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#include "chunk.hpp"
#include <Magnum/ImageView.h>
#include <Magnum/GL/TextureFormat.h>
namespace Magnum::Examples {
atlas_texture::atlas_texture(const Trade::ImageData2D& image, Vector2i dims) :
size_{image.size()},
dims_{dims},
tile_size_{size_ / dims}
{
CORRADE_INTERNAL_ASSERT(dims_[0] > 0 && dims_[1] > 0);
CORRADE_INTERNAL_ASSERT(tile_size_ * dims_ == size_);
CORRADE_INTERNAL_ASSERT(size_ % dims_ == Vector2i{});
tex_.setWrapping(GL::SamplerWrapping::ClampToEdge)
.setMagnificationFilter(GL::SamplerFilter::Nearest)
.setMinificationFilter(GL::SamplerFilter::Linear)
.setStorage(1, GL::textureFormat(image.format()), image.size())
.setSubImage(0, {}, image);
}
std::array<Vector2, 4> atlas_texture::texcoords_for_id(int id_) const
{
CORRADE_INTERNAL_ASSERT(id_ >= 0 && id_ < dims_.product());
constexpr Vector2 _05 = { 0.5f, 0.5f };
constexpr Vector2i _1 = { 1, 1 };
Vector2i id = { id_ % dims_[1], id_ / dims_[1] };
auto p0 = (Vector2(id * tile_size_) + _05) / Vector2(size_);
auto p1 = (Vector2((id + _1) * tile_size_) + _05) / Vector2(size_);
return {{
{ p1[0], p1[1] }, // bottom right
{ p1[0], p0[1] }, // top right
{ p0[0], p1[1] }, // bottom left
{ p0[0], p0[1] } // top left
}};
}
std::array<Vector3, 4> atlas_texture::floor_quad(Vector3 center, Vector2 size)
{
float x = size[0]*.5f, y = size[1]*.5f;
return {{
{ x + center[0], -y + center[1], 0},
{ x + center[0], y + center[1], 0},
{-x + center[0], -y + center[1], 0},
{-x + center[0], y + center[1], 0},
}};
}
std::array<UnsignedShort, 6> atlas_texture::indices(int N)
{
CORRADE_INTERNAL_ASSERT(N >= 0);
using u16 = UnsignedShort;
return { /* 3--1 1 */
(u16)(0+N*4), (u16)(1+N*4), (u16)(2+N*4), /* | / /| */
(u16)(2+N*4), (u16)(1+N*4), (u16)(3+N*4), /* |/ / | */
}; /* 2 2--0 */
}
} // namespace Magnum::Examples
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