markv@phoenix.Princeton.EDU (Mark T Vandewettering) (09/21/89)
I have a new application that requires eeking out the highest performance possible from our 4D/220. My current application requires the capability to draw filtered spheres (possibly transparent) as fast as possible. Each point will be relatively small (< 10 pixels) but it is important that they be drawn with relatively sophisticated filtering in order to prevent aliasing in the final image. The current method that I have requires transforming the point into screen space by hand, and then using a table indexed by fractional pixel coordinates to filter the particle and zot it into the frame buffer. I use the blendfunction() call to composite the points, and draw them in back to front order. The main problem is the transform: translating the point by hand is tedious and slow. I have heard that the graphics pipeline of the 4/D is microcoded, and may be dynamically changed. Is this true? If so, is there documentation on coding applications which might take advantage of this? Is there anyway to code the transform and filter operations in microcode? Thanks for your help Mark VandeWettering (markv@acm.princeton.edu)