MeshShape.h

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// Jolt Physics Library (https://github.com/jrouwe/JoltPhysics)
// SPDX-FileCopyrightText: 2021 Jorrit Rouwe
// SPDX-License-Identifier: MIT
 
#pragma once
 
#include <Jolt/Physics/Collision/Shape/Shape.h>
#include <Jolt/Physics/Collision/PhysicsMaterial.h>
#include <Jolt/Core/ByteBuffer.h>
#include <Jolt/Geometry/Triangle.h>
#include <Jolt/Geometry/IndexedTriangle.h>
#ifdef JPH_DEBUG_RENDERER
    #include <Jolt/Renderer/DebugRenderer.h>
#endif // JPH_DEBUG_RENDERER
 
JPH_NAMESPACE_BEGIN
 
class ConvexShape;
class CollideShapeSettings;

class JPH_EXPORT MeshShapeSettings final : public ShapeSettings
{
    JPH_DECLARE_SERIALIZABLE_VIRTUAL(JPH_EXPORT, MeshShapeSettings)
 
public:
                                    MeshShapeSettings() = default;

    explicit                        MeshShapeSettings(const TriangleList &inTriangles, PhysicsMaterialList inMaterials = PhysicsMaterialList());
                                    MeshShapeSettings(VertexList inVertices, IndexedTriangleList inTriangles, PhysicsMaterialList inMaterials = PhysicsMaterialList());

    void                            Sanitize();
 
    // See: ShapeSettings
    virtual ShapeResult             Create() const override;

    VertexList                      mTriangleVertices;

    IndexedTriangleList             mIndexedTriangles;

    PhysicsMaterialList             mMaterials;

    uint                            mMaxTrianglesPerLeaf = 8;

    float                           mActiveEdgeCosThresholdAngle = 0.996195f;                   // cos(5 degrees)

    bool                            mPerTriangleUserData = false;
 
    enum class EBuildQuality
    {
        FavorRuntimePerformance,                                                                
        FavorBuildSpeed,                                                                        
    };

    EBuildQuality                   mBuildQuality = EBuildQuality::FavorRuntimePerformance;
};

class JPH_EXPORT MeshShape final : public Shape
{
public:
    JPH_OVERRIDE_NEW_DELETE

                                    MeshShape() : Shape(EShapeType::Mesh, EShapeSubType::Mesh) { }
                                    MeshShape(const MeshShapeSettings &inSettings, ShapeResult &outResult);
 
    // See Shape::MustBeStatic
    virtual bool                    MustBeStatic() const override                               { return true; }
 
    // See Shape::GetLocalBounds
    virtual AABox                   GetLocalBounds() const override;
 
    // See Shape::GetSubShapeIDBitsRecursive
    virtual uint                    GetSubShapeIDBitsRecursive() const override;
 
    // See Shape::GetInnerRadius
    virtual float                   GetInnerRadius() const override                             { return 0.0f; }
 
    // See Shape::GetMassProperties
    virtual MassProperties          GetMassProperties() const override;
 
    // See Shape::GetMaterial
    virtual const PhysicsMaterial * GetMaterial(const SubShapeID &inSubShapeID) const override;

    const PhysicsMaterialList &     GetMaterialList() const                                     { return mMaterials; }

    uint                            GetMaterialIndex(const SubShapeID &inSubShapeID) const;
 
    // See Shape::GetSurfaceNormal
    virtual Vec3                    GetSurfaceNormal(const SubShapeID &inSubShapeID, Vec3Arg inLocalSurfacePosition) const override;
 
    // See Shape::GetSupportingFace
    virtual void                    GetSupportingFace(const SubShapeID &inSubShapeID, Vec3Arg inDirection, Vec3Arg inScale, Mat44Arg inCenterOfMassTransform, SupportingFace &outVertices) const override;
 
#ifdef JPH_DEBUG_RENDERER
    // See Shape::Draw
    virtual void                    Draw(DebugRenderer *inRenderer, RMat44Arg inCenterOfMassTransform, Vec3Arg inScale, ColorArg inColor, bool inUseMaterialColors, bool inDrawWireframe) const override;
#endif // JPH_DEBUG_RENDERER
 
    // See Shape::CastRay
    virtual bool                    CastRay(const RayCast &inRay, const SubShapeIDCreator &inSubShapeIDCreator, RayCastResult &ioHit) const override;
    virtual void                    CastRay(const RayCast &inRay, const RayCastSettings &inRayCastSettings, const SubShapeIDCreator &inSubShapeIDCreator, CastRayCollector &ioCollector, const ShapeFilter &inShapeFilter = { }) const override;

    virtual void                    CollidePoint(Vec3Arg inPoint, const SubShapeIDCreator &inSubShapeIDCreator, CollidePointCollector &ioCollector, const ShapeFilter &inShapeFilter = { }) const override;
 
    // See: Shape::CollideSoftBodyVertices
    virtual void                    CollideSoftBodyVertices(Mat44Arg inCenterOfMassTransform, Vec3Arg inScale, const CollideSoftBodyVertexIterator &inVertices, uint inNumVertices, int inCollidingShapeIndex) const override;
 
    // See Shape::GetTrianglesStart
    virtual void                    GetTrianglesStart(GetTrianglesContext &ioContext, const AABox &inBox, Vec3Arg inPositionCOM, QuatArg inRotation, Vec3Arg inScale) const override;
 
