Implement image saving in SVG

core/base/inc/TVirtualPS.h

@@ -48,6 +48,7 @@ class TVirtualPS : public TNamed, public TAttLine, public TAttFill, public TAttM
    virtual     ~TVirtualPS();
    virtual void  CellArrayBegin(Int_t W, Int_t H, Double_t x1, Double_t x2, Double_t y1, Double_t y2) = 0;
    virtual void  CellArrayFill(Int_t r, Int_t g, Int_t b) = 0;
+   virtual void  CellArrayPng(char * /* buffer */, int /* size */) {}
    virtual void  CellArrayEnd() = 0;
    virtual void  Close(Option_t *opt="") = 0;
    virtual void  DrawBox(Double_t x1, Double_t y1,Double_t x2, Double_t  y2) = 0;

graf2d/asimage/src/TASImage.cxx

@@ -1337,6 +1337,7 @@ void TASImage::Image2Drawable(ASImage *im, Drawable_t wid, Int_t x, Int_t y,
    if (gc) gVirtualX->ChangeGC(gc, &gv);
 }
 
+
 ////////////////////////////////////////////////////////////////////////////////
 /// Draw image on the drawable wid (pixmap, window) at x,y position.
 ///
@@ -1562,6 +1563,9 @@ void TASImage::Paint(Option_t *option)
 
    // loop over pixmap and draw image to PostScript
    if (gVirtualPS) {
+
+      Bool_t paint_as_png = kFALSE;
+
       if (gVirtualPS->InheritsFrom("TImageDump")) { // PostScript is asimage
          TImage *dump = (TImage *)gVirtualPS->GetStream();
          if (!dump) return;
@@ -1589,23 +1593,12 @@ void TASImage::Paint(Option_t *option)
          Warning("Paint", "PDF not implemented yet");
          return;
       } else if (gVirtualPS->InheritsFrom("TSVG")) {
-         Warning("Paint", "SVG not implemented yet");
-         return;
+         paint_as_png = kTRUE;
       }
 
-      // get special color cell to be reused during image printing
-      TObjArray *colors = (TObjArray*) gROOT->GetListOfColors();
-      TColor *color = nullptr;
-      // Look for color by name
-      if ((color = (TColor*)colors->FindObject("Image_PS")) == nullptr)
-         color = new TColor(colors->GetEntries(), 1., 1., 1., "Image_PS");
-
-      gVirtualPS->SetFillColor(color->GetNumber());
-      gVirtualPS->SetFillStyle(1001);
-
       Double_t dx = gPad->GetX2()-gPad->GetX1();
       Double_t dy = gPad->GetY2()-gPad->GetY1();
-      Double_t x1,x2,y1,y2;
+      Double_t x1, x2, y1, y2;
 
       if (expand) {
          x1 = gPad->GetX1();
@@ -1619,19 +1612,38 @@ void TASImage::Paint(Option_t *option)
          y2 = y1+(dy*(1-gPad->GetTopMargin()-gPad->GetBottomMargin()))/image->height;
       }
 
+      // get special color cell to be reused during image printing
+      gVirtualPS->SetFillColor(TColor::GetColor((Float_t) 1., (Float_t) 1., (Float_t) 1.));
+      gVirtualPS->SetFillStyle(1001);
+
       gVirtualPS->CellArrayBegin(image->width, image->height, x1, x2, y1, y2);
 
-      ASImageDecoder *imdec = start_image_decoding(fgVisual, image, SCL_DO_ALL,
-                                                   0, 0, image->width, image->height, nullptr);
-      if (!imdec) return;
-      for (Int_t yt = 0; yt < (Int_t)image->height; yt++) {
-         imdec->decode_image_scanline(imdec);
-         for (Int_t xt = 0; xt < (Int_t)image->width; xt++)
-            gVirtualPS->CellArrayFill(imdec->buffer.red[xt],
-                                      imdec->buffer.green[xt],
-                                      imdec->buffer.blue[xt]);
+      if (paint_as_png) {
+         char *buffer = nullptr;
+         int size = 0;
+         ASImageExportParams params;
+         params.png.type = ASIT_Png;
+         params.png.flags = EXPORT_ALPHA;
+         params.png.compression = GetImageCompression();
+         if (!params.png.compression)
+            params.png.compression = -1;
+         if (ASImage2PNGBuff(image, (CARD8 **)&buffer, &size, &params)) {
+            gVirtualPS->CellArrayPng(buffer, size);
+            free(buffer);
+         }
+      } else {
+         auto imdec = start_image_decoding(fgVisual, image, SCL_DO_ALL,
+                                           0, 0, image->width, image->height, nullptr);
+         if (imdec)
+            for (Int_t yt = 0; yt < (Int_t)image->height; yt++) {
+               imdec->decode_image_scanline(imdec);
+               for (Int_t xt = 0; xt < (Int_t)image->width; xt++)
+                  gVirtualPS->CellArrayFill(imdec->buffer.red[xt],
+                                          imdec->buffer.green[xt],
+                                          imdec->buffer.blue[xt]);
+            }
+         stop_image_decoding(&imdec);
       }
-      stop_image_decoding(&imdec);
       gVirtualPS->CellArrayEnd();
 
       // print the color bar
@@ -1645,18 +1657,33 @@ void TASImage::Paint(Option_t *option)
          gVirtualPS->CellArrayBegin(grad_im->width, grad_im->height,
                                     x1, x2, y1, y2);
 
