// Copyright (c) 2008-2023 the Urho3D project
// License: MIT

/// \file

#pragma once

#include "../Container/FlagSet.h"
#include "../Container/HashBase.h"
#include "../Math/StringHash.h"
#include "../Math/Vector3.h"

namespace Urho3D
{

class Vector3;

// Graphics capability support level. Web platform (Emscripten) also uses OpenGL ES, but is considered a desktop platform capability-wise
#if defined(IOS) || defined(TVOS) || defined(__ANDROID__) || defined(__arm__) || defined(__aarch64__)
#define MOBILE_GRAPHICS
#else
#define DESKTOP_GRAPHICS
#endif

enum GAPI
{
    GAPI_NONE = 0,
    GAPI_OPENGL,
    GAPI_D3D11
};

#if defined(DESKTOP_GRAPHICS) || defined(URHO3D_GLES3)
#define DESKTOP_GRAPHICS_OR_GLES3
#endif


/// Primitive type.
enum PrimitiveType
{
    TRIANGLE_LIST = 0,
    LINE_LIST,
    POINT_LIST,
    TRIANGLE_STRIP,
    LINE_STRIP,
    TRIANGLE_FAN
};

/// %Geometry type for vertex shader geometry variations.
enum GeometryType
{
    GEOM_STATIC = 0,
    GEOM_SKINNED = 1,
    GEOM_INSTANCED = 2,
    GEOM_BILLBOARD = 3,
    GEOM_DIRBILLBOARD = 4,
    GEOM_TRAIL_FACE_CAMERA = 5,
    GEOM_TRAIL_BONE = 6,
    MAX_GEOMETRYTYPES = 7,
    // This is not a real geometry type for VS, but used to mark objects that do not desire to be instanced
    GEOM_STATIC_NOINSTANCING = 7,
};

/// Blending mode.
enum BlendMode
{
    BLEND_REPLACE = 0,
    BLEND_ADD,
    BLEND_MULTIPLY,
    BLEND_ALPHA,
    BLEND_ADDALPHA,
    BLEND_PREMULALPHA,
    BLEND_INVDESTALPHA,
    BLEND_SUBTRACT,
    BLEND_SUBTRACTALPHA,
    MAX_BLENDMODES
};

/// Depth or stencil compare mode.
enum CompareMode
{
    CMP_ALWAYS = 0,
    CMP_EQUAL,
    CMP_NOTEQUAL,
    CMP_LESS,
    CMP_LESSEQUAL,
    CMP_GREATER,
    CMP_GREATEREQUAL,
    MAX_COMPAREMODES
};

/// Culling mode.
enum CullMode
{
    CULL_NONE = 0,
    CULL_CCW,
    CULL_CW,
    MAX_CULLMODES
};

/// Fill mode.
enum FillMode
{
    FILL_SOLID = 0,
    FILL_WIREFRAME,
    FILL_POINT
};

/// Stencil operation.
enum StencilOp
{
    OP_KEEP = 0,
    OP_ZERO,
    OP_REF,
    OP_INCR,
    OP_DECR
};

/// Vertex/index buffer lock state.
enum LockState
{
    LOCK_NONE = 0,
    LOCK_HARDWARE,
    LOCK_SHADOW,
    LOCK_SCRATCH
};

/// Hardcoded legacy vertex elements.
enum LegacyVertexElement
{
    ELEMENT_POSITION = 0,
    ELEMENT_NORMAL,
    ELEMENT_COLOR,
    ELEMENT_TEXCOORD1,
    ELEMENT_TEXCOORD2,
    ELEMENT_CUBETEXCOORD1,
    ELEMENT_CUBETEXCOORD2,
    ELEMENT_TANGENT,
    ELEMENT_BLENDWEIGHTS,
    ELEMENT_BLENDINDICES,
    ELEMENT_INSTANCEMATRIX1,
    ELEMENT_INSTANCEMATRIX2,
    ELEMENT_INSTANCEMATRIX3,
    // Custom 32-bit integer object index. Due to API limitations, not supported on D3D9
    ELEMENT_OBJECTINDEX,
    MAX_LEGACY_VERTEX_ELEMENTS
};

