Hi! This morning I came out with another simper solution for the STRAIGHT method! It is very exciting! The code I previously figured out was this:
/////////////////////////////////////// OLD CODE cairo_save(cr); // This part would retrieve the current passed surface and copy it on destimage cairo_surface_t* dest=cairo_get_target(cr); cairo_surface_flush(dest); cairo_surface_t* destimage=cairo_surface_map_to_image(dest, NULL); // Then using destimage width and height create newdest int w=cairo_image_surface_get_width(destimage); int h=cairo_image_surface_get_height(destimage); cairo_surface_t* newdest=cairo_image_surface_create(CAIRO_FORMAT_ARGB32, w, h); // Now I paint destimage to newdest with a 1.0 -alpha mask cairo_t* destcr=cairo_create(newdest); cairo_set_source_surface(destcr, destimage, 0, 0); cairo_paint_with_alpha(destcr, 1.0-alpha); cairo_destroy(destcr); // Here I rewrite the newdest to destimage destcr=cairo_create(destimage); cairo_set_source_surface(destcr, newdest, 0, 0); cairo_set_operator(destcr, CAIRO_OPERATOR_SOURCE); cairo_paint(destcr); cairo_destroy(destcr); // and update the cr target (dest) cairo_surface_unmap_image(dest, destimage); cairo_surface_mark_dirty(dest); // destroy and restore cairo_surface_destroy(newdest); cairo_restore(cr); // Finally I paint with he ADD operator using alpha for the current cairo_t commands cairo_set_operator(cr, CAIRO_OPERATOR_ADD); cairo_paint_with_alpha(cr, alpha); ////////////////////////////// OLD CODE - end And I asked my self: Is there other way to fade out a given surface? The solution I did was: extract image, paint with 1.0-alpha, paint back and extract back. I think that I can directly paint on the given surface without need to map and unmap. Also I've found a way to fade out a surface in a single operation: // //////////////////////////////////// NEW CODE // First save the context status cairo_save(cr); // Second paint with the DEST_IN operator. // It would achieve the following result: // aR=aA*aB // xR=xB // which is exactly to fade out the destination surface // by the alpha of the source (1.0-alpha in this case) cairo_set_source_rgba(cr, 1.0, 1.0, 1.0, 1.0-alpha); cairo_set_operator(cr, CAIRO_OPERATOR_DEST_IN); cairo_paint(cr); // Then restore the cairo context cairo_restore(cr); // Then paint using the ADD operator and the alpha value cairo_set_operator(cr, CAIRO_OPERATOR_ADD); cairo_paint_with_alpha(cr, alpha); // //////////////////////////////////// NEW CODE end I cannot test it right now, but I'm very excited on I have found a way to perform the desired blending operation with atomic Cairo instructions!! Cheers! 2012/10/2 Carlos López González <[email protected]>: > Thanks Konstantin. Your backing helps a lot. > > I've finally figured out how to emulate the STRAIGHT blend method > operation in Cairo. > It is an important milestone because I'm confident on being able to > emulate the Synfig's > blend methods that aren't directly supported by Cairo just using a > combination of Cairo's operators. > This means that the performance when blending can have the full > benefit of use Cairo native API. > It is possible that some of the Synfig's blend methods gets difficult > to emulate or impossible but > I hope they would be the less used. > > Cheers! > > 2012/9/29 Konstantin Dmitriev <[email protected]>: >> 2012/9/29 Carlos López González <[email protected]>: >>> Hi! >>> I've added Cairo support for Shade and Bevel layers. >>> Again the results are very similar but slightly slower. These kind of layers >>> that manipulate pixels directly doesn't seem to improve much using Cairo >>> colors. In fact they loose time doing some unwanted operations (due >>> premultiplied and due to need to convert alpha to a 0-1 range) that doesn't >>> compensate the supposed speed increase for handling unsigned char in memory. >>> >>> I've seen that there are room for some improvements in the Paste Canvas >>> layer because in Cairo I didn't clip the Paste Canvas's canvas's context >>> because I didn't understand what was doing the Software. Now that I know >>> more about Cairo and that I understand what does Paste Canvas do, I could >>> try to use clip in Cairo render and so the things should improve the speed >>> for all the encapsulated layers that have defined boundaries. >> >> Hi, Carlos! >> It's awesom to see such a progress. >> >From some moment this week I've got a strong feeling that the >> finished cairo implementation is somewhere near, on the horizon. That >> is awesome. Of course, there's still a lot of work, I understand. But >> it will be such a significant step even if we will not gain desired >> speed increase! >> Please keep your hard work! >> Thank you! >> K. >> >> >> >> -- >> http://morevnaproject.org/ >> >> ------------------------------------------------------------------------------ >> How fast is your code? >> 3 out of 4 devs don\\\'t know how their code performs in production. >> Find out how slow your code is with AppDynamics Lite. >> http://ad.doubleclick.net/clk;262219672;13503038;z? >> http://info.appdynamics.com/FreeJavaPerformanceDownload.html >> _______________________________________________ >> Synfig-devl mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/synfig-devl > > > > -- > Carlos > http://synfig.org -- Carlos http://synfig.org ------------------------------------------------------------------------------ Don't let slow site performance ruin your business. 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