example: add an example SceneClipper

src/examples/SceneClipper.cpp

@@ -0,0 +1,182 @@
+/*
+ * Copyright (c) 2023 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 "Common.h"
+
+/************************************************************************/
+/* Drawing Commands                                                     */
+/************************************************************************/
+
+void tvgDrawCmds(tvg::Canvas* canvas)
+{
+    if (!canvas) return;
+
+/* Using a single shape is sufficient to clip multiple regions.
+   The disabled code below performs the same function. Please try it. */
+#if 1
+    //A scene clipper
+    auto clipper = tvg::Scene::gen();
+
+    auto shape1 = tvg::Shape::gen();
+    shape1->appendCircle(200, 200, 100, 100);
+    clipper->push(move(shape1));
+
+    auto shape2 = tvg::Shape::gen();
+    shape2->appendCircle(400, 400, 150, 150);
+    clipper->push(move(shape2));
+
+    auto shape3 = tvg::Shape::gen();
+    shape3->appendCircle(150, 300, 60, 60);
+    clipper->push(move(shape3));
+
+    auto shape4 = tvg::Shape::gen();
+    shape4->appendCircle(400, 100, 125, 125);
+    clipper->push(move(shape4));
+
+    auto shape5 = tvg::Shape::gen();
+    shape5->appendCircle(150, 500, 100, 100);
+    clipper->push(move(shape5));
+#else
+    //A single clipper with multiple regions
+    auto clipper = tvg::Shape::gen();
+    clipper->appendCircle(200, 200, 100, 100);
+    clipper->appendCircle(400, 400, 150, 150);
+    clipper->appendCircle(150, 300, 60, 60);
+    clipper->appendCircle(400, 100, 125, 125);
+    clipper->appendCircle(150, 500, 100, 100);
+#endif
+
+    //Source
+    auto shape = tvg::Shape::gen();
+    shape->appendRect(100, 100, 400, 400, 50, 50);
+    shape->stroke(0, 0, 255, 255);
+    shape->stroke(10);
+    shape->fill(255, 255, 255, 255);
+    shape->composite(move(clipper), tvg::CompositeMethod::ClipPath);
+    if (canvas->push(move(shape)) != tvg::Result::Success) return;
+}
+
+/************************************************************************/
+/* Sw Engine Test Code                                                  */
+/************************************************************************/
+
+static unique_ptr<tvg::SwCanvas> swCanvas;
+
+void tvgSwTest(uint32_t* buffer)
+{
+    //Create a Canvas
+    swCanvas = tvg::SwCanvas::gen();
+    swCanvas->target(buffer, WIDTH, WIDTH, HEIGHT, tvg::SwCanvas::ARGB8888);
+
+    /* Push the shape into the Canvas drawing list
+       When this shape is into the canvas list, the shape could update & prepare
+       internal data asynchronously for coming rendering.
+       Canvas keeps this shape node unless user call canvas->clear() */
+    tvgDrawCmds(swCanvas.get());
+}
+
+void drawSwView(void* data, Eo* obj)
+{
+    if (swCanvas->draw() == tvg::Result::Success) {
+        swCanvas->sync();
+    }
+}
+
+
+/************************************************************************/
+/* GL Engine Test Code                                                  */
+/************************************************************************/
+
+static unique_ptr<tvg::GlCanvas> glCanvas;
+
+void initGLview(Evas_Object *obj)
+{
+    static constexpr auto BPP = 4;
+
+    //Create a Canvas
+    glCanvas = tvg::GlCanvas::gen();
+    glCanvas->target(nullptr, WIDTH * BPP, WIDTH, HEIGHT);
+
+    /* Push the shape into the Canvas drawing list
+       When this shape is into the canvas list, the shape could update & prepare
+       internal data asynchronously for coming rendering.
+       Canvas keeps this shape node unless user call canvas->clear() */
+    tvgDrawCmds(glCanvas.get());
+}
+
+void drawGLview(Evas_Object *obj)
+{
+    auto gl = elm_glview_gl_api_get(obj);
+    gl->glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+    gl->glClear(GL_COLOR_BUFFER_BIT);
+
+    if (glCanvas->draw() == tvg::Result::Success) {
+        glCanvas->sync();
+    }
+}
+
+
+/************************************************************************/
+/* Main Code                                                            */
+/************************************************************************/
+
+int main(int argc, char **argv)
+{
+    tvg::CanvasEngine tvgEngine = tvg::CanvasEngine::Sw;
+
+    if (argc > 1) {
+        if (!strcmp(argv[1], "gl")) tvgEngine = tvg::CanvasEngine::Gl;
+    }
+
+    //Initialize ThorVG Engine
+    if (tvgEngine == tvg::CanvasEngine::Sw) {
+        cout << "tvg engine: software" << endl;
+    } else {
+        cout << "tvg engine: opengl" << endl;
+    }
+
+    //Threads Count
+    auto threads = std::thread::hardware_concurrency();
+    if (threads > 0) --threads;    //Allow the designated main thread capacity
+
+    //Initialize ThorVG Engine
+    if (tvg::Initializer::init(tvgEngine, threads) == tvg::Result::Success) {
+
+        elm_init(argc, argv);
+
+        if (tvgEngine == tvg::CanvasEngine::Sw) {
+            createSwView();
+        } else {
+            createGlView();
+        }
+
+        elm_run();
+        elm_shutdown();
+
+        //Terminate ThorVG Engine
+        tvg::Initializer::term(tvgEngine);
+
+    } else {
+        cout << "engine is not supported" << endl;
+    }
+    return 0;
+}

src/examples/meson.build

@@ -32,6 +32,7 @@ source_file = [
     'PictureTvg.cpp',
     'RadialGradient.cpp',
     'Scene.cpp',
+    'SceneClipper.cpp',
     'SceneTransform.cpp',
     'Shape.cpp',
     'Stacking.cpp',