1 files changed, 107 insertions, 0 deletions
diff --git a/src/chunk-render.cpp b/src/chunk-render.cpp
new file mode 100644
index 00000000..37440af9
--- /dev/null
+++ b/src/chunk-render.cpp
@@ -0,0 +1,107 @@
+#include "chunk.hpp"
+#include "tile-atlas.hpp"
+#include "shaders/tile.hpp"
+#include <algorithm>
+#include <Magnum/GL/Buffer.h>
+#include <Corrade/Containers/ArrayViewStl.h>
+
+namespace floormat {
+
+static auto make_index_array(std::size_t offset)
+{
+    std::array<std::array<UnsignedShort, 6>, TILE_COUNT> array; // NOLINT(cppcoreguidelines-pro-type-member-init)
+    for (std::size_t i = 0; i < TILE_COUNT; i++)
+        array[i] = tile_atlas::indices(i + offset);
+    return array;
+}
+
+struct vertex {
+    Vector3 position;
+    Vector2 texcoords;
+    float depth = -1;
+};
+
+auto chunk::ensure_ground_mesh() noexcept -> ground_mesh_tuple
+{
+    if (!_ground_modified)
+        return { ground_mesh, ground_indexes };
+    _ground_modified = false;
+
+    for (std::size_t i = 0; i < TILE_COUNT; i++)
+        ground_indexes[i] = std::uint8_t(i);
+    std::sort(ground_indexes.begin(), ground_indexes.end(), [this](std::uint8_t a, std::uint8_t b) {
+        return _ground_atlases[a].get() < _ground_atlases[b].get();
+    });
+
+    std::array<std::array<vertex, 4>, TILE_COUNT> vertexes;
+    for (std::size_t k = 0; k < TILE_COUNT; k++)
+    {
+        const std::uint8_t i = ground_indexes[k];
+        if (auto atlas = _ground_atlases[i]; !atlas)
+            vertexes[k] = {};
+        else
+        {
+            const local_coords pos{i};
+            const auto quad = atlas->floor_quad(Vector3(pos.x, pos.y, 0) * TILE_SIZE, TILE_SIZE2);
+            const auto texcoords = atlas->texcoords_for_id(_ground_variants[i]);
+            const float depth = tile_shader::depth_value(pos);
+            auto& v = vertexes[k];
+            for (std::size_t j = 0; j < 4; j++)
+                v[j] = { quad[j], texcoords[j], depth };
+        }
+    }
+    const auto indexes = make_index_array(0);
+
+    GL::Mesh mesh{GL::MeshPrimitive::Triangles};
+    mesh.addVertexBuffer(GL::Buffer{vertexes}, 0, tile_shader::Position{}, tile_shader::TextureCoordinates{}, tile_shader::Depth{})
+        .setIndexBuffer(GL::Buffer{indexes}, 0, GL::MeshIndexType::UnsignedShort)
+        .setCount(6 * TILE_COUNT);
+    ground_mesh = Utility::move(mesh);
+    return { ground_mesh, ground_indexes };
+}
+
+auto chunk::ensure_wall_mesh() noexcept -> wall_mesh_tuple
+{
+    if (!_walls_modified)
+        return { wall_mesh, wall_indexes };
+    _walls_modified = false;
+
+    for (std::size_t i = 0; i < TILE_COUNT*2; i++)
+        wall_indexes[i] = std::uint16_t(i);
+
+    std::sort(wall_indexes.begin(), wall_indexes.end(), [this](std::uint16_t a, std::uint16_t b) {
+        return _wall_atlases[a] < _wall_atlases[b];
+    });
+
+    std::array<std::array<vertex, 4>, TILE_COUNT*2> vertexes;
+    for (std::size_t k = 0; k < TILE_COUNT*2; k++)
+    {
+        const std::uint16_t i = wall_indexes[k];
+        if (const auto& atlas = _wall_atlases[i]; !atlas)
+            vertexes[k] = {};
+        else
+        {
+            const auto& variant = _wall_variants[i];
+            const local_coords pos{i / 2u};
+            const auto center = Vector3(pos.x, pos.y, 0) * TILE_SIZE;
+            const auto quad = i & 1 ? atlas->wall_quad_W(center, TILE_SIZE) : atlas->wall_quad_N(center, TILE_SIZE);
+            const float depth = tile_shader::depth_value(pos);
+            const auto texcoords = atlas->texcoords_for_id(variant);
+            auto& v = vertexes[k];
+            for (std::size_t j = 0; j < 4; j++)
+                v[j] = { quad[j], texcoords[j], depth, };
+        }
+    }
+
+    using index_t = std::array<std::array<UnsignedShort, 6>, TILE_COUNT>;
+    const index_t indexes[2] = { make_index_array(0), make_index_array(TILE_COUNT) };
+
+    GL::Mesh mesh{GL::MeshPrimitive::Triangles};
+    mesh.addVertexBuffer(GL::Buffer{vertexes}, 0, tile_shader::Position{}, tile_shader::TextureCoordinates{}, tile_shader::Depth{})
+        .setIndexBuffer(GL::Buffer{indexes}, 0, GL::MeshIndexType::UnsignedShort)
+        .setCount(6 * TILE_COUNT);
+    wall_mesh = Utility::move(mesh);
+    return { wall_mesh, wall_indexes };
+}
+
+} // namespace floormat