IBuffers.h

#pragma once
 
#include "VertexFormat.h"
#include "Flags.h"
#include "IContext.h"
 
namespace Cogs
{
  struct IBuffers
  {
    virtual void annotate(BufferHandle handle, const StringView& name) { (void)handle; (void)name; }
 
    virtual void annotate(VertexBufferHandle handle, const StringView& name) { (void)handle; (void)name; }
 
    virtual VertexBufferHandle loadVertexBuffer(const void * vertexData, const size_t count, const VertexFormat & vertexFormat) = 0;
    virtual VertexBufferHandle loadVertexBuffer(const void * vertexData, const size_t count, VertexFormatHandle vertexFormatHandle) = 0;
 
    virtual void releaseVertexBuffer(VertexBufferHandle vertexBufferHandle) = 0;
 
    virtual IndexBufferHandle loadIndexBuffer(const void * indexData, const size_t count, const size_t indexSize) = 0;
 
    virtual void releaseIndexBuffer(IndexBufferHandle indexBufferHandle) = 0;
 
    virtual VertexArrayObjectHandle loadVertexArrayObject(const EffectHandle effectHandle,
                                                          const VertexBufferHandle* vertexBufferHandles, const size_t vertexBufferCount,
                                                          const VertexFormat* const* vertexFormats = nullptr, const uint32_t* vertexBufferStrides = nullptr, const uint32_t* vertexBufferOffsets = nullptr,
                                                          const IndexBufferHandle indexBufferHandle = IndexBufferHandle::NoHandle, uint32_t indexBufferStride = 0) = 0;
 
    virtual void releaseVertexArrayObject(VertexArrayObjectHandle vertexArrayObjectHandle) = 0;
 
    virtual InputLayoutHandle loadInputLayout(const VertexFormatHandle * vertexFormats, const size_t count, EffectHandle effectHandle) = 0;
 
    virtual void releaseInputLayout(InputLayoutHandle inputLayoutHandle) = 0;
 
    virtual BufferHandle loadBuffer(const void * data, const size_t size, Usage::EUsage usage, uint32_t accessMode, uint32_t bindFlags, uint32_t stride = 0) = 0;
 
    virtual VertexFormatHandle createVertexFormat(const VertexElement * elements, size_t count) = 0;
    virtual const VertexFormat * getVertexFormat(VertexFormatHandle handle) = 0;
 
    virtual void retrieveSubBuffer(void * data, BufferHandle source, const size_t offset, const size_t size) = 0;
 
    virtual void releaseBuffer(BufferHandle bufferHandle) = 0;
 
    virtual void * getNativeHandle(BufferHandle bufferHandle) = 0;
 
    virtual void releaseResources() = 0;
  };
 
  template<typename MappedDataType>
  struct MappedBuffer
  {
    MappedBuffer(struct IContext * context, BufferHandle bufferHandle, MapMode::EMapMode mapMode = MapMode::Read, size_t size = 0) :
      context(context),
      bufferHandle(bufferHandle),
      size(size)
    {
      data = reinterpret_cast<MappedDataType *>(context->map(bufferHandle, mapMode, &stride));
    }
 
    MappedBuffer(const MappedBuffer & other) = delete;
 
    ~MappedBuffer()
    {
      if (data) {
        context->unmap(bufferHandle);
      }
    }
 
    MappedDataType * get()
    {
      return data;
    }
 
    MappedDataType * operator->() { return data; }
 
    const MappedDataType * operator->() const { return data; }
 
    operator MappedDataType *() { return data; }
 
    explicit operator bool() const { return data != nullptr; }
 
    MappedDataType & operator[](size_t index)
    {
      if (size != 0) {
        assert(index < size && "Index out of bounds.");
      }
 
      return data[index];
    }
 
    const MappedDataType & operator[](size_t index) const
    {
      if (size != 0) {
        assert(index < size && "Index out of bounds.");
      }
 
      return data[index];
    }
 
    uint32_t getStride() const { return stride; }
 
  private:
    struct IContext * context = nullptr;
    BufferHandle bufferHandle;
    MappedDataType * data = nullptr;
    size_t size = 0;
    uint32_t stride = 0;
  };
}