examples: added image rotation

examples/ImageRotation.cpp

@@ -0,0 +1,99 @@
+/*
+ * 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 <cmath>
+#include "Example.h"
+
+/************************************************************************/
+/* ThorVG Drawing Contents                                              */
+/************************************************************************/
+
+struct UserExample : tvgexam::Example
+{
+    tvg::Picture* pPicture = nullptr;
+
+    float deg2rad(float degree)
+    {
+        return degree * (M_PI / 180.0f);
+    }
+
+    bool content(tvg::Canvas* canvas, uint32_t w, uint32_t h) override
+    {
+        if (!canvas) return false;
+
+        auto picture = tvg::Picture::gen();
+        pPicture = picture.get();
+
+        if (!tvgexam::verify(picture->load(EXAMPLE_DIR"/image/scaledown.jpg"))) return false;
+
+        canvas->push(std::move(picture));
+
+        return true;
+    }
+
+    bool update(tvg::Canvas* canvas, uint32_t elapsed) override
+    {
+        if (!canvas) return false;
+
+        canvas->clear(false);
+
+        tvg::Matrix m = {1.0f, 0.0f, 0.0f, 0.0f, 0.1f, 0.0f, 0.0f, 0.0f, 1.0f};
+
+        //center pivoting
+        m.e13 += 400;
+        m.e23 += 400;
+
+        //rotation
+        auto degree = tvgexam::progress(elapsed, 4.0f) * 360.0f;
+        auto radian = deg2rad(degree);
+        m.e11 = cosf(radian);
+        m.e12 = -sinf(radian);
+        m.e21 = sinf(radian);
+        m.e22 = cosf(radian);
+
+        //scaling
+        m.e11 *= 0.75f;
+        m.e21 *= 0.75f;
+        m.e22 *= 0.75f;
+        m.e12 *= 0.75f;
+
+        //center pivoting
+        m.e13 += (-400 * m.e11 + -400 * m.e12);
+        m.e23 += (-400 * m.e21 + -400 * m.e22);
+
+        pPicture->transform(m);
+
+        canvas->update();
+
+        return true;
+    }
+};
+
+
+/************************************************************************/
+/* Entry Point                                                          */
+/************************************************************************/
+
+int main(int argc, char **argv)
+{
+    return tvgexam::main(new UserExample, argc, argv);
+}

examples/meson.build

@@ -33,6 +33,7 @@ source_file = [
     'GradientMasking.cpp',
     'GradientStroke.cpp',
     'GradientTransform.cpp',
+    'ImageRotation.cpp',
     'ImageScaleDown.cpp',
     'ImageScaleUp.cpp',
     'Interaction.cpp',