//========= Copyright Valve Corporation, All rights reserved. ============//
//                       TOGL CODE LICENSE
//
//  Copyright 2011-2014 Valve Corporation
//  All Rights Reserved.
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
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//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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//
// cglmprogram.h
//	GLMgr buffers (index / vertex)
//	... maybe add PBO later as well
//===============================================================================

#ifndef CGLMBUFFER_H
#define CGLMBUFFER_H

#pragma once

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

extern bool g_bUsePseudoBufs;

// forward declarations

class GLMContext;

enum EGLMBufferType {
    kGLMVertexBuffer,
    kGLMIndexBuffer,
    kGLMUniformBuffer,  // for bindable uniform
    kGLMPixelBuffer,    // for PBO

    kGLMNumBufferTypes
};

// pass this in "options" to constructor to make a dynamic buffer
#define GLMBufferOptionDynamic 0x00000001

struct GLMBuffLockParams {
    uint m_nOffset;
    uint m_nSize;
    bool m_bNoOverwrite;
    bool m_bDiscard;
};

#define GL_STATIC_BUFFER_SIZE (2048 * 1024)
#define GL_MAX_STATIC_BUFFERS 2

extern void glBufferSubDataMaxSize(GLenum target, GLintptr offset,
                                   GLsizeiptr size, const GLvoid *data,
                                   uint nMaxSizePerCall = 128 * 1024);

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

// Creates an immutable storage for a buffer object
// https://www.opengl.org/registry/specs/ARB/buffer_storage.txt
class CPersistentBuffer {
   public:
    CPersistentBuffer();
    ~CPersistentBuffer();

    void Init(EGLMBufferType type, uint nSize);
    void Deinit();

    void InsertFence();
    void BlockUntilNotBusy();

    void Append(uint nSize);

    inline uint GetBytesRemaining() const { return m_nSize - m_nOffset; }
    inline uint GetOffset() const { return m_nOffset; }
    inline void *GetPtr() const { return m_pImmutablePersistentBuf; }
    inline GLuint GetHandle() const { return m_nHandle; }

   private:
    CPersistentBuffer(const CPersistentBuffer &);
    CPersistentBuffer &operator=(const CPersistentBuffer &);

    uint m_nSize;

    EGLMBufferType m_type;
    GLenum m_buffGLTarget;  // GL_ARRAY_BUFFER_ARB / GL_ELEMENT_BUFFER_ARB
    GLuint m_nHandle;       // handle of this program in the GL context

    // Holds a pointer to the persistently mapped buffer
    void *m_pImmutablePersistentBuf;

    uint m_nOffset;

#ifdef HAVE_GL_ARB_SYNC
    GLsync m_nSyncObj;
#endif
};

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

#if GL_ENABLE_INDEX_VERIFICATION

struct GLDynamicBuf_t {
    GLenum m_nGLType;
    uint m_nHandle;
    uint m_nActualBufSize;
    uint m_nSize;

    uint m_nLockOffset;
    uint m_nLockSize;
};

class CGLMBufferSpanManager {
    CGLMBufferSpanManager(const CGLMBufferSpanManager &);
    CGLMBufferSpanManager &operator=(const CGLMBufferSpanManager &);

   public:
    CGLMBufferSpanManager();
    ~CGLMBufferSpanManager();

    void Init(GLMContext *pContext, EGLMBufferType nBufType,
              uint nInitialCapacity, uint nBufSize, bool bDynamic);
    void Deinit();

    inline GLMContext *GetContext() const { return m_pCtx; }

    inline GLenum GetGLBufType() const {
        return (m_nBufType == kGLMVertexBuffer) ? GL_ARRAY_BUFFER_ARB
                                                : GL_ELEMENT_ARRAY_BUFFER_ARB;
    }

    struct ActiveSpan_t {
        uint m_nStart;
        uint m_nEnd;

        GLDynamicBuf_t m_buf;
        bool m_bOriginalAlloc;

        inline ActiveSpan_t() {}
        inline ActiveSpan_t(uint nStart, uint nEnd, GLDynamicBuf_t &buf,
                            bool bOriginalAlloc)
            : m_nStart(nStart),
              m_nEnd(nEnd),
              m_buf(buf),
              m_bOriginalAlloc(bOriginalAlloc) {
            Assert(nStart <= nEnd);
        }
    };

