NSView and NSBezierPath - Graph won't show- Cocoa/Objective-C

0
votes

I'm trying to create an app that would simulate the trajectory of an object on free fall (more info here) with given speed and angle. The GUI is quite simple : 2 number formatted text field (for the speed and angle), 1 button to show to trajectory, and a custom view embed in a scroll view (of class ViewController). My code is here :

ViewController.h : 

#import <Cocoa/Cocoa.h>

@interface ViewController : NSView{
NSBezierPath *path;
NSImage *image;
NSPoint downPoint;
NSPoint currentPoint;
float angle;
float velocity;
}

@property (assign) float angle;
@property (assign) float velocity;
@property (assign) IBOutlet NSTextField *angleField;
@property (assign) IBOutlet NSTextField *speedField;

-(IBAction)fly:(id)sender;
-(NSRect)currentRect; 
@end

ViewController.m : 

#import "ViewController.h"
#import "math.h"

@implementation ViewController
@synthesize angle;
@synthesize velocity;



- (id)initWithFrame:(NSRect)frame
{
self = [super initWithFrame:frame];
if (self) {
    path = [[NSBezierPath alloc] init];
    [path setLineWidth:3.0];
}
return self;
}
- (void)drawRect:(NSRect)dirtyRect
{
NSRect bounds = [self bounds];
[[NSColor greenColor] set];
[NSBezierPath fillRect:bounds];
[[NSColor blackColor] set];
[[self pathWithVelocity:velocity angle:angle] stroke];
}

-(IBAction)fly:(id)sender
{
angle = [_angleField floatValue];
velocity = [_speedField floatValue];
NSLog(@"%f - %f",angle,velocity);
[self drawRect:[self bounds]];
}

-(NSBezierPath *)pathWithVelocity:(float)v angle:(float)a{
NSBezierPath* pat = [[NSBezierPath alloc] init];
NSPoint p;
p.x = 0;
p.y = 0;
[pat moveToPoint:p];
for (float t = 0.5; t < 100; t += 0.5) {
    p.x = v*cosf(a)*t;
    p.y = -9.81*t*t/2+v*sinf(a)*t;
    NSLog(@"(%f;%f)",p.x,p.y);
    [pat lineToPoint:p];
}
[pat closePath];
return pat;
}

-(NSRect)currentRect{
float minX = MIN(downPoint.x,currentPoint.x);
float maxX = MAX(downPoint.x,currentPoint.x);
float minY = MIN(downPoint.y,currentPoint.y);
float maxY = MAX(downPoint.x,currentPoint.x);
return NSMakeRect(minX, minY, maxX-minX,maxY-minY);
}
@end

The problems that occurs when I trigger the fly method are:

  • The view goes correctly green but the path doesn't show (even though the point coordinates seems correct)
  • When scroll the view, the new point coordinates shows as the speed and the angle are both zero even the textfield's values doesn't change

What's wrong in my code?

EDIT : For angle 0.7 and speed 300, I've got this output:

