On Tue, Apr 28, 2009 at 9:41 AM, Viktor Kojouharov <vkojouha...@gmail.com> wrote: > On Tue, 2009-04-28 at 09:11 -0300, Gustavo Sverzut Barbieri wrote: >> On Tue, Apr 28, 2009 at 5:30 AM, Enlightenment SVN >> <no-re...@enlightenment.org> wrote: >> > Log: >> > fix the xpixmap window resizing >> > evas_object_color_set (o, 255, 255, 255, 50); >> >> hummmmmmmmmm.. even this line not being changed in the commit, i just >> spotted it and it is wrong! >> >> in Evas you need colors pre-multiplied, so every R, G and B should be >> <= A, so it is impossible to have 255 red with 50 alpha. In this case, >> use 50 50 50 50. You can google a bit more for pre-multiplied color >> system. >> > thanks. I was wondering why the rect was not transparent. I really need > to understand what values make for correct colors. e.g.: I have no idea > why the rgb have to be 50 with a 50 alpha value. Can I for instance have > 99 132 172 (light blue) with a 200 alpha?
sure, they need to be <= A. Math is simple: r_premul = (r * a) / 255; (a = 255, r_premul == r; a = 0, r_premul == 0) g_premul = (g * a) / 255; (a = 255, g_premul == g; a = 0, g_premul == 0) b_premul = (b * a) / 255; (a = 255, b_premul == b; a = 0, b_premul == 0) -- Gustavo Sverzut Barbieri http://profusion.mobi embedded systems -------------------------------------- MSN: barbi...@gmail.com Skype: gsbarbieri Mobile: +55 (19) 9225-2202 ------------------------------------------------------------------------------ Register Now & Save for Velocity, the Web Performance & Operations Conference from O'Reilly Media. Velocity features a full day of expert-led, hands-on workshops and two days of sessions from industry leaders in dedicated Performance & Operations tracks. Use code vel09scf and Save an extra 15% before 5/3. http://p.sf.net/sfu/velocityconf _______________________________________________ enlightenment-devel mailing list enlightenment-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/enlightenment-devel
