examples: added Interaction sample

The Interaction sample demonstrates
how to handle user input with ThorVG Animation.

examples/Example.h

@@ -62,8 +62,11 @@ bool verify(tvg::Result result, string failMsg = "");
 
 struct Example
 {
+    uint32_t elapsed = 0.0f;
+
     virtual bool content(tvg::Canvas* canvas, uint32_t w, uint32_t h) = 0;
     virtual bool update(tvg::Canvas* canvas, uint32_t elapsed) { return false; }
+    virtual bool clicked(tvg::Canvas* canvas, int32_t x, int32_t y) { return false; }
     virtual void populate(const char* path) {}
     virtual ~Example() {}
 
@@ -196,7 +199,7 @@ struct Window
         auto running = true;
 
         auto ptime = SDL_GetTicks();
-        auto elapsed = 0;
+        example->elapsed = 0;
         uint32_t tickCnt = 0;
 
         while (running) {
@@ -214,6 +217,12 @@ struct Window
                         }
                         break;
                     }
+                    case SDL_MOUSEBUTTONDOWN: {
+                        if (example->clicked(canvas, event.button.x, event.button.y)) {
+                            needDraw = true;
+                        }
+                        break;
+                    }
                     case SDL_WINDOWEVENT: {
                         if (event.window.event == SDL_WINDOWEVENT_RESIZED) {
                             width = event.window.data1;
@@ -231,7 +240,7 @@ struct Window
             }
 
             if (tickCnt > 0) {
-                if (example->update(canvas, elapsed)) {
+                if (example->update(canvas, example->elapsed)) {
                     needDraw = true;
                 }
             }
@@ -242,9 +251,9 @@ struct Window
             }
 
             auto ctime = SDL_GetTicks();
-            elapsed += (ctime - ptime);
+            example->elapsed += (ctime - ptime);
             tickCnt++;
-            if (print) printf("[%5d]: elapsed time = %dms (%dms)\n", tickCnt, (ctime - ptime), (elapsed / tickCnt));
+            if (print) printf("[%5d]: elapsed time = %dms (%dms)\n", tickCnt, (ctime - ptime), (example->elapsed / tickCnt));
             ptime = ctime;
         }
     }
@@ -457,6 +466,7 @@ struct WgWindow : Window
 float progress(uint32_t elapsed, float durationInSec, bool rewind = false)
 {
     auto duration = uint32_t(durationInSec * 1000.0f); //sec -> millisec.
+    if (duration == 0.0f) return 0.0f;
     auto forward = ((elapsed / duration) % 2 == 0) ? true : false;
     auto clamped = elapsed % duration;
     auto progress = ((float)clamped / (float)duration);

examples/Interaction.cpp

@@ -0,0 +1,149 @@
+/*
+ * Copyright (c) 2024 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 "Example.h"
+
+/************************************************************************/
+/* ThorVG Drawing Contents                                              */
+/************************************************************************/
+
+struct UserExample : tvgexam::Example
+{
+    unique_ptr<tvg::Animation> animation;
+
+    bool hitting(const tvg::Paint* paint, int32_t x, int32_t y, float segment1, float segment2)
+    {
+        float px, py, pw, ph;
+        tvgexam::verify(paint->bounds(&px, &py, &pw, &ph, true));
+        if (x >= px && x <= px + pw && y >= py && y <= py + ph) {
+            tvgexam::verify(animation->segment(segment1, segment2));
+            elapsed = 0.0f;
+            return true;
+        }
+        return false;
+    }
+
+    bool clicked(tvg::Canvas* canvas, int32_t x, int32_t y) override
+    {
+        auto picture = animation->picture();
+
+        //pad1 touch?
+        if (auto paint = picture->paint(tvg::Accessor::id("pad1"))) {
+            if (hitting(paint, x, y, 0.2222f, 0.3333f)) return true;
+        }
+
+        //pad3 touch?
+        if (auto paint = picture->paint(tvg::Accessor::id("pad3"))) {
+            if (hitting(paint, x, y, 0.4444f, 0.5555f)) return true;
+        }
+
+        //pad5 touch?
+        if (auto paint = picture->paint(tvg::Accessor::id("pad5"))) {
+            if (hitting(paint, x, y, 0.1111f, 0.2222f)) return true;
+        }
+
+        //pad7 touch?
+        if (auto paint = picture->paint(tvg::Accessor::id("pad7"))) {
+            if (hitting(paint, x, y, 0.0000f, 0.1111f)) return true;
+        }
+
+        //pad9 touch?
+        if (auto paint = picture->paint(tvg::Accessor::id("pad9"))) {
+            if (hitting(paint, x, y, 0.3333f, 0.4444f)) return true;
+        }
+
+        //bar touch?
+        if (auto paint = picture->paint(tvg::Accessor::id("bar"))) {
+            if (hitting(paint, x, y, 0.6666f, 1.0f)) return true;
+        }
+
+        return false;
+    }
+
+    bool content(tvg::Canvas* canvas, uint32_t w, uint32_t h) override
+    {
+        //Animation Controller
+        animation = tvg::Animation::gen();
+        auto picture = animation->picture();
+
+        //Background
+        auto shape = tvg::Shape::gen();
+        shape->appendRect(0, 0, w, h);
+        shape->fill(50, 50, 50);
+        canvas->push(std::move(shape));
+
+        if (!tvgexam::verify(picture->load(EXAMPLE_DIR"/lottie/extensions/locker.json"))) return false;
+
+        //image scaling preserving its aspect ratio
+        float scale;
+        float shiftX = 0.0f, shiftY = 0.0f;
+        float w2, h2;
+        picture->size(&w2, &h2);
+
+        if (w2 > h2) {
+            scale = w / w2;
+            shiftY = (h - h2 * scale) * 0.5f;
+        } else {
+            scale = h / h2;
+            shiftX = (w - w2 * scale) * 0.5f;
+        }
+
+        picture->scale(scale);
+        picture->translate(shiftX, shiftY);
+
+        canvas->push(tvg::cast(picture));
+
+        //Default is a stopped motion
+        animation->segment(0.0f, 0.0f);
+
+        return true;
+    }
+
+    bool update(tvg::Canvas* canvas, uint32_t elapsed) override
+    {
+        if (!canvas) return false;
+
+        auto progress = tvgexam::progress(elapsed, animation->duration());
+
+        //Default is a stopped motion
+        if (progress > 0.95f) {
+            animation->segment(0.0f, 0.0f);
+            elapsed = progress = 0.0f;
+        }
+
+        //Update animation frame only when it's changed
+        animation->frame(animation->totalFrame() * progress);
+        canvas->update();
+
+        return true;
+    }
+};
+
+
+/************************************************************************/
+/* Entry Point                                                          */
+/************************************************************************/
+
+int main(int argc, char **argv)
+{
+    return tvgexam::main(new UserExample, argc, argv, 1024, 1024, 0);
+}

examples/meson.build

@@ -36,6 +36,7 @@ source_file = [
     'GradientTransform.cpp',
     'ImageScaleDown.cpp',
     'ImageScaleUp.cpp',
+    'Interaction.cpp',
     'InvLumaMasking.cpp',
     'InvMasking.cpp',
     'LinearGradient.cpp',