    ActiveSpan_t *AddSpan(uint nOffset, uint nMaxSize, uint nActualSize,
                          bool bDiscard, bool bNoOverwrite);

    void DiscardAllSpans();

    bool IsValid(uint nOffset, uint nSize) const;

   private:
    bool AllocDynamicBuf(uint nSize, GLDynamicBuf_t &buf);
    void ReleaseDynamicBuf(GLDynamicBuf_t &buf);

    GLMContext *m_pCtx;

    EGLMBufferType m_nBufType;

    uint m_nBufSize;
    bool m_bDynamic;

    CUtlVector<ActiveSpan_t> m_ActiveSpans;
    CUtlVector<ActiveSpan_t> m_DeletedSpans;

    int m_nSpanEndMax;

    int m_nNumAllocatedBufs;
    int m_nTotalBytesAllocated;
};

#endif  // GL_ENABLE_INDEX_VERIFICATION

class CGLMBuffer {
   public:
    void Lock(GLMBuffLockParams *pParams, char **pAddressOut);
    void Unlock(int nActualSize = -1, const void *pActualData = NULL);

    GLuint GetHandle() const;

    friend class GLMContext;  // only GLMContext can make CGLMBuffer objects
    friend class GLMTester;
    friend struct IDirect3D9;
    friend struct IDirect3DDevice9;

    CGLMBuffer(GLMContext *pCtx, EGLMBufferType type, uint size, uint options);
    ~CGLMBuffer();

    void SetModes(bool bAsyncMap, bool bExplicitFlush, bool bForce = false);
    void FlushRange(uint offset, uint size);

#if GL_ENABLE_INDEX_VERIFICATION
    bool IsSpanValid(uint nOffset, uint nSize) const;
#endif

    GLMContext *m_pCtx;  // link back to parent context
    EGLMBufferType m_type;
    uint m_nSize;
    uint m_nActualSize;

    bool m_bDynamic;

    GLenum m_buffGLTarget;  // GL_ARRAY_BUFFER_ARB / GL_ELEMENT_BUFFER_ARB
    GLuint m_nHandle;       // name of this program in the context

    uint m_nRevision;  // bump anytime the size changes or buffer is orphaned

    bool m_bEnableAsyncMap;       // mirror of the buffer state
    bool m_bEnableExplicitFlush;  // mirror of the buffer state

    bool m_bMapped;  // is it currently mapped

    uint m_dirtyMinOffset;  // when equal, range is empty
    uint m_dirtyMaxOffset;

    float *m_pLastMappedAddress;

    int m_nPinnedMemoryOfs;

    uint m_nPersistentBufferStartOffset;
    bool m_bUsingPersistentBuffer;

    bool m_bPseudo;  // true if the m_name is 0, and the backing is plain RAM

    // in pseudo mode, there is just one RAM buffer that acts as the backing.
    // expectation is that this mode would only be used for dynamic indices.
    // since indices have to be consumed (copied to command stream) prior to
    // return from a drawing call, there's no need to do any fencing or
    // multibuffering.  orphaning in particular becomes a no-op.

    char *m_pActualPseudoBuf;  // storage for pseudo buffer
    char *m_pPseudoBuf;        // storage for pseudo buffer
    char *m_pStaticBuffer;

    GLMBuffLockParams m_LockParams;

    static char ALIGN16 m_StaticBuffers[GL_MAX_STATIC_BUFFERS]
                                       [GL_STATIC_BUFFER_SIZE] ALIGN16_POST;
    static bool m_bStaticBufferUsed[GL_MAX_STATIC_BUFFERS];

#if GL_ENABLE_INDEX_VERIFICATION
    CGLMBufferSpanManager m_BufferSpanManager;
#endif

#if GL_ENABLE_UNLOCK_BUFFER_OVERWRITE_DETECTION
    uint m_nDirtyRangeStart;
    uint m_nDirtyRangeEnd;
#endif
};

#endif  // CGLMBUFFER_H