InputAssembler.h

#pragma once
 
#include "spark/render/Export.h"
#include "spark/render/IndexBuffer.h"
#include "spark/render/VertexBuffer.h"
 
#include <algorithm>
#include <format>
#include <vector>
 
namespace spark::render
{
    enum class PrimitiveTopology
    {
        PointList = 0x00010001,
 
        LineList = 0x00020001,
 
        TriangleList = 0x00040001,
 
        LineStrip = 0x00020002,
 
        TriangleStrip = 0x00040002
    };
 
    class SPARK_RENDER_EXPORT IInputAssembler
    {
    public:
        virtual ~IInputAssembler() noexcept = default;
 
        [[nodiscard]] std::vector<const IVertexBufferLayout*> vertexBufferLayouts() const noexcept { return genericVertexBufferLayouts(); }
 
        [[nodiscard]] virtual const IVertexBufferLayout& vertexBufferLayout(unsigned int binding) const = 0;
 
        [[nodiscard]] virtual const IIndexBufferLayout& indexBufferLayout() const = 0;
 
        [[nodiscard]] virtual PrimitiveTopology topology() const noexcept = 0;
 
    private:
        [[nodiscard]] virtual std::vector<const IVertexBufferLayout*> genericVertexBufferLayouts() const noexcept = 0;
    };
 
    template <typename VertexBufferLayoutType, typename IndexBufferLayoutType>
    class InputAssembler : public IInputAssembler
    {
    public:
        using VertexBufferLayout = VertexBufferLayoutType;
        using IndexBufferLayout = IndexBufferLayoutType;
 
    public:
        [[nodiscard]] virtual std::vector<const VertexBufferLayoutType*> vertexBufferLayouts() const noexcept = 0;
 
        [[nodiscard]] const VertexBufferLayoutType& vertexBufferLayout(unsigned binding) const override = 0;
 
        [[nodiscard]] const IndexBufferLayoutType& indexBufferLayout() const override = 0;
 
    private:
        [[nodiscard]] std::vector<const IVertexBufferLayout*> genericVertexBufferLayouts() const noexcept override
        {
            auto tmp = vertexBufferLayouts();
            std::vector<const IVertexBufferLayout*> vertex_buffer_layouts_vector;
            vertex_buffer_layouts_vector.reserve(tmp.size());
            std::ranges::transform(tmp,
                                   std::back_inserter(vertex_buffer_layouts_vector),
                                   [](const auto& vertex_buffer_layout) { return static_cast<const IVertexBufferLayout*>(vertex_buffer_layout); });
            return vertex_buffer_layouts_vector;
        }
    };
}
 
template <>
struct std::formatter<spark::render::PrimitiveTopology> : std::formatter<std::string_view>
{
    static constexpr auto parse(format_parse_context& ctx) { return ctx.begin(); }
 
    static constexpr auto format(const spark::render::PrimitiveTopology topology, auto& ctx)
    {
        switch (topology)
        {
        case spark::render::PrimitiveTopology::PointList:
            return std::format_to(ctx.out(), "PointList");
        case spark::render::PrimitiveTopology::LineList:
            return std::format_to(ctx.out(), "LineList");
        case spark::render::PrimitiveTopology::TriangleList:
            return std::format_to(ctx.out(), "TriangleList");
        case spark::render::PrimitiveTopology::LineStrip:
            return std::format_to(ctx.out(), "LineStrip");
        case spark::render::PrimitiveTopology::TriangleStrip:
            return std::format_to(ctx.out(), "TriangleStrip");
        }
        return std::format_to(ctx.out(), "Unknown");
    }
};