1. A method for rendering an image for display, the method comprising:
a computer system executing the following steps:
computing a squash value representing a desired amount of anisotropy for an anisotropic texture sample;
identifying a desired texture map using the squash value, wherein the desired texture map is a ripmap included in a set of potential ripmaps associated with a base texture and having the desired amount of anisotropy;
determining whether the desired texture map is included in a set of available ripmaps;
in response to a determination that the desired texture map is included in the set of available ripmaps, selecting the desired texture map as a selected texture map;
in response to a determination that the desired texture map is not included in the set of available ripmaps, selecting an alternate texture map as the selected texture map, wherein the alternate texture map is an alternate ripmap included in the set of available ripmaps;
modifying a texture state value to match an attribute of the selected texture map;
sampling the selected texture map to determine an anisotropic texture sample value;
using the anisotropic texture sample value to generate a pixel of an image to be displayed;
updating a set of ripmap usage statistics associated with the set of potential ripmaps based on the desired texture map, wherein the set of ripmap usage statistics reflects a frequency of identification of a potential ripmap from the set of potential ripmaps as the desired texture map; and
adding a new ripmap to the set of available ripmaps based on the ripmap usage statistics.
2. The method of claim 1, wherein the squash value is computed from the texture coordinates associated with a group of texture samples.
3. The method of claim 1, wherein selecting a texture map includes using an orientation of the anisotropic texture sample.
4. The method of claim 1, wherein the texture state value is a texture base address.
5. The method of claim 1, wherein the texture state value is a texture map width.
6. The method of claim 1, wherein the texture state value is a texture map height.
7. The method of claim 1, wherein sampling further includes determining the anisotropic texture sample value from a plurality of texture samples from the selected texture map, wherein the plurality of texture samples are arranged to approximate the anisotropic texture sample.
8. The method of claim 1, wherein adding a new ripmap to the set of available ripmaps includes:
creating the new ripmap from the set of potential ripmaps associated with the base texture.
9. The method of claim 1, wherein updating adding a new ripmap to the set of available ripmaps based on the ripmap usage statistics includes determining whether at least one of the set of ripmap statistics exceeds a threshold value.
10. The method of claim 9, wherein the threshold value is based upon a relative visual benefit associated with at least one of the set of potential ripmaps.
11. The method of claim 9, wherein the threshold value is based upon a size of at least one of the set of potential ripmaps.
12. The method of claim 1, wherein determining whether the desired texture map is included in a set of available ripmaps includes an analysis of a bit mask enumerating an availability of each one of the set of potential ripmaps.
13. A graphics processing subsystem adapted to compute an anisotropic texture sample value, the graphics processing subsystem comprising:
a squash computation unit adapted to compute a squash value representing a desired amount of anisotropy for an anisotropic texture sample;
a ripmap threshold unit adapted to identify a desired ripmap from a set of potential ripmaps based at least in part on the squash value;
a ripmap selection unit adapted to select an available ripmap from a set of available ripmaps based upon the desired ripmap, the ripmap selection unit being adapted to select the desired ripmap as the available ripmap in the event that the desired ripmap is in the set of available ripmaps and to select an alternate ripmap as the available ripmap in the event that the desired ripmap is not in the set of available ripmaps;
a sampler adapted to compute an anisotropic texture sample value from the available ripmap and a set of texture state values;
a performance monitoring unit adapted to track a frequency of identification of desired ripmaps from the set of potential ripmaps by the ripmap threshold unit; and
a graphics driver, stored in a computer readable medium, that when executed is adapted to add a new ripmap to the set of available ripmaps based on the frequency of identification of desired ripmaps.
14. The graphics processing subsystem of claim 13, further adapted to modify the set of texture state values in response to the selection of the available ripmap.
15. The graphics processing subsystem of claim 14, wherein the texture state values include a texture width.
16. The graphics processing subsystem of claim 14, wherein the texture state values include a texture height.
17. The graphics processing subsystem of claim 13, wherein the squash computation unit is adapted to compute the squash value from a set of texture coordinates associated with a quad of pixels.
18. The graphics processing subsystem of claim 13, wherein the ripmap threshold unit is adapted to compute an approximate axis of anisotropy used to identify the desired ripmap.
19. The graphics processing subsystem of claim 13, wherein the performance monitoring unit includes a plurality of counters, each counter associated with one of the set of potential ripmaps.
20. The graphics processing subsystem of claim 19, wherein the graphics driver is further adapted to read the counters.
21. The graphics processing subsystem of claim 13, further comprising a texture memory in communication with the sampler and adapted to store the set of available ripmaps.
22. The graphics processing subsystem of claim 13, wherein the graphics driver is adapted to:
create the new ripmap from the set of potential ripmaps.