    // See Shape::GetTrianglesNext
    virtual int                     GetTrianglesNext(GetTrianglesContext &ioContext, int inMaxTrianglesRequested, Float3 *outTriangleVertices, const PhysicsMaterial **outMaterials = nullptr) const override;
 
    // See Shape::GetSubmergedVolume
    virtual void                    GetSubmergedVolume(Mat44Arg inCenterOfMassTransform, Vec3Arg inScale, const Plane &inSurface, float &outTotalVolume, float &outSubmergedVolume, Vec3 &outCenterOfBuoyancy JPH_IF_DEBUG_RENDERER(, RVec3Arg inBaseOffset)) const override { JPH_ASSERT(false, "Not supported"); }
 
    // See Shape
    virtual void                    SaveBinaryState(StreamOut &inStream) const override;
    virtual void                    SaveMaterialState(PhysicsMaterialList &outMaterials) const override;
    virtual void                    RestoreMaterialState(const PhysicsMaterialRefC *inMaterials, uint inNumMaterials) override;
 
    // See Shape::GetStats
    virtual Stats                   GetStats() const override;
 
    // See Shape::GetVolume
    virtual float                   GetVolume() const override                                  { return 0; }
 
    // When MeshShape::mPerTriangleUserData is true, this function can be used to retrieve the user data that was stored in the mesh shape.
    uint32                          GetTriangleUserData(const SubShapeID &inSubShapeID) const;
 
#ifdef JPH_DEBUG_RENDERER
    // Settings
    static bool                     sDrawTriangleGroups;
    static bool                     sDrawTriangleOutlines;
#endif // JPH_DEBUG_RENDERER
 
    // Register shape functions with the registry
    static void                     sRegister();
 
protected:
    // See: Shape::RestoreBinaryState
    virtual void                    RestoreBinaryState(StreamIn &inStream) override;
 
private:
    struct                          MSGetTrianglesContext;                                      
 
    static constexpr int            NumTriangleBits = 3;                                        
    static constexpr int            MaxTrianglesPerLeaf = 1 << NumTriangleBits;                 

    static void                     sFindActiveEdges(const MeshShapeSettings &inSettings, IndexedTriangleList &ioIndices);

    template <class Visitor>
    void                            WalkTree(Visitor &ioVisitor) const;

    template <class Visitor>
    void                            WalkTreePerTriangle(const SubShapeIDCreator &inSubShapeIDCreator2, Visitor &ioVisitor) const;

    inline void                     DecodeSubShapeID(const SubShapeID &inSubShapeID, const void *&outTriangleBlock, uint32 &outTriangleIndex) const;
 
    // Helper functions called by CollisionDispatch
    static void                     sCollideConvexVsMesh(const Shape *inShape1, const Shape *inShape2, Vec3Arg inScale1, Vec3Arg inScale2, Mat44Arg inCenterOfMassTransform1, Mat44Arg inCenterOfMassTransform2, const SubShapeIDCreator &inSubShapeIDCreator1, const SubShapeIDCreator &inSubShapeIDCreator2, const CollideShapeSettings &inCollideShapeSettings, CollideShapeCollector &ioCollector, const ShapeFilter &inShapeFilter);
    static void                     sCollideSphereVsMesh(const Shape *inShape1, const Shape *inShape2, Vec3Arg inScale1, Vec3Arg inScale2, Mat44Arg inCenterOfMassTransform1, Mat44Arg inCenterOfMassTransform2, const SubShapeIDCreator &inSubShapeIDCreator1, const SubShapeIDCreator &inSubShapeIDCreator2, const CollideShapeSettings &inCollideShapeSettings, CollideShapeCollector &ioCollector, const ShapeFilter &inShapeFilter);
    static void                     sCastConvexVsMesh(const ShapeCast &inShapeCast, const ShapeCastSettings &inShapeCastSettings, const Shape *inShape, Vec3Arg inScale, const ShapeFilter &inShapeFilter, Mat44Arg inCenterOfMassTransform2, const SubShapeIDCreator &inSubShapeIDCreator1, const SubShapeIDCreator &inSubShapeIDCreator2, CastShapeCollector &ioCollector);
    static void                     sCastSphereVsMesh(const ShapeCast &inShapeCast, const ShapeCastSettings &inShapeCastSettings, const Shape *inShape, Vec3Arg inScale, const ShapeFilter &inShapeFilter, Mat44Arg inCenterOfMassTransform2, const SubShapeIDCreator &inSubShapeIDCreator1, const SubShapeIDCreator &inSubShapeIDCreator2, CastShapeCollector &ioCollector);

    PhysicsMaterialList             mMaterials;
 
    ByteBuffer                      mTree;                                                      

    enum ETriangleFlags
    {
        FLAGS_MATERIAL_BITS         = 5,
        FLAGS_MATERIAL_MASK         = (1 << FLAGS_MATERIAL_BITS) - 1,

        FLAGS_ACTIVE_EGDE_SHIFT     = FLAGS_MATERIAL_BITS,
        FLAGS_ACTIVE_EDGE_BITS      = 3,
        FLAGS_ACTIVE_EDGE_MASK      = (1 << FLAGS_ACTIVE_EDGE_BITS) - 1
    };
 
#ifdef JPH_DEBUG_RENDERER
    mutable DebugRenderer::GeometryRef  mGeometry;                                              
    mutable bool                    mCachedTrianglesColoredPerGroup = false;                    
    mutable bool                    mCachedUseMaterialColors = false;                           
#endif // JPH_DEBUG_RENDERER
};
 
JPH_NAMESPACE_END