//
// Copyright (c) 2013 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// Helper structures about Generic Vertex Attribute.
//

#ifndef LIBANGLE_VERTEXATTRIBUTE_H_
#define LIBANGLE_VERTEXATTRIBUTE_H_

#include "libANGLE/Buffer.h"

namespace gl
{
class VertexArray;

//
// Implementation of Generic Vertex Attribute Bindings for ES3.1
//
struct VertexBinding final : private angle::NonCopyable
{
    VertexBinding();
    explicit VertexBinding(VertexBinding &&binding);
    VertexBinding &operator=(VertexBinding &&binding);

    GLuint stride;
    GLuint divisor;
    GLintptr offset;

    BindingPointer<Buffer> buffer;
};

//
// Implementation of Generic Vertex Attributes for ES3.1
//
struct VertexAttribute final : private angle::NonCopyable
{
    explicit VertexAttribute(GLuint bindingIndex);
    explicit VertexAttribute(VertexAttribute &&attrib);
    VertexAttribute &operator=(VertexAttribute &&attrib);

    bool enabled;  // For glEnable/DisableVertexAttribArray
    GLenum type;
    GLuint size;
    bool normalized;
    bool pureInteger;

    const void *pointer;
    GLintptr relativeOffset;

    GLuint vertexAttribArrayStride;  // ONLY for queries of VERTEX_ATTRIB_ARRAY_STRIDE
    GLuint bindingIndex;
};

size_t ComputeVertexAttributeTypeSize(const VertexAttribute &attrib);

// Warning: you should ensure binding really matches attrib.bindingIndex before using this function.
size_t ComputeVertexAttributeStride(const VertexAttribute &attrib, const VertexBinding &binding);

// Warning: you should ensure binding really matches attrib.bindingIndex before using this function.
GLintptr ComputeVertexAttributeOffset(const VertexAttribute &attrib, const VertexBinding &binding);

size_t ComputeVertexBindingElementCount(const VertexBinding &binding,
                                        size_t drawCount,
                                        size_t instanceCount);

struct VertexAttribCurrentValueData
{
    union {
        GLfloat FloatValues[4];
        GLint IntValues[4];
        GLuint UnsignedIntValues[4];
    };
    GLenum Type;

    VertexAttribCurrentValueData();

    void setFloatValues(const GLfloat floatValues[4]);
    void setIntValues(const GLint intValues[4]);
    void setUnsignedIntValues(const GLuint unsignedIntValues[4]);
};

bool operator==(const VertexAttribCurrentValueData &a, const VertexAttribCurrentValueData &b);
bool operator!=(const VertexAttribCurrentValueData &a, const VertexAttribCurrentValueData &b);

}  // namespace gl

#include "VertexAttribute.inl"

#endif  // LIBANGLE_VERTEXATTRIBUTE_H_
