//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose:
//
// $NoKeywords: $
//
//=============================================================================//

#ifndef ISHADER_H
#define ISHADER_H

#ifdef _WIN32
#pragma once
#endif

//==================================================================================================
// **this goes into both platforms which run the translator, either the real Mac
// client or the Windows client running with r_emulategl mode **
//
// size of the VS register bank in ARB / GLSL we expose
// it's not 256, because you can't use all 256 slots in 10.5.x.
// use this constant everywhere you might normally use "256" in reference to a
// parameter array size. The highest shader constant is c218, plus we allocate
// c219 and c220 for two clip planes
#define DXABSTRACT_VS_PARAM_SLOTS 228
#define DXABSTRACT_VS_FIRST_BONE_SLOT VERTEX_SHADER_MODEL
#define DXABSTRACT_VS_LAST_BONE_SLOT \
    (VERTEX_SHADER_SHADER_SPECIFIC_CONST_13 - 1)

// user clip plane 0 goes in DXABSTRACT_VS_CLIP_PLANE_BASE... plane 1 goes in
// the slot after that dxabstract uses these constants to check plane index
// limit and to deliver planes to shader for DP4 -> oCLP[n]
#define DXABSTRACT_VS_CLIP_PLANE_BASE (DXABSTRACT_VS_PARAM_SLOTS - 2)

//==================================================================================================

#include "materialsystem/imaterialsystem.h"
#include "materialsystem/ishaderapi.h"
#include "materialsystem/ishadersystem_declarations.h"

//-----------------------------------------------------------------------------
// forward declarations
//-----------------------------------------------------------------------------
class IMaterialVar;
class IShaderShadow;
class IShaderDynamicAPI;
class IShaderInit;
class CBasePerMaterialContextData;

//-----------------------------------------------------------------------------
// Information about each shader parameter
//-----------------------------------------------------------------------------
struct ShaderParamInfo_t {
    const char* m_pName;
    const char* m_pHelp;
    ShaderParamType_t m_Type;
    const char* m_pDefaultValue;
    int m_nFlags;
};

#define VERTEX_SHADER_BONE_TRANSFORM(k) (VERTEX_SHADER_MODEL + 3 * (k))

// The public methods exposed by each shader
//-----------------------------------------------------------------------------
abstract_class IShader {
   public:
    // Returns the shader name
    virtual char const* GetName() const = 0;

    // returns the shader fallbacks
    virtual char const* GetFallbackShader(IMaterialVar * *params) const = 0;

    // Shader parameters
    virtual int GetNumParams() const = 0;

    // These functions must be implemented by the shader
    virtual void InitShaderParams(IMaterialVar * *ppParams,
                                  const char* pMaterialName) = 0;
    virtual void InitShaderInstance(
        IMaterialVar * *ppParams, IShaderInit * pShaderInit,
        const char* pMaterialName, const char* pTextureGroupName) = 0;
    virtual void DrawElements(
        IMaterialVar * *params, int nModulationFlags,
        IShaderShadow* pShaderShadow, IShaderDynamicAPI* pShaderAPI,
        VertexCompressionType_t vertexCompression,
        CBasePerMaterialContextData** pContextDataPtr) = 0;

    virtual char const* GetParamName(int paramIndex) const = 0;
    virtual char const* GetParamHelp(int paramIndex) const = 0;
    virtual ShaderParamType_t GetParamType(int paramIndex) const = 0;
    virtual char const* GetParamDefault(int paramIndex) const = 0;

    // FIXME: Figure out a better way to do this?
    virtual int ComputeModulationFlags(IMaterialVar * *params,
                                       IShaderDynamicAPI * pShaderAPI) = 0;
    virtual bool NeedsPowerOfTwoFrameBufferTexture(
        IMaterialVar * *params, bool bCheckSpecificToThisFrame = true)
        const = 0;
    virtual bool NeedsFullFrameBufferTexture(
        IMaterialVar * *params, bool bCheckSpecificToThisFrame) const = 0;
    virtual bool IsTranslucent(IMaterialVar * *params) const = 0;

    virtual int GetParamFlags(int paramIndex) const = 0;

    virtual int GetFlags() const = 0;

    // FIXME: Remove GetParamName, etc. above
    //	virtual const ShaderParamInfo_t& GetParamInfo( int paramIndex ) const =
    //0;
};

#endif  // ISHADER_H