VertexArray.cpp

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#include <glm/mat4x4.hpp>
 
#include "galaxy/graphics/gl/Enums.hpp"
 
#include "VertexArray.hpp"
 
namespace galaxy
{
    namespace graphics
    {
        VertexArray::VertexArray()
            : m_id {0}
            , m_instances {1}
        {
            glCreateVertexArrays(1, &m_id);
        }
 
        VertexArray::VertexArray(VertexArray&& v)
        {
            if (this->m_id != 0)
            {
                glDeleteVertexArrays(1, &this->m_id);
            }
 
            this->m_id        = v.m_id;
            this->m_vbo       = std::move(v.m_vbo);
            this->m_instances = v.m_instances;
 
            v.m_id = 0;
        }
 
        VertexArray& VertexArray::operator=(VertexArray&& v)
        {
            if (this != &v)
            {
                if (this->m_id != 0)
                {
                    glDeleteVertexArrays(1, &this->m_id);
                }
 
                this->m_id        = v.m_id;
                this->m_vbo       = std::move(v.m_vbo);
                this->m_instances = v.m_instances;
 
                v.m_id = 0;
            }
 
            return *this;
        }
 
        VertexArray::~VertexArray()
        {
            if (m_id != 0)
            {
                glDeleteVertexArrays(1, &m_id);
            }
        }
 
        void VertexArray::buffer(std::span<Vertex> vertices, std::span<unsigned int> indicies)
        {
            m_vbo.buffer(vertices, indicies);
 
            // Bind vertex to 0 (vertex buffer bind point, different from attribute bind point).
            glVertexArrayVertexBuffer(m_id, static_cast<unsigned int>(BufferBinding::VERTEX_BUFFER_POINT), m_vbo.id(), 0, sizeof(Vertex));
            glVertexArrayElementBuffer(m_id, m_vbo.id());
 
            glEnableVertexArrayAttrib(m_id, static_cast<unsigned int>(AttributeBinding::POSITION_POINT)); // Pos
            glEnableVertexArrayAttrib(m_id, static_cast<unsigned int>(AttributeBinding::TEXEL_POINT));    // Texels
 
            // bind point, size (i.e. vec2, vec3, etc) floats not unsigned ints, not normalized, offset in data structure.
            glVertexArrayAttribFormat(m_id, static_cast<unsigned int>(AttributeBinding::POSITION_POINT), 2, GL_FLOAT, GL_FALSE, offsetof(Vertex, m_pos));
            glVertexArrayAttribFormat(m_id, static_cast<unsigned int>(AttributeBinding::TEXEL_POINT), 2, GL_FLOAT, GL_FALSE, offsetof(Vertex, m_texels));
 
            // VAO, attribute bind point, vertex buffer bind point.
            glVertexArrayAttribBinding(m_id, static_cast<unsigned int>(AttributeBinding::POSITION_POINT), static_cast<unsigned int>(BufferBinding::VERTEX_BUFFER_POINT));
            glVertexArrayAttribBinding(m_id, static_cast<unsigned int>(AttributeBinding::TEXEL_POINT), static_cast<unsigned int>(BufferBinding::VERTEX_BUFFER_POINT));
        }
 
        void VertexArray::buffer(const int vertex_count, std::span<unsigned int> indicies)
        {
            m_vbo.buffer(vertex_count, indicies);
 
            // Bind vertex to 0 (, different from attribute bind point).
            glVertexArrayVertexBuffer(m_id, static_cast<unsigned int>(BufferBinding::VERTEX_BUFFER_POINT), m_vbo.id(), 0, sizeof(Vertex));
            glVertexArrayElementBuffer(m_id, m_vbo.id());
 
            glEnableVertexArrayAttrib(m_id, static_cast<unsigned int>(AttributeBinding::POSITION_POINT)); // Pos
            glEnableVertexArrayAttrib(m_id, static_cast<unsigned int>(AttributeBinding::TEXEL_POINT));    // Texels
 
            // bind point, size (i.e. vec2, vec3, etc) floats not unsigned ints, not normalized, offset in data structure.
            glVertexArrayAttribFormat(m_id, static_cast<unsigned int>(AttributeBinding::POSITION_POINT), 2, GL_FLOAT, GL_FALSE, offsetof(Vertex, m_pos));
            glVertexArrayAttribFormat(m_id, static_cast<unsigned int>(AttributeBinding::TEXEL_POINT), 2, GL_FLOAT, GL_FALSE, offsetof(Vertex, m_texels));
 
