<html> <head> <style> .hmmessage P { margin:0px; padding:0px } body.hmmessage { font-size: 10pt; font-family:Verdana } </style> </head> <body class='hmmessage'> Hmm, i wanna build a pipette tool, for getting the colorvalue at a certain pixel on my cairo_surface_t. here is some code which I found on this list, which doesn't seem to work in my case... void pipette (int x, int y) //arguments are coordinates the mouse { cairo_surface_t* imageSurface; imageSurface=layers[model->getCurrentLayer]->getSurface() ;  //gets one of my apps layers surface unsigned* char data = cairo_image_surface_get_data(imageSurface); int stride=  cairo_image_surface_get_stride(imageSurface); unsigned char* pixelRGB = data+(y*stride) + (x*CAIRO_FORMAT_ARGB32); printf ("pixel rgb: %i \n", (int) pixelRGB); } This seems to only return me the adress of that pixel in int. Well, that's my guess, since the number gets higher and higher if i move the mousepointer to the bottom right corner of the window, and lower in the other direction. Any idea for me? Thanks, Mike > Date: Thu, 9 Jul 2009 11:48:47 +0200 > From: david@bjorkevik.se > To: steril707@hotmail.com > CC: cairo@cairographics.org > Subject: Re: [cairo] Pixel RGB Values... > > Steril 707 wrote: > > I am working on a little image processing app, and would need to be > > able to get the RGB values of certain pixels on a surface. Is there > > any way to do that already with cairo at the moment? I cannot find > > anything in the API reference on that, so I thought I should ask you > > people here... And, if that's not possible, are there any plans for > > this to get implemented? > > In your question you are making an assumption: that surfaces are made > out of pixels. This is certainly not always the case, for instance with > Postscript or PDF surfaces. > > Perhaps you can give us some more info on what you want to achieve in > your application? > > Regards, > David <hr />check out the rest of the Windows Live™. More than mail–Windows Live™ goes way beyond your inbox. <a href='http://www.microsoft.com/windows/windowslive/' target='_new'>More than messages</a></body> </html>