Hi,
I’d like to draw a trace of user’s finger moving on the screen. I wanted to draw a 2-pixel radius circle when the touch event gets the “moved” phase - but if I move my mouse of simulator / finger on device fast, I don’t get every position registered. It seems like it’s missing some… Is there any workaround for that?
thanks,
[import]uid: 120659 topic_id: 33264 reply_id: 333264[/import]
I’m not 100% sure how it is done, but check this out : http://techority.com/store/drawing/
Its a template made by Peach Pellan. It’s not free, but I have used one of her previous templates and they are very well made and well documented. [import]uid: 62706 topic_id: 33264 reply_id: 132177[/import]
There are some tricks to get it more accurate, but it’s not really possible to get a perfectly smooth trace on a very fast screen “swipe”. The device reads in a touch location each processor cycle, and if the swipe is zipping across the screen, it will only pick up the location(s) each cycle.
You should definitely ensure your FPS is set to 60, not 30. This will give you double the “sampling rate”.
Beyond that, the more comprehensive solution is to fill in missing gaps on a predictive math curve, reading in points, delta angles between points, etc., then filling in the gap along a smooth bezier curve. It’s some rather insanely complicated math, but if you need fine-tuned accuracy, it’s ultimately the best approach.
Brent Sorrentino [import]uid: 9747 topic_id: 33264 reply_id: 132248[/import]
I’m not 100% sure how it is done, but check this out : http://techority.com/store/drawing/
Its a template made by Peach Pellan. It’s not free, but I have used one of her previous templates and they are very well made and well documented. [import]uid: 62706 topic_id: 33264 reply_id: 132177[/import]
There are some tricks to get it more accurate, but it’s not really possible to get a perfectly smooth trace on a very fast screen “swipe”. The device reads in a touch location each processor cycle, and if the swipe is zipping across the screen, it will only pick up the location(s) each cycle.
You should definitely ensure your FPS is set to 60, not 30. This will give you double the “sampling rate”.
Beyond that, the more comprehensive solution is to fill in missing gaps on a predictive math curve, reading in points, delta angles between points, etc., then filling in the gap along a smooth bezier curve. It’s some rather insanely complicated math, but if you need fine-tuned accuracy, it’s ultimately the best approach.
Brent Sorrentino [import]uid: 9747 topic_id: 33264 reply_id: 132248[/import]