2013-03-08 07:14:41.892 Flight[10278:303] (114.73;95.41) 
2013-03-08 07:14:41.893 Flight[10278:303] (229.45;188.36)
2013-03-08 07:14:41.893 Flight[10278:303] (344.18;278.86)
2013-03-08 07:14:41.894 Flight[10278:303] (458.91;366.91)
2013-03-08 07:14:41.894 Flight[10278:303] (573.63;452.51)
2013-03-08 07:14:41.894 Flight[10278:303] (688.36;535.65)
2013-03-08 07:14:41.895 Flight[10278:303] (803.08;616.34)
2013-03-08 07:14:41.895 Flight[10278:303] (917.81;694.58)
2013-03-08 07:14:41.896 Flight[10278:303] (1032.54;770.37)
2013-03-08 07:14:41.896 Flight[10278:303] (1147.26;843.70)
2013-03-08 07:14:41.897 Flight[10278:303] (1261.99;914.58)
2013-03-08 07:14:41.897 Flight[10278:303] (1376.72;983.01)
2013-03-08 07:14:41.897 Flight[10278:303] (1491.44;1048.99)
2013-03-08 07:14:41.898 Flight[10278:303] (1606.17;1112.51)
2013-03-08 07:14:41.898 Flight[10278:303] (1720.90;1173.58)
2013-03-08 07:14:41.898 Flight[10278:303] (1835.62;1232.20)
2013-03-08 07:14:41.899 Flight[10278:303] (1950.35;1288.37)
2013-03-08 07:14:41.899 Flight[10278:303] (2065.07;1342.08)
2013-03-08 07:14:41.899 Flight[10278:303] (2179.80;1393.34)
2013-03-08 07:14:41.900 Flight[10278:303] (2294.53;1442.15)
2013-03-08 07:14:41.900 Flight[10278:303] (2409.25;1488.51)
2013-03-08 07:14:41.900 Flight[10278:303] (2523.98;1532.41)
2013-03-08 07:14:41.901 Flight[10278:303] (2638.71;1573.86)  
2013-03-08 07:14:41.901 Flight[10278:303] (2753.43;1612.86)
2013-03-08 07:14:41.901 Flight[10278:303] (2868.16;1649.41)
2013-03-08 07:14:41.901 Flight[10278:303] (2982.88;1683.50)
2013-03-08 07:14:41.902 Flight[10278:303] (3097.61;1715.15)
2013-03-08 07:14:41.902 Flight[10278:303] (3212.34;1744.33)
2013-03-08 07:14:41.902 Flight[10278:303] (3327.06;1771.07)
2013-03-08 07:14:41.903 Flight[10278:303] (3441.79;1795.35)
2013-03-08 07:14:41.903 Flight[10278:303] (3556.52;1817.19)
2013-03-08 07:14:41.903 Flight[10278:303] (3671.24;1836.56)
2013-03-08 07:14:41.904 Flight[10278:303] (3785.97;1853.49)
2013-03-08 07:14:41.904 Flight[10278:303] (3900.70;1867.97)
2013-03-08 07:14:41.905 Flight[10278:303] (4015.42;1879.99)
2013-03-08 07:14:41.905 Flight[10278:303] (4130.15;1889.56)
2013-03-08 07:14:41.906 Flight[10278:303] (4244.87;1896.67)
2013-03-08 07:14:41.906 Flight[10278:303] (4359.60;1901.34)
2013-03-08 07:14:41.906 Flight[10278:303] (4474.33;1903.55)
2013-03-08 07:14:41.907 Flight[10278:303] (4589.05;1903.31)
2013-03-08 07:14:41.907 Flight[10278:303] (4703.78;1900.61)
2013-03-08 07:14:41.907 Flight[10278:303] (4818.51;1895.47)
2013-03-08 07:14:41.908 Flight[10278:303] (4933.23;1887.87)
2013-03-08 07:14:41.908 Flight[10278:303] (5047.96;1877.82)
2013-03-08 07:14:41.908 Flight[10278:303] (5162.69;1865.31)
2013-03-08 07:14:41.909 Flight[10278:303] (5277.41;1850.36)
2013-03-08 07:14:41.909 Flight[10278:303] (5392.14;1832.95)
2013-03-08 07:14:41.909 Flight[10278:303] (5506.86;1813.09)
2013-03-08 07:14:41.910 Flight[10278:303] (5621.59;1790.77)
2013-03-08 07:14:41.910 Flight[10278:303] (5736.32;1766.01)
2013-03-08 07:14:41.910 Flight[10278:303] (5851.04;1738.79)
2013-03-08 07:14:41.911 Flight[10278:303] (5965.77;1709.12)
2013-03-08 07:14:41.911 Flight[10278:303] (6080.50;1676.99)
2013-03-08 07:14:41.911 Flight[10278:303] (6195.22;1642.42)
2013-03-08 07:14:41.912 Flight[10278:303] (6309.95;1605.39)
2013-03-08 07:14:41.912 Flight[10278:303] (6424.67;1565.91)
2013-03-08 07:14:41.912 Flight[10278:303] (6539.40;1523.97)
2013-03-08 07:14:41.913 Flight[10278:303] (6654.13;1479.59)
2013-03-08 07:14:41.913 Flight[10278:303] (6768.85;1432.75)
2013-03-08 07:14:41.913 Flight[10278:303] (6883.58;1383.46)
2013-03-08 07:14:41.914 Flight[10278:303] (6998.31;1331.72)
2013-03-08 07:14:41.915 Flight[10278:303] (7113.03;1277.52)
2013-03-08 07:14:41.915 Flight[10278:303] (7227.76;1220.87)
2013-03-08 07:14:41.915 Flight[10278:303] (7342.49;1161.77)
2013-03-08 07:14:41.916 Flight[10278:303] (7457.21;1100.22)
2013-03-08 07:14:41.916 Flight[10278:303] (7571.94;1036.21)
2013-03-08 07:14:41.917 Flight[10278:303] (7686.66;969.75)
