add particles (WIP)

src/graphics/render/ParticlesRenderer.cpp

@@ -0,0 +1,75 @@
+#include "ParticlesRenderer.hpp"
+
+#include "assets/Assets.hpp"
+#include "graphics/core/Shader.hpp"
+#include "graphics/core/Texture.hpp"
+#include "graphics/render/MainBatch.hpp"
+#include "window/Camera.hpp"
+
+ParticlesRenderer::ParticlesRenderer(const Assets& assets)
+    : batch(std::make_unique<MainBatch>(1024)) {
+
+    Emitter emitter(glm::vec3(0, 100, 0), Particle {
+        glm::vec3(), glm::vec3(), 5.0f, UVRegion(0,0,1,1)
+    }, assets.get<Texture>("gui/error"), 0.003f, -1);
+    emitters.push_back(std::move(emitter));
+}
+
+ParticlesRenderer::~ParticlesRenderer() = default;
+
+void ParticlesRenderer::render(
+    const Assets& assets, const Camera& camera, float delta
+) {
+    const auto& right = camera.right;
+    const auto& up = camera.up;
+
+    batch->begin();
+    for (auto& [texture, vec] : particles) {
+        batch->setTexture(texture);
+
+        auto iter = vec.begin();
+        while (iter != vec.end()) {
+            auto& particle = *iter;
+
+            particle.position += particle.velocity * delta;
+
+            batch->quad(
+                particle.position,
+                right,
+                up,
+                glm::vec2(0.3f),
+                glm::vec4(1),
+                glm::vec3(1.0f),
+                particle.region
+            );
+
+            particle.lifetime -= delta;
+            if (particle.lifetime <= 0.0f) {
+                iter = vec.erase(iter);
+            } else {
+                iter++;
+            }
+        }
+    }
+    batch->flush();
+    
+    auto iter = emitters.begin();
+    while (iter != emitters.end()) {
+        auto& emitter = *iter;
+        auto texture = emitter.getTexture();
+        const auto& found = particles.find(texture);
+        std::vector<Particle>* vec;
+        if (found == particles.end()) {
+            vec = &particles[texture];
+        } else {
+            vec = &found->second;
+        }
+        emitter.update(delta, *vec);
+
+        if (emitter.isDead()) {
+            iter = emitters.erase(iter);
+        } else {
+            iter++;
+        }
+    }
+}