３Dの円グラフを表示するiPhoneアプリのサンプルコードを描いてみます。
#import “ViewController.h”
@import SceneKit;
@interface ViewController ()
@property (nonatomic, weak) SCNView *sceneView;
@property (nonatomic, strong) NSMutableArray *sliders;
@end
@implementation ViewController
– (void)viewDidLoad {
[super viewDidLoad];
[self setupScene];
[self createSlider];
[self createPiChart];
[self createCamera];
}
– (void)setupScene {
SCNView *sv = [[SCNView alloc] initWithFrame:self.view.bounds];
sv.scene = [SCNScene scene];
sv.autoenablesDefaultLighting = YES;
sv.backgroundColor = [self color:0];
[self.view addSubview:sv];
self.sceneView = sv;
}
– (void)createPiChart {
for (int i=0; i<3; i++) {
UIBezierPath *path = [UIBezierPath bezierPath];
SCNShape *arc = [SCNShape shapeWithPath:path extrusionDepth:4.0];
arc.firstMaterial.diffuse.contents = [self color:i+1];
SCNNode *node = [SCNNode nodeWithGeometry:arc];
node.name = @[@”chartA”, @”chartB”, @”chartC”][i];
[self.sceneView.scene.rootNode addChildNode:node];
}
[self updatePiChart];
}
– (void)updatePiChart {
float startAngle = 0;
float endAngle = 0;
for (int i=0; i<3; i++) {
NSString *name = @[@”chartA”, @”chartB”, @”chartC”][i];
endAngle += ((UISlider *)self.sliders[i]).value;
SCNNode *node = [self.sceneView.scene.rootNode childNodeWithName:name recursively:NO];
UIBezierPath *path = [UIBezierPath bezierPath];
[path moveToPoint:CGPointZero];
float r = 20;
float dAngle = 2.0 * M_PI / (((UISlider *)self.sliders[0]).value
+ ((UISlider *)self.sliders[1]).value
+ ((UISlider *)self.sliders[2]).value);
for (float i=startAngle; i<endAngle; i+=0.1) {
[path addLineToPoint:CGPointMake(r * cos(dAngle * i), r * sin(dAngle * i))];
}
[path addLineToPoint:CGPointMake(r * cos(dAngle * endAngle), r * sin(dAngle * endAngle))];
[path closePath];
((SCNShape *)node.geometry).path = path;
startAngle = endAngle;
}
}
– (void)createSlider {
self.sliders = [NSMutableArray array];
for (int i=0; i<3; i++) {
UISlider *slider = [[UISlider alloc] init];
slider.center = CGPointMake(CGRectGetMidX(self.view.bounds), CGRectGetMaxY(self.view.bounds) – 200 + 50 * i);
slider.minimumValue = 1.0;
slider.maximumValue = 100.0;
slider.value = 100.0/3.0;
[self.view addSubview:slider];
[slider addTarget:self action:@selector(slide:) forControlEvents:UIControlEventValueChanged];
[self.sliders addObject:slider];
}
}
– (void)slide:(UISlider *)sender {
[self updatePiChart];
}
– (void)createCamera {
SCNNode *camera = [SCNNode node];
camera.camera = [SCNCamera camera];
camera.position = SCNVector3Make(0, –50, 50);
camera.rotation = SCNVector4Make(1, 0, 0, 0.6);
[self.sceneView.scene.rootNode addChildNode:camera];
}
#define ColorHex(rgb) [UIColor colorWithRed:((rgb & 0xFF0000) >> 16)/255.0 green:((rgb & 0xFF00) >> 8)/255.0 blue:(rgb &0xFF)/255.0 alpha:1.0]
– (UIColor *)color:(int)i {
switch (i) {
case 0: return ColorHex(0xE9F1DF);
case 1: return ColorHex(0xF2385A);
case 2: return ColorHex(0xF5A503);
case 3: return ColorHex(0x4AD9D9);
}
return nil;
}
@end