-         imdec = start_image_decoding(fgVisual, grad_im, SCL_DO_ALL,
-                                      0, 0, grad_im->width, grad_im->height, nullptr);
-         if (imdec) {
-            for (Int_t yt = 0; yt < (Int_t)grad_im->height; yt++) {
-               imdec->decode_image_scanline(imdec);
-               for (Int_t xt = 0; xt < (Int_t)grad_im->width; xt++)
-                  gVirtualPS->CellArrayFill(imdec->buffer.red[xt],
-                                            imdec->buffer.green[xt],
-                                            imdec->buffer.blue[xt]);
+         if (paint_as_png) {
+            char *buffer = nullptr;
+            int size = 0;
+            ASImageExportParams params;
+            params.png.type = ASIT_Png;
+            params.png.flags = EXPORT_ALPHA;
+            params.png.compression = GetImageCompression();
+            if (!params.png.compression)
+               params.png.compression = -1;
+
+            if (ASImage2PNGBuff(grad_im, (CARD8 **)&buffer, &size, &params)) {
+               gVirtualPS->CellArrayPng(buffer, size);
+               free(buffer);
             }
+         } else {
+            auto imdec = start_image_decoding(fgVisual, grad_im, SCL_DO_ALL,
+                                              0, 0, grad_im->width, grad_im->height, nullptr);
+            if (imdec)
+               for (Int_t yt = 0; yt < (Int_t)grad_im->height; yt++) {
+                  imdec->decode_image_scanline(imdec);
+                  for (Int_t xt = 0; xt < (Int_t)grad_im->width; xt++)
+                     gVirtualPS->CellArrayFill(imdec->buffer.red[xt],
+                                             imdec->buffer.green[xt],
+                                             imdec->buffer.blue[xt]);
+               }
+            stop_image_decoding(&imdec);
          }
-         stop_image_decoding(&imdec);
          gVirtualPS->CellArrayEnd();
 
          // values of palette

graf2d/postscript/inc/TSVG.h

@@ -42,6 +42,7 @@ class TSVG : public TVirtualPS {
 
    void  CellArrayBegin(Int_t W, Int_t H, Double_t x1, Double_t x2, Double_t y1, Double_t y2) override;
    void  CellArrayFill(Int_t r, Int_t g, Int_t b) override;
+   void  CellArrayPng(char *buffer, int size) override;
    void  CellArrayEnd() override;
    void  Close(Option_t *opt="") override;
    Double_t CMtoSVG(Double_t u) { return 0.5 + 72*u/2.54; }

graf2d/postscript/src/TSVG.cxx

@@ -21,6 +21,7 @@
 
 #include "TROOT.h"
 #include "TDatime.h"
+#include "TBase64.h"
 #include "TColor.h"
 #include "TVirtualPad.h"
 #include "TPoints.h"
@@ -944,6 +945,55 @@ void TSVG::DrawPS(Int_t nn, Double_t *xw, Double_t *yw)
    PrintFast(2,"/>");
 }
 
+////////////////////////////////////////////////////////////////////////////////
+/// Begin the Cell Array painting
+
+void TSVG::CellArrayBegin(Int_t width, Int_t height, Double_t x1, Double_t x2, Double_t y1, Double_t y2)
+{
+   Double_t svgx1 = XtoSVG(x1);
+   Double_t svgx2 = XtoSVG(x1 + (x2 - x1) * width);
+   Double_t svgy1 = YtoSVG(y1);
+   Double_t svgy2 = YtoSVG(y1 - (y2 - y1) * height);
+
+   PrintStr("@<g transform=\"translate(");
+   WriteReal(svgx1, kFALSE);
+   WriteReal(svgy1, kTRUE);
+   PrintStr(") scale(");
+   WriteReal((svgx2 - svgx1) / width, kFALSE);
+   WriteReal((svgy2 - svgy1) / height, kTRUE);
+   PrintStr(")\">@");
+   PrintStr(TString::Format("<image width=\"%d\" height=\"%d\" href=\"data:image/png;base64,", width, height));
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// Paint the Cell Array as single pixel
+
+void TSVG::CellArrayFill(Int_t, Int_t, Int_t)
+{
+   Warning("CellArrayFill", "not implemented");
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// Paint the Cell Array as png image
+/// Disabled in compact mode to avoid creation of large SVG files
+
+void TSVG::CellArrayPng(char *buffer, int size)
+{
+   if (!fCompact) {
+      TString base64 = TBase64::Encode(reinterpret_cast<char *>(buffer), size);
+      PrintFast(base64.Length(), base64.Data());
+   }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+/// End the Cell Array painting
+
+void TSVG::CellArrayEnd()
+{
+   PrintStr("\"></image>@");
+   PrintStr("</g>@");
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 /// Initialize the SVG file. The main task of the function is to output the
 /// SVG header file which consist in `<title>`, `<desc>` and `<defs>`. The
@@ -1508,31 +1558,6 @@ Double_t TSVG::YtoSVG(Double_t y)
    return  fYsizeSVG-VtoSVG(v);
 }
 
-////////////////////////////////////////////////////////////////////////////////
-/// Begin the Cell Array painting
-
-void TSVG::CellArrayBegin(Int_t, Int_t, Double_t, Double_t, Double_t,
-                          Double_t)
-{
-   Warning("TSVG::CellArrayBegin", "not yet implemented");
-}
-
-////////////////////////////////////////////////////////////////////////////////
-/// Paint the Cell Array
-
-void TSVG::CellArrayFill(Int_t, Int_t, Int_t)
-{
-   Warning("TSVG::CellArrayFill", "not yet implemented");
-}
-
-////////////////////////////////////////////////////////////////////////////////
-/// End the Cell Array painting
-
-void TSVG::CellArrayEnd()
-{
-   Warning("TSVG::CellArrayEnd", "not yet implemented");
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 /// Not needed in SVG case