/// Arbitrary vertex declaration element datatypes.
enum VertexElementType
{
    TYPE_INT = 0,
    TYPE_FLOAT,
    TYPE_VECTOR2,
    TYPE_VECTOR3,
    TYPE_VECTOR4,
    TYPE_UBYTE4,
    TYPE_UBYTE4_NORM,
    MAX_VERTEX_ELEMENT_TYPES
};

/// Arbitrary vertex declaration element semantics.
enum VertexElementSemantic
{
    SEM_POSITION = 0,
    SEM_NORMAL,
    SEM_BINORMAL,
    SEM_TANGENT,
    SEM_TEXCOORD,
    SEM_COLOR,
    SEM_BLENDWEIGHTS,
    SEM_BLENDINDICES,
    SEM_OBJECTINDEX,
    MAX_VERTEX_ELEMENT_SEMANTICS
};

/// Vertex element description for arbitrary vertex declarations.
struct URHO3D_API VertexElement
{
    /// Default-construct.
    VertexElement() noexcept :
        type_(TYPE_VECTOR3),
        semantic_(SEM_POSITION),
        index_(0),
        perInstance_(false),
        offset_(0)
    {
    }

    /// Construct with type, semantic, index and whether is per-instance data.
    VertexElement(VertexElementType type, VertexElementSemantic semantic, i8 index = 0, bool perInstance = false) noexcept :
        type_(type),
        semantic_(semantic),
        index_(index),
        perInstance_(perInstance),
        offset_(0)
    {
    }

    /// Test for equality with another vertex element. Offset is intentionally not compared, as it's relevant only when an element exists within a vertex buffer.
    bool operator ==(const VertexElement& rhs) const
    {
        return type_ == rhs.type_ && semantic_ == rhs.semantic_ && index_ == rhs.index_ && perInstance_ == rhs.perInstance_;
    }

    /// Test for inequality with another vertex element.
    bool operator !=(const VertexElement& rhs) const { return !(*this == rhs); }

    /// Data type of element.
    VertexElementType type_;
    /// Semantic of element.
    VertexElementSemantic semantic_;
    /// Semantic index of element, for example multi-texcoords.
    i8 index_;
    /// Per-instance flag.
    bool perInstance_;
    /// Offset of element from vertex start. Filled by VertexBuffer once the vertex declaration is built.
    i32 offset_;
};

/// Sizes of vertex element types.
extern URHO3D_API const i32 ELEMENT_TYPESIZES[];

/// Vertex element definitions for the legacy elements.
extern URHO3D_API const VertexElement LEGACY_VERTEXELEMENTS[];

/// Texture filtering mode.
enum TextureFilterMode
{
    FILTER_NEAREST = 0,
    FILTER_BILINEAR,
    FILTER_TRILINEAR,
    FILTER_ANISOTROPIC,
    FILTER_NEAREST_ANISOTROPIC,
    FILTER_DEFAULT,
    MAX_FILTERMODES
};

/// Texture addressing mode.
enum TextureAddressMode
{
    ADDRESS_WRAP = 0,
    ADDRESS_MIRROR,
    ADDRESS_CLAMP,
    ADDRESS_BORDER,
    MAX_ADDRESSMODES
};

/// Texture coordinates.
enum TextureCoordinate
{
    COORD_U = 0,
    COORD_V,
    COORD_W,
    MAX_COORDS
};

/// Texture usage types.
enum TextureUsage
{
    TEXTURE_STATIC = 0,
    TEXTURE_DYNAMIC,
    TEXTURE_RENDERTARGET,
    TEXTURE_DEPTHSTENCIL
};

/// Cube map faces.
enum CubeMapFace
{
    FACE_POSITIVE_X = 0,
    FACE_NEGATIVE_X,
    FACE_POSITIVE_Y,
    FACE_NEGATIVE_Y,
    FACE_POSITIVE_Z,
    FACE_NEGATIVE_Z,
    MAX_CUBEMAP_FACES
};

/// Cubemap single image layout modes.
enum CubeMapLayout
{
    CML_HORIZONTAL = 0,
    CML_HORIZONTALNVIDIA,
    CML_HORIZONTALCROSS,
    CML_VERTICALCROSS,
    CML_BLENDER
};

/// Update mode for render surface viewports.
enum RenderSurfaceUpdateMode
{
    SURFACE_MANUALUPDATE = 0,
    SURFACE_UPDATEVISIBLE,
    SURFACE_UPDATEALWAYS
};

