lib/game: Start working on game internals

Btw: I lost the game.

src/lib/game/block.hpp

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+#pragma once
+
+#include <cstdint>
+
+namespace block {
+
+    // For internal use only. These are examples, we will probably need
+    // a different way of assigning IDs in the future but a list should
+    // be fine for now, I guess.
+    // I don’t know how Minecraft assigns its IDs or if it even matters
+    // given that it has used string IDs for a while now. We just need an
+    // internal way to distinguish between classes.
+    namespace ids {
+        const uint16_t AIR = 0;
+        const uint16_t STONE = 1;
+    }
+
+    // These are intended to be combined using bitwise OR.
+    namespace collisionBehavior {
+        // Let the block handle it.
+        // A function on the relevant block class will deal with it.
+        const uint8_t UNKNOWN = 0b00000000;
+
+        // Collision box inhibits movement?
+        // (stone or stone slab)
+        const uint8_t SOLID = 0b00000001;
+
+        // Does collision box fill entire block?
+        // (stone or grass block)
+        //
+        // The shape of the collision box is part of the relevant block class
+        // when this bit is unset.
+        const uint8_t FULL_BLOCK = 0b00000010;
+
+        const uint8_t SOLID_FULL_BLOCK = SOLID | FULL_BLOCK;
+
+        // Slow down entities when inside the block?
+        // (vines or soulsand)
+        //
+        // Entities are considered to be inside a given block when rounding
+        // their coordinates results in the coordinates of the block.
+        //
+        // The amount of slowdown is controlled by a function on the relevant
+        // block class.
+        const uint8_t SLOWDOWN = 0b00000100;
+
+        // Slow down entities when touching the collision box of the block?
+        // (honey block)
+        //
+        // The amount of slowdown is controlled by a function on the relevant
+        // block class.
+        const uint8_t SURFACE_SLOWDOWN = 0b00001000;
+
+        // Deal damage when entities are inside it?
+        // (berry bush)
+        //
+        // Entities are considered to be inside a given block when rounding
+        // their coordinates results in the coordinates of the block.
+        //
+        // The amount of damage is controlled by a function on the relevant
+        // block class.
+        const uint8_t DAMAGE = 0b00010000;
+
+        // Deal damage when entities touch the collision box?
+        // (magma block)
+        //
+        // The amount of damage is controlled by a function on the relevant
+        // block class.
+        const uint8_t SURFACE_DAMAGE = 0b00010000;
+
+        // Is the block bouncy?
+        // (bed or slime block)
+        //
+        // The bounciness of the block is handled by the relevant block class.
+        const uint8_t BOUNCY = 0b00100000;
+    }
+
+    class Generic {
+        private:
+        public:
+            virtual uint16_t id() = 0;
+            virtual uint8_t collisionBehavior() = 0;
+
+            //TODO: (not pure) virtual functions for collision box, slowdown, damage, bounciness, etc.
+
+            //TODO: (not pure) virtual function for hitbox (defaults to full block)
+    }
+
+    class Air {
+        public:
+            uint16_t id() {
+                return ids::AIR;
+            }
+            uint8_t collisionBehavior() {
+                // is a full block but doesn't collide or anything else
+                return collisionBehavior::FULL_BLOCK;
+            }
+    }
+
+    BlockGeneric* getNewBlockFromID(uint16_t id) {
+        //TODO
+    }
+}