/*

     File: ASCSlideSkinning.m

 Abstract: Illustates how skinning can be used to animate characters.

  Version: 1.1

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 */

#import "ASCPresentationViewController.h"

#import "ASCSlideTextManager.h"

#import "ASCSlide.h"

#import "Utils.h"

@interface ASCSlideSkinning : ASCSlide

@end

@implementation ASCSlideSkinning {

    CAAnimationGroup *_idleAnimationGroup;

    CAAnimationGroup *_animationGroup1;

    CAAnimationGroup *_animationGroup2;

    SCNNode *_characterNode;

    SCNNode *_skeletonNode;

}

- (void)setupSlideWithPresentationViewController:(ASCPresentationViewController *)presentationViewController

{

    // Using a scene source allows us to retrieve the animations using their identifier

    NSURL *sceneURL = [[NSBundle mainBundle] URLForResource:@"skinning" withExtension:@"dae"];

    SCNSceneSource *sceneSource = [SCNSceneSource sceneSourceWithURL:sceneURL options:nil];

    // Place the character in the scene

    SCNScene *scene = [sceneSource sceneWithOptions:nil error:nil];

    _characterNode = [scene.rootNode childNodeWithName:@"avatar_attach" recursively:YES];

    _characterNode.scale = SCNVector3Make(0.004, 0.004, 0.004);

    _characterNode.position = SCNVector3Make(5, 0, 12);

    _characterNode.rotation = SCNVector4Make(0, 1, 0, -M_PI / 8);

    _characterNode.hidden = YES;

    [self.groundNode addChildNode:_characterNode];

    _skeletonNode = [_characterNode childNodeWithName:@"skeleton" recursively:YES];

    // Prepare the other resources

    [self loadGhostEffect];

    [self extractAnimationsFromSceneSource:sceneSource];

}

- (NSUInteger)numberOfSteps

{

    return 7;

}

- (void)presentStepIndex:(NSUInteger)index withPresentionViewController:(ASCPresentationViewController *)presentationViewController

{

    [SCNTransaction begin];

    switch (index) {

        case 0:

        {

            // Set the slide's title and subtitle and add some text

            self.textManager.title = @"Skinning";

            [self.textManager addBullet:@"Animate characters" atLevel:0];

            [self.textManager addBullet:@"Deform geometries with a skeleton" atLevel:0];

            [self.textManager addBullet:@"Joints and bones" atLevel:0];

            // Animate the character

            [_characterNode addAnimation:_idleAnimationGroup forKey:@"idleAnimation"];

            // The character is hidden. Wait a little longer before showing it

            // otherwise it may slow down the transition from the previous slide

            double delayInSeconds = 1.5;

            dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));

            dispatch_after(popTime, dispatch_get_main_queue(), ^(void) {

                [SCNTransaction begin];

                [SCNTransaction setAnimationDuration:0];

                {

                    _characterNode.hidden = NO;

                    _characterNode.opacity = 0;

                }

                [SCNTransaction commit];

                [SCNTransaction begin];

                [SCNTransaction setAnimationDuration:1.5];

                [SCNTransaction setAnimationTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn]];

                {

                    _characterNode.opacity = 1;

                }

                [SCNTransaction commit];

            });

            break;

        }

        case 1:

            [SCNTransaction setAnimationDuration:1.5];

            [self setShowsBones:YES];

            break;

        case 2:

            [_characterNode addAnimation:_animationGroup1 forKey:@"animation"];

            break;

        case 3:

            [SCNTransaction setAnimationDuration:1.5];

            [self setShowsBones:NO];

            break;

        case 4:

            [_characterNode addAnimation:_animationGroup1 forKey:@"animation"];

            break;

        case 5:

            // Simulate a new slide by changing all the text and animate these changes

            [self.textManager flipOutTextOfType:ASCTextTypeBullet];

            self.textManager.subtitle = @"SCNSkinner";

            [self.textManager addBullet:@"Can be loaded from DAEs" atLevel:0];

            [self.textManager addBullet:@"Can't be created programmatically" atLevel:0];

            [self.textManager flipInTextOfType:ASCTextTypeBullet];

            [self.textManager flipInTextOfType:ASCTextTypeSubtitle];

            break;

        case 6:

            [_characterNode addAnimation:_animationGroup2 forKey:@"animation"];

            break;

    }

    [SCNTransaction commit];

}

#pragma mark - Animations

- (void)extractAnimationsFromSceneSource:(SCNSceneSource *)sceneSource

{

    // In this scene objects are animated separately using long animations

    // playing 3 successive animations. We will group these long animations

    // and then split the group in 3 different animation groups.