/// Shader types.
enum ShaderType
{
    VS = 0,
    PS,
};

/// Shader parameter groups for determining need to update. On APIs that support constant buffers, these correspond to different constant buffers.
enum ShaderParameterGroup
{
    SP_FRAME = 0,
    SP_CAMERA,
    SP_ZONE,
    SP_LIGHT,
    SP_MATERIAL,
    SP_OBJECT,
    SP_CUSTOM,
    MAX_SHADER_PARAMETER_GROUPS
};

/// Texture units.
/// @manualbind
enum TextureUnit
{
    TU_DIFFUSE = 0,
    TU_ALBEDOBUFFER = 0,
    TU_NORMAL = 1,
    TU_NORMALBUFFER = 1,
    TU_SPECULAR = 2,
    TU_EMISSIVE = 3,
    TU_ENVIRONMENT = 4,
#ifdef DESKTOP_GRAPHICS_OR_GLES3
    TU_VOLUMEMAP = 5,
    TU_CUSTOM1 = 6,
    TU_CUSTOM2 = 7,
    TU_LIGHTRAMP = 8,
    TU_LIGHTSHAPE = 9,
    TU_SHADOWMAP = 10,
    TU_FACESELECT = 11,
    TU_INDIRECTION = 12,
    TU_DEPTHBUFFER = 13,
    TU_LIGHTBUFFER = 14,
    TU_ZONE = 15,
    MAX_MATERIAL_TEXTURE_UNITS = 8,
    MAX_TEXTURE_UNITS = 16
#else
    TU_LIGHTRAMP = 5,
    TU_LIGHTSHAPE = 6,
    TU_SHADOWMAP = 7,
    MAX_MATERIAL_TEXTURE_UNITS = 5,
    MAX_TEXTURE_UNITS = 8
#endif
};

/// Billboard camera facing modes.
enum FaceCameraMode
{
    FC_NONE = 0,
    FC_ROTATE_XYZ,
    FC_ROTATE_Y,
    FC_LOOKAT_XYZ,
    FC_LOOKAT_Y,
    FC_LOOKAT_MIXED,
    FC_DIRECTION,
};

/// Shadow type.
enum ShadowQuality
{
    SHADOWQUALITY_SIMPLE_16BIT = 0,
    SHADOWQUALITY_SIMPLE_24BIT,
    SHADOWQUALITY_PCF_16BIT,
    SHADOWQUALITY_PCF_24BIT,
    SHADOWQUALITY_VSM,
    SHADOWQUALITY_BLUR_VSM
};

// Inbuilt shader parameters.
inline const StringHash VSP_AMBIENTENDCOLOR{"AmbientEndColor"};
inline const StringHash VSP_AMBIENTSTARTCOLOR{"AmbientStartColor"};
inline const StringHash VSP_BILLBOARDROT{"BillboardRot"};
inline const StringHash VSP_CLIPPLANE{"ClipPlane"};
inline const StringHash VSP_DEPTHMODE{"DepthMode"};
inline const StringHash VSP_FRUSTUMSIZE{"FrustumSize"};
inline const StringHash VSP_GBUFFEROFFSETS{"GBufferOffsets"};
inline const StringHash VSP_MODEL{"Model"};
inline const StringHash VSP_SKINMATRICES{"SkinMatrices"};
inline const StringHash VSP_UOFFSET{"UOffset"};
inline const StringHash VSP_VERTEXLIGHTS{"VertexLights"};
inline const StringHash VSP_VIEW{"View"};
inline const StringHash VSP_VIEWINV{"ViewInv"};
inline const StringHash VSP_VIEWPROJ{"ViewProj"};
inline const StringHash VSP_VOFFSET{"VOffset"};
inline const StringHash VSP_ZONE{"Zone"};
inline const StringHash PSP_AMBIENTCOLOR{"AmbientColor"};
inline const StringHash PSP_DEPTHRECONSTRUCT{"DepthReconstruct"};
inline const StringHash PSP_FOGCOLOR{"FogColor"};
inline const StringHash PSP_FOGPARAMS{"FogParams"};
inline const StringHash PSP_GBUFFERINVSIZE{"GBufferInvSize"};
inline const StringHash PSP_LIGHTCOLOR{"LightColor"};
inline const StringHash PSP_LIGHTLENGTH{"LightLength"};
inline const StringHash PSP_LIGHTRAD{"LightRad"};
inline const StringHash PSP_MATDIFFCOLOR{"MatDiffColor"};
inline const StringHash PSP_MATEMISSIVECOLOR{"MatEmissiveColor"};
inline const StringHash PSP_MATENVMAPCOLOR{"MatEnvMapColor"};
inline const StringHash PSP_MATSPECCOLOR{"MatSpecColor"};
inline const StringHash PSP_METALLIC{"Metallic"};
inline const StringHash PSP_ROUGHNESS{"Roughness"};
inline const StringHash PSP_SHADOWCUBEADJUST{"ShadowCubeAdjust"};
inline const StringHash PSP_SHADOWDEPTHFADE{"ShadowDepthFade"};
inline const StringHash PSP_SHADOWINTENSITY{"ShadowIntensity"};
inline const StringHash PSP_SHADOWMAPINVSIZE{"ShadowMapInvSize"};
inline const StringHash PSP_SHADOWSPLITS{"ShadowSplits"};
inline const StringHash PSP_VSMSHADOWPARAMS{"VSMShadowParams"};
inline const StringHash PSP_ZONEMAX{"ZoneMax"};
inline const StringHash PSP_ZONEMIN{"ZoneMin"};

