Method and system for ink data generation, ink data rendering, ink data manipulation and ink data communication
Methods and systems are provided for generating, rendering, manipulating (e.g., slicing), and communicating stroke objects that form ink data. In a method of generating a stroke object, pen event data indicative of pen down, pen movement, and pen up events are sequentially received to generate point objects that collectively form a stroke object. The point objects serve as control points for interpolating curve segments. Further, a start parameter indicative of a start point within a starting curve segment of the curve segments at which display of the stroke object starts, and an end parameter indicative of an end point within an ending curve segment of at which display of the stroke object ends, are generated for the stroke object. When rendering the stroke object, a system limits display of the stroke object to a range bound by the start and end parameters, as opposed to displaying the entire stroke object.
1. A method of generating ink data in a device including a processor which is coupled to memory and to a position input sensor, the ink data including stroke objects that are vector data configured to reproduce paths formed by operating a pointer, the method comprising:
sequentially receiving, in the processor, pen event data detected by the input sensor, the pen event data being indicative of pen down, pen movement, and pen up events;
sequentially generating, in the processor, point objects based on coordinate values included in the received pen event data, wherein the point objects serve as control points for interpolating curve segments according to a defined curve interpolation algorithm to form a stroke object;
generating, in the processor, a start parameter indicative of a start point within a starting curve segment of the curve segments at which display of the stroke object starts and an end parameter indicative of an end point within an ending curve segment of the curve segments at which display of the stroke object ends, wherein the start point indicates an internal division point between two end points of the starting curve segment where the display starts and the end point indicates an internal division point between two end points of the ending curve segment where the display ends; and
outputting, from the processor, the start parameter and the end parameter as well as the point objects as part of the stroke object in a defined format.
2. The method of claim 1 , wherein the defined curve interpolation algorithm is a local-control algorithm in which a value of i-th point object impacts a limited number of curve segments adjacent to the i-th point object.
3. The method of claim 2 , wherein the defined curve interpolation algorithm is a Catmull-Rom Curve algorithm.
4. The method of claim 1 , further comprising:
generating, in the processor, a point object to serve as an additional control point on an initial point object of the stroke object to form the starting curve segment by duplicating a value of the initial point object.
5. The method of claim 1 , further comprising:
determining, in the processor, whether smoothing is to be applied; and
if it is determined that the smoothing is to be applied, generating, in the processor, one or more point objects to serve as additional control points on a last point object of the stroke object to form the end curve segment by duplicating a value of the last point object to fill a lag between a smoothed coordinate of the last point object and an original coordinate of the last point object.
6. The method of claim 1 , wherein the defined curve interpolation algorithm is a Catmull-Rom Curve algorithm, and the method further comprises one or both of:
duplicating a value of an initial point object to create a starting control point to fix a shape of curve of the starting curve segment; and
duplicating a value of a last point object to create an ending control point to fix a shape of curve of the ending curve segment.
7. A non-transitory computer readable medium including processor-executable instructions which, when loaded onto a processor, causes the processor to execute a process of generating ink data including stroke objects that are vector data configured to reproduce paths formed by operating a pointer on an input sensor, the process comprising:
sequentially receiving, in the processor, pen event data detected by the input sensor, the pen event data being indicative of pen down, pen movement, and pen up events;
sequentially generating, in the processor, point objects based on coordinate values included in the received pen event data, wherein the point objects serve as control points for interpolating curve segments according to a defined curve interpolation algorithm to form a stroke object;
generating, in the processor, a start parameter indicative of a start point within a starting curve segment of the curve segments at which display of the stroke object starts and an end parameter indicative of an end point within an ending curve segment of the curve segments at which display of the stroke object ends, wherein the start point indicates an internal division point between two end points of the starting curve segment where the display starts and the end point indicates an internal division point between two end points of the ending curve segment where the display ends; and
outputting, from the processor, the start parameter and the end parameter as well as the point objects as part of the stroke object in a defined format.
8. The computer readable medium of claim 7 , wherein the defined curve interpolation algorithm is a local-control algorithm in which a value of i-th point object impacts a limited number of curve segments adjacent to the i-th point object.
9. The computer readable medium of claim 8 , wherein the defined curve interpolation algorithm is a Catmull-Rom Curve algorithm.
10. The computer readable medium of claim 7 , wherein the process further comprises:
generating, in the processor, a point object to serve as an additional control point on an initial point object of the stroke object to form the starting curve segment by duplicating a value of the initial point object.
11. The computer readable medium of claim 7 , wherein the process further comprises:
determining, in the processor, whether smoothing is to be applied; and
if it is determined that the smoothing is to be applied, generating, in the processor, one or more point objects to serve as additional control points on a last point object of the stroke object to form the end curve segment by duplicating a value of the last point object to fill a lag between a smoothed coordinate of the last point object and an original coordinate of the last point object.
12. The computer readable medium of claim 7 , wherein the defined curve interpolation algorithm is a Catmull-Rom Curve algorithm, and the process further comprises one or both of:
duplicating a value of an initial point object to create a starting control point to fix a shape of curve of the starting curve segment; and
duplicating a value of a last point object to create an ending control point to fix a shape of curve of the ending curve segment.