23. The graphics processing subsystem of claim 13, wherein executing the graphics driver comprises a central processing unit executing a driver program for the graphics processing subsystem.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A system for the monitoring of a gaseous atmosphere to detect a particular chemical compound in said atmosphere and to confirm the presence or absence of that compound, said system comprising:
a monitor and alarm system that is arranged to cyclically and continuously monitor said gaseous atmosphere by drawing a sample from said gaseous atmosphere and to immediately thereafter analyze said sample to detect and to report the presence of said compound;
a confirmation sampler, said confirmation sampler having at least two sorbent-containing sampling tubes and including a four-port, two-position valve and four check valves arranged in association with said sampling tubes to direct flow of the gas being sampled through a first one of said sampling tubes and then to exhaust and to direct a stream of hot purge gas through the second one of said sampling tubes and then to an analytical instrument when said two-position valve is in a first position, and to direct a stream of hot purge gas through the first of said sampling tubes and then to an analytical instrument, and to direct flow of the gas being sampled through the second one of said sampling tubes and then to exhaust when said two-position valve is in its second position;
means for drawing a gaseous sample alternately through the first of said sampling tubes and then through the second of said sampling tubes;
means for purging contaminants sorbed on packing contained in said sampling tubes after said gaseous sample has been drawn through the tubes;
means to synchronize the cyclic operation of said monitor and said confirmation sampler so that during that time interval during which the monitor is sampling, so also is one of said tubes of the confirmation sampler;
means responsive to a report of said chemical compound generated by the monitor, said responsive means arranged to cause said confirmation sampler to retain and not to purge that sampling tube employed during the cycle of said monitor that generated said report.
2. The system of claim 1 wherein said means for drawing a gaseous sample through said sampling tubes includes a vacuum pump and means to measure and control the flow of gas through said tubes.
3. The system of claim 2 wherein said vacuum pump is located downstream from said gas measurement and control means.
4. The system of claim 3 wherein said vacuum pump is a diaphragm pump, said system including means to relieve back pressure upon the pump at start-up.
5. The system of claim 4 wherein said back pressure relief means comprises a valve that is arranged to allow gas communication between the atmosphere and the suction side of said pump when the pump is not powered.
6. The system of claim 1 wherein said means for purging contaminants sorbed on packing contained in said sampling tubes comprises means for flowing a heated stream of purge gas through said sampling tubes in a direction opposite to the direction of gas flow during sampling.
7. The system of claim 1 wherein said means for purging contaminants sorbed on packing contained in said sampling tubes comprises means for directly heating said sampling tubes while flowing a stream of purge gas through said sampling tubes in a direction opposite to the direction of gas flow during sampling.
8. The system of claim 1 wherein said analyzer is either a gas chromatograph or a mass spectrograph.
9. The system of claim 1 wherein said means to synchronize the cyclic operation of said monitor and said confirmation sampler includes means to generate a timing signal that is transmitted to said sampler at the beginning of a monitor cycle.
10. A sampler for monitoring a gaseous atmosphere comprising:
sampling means having at least two sorbent-containing sampling tubes and including a four-port, two-position valve and four check valves arranged in association with said sampling tubes to direct flow of the gas being sampled through a first one of said sampling tubes and then to exhaust and to direct a stream of hot purge gas through the second one of said sampling tubes and then to an analytical instrument when said two-position valve is in a first position, and to direct a stream of hot purge gas through the first of said sampling tubes and then to an analytical instrument, and to direct flow of the gas being sampled through the second one of said sampling tubes and then to exhaust when said two-position valve is in its second position;
pump and valve means for drawing a gaseous sample alternately through the first of said sampling tubes and then through the second of said sampling tubes;
means for purging contaminants sorbed on packing contained in said sampling tubes after said gaseous sample has been drawn through the tubes; and
timing means controlling said valve means to toggle between two positions, the first of said positions causing said gaseous sample to be drawn through the first of said tubes, and the second of said positions causing said gaseous sample to be drawn through the second of said positions.
11. The sampler of claim 10 wherein said pump means comprises a diaphragm vacuum pump and wherein said sampler includes gas flow control means to control the flow rate through the sampling tubes of the gas being sampled.
12. The sampler of claim 11 wherein said pump means is downstream from said gas flow control means.
13. The sampler of claim 12 including means to relieve the back pressure on said pump upon start up of the sampler.
14. The sampler of claim 13 wherein said back pressure relief means comprises a two-port, two-position, solenoid valve arranged to open communication between the atmosphere and the suction side of said pump when said pump is not powered.
15. The system of claim 10 wherein said means for purging contaminants sorbed on packing contained in said sampling tubes comprises means for directly heating said sampling tubes while flowing a stream of purge gas through said sampling tubes in a direction opposite to the direction of gas flow during sampling.