https://github.com/karnkaul/decf
Dumb simple Entity-Component framework in C++17
https://github.com/karnkaul/decf
cpp cpp17 cpp17-library ecs entity-framework
Last synced: 11 months ago
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Dumb simple Entity-Component framework in C++17
- Host: GitHub
- URL: https://github.com/karnkaul/decf
- Owner: karnkaul
- License: gpl-3.0
- Created: 2021-02-17T06:32:09.000Z (almost 5 years ago)
- Default Branch: main
- Last Pushed: 2021-11-05T04:51:12.000Z (about 4 years ago)
- Last Synced: 2025-01-25T06:11:21.117Z (about 1 year ago)
- Topics: cpp, cpp17, cpp17-library, ecs, entity-framework
- Language: C++
- Homepage:
- Size: 43 KB
- Stars: 2
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
## Dumb Entity-Component (Framework)
[](https://ci.appveyor.com/project/karnkaul/decf)
This is a "dumb simple" Entity-Component framework.
### Features
- Lightweight strongly-typed 64-bit unsigned int wrapper as `entity`
- Type-erased storage of any moveable type `T` as components
- Supports one instance of any `T` attached to any `entity`
- Performant `attach` / `detach`
- Highly performant `O(1)` lookup for `find` / `get`
- Optimised, performant `view()`
**Public KT submodules**
- [`enum_flags`](https://github.com/karnkaul/enum-flags.git): `enum class` wrapper over `std::bitset`
### Usage
**Requirements**
- CMake
- C++17 compiler (and stdlib)
**Steps**
1. Clone repo to appropriate subdirectory, say `dumb_ec`
1. Add library to project via: `add_subdirectory(dumb_ec)` and `target_link_libraries(foo decf::dec)`
1. Use via: `#include `
**Example**
```cpp
// ...
#include
struct foo {
int i;
char c;
foo(int i = 0, char c = ' ') : i(i), c(c) {
}
};
// ...
std::unordered_set spawned;
decf::registry registry; // Multiple instances can coexist
auto [e0, c0] = registry.spawn("ent0");
auto& [name] = c0; // tuple => structured binding
name = "ent0";
spawned.insert(e0); // std::hash specialized
auto [e1, _] = registry.spawn("ent1", 42, 'x'); // Args forwarded as T{args...}
spawned.insert(e1);
auto [e2, c2] = registry.spawn("ent2"); // Multiple attachments (no args possible)
auto& [i, c] = c2; // tuple => structured binding
i = registry.get(e1).i; // assumes foo is attached to e1
if (auto f = registry.find(e1)) { // returns pointer (nullptr if not present)
c = f->c;
}
if (registry.contains(e0)) {
std::cout << registry.name(e0) << " destroyed\n";
ensure(registry.destroy(e0)); // assuming ensure() to behave like assert(), regardless of _DEBUG
}
if (auto f = registry.attach(e1)) { // Returns nullptr if entity doesn't exist
*f = {-1, 'z'};
}
ensure(registry.detach(e2));
auto [e3, _] = registry.spawn("ent3");
spawned.insert(e3);
registry.enable(e3, false);
auto view = registry.view(decf::flag_t::disabled, {}); // enabled entities with foo attached (default)
view = registry.view(decf::flag_t::disabled, decf::flag_t::disabled); // disabled entities with foo attached
view = registry.view({}, {}); // all entities with foo attached
auto view2 = registry.view(); // enabled entities with foo and int attached
for (auto& [e, c] : view2) {
auto& [f, i] = c;
// ...
}
for (auto const& e : spawned) {
if (registry.contains(e)) {
std::cout << registry.name(e) << " destroyed\n";
ensure(registry.destroy(e));
}
}
```
### Contributing
Pull/merge requests are welcome.
**[Original Repository](https://github.com/karnkaul/decf)**