forked from Green-Sky/tomato
Green Sky
5c7231b7a3
git-subtree-dir: external/entt/entt git-subtree-split: fef921132cae7588213d0f9bcd2fb9c8ffd8b7fc
57 lines
1.1 KiB
C++
57 lines
1.1 KiB
C++
#include <entt/entt.hpp>
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#include <cstdint>
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struct position {
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float x;
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float y;
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};
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struct velocity {
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float dx;
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float dy;
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};
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void update(entt::registry ®istry) {
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auto view = registry.view<position, velocity>();
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for(auto entity: view) {
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// gets only the components that are going to be used ...
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auto &vel = view.get<velocity>(entity);
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vel.dx = 0.;
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vel.dy = 0.;
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// ...
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}
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}
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void update(std::uint64_t dt, entt::registry ®istry) {
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registry.view<position, velocity>().each([dt](auto &pos, auto &vel) {
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// gets all the components of the view at once ...
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pos.x += vel.dx * dt;
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pos.y += vel.dy * dt;
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// ...
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});
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}
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int main() {
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entt::registry registry;
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std::uint64_t dt = 16;
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for(auto i = 0; i < 10; ++i) {
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auto entity = registry.create();
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registry.emplace<position>(entity, i * 1.f, i * 1.f);
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if(i % 2 == 0) { registry.emplace<velocity>(entity, i * .1f, i * .1f); }
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}
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update(dt, registry);
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update(registry);
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// ...
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return EXIT_SUCCESS;
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}
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