/*

 Copyright (C) 2016 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 Definition of the `RenderableObject` class.

 */

import Foundation

import Metal

class RenderableObject

{

    let mesh : MTLBuffer?

    let indexBuffer : MTLBuffer?

    let texture : MTLTexture?

    var count : Int

    var scale : vector_float3 = float3(1.0)

    var position : vector_float4

    var rotation : vector_float3

    var rotationRate : vector_float3

    var objectData : ObjectData

    init()

    {

        self.mesh = nil

        self.indexBuffer = nil

        self.texture = nil

        self.count = 0

        self.objectData = ObjectData()

        self.objectData.LocalToWorld = matrix_identity_float4x4

        self.position = vector_float4(0.0, 0.0, 0.0, 1.0)

        self.rotation = float3(0.0, 0.0, 0.0)

        self.rotationRate = float3(0.0, 0.0, 0.0)

    }

    init(m : MTLBuffer, idx : MTLBuffer?, count : Int, tex : MTLTexture?)

    {

        self.mesh = m

        self.indexBuffer = idx

        self.texture = tex

        self.count = count

        self.objectData = ObjectData()

        self.objectData.LocalToWorld = matrix_identity_float4x4

        self.objectData.color = float4(0.0, 0.0, 0.0, 0.0)

        self.objectData.pad1 = matrix_identity_float4x4

        self.objectData.pad2 = matrix_identity_float4x4

        self.position = vector_float4(0.0, 0.0, 0.0, 1.0)

        self.rotation = float3(0.0, 0.0, 0.0)

        self.rotationRate = float3(0.0, 0.0, 0.0)

    }

    func SetRotationRate(_ rot : vector_float3)

    {

        rotationRate = rot

    }

    func UpdateData(_ dest : UnsafeMutablePointer<ObjectData>, deltaTime : Float) -> UnsafeMutablePointer<ObjectData>

    {

        rotation += rotationRate * deltaTime

        objectData.LocalToWorld = getScaleMatrix(scale.x, y: scale.y, z: scale.z)

        objectData.LocalToWorld = matrix_multiply(getRotationAroundX(rotation.x), objectData.LocalToWorld)

        objectData.LocalToWorld = matrix_multiply(getRotationAroundY(rotation.y), objectData.LocalToWorld)

        objectData.LocalToWorld = matrix_multiply(getRotationAroundZ(rotation.z), objectData.LocalToWorld)

        objectData.LocalToWorld = matrix_multiply(getTranslationMatrix(position), objectData.LocalToWorld)

        dest.pointee = objectData

        return dest.advanced(by: 1)

    }

    func DrawZPass(_ enc :MTLRenderCommandEncoder, offset : Int)

    {

        enc.setVertexBufferOffset(offset, at: 1)

        if(indexBuffer != nil)

        {

            enc.drawIndexedPrimitives(type: MTLPrimitiveType.triangle, indexCount: count, indexType: MTLIndexType.uint16, indexBuffer: indexBuffer!, indexBufferOffset: 0)

        }

        else

        {

            enc.drawPrimitives(type: MTLPrimitiveType.triangle, vertexStart: 0, vertexCount: count)

        }

    }

    func Draw(_ enc : MTLRenderCommandEncoder, offset : Int)

    {

        enc.setVertexBufferOffset(offset, at: 1)

        enc.setFragmentBufferOffset(offset, at: 1)

        if(indexBuffer != nil)

        {

            enc.drawIndexedPrimitives(type: MTLPrimitiveType.triangle, indexCount: count, indexType: MTLIndexType.uint16, indexBuffer: indexBuffer!, indexBufferOffset: 0)

        }

        else

        {

            enc.drawPrimitives(type: MTLPrimitiveType.triangle, vertexStart: 0, vertexCount: count)

        }

    }

}

class StaticRenderableObject : RenderableObject

{

    override func UpdateData(_ dest: UnsafeMutablePointer<ObjectData>, deltaTime: Float) -> UnsafeMutablePointer<ObjectData>

    {

        return dest

    }

    override func Draw(_ enc: MTLRenderCommandEncoder, offset: Int)

    {

        enc.setVertexBuffer(mesh, offset: 0, at: 0)

        enc.setVertexBytes(&objectData, length: MemoryLayout<ObjectData>.size, at: 1)

        enc.setFragmentBytes(&objectData, length: MemoryLayout<ObjectData>.size, at: 1)

        enc.drawPrimitives(type: .triangle, vertexStart: 0, vertexCount: count)

    }

}