2013-03-08 07:14:41.917 Flight[10278:303] (7801.39;900.84)
2013-03-08 07:14:41.918 Flight[10278:303] (7916.12;829.48)
2013-03-08 07:14:41.918 Flight[10278:303] (8030.84;755.66)
2013-03-08 07:14:41.919 Flight[10278:303] (8145.57;679.39)
2013-03-08 07:14:41.919 Flight[10278:303] (8260.30;600.67)
2013-03-08 07:14:41.919 Flight[10278:303] (8375.02;519.50)
2013-03-08 07:14:41.920 Flight[10278:303] (8489.75;435.87)
2013-03-08 07:14:41.920 Flight[10278:303] (8604.47;349.79)
2013-03-08 07:14:41.921 Flight[10278:303] (8719.20;261.26)
2013-03-08 07:14:41.921 Flight[10278:303] (8833.93;170.28)
2013-03-08 07:14:41.921 Flight[10278:303] (8948.65;76.84)
2013-03-08 07:14:41.922 Flight[10278:303] (9063.38;-19.05)
2013-03-08 07:14:41.922 Flight[10278:303] (9178.11;-117.39)
2013-03-08 07:14:41.922 Flight[10278:303] (9292.83;-218.18)
2013-03-08 07:14:41.923 Flight[10278:303] (9407.56;-321.43)
2013-03-08 07:14:41.923 Flight[10278:303] (9522.29;-427.13)
2013-03-08 07:14:41.924 Flight[10278:303] (9637.01;-535.28)
2013-03-08 07:14:41.924 Flight[10278:303] (9751.74;-645.88)
2013-03-08 07:14:41.924 Flight[10278:303] (9866.46;-758.94)
2013-03-08 07:14:41.925 Flight[10278:303] (9981.19;-874.45)
2013-03-08 07:14:41.925 Flight[10278:303] (10095.92;-992.41)
2013-03-08 07:14:41.925 Flight[10278:303] (10210.64;-1112.82)
2013-03-08 07:14:41.926 Flight[10278:303] (10325.37;-1235.69)
2013-03-08 07:14:41.926 Flight[10278:303] (10440.10;-1361.00)
2013-03-08 07:14:41.927 Flight[10278:303] (10554.82;-1488.78)
2013-03-08 07:14:41.927 Flight[10278:303] (10669.55;-1619.00)
2013-03-08 07:14:41.927 Flight[10278:303] (10784.28;-1751.68)
2013-03-08 07:14:41.928 Flight[10278:303] (10899.00;-1886.80)
2013-03-08 07:14:41.928 Flight[10278:303] (11013.73;-2024.39)
2013-03-08 07:14:41.929 Flight[10278:303] (11128.45;-2164.42)
2013-03-08 07:14:41.929 Flight[10278:303] (11243.18;-2306.91)
2013-03-08 07:14:41.929 Flight[10278:303] (11357.91;-2451.84)
2013-03-08 07:14:41.930 Flight[10278:303] (11472.63;-2599.23)
2013-03-08 07:14:41.930 Flight[10278:303] (11587.36;-2749.08)
2013-03-08 07:14:41.930 Flight[10278:303] (11702.09;-2901.37)
2013-03-08 07:14:41.931 Flight[10278:303] (11816.81;-3056.12)
2013-03-08 07:14:41.931 Flight[10278:303] (11931.54;-3213.32)
2013-03-08 07:14:41.932 Flight[10278:303] (12046.26;-3372.98)
2013-03-08 07:14:41.932 Flight[10278:303] (12160.99;-3535.08)
2013-03-08 07:14:41.933 Flight[10278:303] (12275.72;-3699.64)
2013-03-08 07:14:41.933 Flight[10278:303] (12390.44;-3866.65)
2013-03-08 07:14:41.934 Flight[10278:303] (12505.17;-4036.12)
2013-03-08 07:14:41.934 Flight[10278:303] (12619.90;-4208.03)
2013-03-08 07:14:41.935 Flight[10278:303] (12734.62;-4382.40)
2013-03-08 07:14:41.935 Flight[10278:303] (12849.35;-4559.22)
2013-03-08 07:14:41.935 Flight[10278:303] (12964.08;-4738.50)
2013-03-08 07:14:41.936 Flight[10278:303] (13078.80;-4920.22)
2013-03-08 07:14:41.936 Flight[10278:303] (13193.53;-5104.40)
2013-03-08 07:14:41.936 Flight[10278:303] (13308.25;-5291.03)
2013-03-08 07:14:41.937 Flight[10278:303] (13422.98;-5480.12)
2013-03-08 07:14:41.937 Flight[10278:303] (13537.71;-5671.65)
2013-03-08 07:14:41.937 Flight[10278:303] (13652.43;-5865.64)
2013-03-08 07:14:41.937 Flight[10278:303] (13767.16;-6062.08)
2013-03-08 07:14:41.938 Flight[10278:303] (13881.89;-6260.98)
2013-03-08 07:14:41.938 Flight[10278:303] (13996.61;-6462.32)
2013-03-08 07:14:41.939 Flight[10278:303] (14111.34;-6666.12)
2013-03-08 07:14:41.939 Flight[10278:303] (14226.07;-6872.37)    
2013-03-08 07:14:41.940 Flight[10278:303] (14340.79;-7081.08)
2013-03-08 07:14:41.940 Flight[10278:303] (14455.52;-7292.23)
2013-03-08 07:14:41.940 Flight[10278:303] (14570.24;-7505.84)
2013-03-08 07:14:41.941 Flight[10278:303] (14684.97;-7721.90)
2013-03-08 07:14:41.941 Flight[10278:303] (14799.70;-7940.41)
1
objective-ccocoasimulationnsviewnsbezierpath

1 Answers

0
votes

The Y axis for the coordinates you are getting seems to be -ve. Try to print the coordinated and see whether where your drawing is started. It may be drawing out of your view bounds.