Hi Andrew, You must call XDoubleToFixed when setting the triangle coordinates, since XTriangle has p1, p2 and p3 that are XPointFixed, that has x and y that are XFixed: triangle.p1.x = XDoubleToFixed (5); triangle.p1.y = XDoubleToFixed (5); triangle.p2.x = XDoubleToFixed (5); triangle.p2.y = XDoubleToFixed (100); triangle.p3.x = XDoubleToFixed (100); triangle.p3.y = XDoubleToFixed (100); best regards, Carlos. <div>2007/7/20, Andrew Chant <<a href="mailto:andrew.chant@gmail.com">andrew.chant@gmail.com</a>>:<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Hi, I'm not sure if there's a bug in XRenderCompositeTriangles, or I am just not using it correctly. Using the over op and XRenderComposite, I successfully render a black pixmap over the right half of a white window. Using the over op and XRenderCompositeTriangles, I expect a black triangle to be rendered over the left half of the white window, but it remains white. My only guess is it has something to do with the fact that the src and dst are RGB24 not ARGB32. Could someone please take a quick look at my attached test program to see where I am wrong? If it's not wrong then I'll file a bug report I guess. Thanks, -Andrew Chant _______________________________________________ xorg mailing list <a href="mailto:xorg@lists.freedesktop.org">xorg@lists.freedesktop.org</a> <a href="http://lists.freedesktop.org/mailman/listinfo/xorg">http://lists.freedesktop.org/mailman/listinfo/xorg </a> </blockquote></div>