inline const StringHash VSP_CAMERAPOS{"CameraPos"};
inline const StringHash PSP_CAMERAPOS{"CameraPosPS"};

inline const StringHash VSP_DELTATIME{"DeltaTime"};
inline const StringHash PSP_DELTATIME{"DeltaTimePS"};

inline const StringHash VSP_ELAPSEDTIME{"ElapsedTime"};
inline const StringHash PSP_ELAPSEDTIME{"ElapsedTimePS"};

inline const StringHash VSP_FARCLIP{"FarClip"};
inline const StringHash PSP_FARCLIP{"FarClipPS"};

inline const StringHash VSP_LIGHTDIR{"LightDir"};
inline const StringHash PSP_LIGHTDIR{"LightDirPS"};

inline const StringHash VSP_LIGHTMATRICES{"LightMatrices"};
inline const StringHash PSP_LIGHTMATRICES{"LightMatricesPS"};

inline const StringHash VSP_LIGHTPOS{"LightPos"};
inline const StringHash PSP_LIGHTPOS{"LightPosPS"};

inline const StringHash VSP_NEARCLIP{"NearClip"};
inline const StringHash PSP_NEARCLIP{"NearClipPS"};

inline const StringHash VSP_NORMALOFFSETSCALE{"NormalOffsetScale"};
inline const StringHash PSP_NORMALOFFSETSCALE{"NormalOffsetScalePS"};

// Scale calculation from bounding box diagonal.
inline const Vector3 DOT_SCALE{1 / 3.0f, 1 / 3.0f, 1 / 3.0f};

enum MaterialQuality : u32
{
    QUALITY_LOW = 0,
    QUALITY_MEDIUM = 1,
    QUALITY_HIGH = 2,
    QUALITY_MAX = 15,
};

enum ClearTarget : u32
{
    CLEAR_COLOR = 0x1,
    CLEAR_DEPTH = 0x2,
    CLEAR_STENCIL = 0x4,
};
URHO3D_FLAGSET(ClearTarget, ClearTargetFlags);

/// Legacy vertex element bitmasks.
enum class VertexElements : u32
{
    None            = 0,
    Position        = 1 << 0,
    Normal          = 1 << 1,
    Color           = 1 << 2,
    TexCoord1       = 1 << 3,
    TexCoord2       = 1 << 4,
    CubeTexCoord1   = 1 << 5,
    CubeTexCoord2   = 1 << 6,
    Tangent         = 1 << 7,
    BlendWeights    = 1 << 8,
    BlendIndices    = 1 << 9,
    InstanceMatrix1 = 1 << 10,
    InstanceMatrix2 = 1 << 11,
    InstanceMatrix3 = 1 << 12,
    ObjectIndex     = 1 << 13
};
URHO3D_FLAGS(VertexElements);

inline constexpr i32 MAX_RENDERTARGETS = 4;
inline constexpr i32 MAX_VERTEX_STREAMS = 4;
inline constexpr i32 MAX_CONSTANT_REGISTERS = 256;

inline constexpr i32 BITS_PER_COMPONENT = 8;

} // namespace Urho3D