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2014/10/15 ¤U¤È 10:12:27
iphone Programming Glossary: p2Objective-C check if subviews of rotated UIViews intersect? http://stackoverflow.com/questions/15710853/objective-c-check-if-subviews-of-rotated-uiviews-intersect poly2 count int count2 for int i 0 i count1 i Perpendicular vector for one edge of poly1 CGPoint p1 poly1 i CGPoint p2 poly1 i 1 count1 CGPoint perp CGPointMake p2.y p1.y p2.x p1.x Projection intervals of poly1 poly2 onto perpendicular vector.. i Perpendicular vector for one edge of poly1 CGPoint p1 poly1 i CGPoint p2 poly1 i 1 count1 CGPoint perp CGPointMake p2.y p1.y p2.x p1.x Projection intervals of poly1 poly2 onto perpendicular vector CGFloat minp1 maxp1 minp2 maxp2 self projectionOfPolygon.. vector for one edge of poly1 CGPoint p1 poly1 i CGPoint p2 poly1 i 1 count1 CGPoint perp CGPointMake p2.y p1.y p2.x p1.x Projection intervals of poly1 poly2 onto perpendicular vector CGFloat minp1 maxp1 minp2 maxp2 self projectionOfPolygon..
iPhone image stretching (skew) http://stackoverflow.com/questions/2351586/iphone-image-stretching-skew image stretching skew How do I skew an image For example each corner has a CGPoint with coords p1 p2 p3 p4. Then I need to set p4.x 50 p4.y 30. So this corner p4 should be stretched in a 2D perspective and the image should.. transform does not. For your transform it can be done in two steps. One to convert the square into a trapezoid. p1 p2 p1 p2 p3 p4 p3 p4' Another to the vertical direction. A naive transformation rule is y c x' x p1.x ”——————†p1.x.. does not. For your transform it can be done in two steps. One to convert the square into a trapezoid. p1 p2 p1 p2 p3 p4 p3 p4' Another to the vertical direction. A naive transformation rule is y c x' x p1.x ”——————†p1.x p1.y..
Find the tangent of a point on a cubic bezier curve (on an iPhone) http://stackoverflow.com/questions/4089443/find-the-tangent-of-a-point-on-a-cubic-bezier-curve-on-an-iphone those coefficients return C1 t t t C2 t t C3 t C4 @implementation MBBezierView void drawRect CGRect rect CGPoint p1 p2 p3 p4 p1 CGPointMake 30 rect.size.height 0.33 p2 CGPointMake CGRectGetMidX rect CGRectGetMinY rect p3 CGPointMake CGRectGetMidX.. C4 @implementation MBBezierView void drawRect CGRect rect CGPoint p1 p2 p3 p4 p1 CGPointMake 30 rect.size.height 0.33 p2 CGPointMake CGRectGetMidX rect CGRectGetMinY rect p3 CGPointMake CGRectGetMidX rect CGRectGetMaxY rect p4 CGPointMake 30.. bezierPath UIBezierPath alloc init autorelease bezierPath moveToPoint p1 bezierPath addCurveToPoint p4 controlPoint1 p2 controlPoint2 p3 bezierPath stroke UIColor brownColor setStroke now mark in points along the bezier for CGFloat t 0.0 t..
Help calculating X and Y from Latitude and Longitude in iPhone http://stackoverflow.com/questions/6852195/help-calculating-x-and-y-from-latitude-and-longitude-in-iphone the distance in lat lon space via equirectangular projection p1 lonp lon1 cos 0.5 latp lat1 convert lat lon to radians p2 latp lat1 distance R sqrt p1 p1 p2 p2 use R 6371000 and your distance will be in meters Now scale this distance to your.. projection p1 lonp lon1 cos 0.5 latp lat1 convert lat lon to radians p2 latp lat1 distance R sqrt p1 p1 p2 p2 use R 6371000 and your distance will be in meters Now scale this distance to your map scale At this point you have polar.. projection p1 lonp lon1 cos 0.5 latp lat1 convert lat lon to radians p2 latp lat1 distance R sqrt p1 p1 p2 p2 use R 6371000 and your distance will be in meters Now scale this distance to your map scale At this point you have polar..
