const char *clippath, unsigned int logic){
+    int op = combine_ops_to_livarot(logic);
+    Geom::PathVector combined_vect;
+    char *combined = NULL;
+    if (op >= 0 && d->dc[d->level].clip_id) {
+        unsigned int real_idx = d->dc[d->level].clip_id - 1;
+        Geom::PathVector old_vect = sp_svg_read_pathv(d->clips.strings[real_idx]);
+        Geom::PathVector new_vect = sp_svg_read_pathv(clippath);
+        combined_vect = sp_pathvector_boolop(new_vect, old_vect, (bool_op) op , (FillRule) fill_oddEven, (FillRule) fill_oddEven);
+        combined = sp_svg_write_path(combined_vect);
+    }
+    else {
+        combined = strdup(clippath);  // COPY operation, erases everything and starts a new one
+    }
+
+    uint32_t  idx = in_clips(d, combined);
+    if(!idx){  // add clip if not already present
+        if(d->clips.count == d->clips.size){  enlarge_clips(d); }
+        d->clips.strings[d->clips.count++]=strdup(combined);
+        d->dc[d->level].clip_id = d->clips.count;  // one more than the slot where it is actually stored
+        SVGOStringStream tmp_clippath;
+        tmp_clippath << "\n<clipPath";
+        tmp_clippath << "\n\tclipPathUnits=\"userSpaceOnUse\" ";
+        tmp_clippath << "\n\tid=\"clipEmfPath" << d->dc[d->level].clip_id << "\"";
+        tmp_clippath << " >";
+        tmp_clippath << "\n\t<path d=\"";
+        tmp_clippath << combined;
+        tmp_clippath << "\"";
+        tmp_clippath << "\n\t/>";
+        tmp_clippath << "\n</clipPath>";
+        d->outdef += tmp_clippath.str().c_str();
+    }
+    else {
+        d->dc[d->level].clip_id = idx;
+    }
+    free(combined);
+}
+
+
+
 void
 Wmf::output_style(PWMF_CALLBACK_DATA d)
 {
@@ -833,9 +895,8 @@ Wmf::output_style(PWMF_CALLBACK_DATA d)
         tmp_style << "stroke-opacity:1;";
     }
     tmp_style << "\" ";
-    if (clipset)
-        tmp_style << "\n\tclip-path=\"url(#clipWmfPath" << d->id << ")\" ";
-    clipset = false;
+    if (d->dc[d->level].clip_id)
+        tmp_style << "\n\tclip-path=\"url(#clipEmfPath" << d->dc[d->level].clip_id << ")\" ";
 
     d->outsvg += tmp_style.str().c_str();
 }
@@ -1913,34 +1974,51 @@ std::cout << "BEFORE DRAW"
                 "\n\tM " << pix_to_xy( d, pt16.x, pt16.y ) << " ";
             break;
         }
-        case U_WMR_EXCLUDECLIPRECT:       dbg_str << "<!-- U_WMR_EXCLUDECLIPRECT -->\n";    break;
+        case U_WMR_EXCLUDECLIPRECT:
+        {
+            dbg_str << "<!-- U_WMR_EXCLUDECLIPRECT -->\n";
+
+            U_RECT16   rc;
+            nSize = U_WMREXCLUDECLIPRECT_get(contents, &rc);
+
+            SVGOStringStream tmp_path;
+            float faraway = 10000000; // hopefully well outside any real drawing!
+            //outer rect, clockwise 
+            tmp_path << "M " <<  faraway << "," <<  faraway << " ";
+            tmp_path << "L " <<  faraway << "," << -faraway << " ";
+            tmp_path << "L " << -faraway << "," << -faraway << " ";
+            tmp_path << "L " << -faraway << "," <<  faraway << " ";
+            tmp_path << "z ";
+            //inner rect, counterclockwise (sign of Y is reversed)
+            tmp_path << "M " << pix_to_xy( d, rc.left , rc.top )     << " ";
+            tmp_path << "L " << pix_to_xy( d, rc.right, rc.top )     << " ";
+            tmp_path << "L " << pix_to_xy( d, rc.right, rc.bottom )  << " ";
+            tmp_path << "L " << pix_to_xy( d, rc.left,  rc.bottom )  << " ";
+            tmp_path << "z";
+            
+            add_clips(d, tmp_path.str().c_str(), U_RGN_AND);
+
+            d->path = "";
+            d->drawtype = 0;
+            break;
+        }
         case U_WMR_INTERSECTCLIPRECT:
         {
             dbg_str << "<!-- U_WMR_INTERSECTCLIPRECT -->\n";
 
             nSize = U_WMRINTERSECTCLIPRECT_get(contents, &rc);
-            clipset = true;
-            if ((rc.left == rc_old.left) && (rc.top == rc_old.top) && (rc.right == rc_old.right) && (rc.bottom == rc_old.bottom))
-                break;
-            rc_old = rc;
 
-            double dx = pix_to_x_point(  d, rc.left,    rc.top     );
-            double dy = pix_to_y_point(  d, rc.left,    rc.top     );
-            double dw = pix_to_abs_size( d, rc.right  - rc.left + 1);
-            double dh = pix_to_abs_size( d, rc.bottom - rc.top  + 1);
+            SVGOStringStream tmp_path;
+            tmp_path << "M " << pix_to_xy( d, rc.left , rc.top )     << " ";
+            tmp_path << "L " << pix_to_xy( d, rc.right, rc.top )     << " ";
+            tmp_path << "L " << pix_to_xy( d, rc.right, rc.bottom )  << " ";
+            tmp_path << "L " << pix_to_xy( d, rc.left,  rc.bottom )  << " ";
+            tmp_path << "z";
+            
+            add_clips(d, tmp_path.str().c_str(), U_RGN_AND);
 
