Implement TileSet and TileMap classes

src/core/drawing/tile_set.cppm

@@ -0,0 +1,94 @@
+module;
+
+#include <cassert>
+#include <string>
+#include <utility>
+#include <vector>
+
+export module core.drawing.tile_set;
+
+import core.render_server;
+import wrappers.sdl;
+
+export namespace core
+{
+    using TileSetID = unsigned int;
+    using TileID = unsigned int;
+
+    struct TileDefinition
+    {
+        sdl::FRect atlas_src_rect;
+    };
+
+    class TileSet
+    {
+        // Texture ID of tileset atlas texture
+        TextureID texture_id_;
+
+        // Size of each tile in pixels
+        // TODO: Do we need this?
+        // int tile_size_;
+
+        // Tile definitions: Maps tile ID to a struct describing the tile, e.g. the texture source boundaries,
+        // collision data, etc.
+        std::vector<TileDefinition> tile_definitions_;
+
+        public:
+            TileSet() = delete;
+
+            explicit TileSet(
+                const TextureID texture_id,
+                std::vector<TileDefinition> tile_definitions
+            )
+                : texture_id_{texture_id},
+                  tile_definitions_{std::move(tile_definitions)}
+            {}
+
+            static TileSet create_from_texture(
+                RenderServer& render_server,
+                const std::string& filename,
+                const int tile_size,
+                const std::vector<sdl::Point>& tile_atlas_coords
+            )
+            {
+                const TextureID texture_id = render_server.load_texture(filename);
+                const sdl::Texture& texture = render_server.get_texture(texture_id);
+
+                assert(tile_size > 0);
+                // TODO: These probably shouldn't be asserts...
+                assert(texture.get_width() % tile_size == 0);
+                assert(texture.get_height() % tile_size == 0);
+
+                std::vector<TileDefinition> tile_definitions;
+
+                // TODO: Should we automatically create tile 0 (no tile) instead of listing it in tile_atlas_coords?
+                for (const auto& [x, y] : tile_atlas_coords) {
+                    const TileDefinition tile{
+                        {
+                            static_cast<float>(x * tile_size),
+                            static_cast<float>(y * tile_size),
+                            static_cast<float>(tile_size),
+                            static_cast<float>(tile_size),
+                        }
+                    };
+
+                    // TODO: These probably shouldn't be asserts...
+                    assert(tile.atlas_src_rect.x + tile.atlas_src_rect.w <= texture.get_width());
+                    assert(tile.atlas_src_rect.y + tile.atlas_src_rect.h <= texture.get_height());
+                    tile_definitions.push_back(tile);
+                }
+
+                return TileSet(texture_id, tile_definitions);
+            }
+
+            constexpr TextureID get_texture_id() const
+            {
+                return texture_id_;
+            }
+
+            constexpr const TileDefinition& get_tile_definition(const TileID tile_id) const
+            {
+                return tile_definitions_.at(tile_id);
+            }
+    };
+}