            // VAO, attribute bind point, vertex buffer bind point.
            glVertexArrayAttribBinding(m_id, static_cast<unsigned int>(AttributeBinding::POSITION_POINT), static_cast<unsigned int>(BufferBinding::VERTEX_BUFFER_POINT));
            glVertexArrayAttribBinding(m_id, static_cast<unsigned int>(AttributeBinding::TEXEL_POINT), static_cast<unsigned int>(BufferBinding::VERTEX_BUFFER_POINT));
        }
 
        void VertexArray::sub_buffer(const unsigned int index, std::span<Vertex> vertices)
        {
            m_vbo.sub_buffer(index, vertices);
        }
 
        void VertexArray::set_instanced(const InstanceBuffer& ib)
        {
            m_instances = ib.amount();
 
            glVertexArrayVertexBuffer(m_id, static_cast<unsigned int>(BufferBinding::INSTANCE_BUFFER_POINT), ib.id(), 0, sizeof(glm::mat4));
 
            glEnableVertexArrayAttrib(m_id, static_cast<unsigned int>(AttributeBinding::OFFSET_POINT));
            glEnableVertexArrayAttrib(m_id, static_cast<unsigned int>(AttributeBinding::OFFSET_POINT) + 1u);
            glEnableVertexArrayAttrib(m_id, static_cast<unsigned int>(AttributeBinding::OFFSET_POINT) + 2u);
            glEnableVertexArrayAttrib(m_id, static_cast<unsigned int>(AttributeBinding::OFFSET_POINT) + 3u);
 
            glVertexArrayAttribFormat(m_id, static_cast<unsigned int>(AttributeBinding::OFFSET_POINT), 4, GL_FLOAT, GL_FALSE, 0);
            glVertexArrayAttribFormat(m_id, static_cast<unsigned int>(AttributeBinding::OFFSET_POINT) + 1u, 4, GL_FLOAT, GL_FALSE, (sizeof(glm::vec4)));
            glVertexArrayAttribFormat(m_id, static_cast<unsigned int>(AttributeBinding::OFFSET_POINT) + 2u, 4, GL_FLOAT, GL_FALSE, (2 * sizeof(glm::vec4)));
            glVertexArrayAttribFormat(m_id, static_cast<unsigned int>(AttributeBinding::OFFSET_POINT) + 3u, 4, GL_FLOAT, GL_FALSE, (3 * sizeof(glm::vec4)));
 
            glVertexArrayAttribBinding(m_id, static_cast<unsigned int>(AttributeBinding::OFFSET_POINT), static_cast<unsigned int>(BufferBinding::INSTANCE_BUFFER_POINT));
            glVertexArrayAttribBinding(m_id, static_cast<unsigned int>(AttributeBinding::OFFSET_POINT) + 1u, static_cast<unsigned int>(BufferBinding::INSTANCE_BUFFER_POINT));
            glVertexArrayAttribBinding(m_id, static_cast<unsigned int>(AttributeBinding::OFFSET_POINT) + 2u, static_cast<unsigned int>(BufferBinding::INSTANCE_BUFFER_POINT));
            glVertexArrayAttribBinding(m_id, static_cast<unsigned int>(AttributeBinding::OFFSET_POINT) + 3u, static_cast<unsigned int>(BufferBinding::INSTANCE_BUFFER_POINT));
 
            glVertexArrayBindingDivisor(m_id, static_cast<unsigned int>(AttributeBinding::OFFSET_POINT), 1);
            glVertexArrayBindingDivisor(m_id, static_cast<unsigned int>(AttributeBinding::OFFSET_POINT) + 1u, 1);
            glVertexArrayBindingDivisor(m_id, static_cast<unsigned int>(AttributeBinding::OFFSET_POINT) + 2u, 1);
            glVertexArrayBindingDivisor(m_id, static_cast<unsigned int>(AttributeBinding::OFFSET_POINT) + 3u, 1);
        }
 
        void VertexArray::bind()
        {
            glBindVertexArray(m_id);
        }
 
        void VertexArray::unbind()
        {
            glBindVertexArray(0);
        }
 
        int VertexArray::count() const
        {
            return m_vbo.count();
        }
 
        void* VertexArray::offset()
        {
            return m_vbo.offset();
        }
 
        int VertexArray::instances() const
        {
            return m_instances;
        }
 
        VertexBuffer& VertexArray::vbo()
        {
            return m_vbo;
        }
 
        unsigned int VertexArray::id() const
        {
            return m_id;
        }
    } // namespace graphics
} // namespace galaxy