example: added particle effects

examples/Particles.cpp

@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2025 the ThorVG project. All rights reserved.
+
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include <vector>
+#include "Example.h"
+
+/************************************************************************/
+/* ThorVG Drawing Contents                                              */
+/************************************************************************/
+
+struct UserExample : tvgexam::Example
+{
+    struct Particle {
+        tvg::Shape* shape;
+        float x, y;
+        float speed;
+    };
+
+    const float COUNT = 1200.0f;
+    std::vector<Particle> rects;
+
+    uint32_t w, h;
+
+    bool content(tvg::Canvas* canvas, uint32_t w, uint32_t h) override
+    {
+        if (!canvas) return false;
+
+        srand(100);
+
+        auto city = tvg::Picture::gen();
+        city->load(EXAMPLE_DIR"/image/particle.jpg");
+        canvas->push(city);
+
+        auto night = tvg::Shape::gen();
+        night->appendRect(0, 0, w, h);
+        night->fill(0, 0, 0, 220);
+        canvas->push(night);
+
+        //rain drops
+        auto size = w / COUNT;
+        rects.reserve(COUNT);
+
+        for (int i = 0; i < COUNT; ++i) {
+            auto shape = tvg::Shape::gen();
+            float x = size * i;
+            rects.push_back({shape, x, float(rand()%h), 10 + float(rand() % 100) * 0.1f});
+            shape->appendRect(0, 0, 1, rand() % 15 + size);
+            shape->fill(255, 255, 255, 55 + rand() % 100);
+            canvas->push(shape);
+        }
+
+        this->w = w;
+        this->h = h;
+
+        return true;
+    }
+
+    bool update(tvg::Canvas* canvas, uint32_t elapsed) override
+    {
+        if (!canvas) return false;
+        for (auto& p : rects) {
+            p.y += p.speed;
+            if (p.y > h) {
+                p.y -= h;
+            }
+            p.shape->translate(p.x, p.y);
+        }
+        canvas->update();
+        return true;
+    }
+};
+
+
+/************************************************************************/
+/* Entry Point                                                          */
+/************************************************************************/
+
+int main(int argc, char **argv)
+{
+    return tvgexam::main(new UserExample, argc, argv, false, 2440, 1280, 0, true);
+}

examples/meson.build

@@ -46,6 +46,7 @@ source_file = [
     'MultiCanvas.cpp',
     'Opacity.cpp',
     'Path.cpp',
+    'Particles.cpp',
     'PictureJpg.cpp',
     'PicturePng.cpp',
     'PictureRaw.cpp',