//
//  SCNSceneRenderer.h
//
//  Copyright 2012 Apple Inc. All rights reserved.
//

@class SCNScene;
@class SCNNode;
@protocol SCNSceneRendererDelegate;


/*! @group Hit test options */

/*! If set to YES, returns the first object found. This object is not necessarily the nearest. Defaults to NO. */
SCENEKIT_EXTERN NSString * const SCNHitTestFirstFoundOnlyKey;
/*! Determines whether the results should be sorted. If set to YES sorts nearest objects first. Defaults to YES. */
SCENEKIT_EXTERN NSString * const SCNHitTestSortResultsKey;
/*! If set to YES ignores the objects clipped by the zNear/zFar range of the current point of view. Defaults to YES. */
SCENEKIT_EXTERN NSString * const SCNHitTestClipToZRangeKey;
/*! If set to YES ignores the faces not facing to the camera. Defaults to YES. */
SCENEKIT_EXTERN NSString * const SCNHitTestBackFaceCullingKey;
/*!  If set to YES only tests the bounding boxes of the 3D objects. Defaults to NO. */
SCENEKIT_EXTERN NSString * const SCNHitTestBoundingBoxOnlyKey;
/*! Determines whether the child nodes are ignored. Defaults to NO. */
SCENEKIT_EXTERN NSString * const SCNHitTestIgnoreChildNodesKey;
/*! Specifies the root node to use for the hit test. Defaults to the root node of the scene. */
SCENEKIT_EXTERN NSString * const SCNHitTestRootNodeKey;


/*! @class SCNHitTestResult
    @abstract Results returned by the hit test methods.
 */

SCENEKIT_AVAILABLE(10_7, NA)
@interface SCNHitTestResult : NSObject
{	
@private
	id _reserved;
}

/*! The node hit. */
@property(nonatomic, readonly) SCNNode*      node;
/*! Index of the geometry hit. */
@property(nonatomic, readonly) NSInteger     geometryIndex;
/*! Index of the face hit. */
@property(nonatomic, readonly) NSInteger     faceIndex;
/*! Intersection point in the node local coordinate system. */
@property(nonatomic, readonly) SCNVector3    localCoordinates;
/*! Intersection point in the world coordinate system. */
@property(nonatomic, readonly) SCNVector3    worldCoordinates;
/*! Intersection normal in the node local coordinate system. */
@property(nonatomic, readonly) SCNVector3    localNormal;
/*! Intersection normal in the world coordinate system. */
@property(nonatomic, readonly) SCNVector3    worldNormal;
/*! World transform of the node intersected. */
@property(nonatomic, readonly) CATransform3D modelTransform;

/*! 
 @method textureCoordinatesWithMappingChannel:
 @abstract Returns the texture coordinates at the point of intersection, for a given mapping channel.
 @param channel The texture coordinates source index of the geometry to use. The channel must exists on the geometry otherwise {0,0} will be returned.
 */
- (CGPoint) textureCoordinatesWithMappingChannel:(NSInteger) channel;

@end



/*! @protocol SCNSceneRenderer
    @abstract Protocol adopted by the various renderers (SCNScene, SCNLayer, SCNRenderer)
 */
@protocol SCNSceneRenderer <NSObject>

@required

/*! 
 @property currentTime
 @abstract Specifies the current time to display the scene.
 */
@property(nonatomic) NSTimeInterval currentTime;

/*! 
 @property delegate
 @abstract Specifies the renderer delegate.
 */
@property(nonatomic, assign) id <SCNSceneRendererDelegate> delegate;

/*! 
 @method hitTest:options:
 @abstract Returns an array of SCNHitTestResult for each node that contains a specified point.
 @param thePoint A point in the coordinate system of the receiver.
 @param options Optional parameters (see the "Hit test options" group for the available options).
 */
- (NSArray *)hitTest:(CGPoint)thePoint options:(NSDictionary *)options;

/*! 
 @property playing
 @abstract Returns YES if the scene is playing, NO otherwise.
 */
@property(getter=isPlaying) BOOL playing;

/*! 
 @property loops
 @abstract Indicates whether the receiver restarts playback when it reaches the end of its content. Default: YES.
 @discussion YES when the receiver restarts playback when it finishes, NO otherwise.
 */
@property(nonatomic) BOOL loops;

/*! 
 @property pointOfView
 @abstract Specifies the point of view used to render the scene. 
 @discussion A point of view must have either a camera or a spot light attached.
 */
@property(nonatomic, retain) SCNNode *pointOfView;

/*! 
 @property autoenablesDefaultLighting
 @abstract Specifies whether the receiver should automatically light up scenes that have no light source. The default is NO.
 @discussion When enabled, a diffuse light is automatically added and placed while rendering scenes that have no light or only ambient lights.
 */
@property(nonatomic) BOOL autoenablesDefaultLighting;

/*! 
 @property jitteringEnabled
 @abstract Specifies whether the receiver should jitter the rendered scene to reduce aliasing artifacts. 
 @discussion When enabled, the jittering is performed asynchronously and automatically by SCNView and SCNLayer. It is done synchronously by SCNRenderer.
 */
@property(nonatomic, getter=isJitteringEnabled) BOOL jitteringEnabled;

/*! 
 @property context
 @abstract A Core OpenGL render context that is used as the render target (usually a CGLContextObj).
 */
@property(nonatomic, readonly) void *context;

@end






/*!
 @protocol SCNSceneRendererDelegate
 @abstract Implement this protocol to perform operations at various times during the rendering
 */
@protocol SCNSceneRendererDelegate <NSObject>

@optional

/*! 
 @method renderer:willRenderScene:atTime:
 @abstract Invoked on the delegate before the scene renderer renders the scene.
 @param aRenderer The renderer that will render the scene.
 @param scene The scene to be rendered.
 @param time The time at which the scene is to be rendered.
 */
- (void)renderer:(id <SCNSceneRenderer>)aRenderer willRenderScene:(SCNScene *)scene atTime:(NSTimeInterval)time;

/*! 
 @method renderer:didRenderScene:atTime:
 @abstract Invoked on the delegate once the scene renderer did render the scene.
 @param aRenderer The renderer that did render the scene.
 @param scene The rendered scene.
 @param time The time at which the scene was rendered.
 */
- (void)renderer:(id <SCNSceneRenderer>)aRenderer didRenderScene:(SCNScene *)scene atTime:(NSTimeInterval)time;

@end