first example (#283)

samples/Samples.md

@@ -181,7 +181,7 @@ Mesh patterns are tensor-product patch meshes (type 7 shadings in PDF), read mor
 
 ![mesh pattern .png](sample_meshpattern.png "mesh pattern example")
 
-## Recording and Scripting Surfaces
+### Recording and Scripting Surfaces
 
 Example of using Recording surface, simple copy, then scaled and offset.
 
@@ -190,4 +190,10 @@ Example of using Recording surface, simple copy, then scaled and offset.
 
 Example of writing to script, put script text into frame.
 
-![sample script0.png](sample_script0.png "scrip0 example")
+![sample script0.png](sample_script0.png "scrip0 example")
+
+### current point 
+
+Example of using current point
+
+![sample current point.png](sample_current_point.png "current point example")

samples/sample_current_point.jl

@@ -0,0 +1,66 @@
+using Compat
+using Cairo
+
+function common_header()
+    ## header to provide surface and context
+    c = CairoRGBSurface(256,256);
+    cr = CairoContext(c);
+
+    save(cr);
+    set_source_rgb(cr,0.8,0.8,0.8);    # light gray
+    rectangle(cr,0.0,0.0,256.0,256.0); # background
+    fill(cr);
+    restore(cr);
+
+    return c,cr
+end
+
+function write_out_picture(filename::AbstractString,c::CairoSurface)
+    ## mark picture with current date
+    move_to(cr,0.0,12.0);
+    set_source_rgb(cr, 0,0,0);
+    show_text(cr,Libc.strftime(time()));
+    ##
+    write_to_png(c,filename);
+    nothing
+end
+
+function example_current_point(cr)
+    save(cr);
+
+    x=25.6;  y=128.0;
+    x1=102.4; y1=30.4;
+    x2=123.6; y2=45.6;
+    x3=130.4; y3=128.0;
+
+    move_to(cr, x, y);
+    curve_to(cr, x1, y1, x2, y2, x3, y3);
+
+    if has_current_point(cr)
+        x,y = get_current_point(cr);
+        save(cr)
+        move_to(cr,x,y)
+        set_source_rgb(cr, 0,0,1.0);
+        show_text(cr,"current point")
+        restore(cr)
+    end
+
+set_line_width(cr, 10.0);
+stroke(cr);
+
+
+    restore(cr);
+    save(cr);
+
+    nothing
+end
+
+
+c,cr = common_header();
+save(cr);
+example_current_point(cr);
+restore(cr);
+write_out_picture("sample_current_point.png",c);
+
+
+

src/Cairo.jl

@@ -87,6 +87,9 @@ export
     # path copy
     copy_path, copy_path_flat, convert_cairo_path_data,
 
+    # other path operations
+    get_current_point, has_current_point,
+
     # text
     text,
     update_layout, show_layout, get_layout_size, layout_text,
@@ -807,6 +810,22 @@ function convert_cairo_path_data(p::CairoPath)
     path_data
 end
 
+# other path operations
+
+function get_current_point(ctx::CairoContext)
+
+    x = Ref{Cdouble}(0)
+    y = Ref{Cdouble}(0)
+    ccall((:cairo_get_current_point, _jl_libcairo),
+            Nothing, (Ptr{Nothing},Ref{Cdouble},Ref{Cdouble}),ctx.ptr,x,y)
+
+    x[],y[]
+end
+
+function has_current_point(ctx::CairoContext)
+    Bool(ccall((:cairo_has_current_point, _jl_libcairo),
+            Cint, (Ptr{Nothing},),ctx.ptr))
+end
 
 # user<->device coordinate translation