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#pragma once
#include "tile-atlas.hpp"
#include "tile-defs.hpp"
#include <array>
#include <utility>
#include <Corrade/Containers/ArrayViewStl.h>
#include <Magnum/Math/Vector2.h>
#include <Magnum/GL/Buffer.h>
#include <Magnum/GL/Mesh.h>
#include "Magnum/GL/RectangleTexture.h"
namespace Magnum::Examples {
struct tile_shader;
namespace wireframe_traits {
template<typename T>
concept traits = requires (const T& x) {
{T::num_vertices} -> std::convertible_to<std::size_t>;
{T::num_indices} -> std::convertible_to<std::size_t>;
{x.primitive} -> std::convertible_to<GL::MeshPrimitive>;
{x.make_vertex_positions_array() } -> std::same_as<std::array<Vector3, T::num_vertices>>;
{x.make_index_array() } -> std::same_as<std::array<UnsignedShort, T::num_indices>>;
};
struct null final
{
static constexpr auto primitive = GL::MeshPrimitive::Triangles;
static constexpr std::size_t num_vertices = 0, num_indices = 0;
static GL::RectangleTexture make_constant_texture();
static std::array<Vector3, 0> make_vertex_positions_array() { return {}; }
static std::array<UnsignedShort, 0> make_index_array() { return {}; }
};
struct quad final
{
quad(Vector3 center, Vector2 size = {TILE_SIZE[0], TILE_SIZE[1]});
constexpr quad() = default;
static constexpr std::size_t num_vertices = 4;
static constexpr std::size_t num_indices = 0;
static constexpr GL::MeshPrimitive primitive = GL::MeshPrimitive::LineLoop;
using vertex_array = std::array<Vector3, num_vertices>;
using index_array = std::array<UnsignedShort, num_indices>;
vertex_array make_vertex_positions_array() const;
static index_array make_index_array() { return {}; }
private:
Vector3 center = {};
Vector2 size = { TILE_SIZE[0], TILE_SIZE[1] };
};
} // namespace wireframe_traits
template<wireframe_traits::traits T>
struct wireframe_mesh final
{
wireframe_mesh();
void draw(tile_shader& shader, T traits);
private:
GL::Buffer _positions_buffer{},
_texcoords_buffer{std::array<Vector2, T::num_vertices>{}},
_index_buffer{T::num_indices == 0 ? GL::Buffer{NoCreate} : GL::Buffer{}};
GL::RectangleTexture _texture = wireframe_traits::null::make_constant_texture();
GL::Mesh _mesh;
};
extern template struct wireframe_mesh<wireframe_traits::null>;
extern template struct wireframe_mesh<wireframe_traits::quad>;
} // namespace Magnum::Examples
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