1 files changed, 82 insertions, 0 deletions
diff --git a/src/wall-mesh.cpp b/src/wall-mesh.cpp
new file mode 100644
index 00000000..ee998e63
--- /dev/null
+++ b/src/wall-mesh.cpp
@@ -0,0 +1,82 @@
+#include "wall-mesh.hpp"
+#include "tile-atlas.hpp"
+#include "shaders/tile-shader.hpp"
+#include "chunk.hpp"
+#include <Magnum/GL/RectangleTexture.h>
+#include <Magnum/GL/MeshView.h>
+
+namespace Magnum::Examples {
+
+constexpr auto quad_index_count = 6;
+
+wall_mesh::wall_mesh()
+{
+    _mesh.setCount((int)(quad_index_count * COUNT))
+         .addVertexBuffer(_vertex_buffer, 0, tile_shader::TextureCoordinates{}, tile_shader::Position{})
+         .setIndexBuffer(_index_buffer, 0, GL::MeshIndexType::UnsignedShort);
+    CORRADE_INTERNAL_ASSERT(_mesh.isIndexed());
+}
+
+void wall_mesh::add_wall(vertex_array& data, texture_array& textures, std::size_t& pos_,
+                         tile_image& img, const position_array& positions)
+{
+    const auto pos = pos_++;
+    CORRADE_INTERNAL_ASSERT(pos < data.size());
+    auto texcoords = img.atlas->texcoords_for_id(img.variant);
+    for (std::size_t i = 0; i < 4; i++)
+    {
+        data[pos][i] = { texcoords[i], positions[i] };
+        textures[pos] = &img.atlas->texture();
+    }
+}
+
+void wall_mesh::maybe_add_tile(vertex_array& data, texture_array& textures, std::size_t& pos, tile& x, local_coords pt)
+{
+    constexpr float X = TILE_SIZE[0], Y = TILE_SIZE[1], Z = TILE_SIZE[2];
+    constexpr Vector3 size = {X, Y, Z};
+    Vector3 center{(float)(X*pt.x), (float)(Y*pt.y), 0};
+
+    if (auto& wall = x.wall_north; wall.atlas)
+        add_wall(data, textures, pos, wall, tile_atlas::wall_quad_N(center, size));
+    if (auto& wall = x.wall_west; wall.atlas)
+        add_wall(data, textures, pos, wall, tile_atlas::wall_quad_W(center, size));
+}
+
+void wall_mesh::draw(tile_shader& shader, chunk& c)
+{
+    texture_array textures = {};
+    std::size_t pos = 0;
+    {
+        vertex_array data;
+        c.foreach_tile([&](tile& x, std::size_t, local_coords pt) {
+          maybe_add_tile(data, textures, pos, x, pt);
+        });
+        _vertex_buffer.setSubData(0, Containers::arrayView(data.data(), pos));
+    }
+
+    const GL::RectangleTexture* last_texture = nullptr;
+    Magnum::GL::MeshView mesh{_mesh};
+    for (std::size_t i = 0; i < pos; i++)
+    {
+        auto* const tex = textures[i];
+        CORRADE_INTERNAL_ASSERT(tex != nullptr);
+        mesh.setCount(quad_index_count);
+        mesh.setIndexRange((int)(i*quad_index_count), 0, quad_index_count*COUNT - 1);
+        if (tex != last_texture)
+            tex->bind(0);
+        last_texture = tex;
+        shader.draw(mesh);
+    }
+}
+
+std::array<std::array<UnsignedShort, 6>, wall_mesh::COUNT> wall_mesh::make_index_array()
+{
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-member-init)
+    std::array<std::array<UnsignedShort, 6>, COUNT> array;
+
+    for (std::size_t i = 0; i < std::size(array); i++)
+        array[i] = tile_atlas::indices(i);
+    return array;
+}
+
+} // namespace Magnum::Examples