Merge pull request #22 from ljubobratovicrelja/ggplotd-gtk-drawToSurface

Improved interfacing with GtkD for GGPlotD.drawToSurface

source/ggplotd/ggplotd.d

@@ -136,7 +136,17 @@ struct Margins
 /// GGPlotD contains the needed information to create a plot
 struct GGPlotD
 {
-    /// Draw the plot to a cairo surface
+    /**
+    Draw the plot to a cairoD cairo surface.
+
+    Params:
+        surface = Surface object of type cairo.Surface from cairoD library, on top of which this plot is drawn.
+        width = Width of the given surface.
+        height = Height of the given surface.
+
+    Returns:
+        Resulting surface of the same type as input surface, with this plot drawn on top of it.
+    */
     auto drawToSurface( ref cairo.Surface surface, int width, int height ) const
     {
         import std.range : empty, front;
@@ -233,6 +243,35 @@ struct GGPlotD
         return surface;
     }
 
+    version(ggplotdGTK) 
+    {
+        import gtkdSurface = cairo.Surface; // cairo surface module in GtkD package.
+
+        /**
+        Draw the plot to a GtkD cairo surface.
+
+        Params:
+            surface = Surface object of type cairo.Surface from GtkD library, on top of which this plot is drawn.
+            width = Width of the given surface.
+            height = Height of the given surface.
+
+        Returns:
+            Resulting surface of the same type as input surface, with this plot drawn on top of it.
+        */
+        auto drawToSurface( ref gtkdSurface.Surface surface, int width, int height ) const
+        {
+            import gtkc = gtkc.cairotypes;
+            import cairod = cairo.c.cairo;
+
+            alias gtkd_surface_t = gtkc.cairo_surface_t;
+            alias cairod_surface_t = cairod.cairo_surface_t;
+
+            cairo.Surface cairodSurface = new cairo.Surface(cast(cairod_surface_t*)surface.getSurfaceStruct());
+            drawToSurface(cairodSurface, width, height);
+
+            return surface;
+        }
+    }
 
     /// save the plot to a file
     void save( string fname, int width = 470, int height = 470 ) const
@@ -349,6 +388,47 @@ unittest
     assertEqual( dim, gg.geomRange.data.length );
 }
 
+version(ggplotdGTK) 
+{
+    unittest 
+    {
+        // Draw same plot on cairod.ImageSurface, and on gtkd.cairo.ImageSurface,
+        // and prove resulting images are the same.
+
+        import ggplotd.geom;
+        import ggplotd.aes;
+
+        import gtkSurface = cairo.Surface;
+        import gtkImageSurface = cairo.ImageSurface;
+        import gtkCairoTypes = gtkc.cairotypes;
+
+        const win_width = 1024;
+        const win_height = 1024;
+
+        const radius = 400.;
+
+        auto line_aes11 = Aes!(double[], "x", double[], "y")( [ 0, radius*0.45 ], [ 0, radius*0.45]);
+        auto line_aes22 = Aes!(double[], "x", double[], "y")( [ 300, radius*0.45 ], [ 210, radius*0.45]);
+
+        auto gg = GGPlotD();
+        gg.put( geomLine(line_aes11) );
+        gg.put( geomLine(line_aes22) );
+
+        cairo.Surface cairodSurface = new cairo.ImageSurface(cairo.Format.CAIRO_FORMAT_RGB24, win_width, win_height);
+        gtkSurface.Surface gtkdSurface = gtkImageSurface.ImageSurface.create(gtkCairoTypes.cairo_format_t.RGB24, win_width, win_height);
+
+        auto cairodImageSurface = cast(cairo.ImageSurface)cairodSurface;
+        auto gtkdImageSurface = cast(gtkImageSurface.ImageSurface)gtkdSurface;
+
+        gg.drawToSurface(cairodSurface, win_width, win_height);
+        gg.drawToSurface(gtkdSurface, win_width, win_height);
+
+        auto byteSize = win_width*win_height*4;
+
+        assertEqual(cairodImageSurface.getData()[0..byteSize], gtkdImageSurface.getData()[0..byteSize]);
+    }
+}
+
 unittest
 {
     auto gg = GGPlotD()