Multi-touch device having dynamic haptic effects

1. A method of generating haptic effects comprising:

sensing at least two generally simultaneous touches on a touchscreen; and

generating a dynamic haptic effect in response to the sensing;

wherein the dynamic haptic effect is a vibration that comprises a variation of at least one parameter.

2. The method of claim 1 , wherein the sensing comprises determining a location of the touches.

3. The method of claim 1 , wherein the sensing comprises determining a number of touches on the touchscreen.

4. The method of claim 1 , wherein the at least one parameter is one or more of amplitude, frequency and duration.

5. The method of claim 1 , wherein the dynamic haptic effect is generated by at least one actuator.

6. The method of claim 1 , wherein the sensing comprises a first determination that a first finger and a second finger are being moved apart, and the dynamic haptic effect comprises increasing the parameter.

7. The method of claim 6 , wherein the sensing comprises a second determination that the first finger and a second finger are being moved together, and the dynamic haptic effect comprises decreasing the parameter.

8. The method of claim 1 , wherein the sensing comprises a determination that a first finger and a second finger are being rotated, and the dynamic haptic effect comprises generating a detent simulation from the variation.

9. The method of claim 1 , wherein the sensing comprises a determination that a first finger and a second finger created a boundary box and the box is being dragged, wherein the dynamic haptic effect comprises generating a dragging speed indication from the variation.

10. The method of claim 1 , wherein the dynamic haptic effect is generated substantially solely at points of contact of the touches.

11. A multi-touch device comprising:

a touchscreen;

a processor coupled to the touchscreen; and

a haptic feedback system coupled to the processor;

wherein the processor is adapted to sense at least two generally simultaneous touches on a touchscreen; and

the processor is adapted to generate through the haptic feedback system a dynamic haptic effect in response to the sensing;

wherein the dynamic haptic effect is a vibration that comprises a variation of at least one parameter.

12. The multi-touch device of claim 11 , wherein the haptic feedback system comprises at least one actuator.

13. The multi-touch device of claim 11 , wherein the sensing comprises determining a location of the touches.

14. The multi-touch device of claim 11 , wherein the sensing comprises determining a number of touches on the touchscreen.

15. The multi-touch device of claim 11 , wherein the at least one parameter is one or more of amplitude, frequency and duration.

16. The multi-touch device of claim 11 , wherein the sensing comprises a first determination that a first finger and a second finger are being moved apart, and the dynamic haptic effect comprises increasing the parameter.

17. The multi-touch device of claim 11 , wherein the sensing comprises a second determination that the first finger and a second finger are being moved together, and the dynamic haptic effect comprises decreasing the parameter.

18. The multi-touch device of claim 11 , wherein the sensing comprises a determination that a first finger and a second finger are being rotated, and the dynamic haptic effect comprises generating a detent simulation from the variation.

19. The multi-touch device of claim 11 , wherein the sensing comprises a determination that a first finger and a second finger created a boundary box and the box is being dragged, wherein the dynamic haptic effect comprises generating a dragging speed indication from the variation.

20. The multi-touch device of claim 11 , wherein the dynamic haptic effect is generated substantially solely at points of contact of the touches on the touchscreen.

21. A computer readable medium having instructions stored thereon that, when executed by a processor, causes the processor to:

sense at least two generally simultaneous touches on a touchscreen; and

generate a dynamic haptic effect in response to the sensing;

wherein the dynamic haptic effect is a vibration that comprises a variation of at least one parameter.

22. A system for generating haptic effects comprising:

means for sensing at least two generally simultaneous touches on a touchscreen; and

means for generating a dynamic haptic effect in response to the sensing;

wherein the dynamic haptic effect is a vibration that comprises a variation of at least one parameter.