    // We could also have used three DAEs (one per animation).

    NSArray *animationIDs = [sceneSource identifiersOfEntriesWithClass:[CAAnimation class]];

    NSUInteger animationCount = [animationIDs count];

    NSMutableArray *longAnimations = [[NSMutableArray alloc] initWithCapacity:animationCount];

    CFTimeInterval maxDuration = 0;

    for (NSInteger index = 0; index < animationCount; index++) {

        CAAnimation *animation = [sceneSource entryWithIdentifier:animationIDs[index] withClass:[CAAnimation class]];

        if (animation) {

            maxDuration = MAX(maxDuration, animation.duration);

            [longAnimations addObject:animation];

        }

    }

    CAAnimationGroup *longAnimationsGroup = [[CAAnimationGroup alloc] init];

    longAnimationsGroup.animations = longAnimations;

    longAnimationsGroup.duration = maxDuration;

    CAAnimationGroup *idleAnimationGroup = [longAnimationsGroup copy];

    idleAnimationGroup.timeOffset = 6.45833333333333;

    _idleAnimationGroup = [CAAnimationGroup animation];

    _idleAnimationGroup.animations = @[idleAnimationGroup];

    _idleAnimationGroup.duration = 24.71 - 6.45833333333333;

    _idleAnimationGroup.repeatCount = FLT_MAX;

    _idleAnimationGroup.autoreverses = YES;

    CAAnimationGroup *animationGroup1 = [longAnimationsGroup copy];

    _animationGroup1 = [CAAnimationGroup animation];

    _animationGroup1.animations = @[animationGroup1];

    _animationGroup1.duration = 1.4;

    _animationGroup1.fadeInDuration = 0.1;

    _animationGroup1.fadeOutDuration = 0.5;

    CAAnimationGroup *animationGroup2 = [longAnimationsGroup copy];

    animationGroup2.timeOffset = 3.666666666666667;

    _animationGroup2 = [CAAnimationGroup animation];

    _animationGroup2.animations = @[animationGroup2];

    _animationGroup2.duration = 6.416666666666667 - 3.666666666666667;

    _animationGroup2.fadeInDuration = 0.1;

    _animationGroup2.fadeOutDuration = 0.5;

}

#pragma mark - Ghost effect

- (void)loadGhostEffect

{

    NSURL *shaderURL = [[NSBundle mainBundle] URLForResource:@"character" withExtension:@"shader"];

    NSString *fragmentModifier = [NSString stringWithContentsOfURL:shaderURL encoding:NSUTF8StringEncoding error:nil];

    NSDictionary *modifiers = @{ SCNShaderModifierEntryPointFragment : fragmentModifier };

    [self setShaderModifiers:modifiers onNode:_characterNode];

}

- (void)applyGhostEffect:(BOOL)show onNode:(SCNNode *)node

{

    // Uniforms in your GLSL shaders can be set using KVC

    // The following line will set the 'ghostFactor' uniform found in the 'character.shader' file

    [node.geometry setValue:@(show) forKey:@"ghostFactor"];

    for (SCNNode *child in node.childNodes)

        [self applyGhostEffect:show onNode:child];

}

- (void)setShaderModifiers:(NSDictionary *)modifiers onNode:(SCNNode *)node

{

    node.geometry.shaderModifiers = modifiers;

    for (SCNNode *childNode in node.childNodes)

        [self setShaderModifiers:modifiers onNode:childNode];

}

#pragma mark - Skeleton visualisation

- (void)setShowsBones:(BOOL)show

{

    [self visualizeBones:show ofNode:_skeletonNode inheritedScale:1];

    [self applyGhostEffect:show onNode:_characterNode];

}

- (void)visualizeBones:(BOOL)show ofNode:(SCNNode *)node inheritedScale:(CGFloat)scale

{

    // We propagate an inherited scale so that the boxes

    // representing the bones will be of the same size

    scale *= node.scale.x;

    if (show) {

        if (node.geometry == nil)

            node.geometry = [SCNBox boxWithWidth:6.0 / scale height:6.0 / scale length:6.0 / scale chamferRadius:0.5];

    }

    else {

        if ([node.geometry isKindOfClass:[SCNBox class]])

            node.geometry = nil;

    }

    for (SCNNode *child in node.childNodes)

        [self visualizeBones:show ofNode:child inheritedScale:scale];

}

@end