per block type "gravity"

[blank.git] / src / world / BlockGravity.hpp

diff --git a/src/world/BlockGravity.hpp b/src/world/BlockGravity.hpp
new file mode 100644 (file)
index 0000000..6a17b61
--- /dev/null
+++ b/src/world/BlockGravity.hpp
@@ -0,0 +1,28 @@
+#ifndef BLANK_WORLD_BLOCKGRAVITY_HPP_
+#define BLANK_WORLD_BLOCKGRAVITY_HPP_
+
+#include <memory>
+#include <glm/glm.hpp>
+
+
+namespace blank {
+
+class TokenStreamReader;
+
+struct BlockGravity {
+
+       virtual ~BlockGravity();
+
+       /// get gravitational force for a unit mass at relative position diff
+       /// diff is target - block, i.e. pointing from block towards the target
+       /// orientation of the block in question is given by M
+       /// return value should be world absolute
+       virtual glm::vec3 GetGravity(const glm::vec3 &diff, const glm::mat4 &M) const noexcept = 0;
+
+       static std::unique_ptr<BlockGravity> Read(TokenStreamReader &in);
+
+};
+
+}
+
+#endif