On 11 May, Keith Packard wrote: > unification between translucency and partial pixel coverage. At the pixel > level, partial coverage is indistinguishable from translucency.
Isn't it less misleading to say partial coverage is indistinguishable from a transmissivity less than one. Translucency usually implies some degree of dispersive effects. E.g. translucent objects cause blurring of the background object, not merely reduced light transmission. I'm being a nitpicker because when you use alpha to manage edge effects, you are assuming that alpha behaves like transmissivity. And the various problems with text and gamma are the result of alpha not implementing transmissivity. The OpenGL specification states that alpha shall implement transmissivity, but the DirectX specification states that alpha implements voltage interpolation. Since voltage interpolation is immensely easier to implement in hardware, all of the affordable PC graphics cards only support voltage interpolation. If we wanted to put in the effort, Render could define a software implementation (with some new pixrect definitions required) that truly did implement transmissivity computations. This would prevent use of hardware accelerations but give more pleasing results. For some of today's fast processors it might even have acceptable performance. R Horn _______________________________________________ Render mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/render