-            SVGOStringStream tmp_rectangle;
-            tmp_rectangle << "\n<clipPath\n\tclipPathUnits=\"userSpaceOnUse\" ";
-            tmp_rectangle << "\nid=\"clipWmfPath" << ++(d->id) << "\" >";
-            tmp_rectangle << "\n<rect ";
-            tmp_rectangle << "\n   x=\""      << dx << "\" ";
-            tmp_rectangle << "\n   y=\""      << dy << "\" ";
-            tmp_rectangle << "\n   width=\""  << dw << "\" ";
-            tmp_rectangle << "\n   height=\"" << dh << "\" />";
-            tmp_rectangle << "\n</clipPath>";
-
-            d->outdef += tmp_rectangle.str().c_str();
             d->path = "";
+            d->drawtype = 0;
             break;
         }
         case U_WMR_ARC:
@@ -2134,7 +2212,24 @@ std::cout << "BEFORE DRAW"
             break;
         }
         case U_WMR_SETPIXEL:              dbg_str << "<!-- U_WMR_SETPIXEL -->\n";                break;
-        case U_WMR_OFFSETCLIPRGN:         dbg_str << "<!-- U_WMR_OFFSETCLIPRGN/POLYLINE -->\n";  break;
+        case U_WMR_OFFSETCLIPRGN:
+        {
+            dbg_str << "<!-- U_EMR_OFFSETCLIPRGN -->\n"; 
+            U_POINT16  off;
+            nSize = U_WMROFFSETCLIPRGN_get(contents,&off);
+            if (d->dc[d->level].clip_id) { // can only offset an existing clipping path
+                unsigned int real_idx = d->dc[d->level].clip_id - 1;
+                Geom::PathVector tmp_vect = sp_svg_read_pathv(d->clips.strings[real_idx]);
+                double ox = pix_to_x_point(d, off.x, off.y) - pix_to_x_point(d, 0, 0); // take into account all active transforms
+                double oy = pix_to_y_point(d, off.x, off.y) - pix_to_y_point(d, 0, 0);
+                Geom::Affine tf = Geom::Translate(ox,oy);
+                tmp_vect *= tf;
+                char *tmp_path = sp_svg_write_path(tmp_vect);
+                add_clips(d, tmp_path, U_RGN_COPY);
+                free(tmp_path);
+            }
+            break;
+        }
         // U_WMR_TEXTOUT should be here, but has been moved down to merge with U_WMR_EXTTEXTOUT
         case U_WMR_BITBLT:
         {
@@ -2922,6 +3017,8 @@ void Wmf::free_wmf_strings(WMF_STRINGS name){
         for(int i=0; i< name.count; i++){ free(name.strings[i]); }
         free(name.strings);
     }
+    name.count = 0;
+    name.size = 0;
 }
 
 SPDocument *
@@ -2981,6 +3078,7 @@ Wmf::open( Inkscape::Extension::Input * /*mod*/, const gchar *uri )
 
     free_wmf_strings(d.hatches);
     free_wmf_strings(d.images);
+    free_wmf_strings(d.clips);
 
     if (d.wmf_obj) {
         int i;
diff --git a/src/extension/internal/wmf-inout.h b/src/extension/internal/wmf-inout.h
index 6006479c7..27ec14358 100644
--- a/src/extension/internal/wmf-inout.h
+++ b/src/extension/internal/wmf-inout.h
@@ -52,6 +52,7 @@ typedef struct wmf_device_context {
     wmf_device_context() :
         // SPStyle: class with constructor
         font_name(NULL),
+        clip_id(0),
         stroke_set(false), stroke_mode(0), stroke_idx(0), stroke_recidx(0),
         fill_set(false),   fill_mode(0),   fill_idx(0),   fill_recidx(0),
         dirty(0),
@@ -75,6 +76,7 @@ typedef struct wmf_device_context {
     };
     SPStyle         style;
     char           *font_name;
+    int             clip_id;      // 0 if none, else 1 + index into clips
     bool            stroke_set;
     int             stroke_mode;  // enumeration from drawmode, not used if fill_set is not True
     int             stroke_idx;   // used with DRAW_PATTERN and DRAW_IMAGE to return the appropriate fill
@@ -155,6 +157,7 @@ typedef struct wmf_callback_data {
                               // both of these end up in <defs> under the names shown here.  These structures allow duplicates to be avoided.
     WMF_STRINGS hatches;      // hold pattern names, all like WMFhatch#_$$$$$$ where # is the WMF hatch code and $$$$$$ is the color
     WMF_STRINGS images;       // hold images, all like Image#, where # is the slot the image lives.
+    WMF_STRINGS clips;        // hold clipping paths, referred to be the slot where the clipping path lives
     TR_INFO    *tri;          // Text Reassembly data structure
 
 
@@ -195,6 +198,11 @@ protected:
    static int         in_images(PWMF_CALLBACK_DATA d, char *test);
    static uint32_t    add_dib_image(PWMF_CALLBACK_DATA d, const char *dib, uint32_t iUsage);
    static uint32_t    add_bm16_image(PWMF_CALLBACK_DATA d, U_BITMAP16 Bm16, const char *px);
+
+   static void        enlarge_clips(PWMF_CALLBACK_DATA d);
+   static int         in_clips(PWMF_CALLBACK_DATA d, const char *test);
+   static void        add_clips(PWMF_CALLBACK_DATA d, const char *clippath, unsigned int logic);
+
    static void        output_style(PWMF_CALLBACK_DATA d);
    static double      _pix_x_to_point(PWMF_CALLBACK_DATA d, double px);
    static double      _pix_y_to_point(PWMF_CALLBACK_DATA d, double py);