Re: GTKD Cairo get pixel color

[Mike Wey via Digitalmars-d-learn]

On 01/01/2016 01:37 PM, TheDGuy wrote:

On Wednesday, 30 December 2015 at 23:20:23 UTC, Basile B. wrote:

On Wednesday, 30 December 2015 at 20:44:44 UTC, TheDGuy wrote:

Hello,

is there any way to get the pixel color of a single pixel by x and y
coordinates of a context?

render to a png back buffer.

see cairo_image_surface_create_for_data

then you'll be able to access the data and, at the same time, to blit
your buffer to screen.

Thanks for your answer. But how do i access the function via the context?

It does not work like this:

class DW:DrawingArea{
     this(){
         addOnDraw(&drawCallback);
     }
     bool drawCallback(Scoped!Context cr, Widget widget){
         char[] c = new char[](256*256);
         auto val =
cr.cairo_image_surface_create_for_data(c,cairo_format_t.CAIRO_FORMAT_ARGB32,
256,256,
cairo.format_stride_for_width(cairo_format_t.CAIRO_FORMAT_ARGB32,256));
         return true;
     }
}
"no property 'cairo_image_surface_create_for_data' for type 'Scoped'"

you would either cr.getTarget(); or cairo.ImageSurface.ImageSurface.create.

I'm not sure how those would get you access to the pixel data.

--
Mike Wey