Drawing Smooth Curves - Methods Needed http://stackoverflow.com/questions/8702696/drawing-smooth-curves-methods-needed POINT 0 for NSUInteger index 1 index points.count 2 index CGPoint p0 POINT index 1 CGPoint p1 POINT index CGPoint p2 POINT index 1 CGPoint p3 POINT index 2 now add n points starting at p1 dx dy up until p2 using Catmull Rom splines for int.. p1 POINT index CGPoint p2 POINT index 1 CGPoint p3 POINT index 2 now add n points starting at p1 dx dy up until p2 using Catmull Rom splines for int i 1 i granularity i float t float i 1.0f float granularity float tt t t float ttt tt.. i float t float i 1.0f float granularity float tt t t float ttt tt t CGPoint pi intermediate point pi.x 0.5 2 p1.x p2.x p0.x t 2 p0.x 5 p1.x 4 p2.x p3.x tt 3 p1.x p0.x 3 p2.x p3.x ttt pi.y 0.5 2 p1.y p2.y p0.y t 2 p0.y 5 p1.y 4 p2.y p3.y..
How can I add CGPoint objects to an NSArray the easy way? http://stackoverflow.com/questions/899600/how-can-i-add-cgpoint-objects-to-an-nsarray-the-easy-way that will just return the corresponding CGPoint for an given index. I don't want to create 50 variables like p1 ... p2 ... and so on. Is there an easy way that would let me to define those points instantly when initializing the NSArray with..
how can i trace the finger movement on touch for drawing smooth curves? http://stackoverflow.com/questions/1052119/how-can-i-trace-the-finger-movement-on-touch-for-drawing-smooth-curves Catmull Rom spline into a series of cubic Bezier curves. Here's how. Say you have four consecutive sample points P0 P1 P2 and P3 the cubic Bezier curve that connects P1 to P2 is defined by the following control points B0 P1 B1 P1 P2 P0 6 B3 P2.. Here's how. Say you have four consecutive sample points P0 P1 P2 and P3 the cubic Bezier curve that connects P1 to P2 is defined by the following control points B0 P1 B1 P1 P2 P0 6 B3 P2 P1 P3 6 B4 P2 This should work well as long as your.. P0 P1 P2 and P3 the cubic Bezier curve that connects P1 to P2 is defined by the following control points B0 P1 B1 P1 P2 P0 6 B3 P2 P1 P3 6 B4 P2 This should work well as long as your sample points aren't too dense and it's super easy. The only..
Find the tangent of a point on a cubic bezier curve (on an iPhone) http://stackoverflow.com/questions/4089443/find-the-tangent-of-a-point-on-a-cubic-bezier-curve-on-an-iphone of a curve is simply its derivative. The parametric equation that Michal uses P t 1 t ^3 P0 3t 1 t ^2 P1 3t^2 1 t P2 t^3 P3 should have a derivative of dP t dt 3 1 t ^2 P0 3 1 t ^2 P1 6t 1 t P1 3t^2 P2 6t 1 t P2 3t^2 P3 Which by the way.. t 1 t ^3 P0 3t 1 t ^2 P1 3t^2 1 t P2 t^3 P3 should have a derivative of dP t dt 3 1 t ^2 P0 3 1 t ^2 P1 6t 1 t P1 3t^2 P2 6t 1 t P2 3t^2 P3 Which by the way appears to be wrong in your earlier question. I believe you're using the slope for a.. 3t 1 t ^2 P1 3t^2 1 t P2 t^3 P3 should have a derivative of dP t dt 3 1 t ^2 P0 3 1 t ^2 P1 6t 1 t P1 3t^2 P2 6t 1 t P2 3t^2 P3 Which by the way appears to be wrong in your earlier question. I believe you're using the slope for a quadratic..
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