1 files changed, 87 insertions, 0 deletions
diff --git a/draw/floor.cpp b/draw/floor.cpp
new file mode 100644
index 00000000..3813cf56
--- /dev/null
+++ b/draw/floor.cpp
@@ -0,0 +1,87 @@
+#include "floor.hpp"
+#include "shaders/tile-shader.hpp"
+#include "tile.hpp"
+#include "chunk.hpp"
+#include "tile-atlas.hpp"
+#include <Magnum/GL/MeshView.h>
+
+namespace floormat {
+
+constexpr auto quad_index_count = 6;
+
+floor_mesh::floor_mesh()
+{
+    _mesh.setCount((int)(quad_index_count * TILE_COUNT))
+         .addVertexBuffer(_positions_buffer, 0, tile_shader::Position{})
+         .addVertexBuffer(_vertex_buffer, 0, tile_shader::TextureCoordinates{})
+         .setIndexBuffer(_index_buffer, 0, GL::MeshIndexType::UnsignedShort);
+}
+
+void floor_mesh::set_tile(quad_data& data, tile& x)
+{
+    if (x.ground_image)
+    {
+        auto texcoords = x.ground_image.atlas->texcoords_for_id(x.ground_image.variant);
+        for (size_t i = 0; i < 4; i++)
+            data[i] = { texcoords[i] };
+    }
+    else
+        for (size_t i = 0; i < 4; i++)
+            data[i] = {};
+}
+
+void floor_mesh::draw(tile_shader& shader, chunk& c)
+{
+    //_vertex_buffer.setData({nullptr, sizeof(quad_data) * TILE_COUNT}, Magnum::GL::BufferUsage::DynamicDraw); // orphan the buffer
+    std::array<quad_data, TILE_COUNT> data;
+    for (auto& [x, idx, pt] : c) {
+        set_tile(data[idx], x);
+    }
+    _vertex_buffer.setSubData(0, data);
+    Magnum::GL::MeshView mesh{_mesh};
+
+    tile_atlas* last_atlas = nullptr;
+    std::size_t last_pos = 0;
+
+    const auto do_draw = [&](std::size_t i, tile_atlas* atlas) {
+        if (atlas == last_atlas)
+            return;
+        if (auto len = i - last_pos; last_atlas != nullptr && len > 0)
+        {
+            last_atlas->texture().bind(0);
+            mesh.setCount((int)(quad_index_count * len));
+            mesh.setIndexRange((int)(last_pos*quad_index_count), 0, quad_index_count*TILE_COUNT - 1);
+            shader.draw(mesh);
+        }
+        last_atlas = atlas;
+        last_pos = i;
+    };
+
+    for (auto& [x, i, pt] : c)
+        do_draw(i, x.ground_image.atlas.get());
+    do_draw(TILE_COUNT, nullptr);
+}
+
+std::array<std::array<UnsignedShort, 6>, TILE_COUNT> floor_mesh::make_index_array()
+{
+    // NOLINTNEXTLINE(cppcoreguidelines-pro-type-member-init)
+    std::array<std::array<UnsignedShort, quad_index_count>, TILE_COUNT> array;
+    for (std::size_t i = 0; i < std::size(array); i++)
+        array[i] = tile_atlas::indices(i);
+    return array;
+}
+
+std::array<std::array<Vector3, 4>, TILE_COUNT> floor_mesh::make_position_array()
+{
+    std::array<std::array<Vector3, 4>, TILE_COUNT> array;
+    constexpr float X = TILE_SIZE[0], Y = TILE_SIZE[1];
+    for (std::size_t j = 0, k = 0; j < TILE_MAX_DIM; j++)
+        for (std::size_t i = 0; i < TILE_MAX_DIM; i++, k++)
+        {
+            Vector3 center {(float)(X*i), (float)(Y*j), 0};
+            array[k] = { tile_atlas::floor_quad(center, {X, Y}) };
+        }
+    return array;
+}
+
+} // namespace floormat