examples: add stacking example

This example shows how to restack paints node

src/examples/Stacking.cpp

@@ -0,0 +1,195 @@
+#include "Common.h"
+
+/************************************************************************/
+/* Drawing Commands                                                     */
+/************************************************************************/
+
+static tvg::Shape* paints[3];
+static int order = 0;
+
+void tvgDrawCmds(tvg::Canvas* canvas)
+{
+    if (!canvas) return;
+
+    canvas->reserve(3);                          //reserve 3 shape nodes (optional)
+
+    //Prepare Round Rectangle
+    auto shape1 = tvg::Shape::gen();
+    paints[0] = shape1.get();
+    shape1->appendRect(0, 0, 400, 400, 50, 50);  //x, y, w, h, rx, ry
+    shape1->fill(0, 255, 0, 255);                //r, g, b, a
+    if (canvas->push(move(shape1)) != tvg::Result::Success) return;
+
+    //Prepare Circle
+    auto shape2 = tvg::Shape::gen();
+    paints[1] = shape2.get();
+    shape2->appendRect(100, 100, 400, 400, 50, 50);  //x, y, w, h, rx, ry
+    shape2->fill(255, 255, 0, 255);              //r, g, b, a
+    if (canvas->push(move(shape2)) != tvg::Result::Success) return;
+
+    //Prepare Ellipse
+    auto shape3 = tvg::Shape::gen();
+    paints[2] = shape3.get();
+    shape3->appendRect(200, 200, 400, 400, 50, 50);  //x, y, w, h, rx, ry
+    shape3->fill(0, 255, 255, 255);              //r, g, b, a
+    if (canvas->push(move(shape3)) != tvg::Result::Success) return;
+}
+
+
+void tvgUpdateCmds(tvg::Canvas* canvas)
+{
+    if (!canvas) return;
+
+    //Explicitly clear all retained paint nodes from canvas but not free them.
+    if (canvas->clear(false) != tvg::Result::Success) return;
+
+    switch (order) {
+        case 0:
+            canvas->push(unique_ptr<tvg::Shape>(paints[0]));
+            canvas->push(unique_ptr<tvg::Shape>(paints[1]));
+            canvas->push(unique_ptr<tvg::Shape>(paints[2]));
+            break;
+        case 1:
+            canvas->push(unique_ptr<tvg::Shape>(paints[1]));
+            canvas->push(unique_ptr<tvg::Shape>(paints[2]));
+            canvas->push(unique_ptr<tvg::Shape>(paints[0]));
+            break;
+        case 2:
+            canvas->push(unique_ptr<tvg::Shape>(paints[2]));
+            canvas->push(unique_ptr<tvg::Shape>(paints[0]));
+            canvas->push(unique_ptr<tvg::Shape>(paints[1]));
+            break;
+    }
+
+    ++order;
+
+    if (order > 2) order = 0;
+}
+
+
+/************************************************************************/
+/* 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();
+    }
+}
+
+
+Eina_Bool timerSwCb(void *data)
+{
+    tvgUpdateCmds(swCanvas.get());
+
+    Eo* img = (Eo*) data;
+    evas_object_image_data_update_add(img, 0, 0, WIDTH, HEIGHT);
+    evas_object_image_pixels_dirty_set(img, EINA_TRUE);
+
+    return ECORE_CALLBACK_RENEW;
+}
+
+
+/************************************************************************/
+/* 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();
+    }
+}
+
+
+Eina_Bool timerGlCb(void *data)
+{
+    tvgUpdateCmds(glCanvas.get());
+
+    return ECORE_CALLBACK_RENEW;
+}
+
+
+/************************************************************************/
+/* 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();
+
+    //Initialize ThorVG Engine
+    if (tvg::Initializer::init(tvgEngine, threads) == tvg::Result::Success) {
+
+        elm_init(argc, argv);
+
+        if (tvgEngine == tvg::CanvasEngine::Sw) {
+            auto view = createSwView();
+            ecore_timer_add(0.5, timerSwCb, view);
+        } else {
+            auto view = createGlView();
+            ecore_timer_add(0.5, timerGlCb, view);
+        }
+
+        elm_run();
+        elm_shutdown();
+
+        //Terminate ThorVG Engine
+        tvg::Initializer::term(tvgEngine);
+
+    } else {
+        cout << "engine is not supported" << endl;
+    }
+    return 0;
+}

src/examples/meson.build

@@ -19,6 +19,7 @@ source_file = [
     'Scene.cpp',
     'SceneTransform.cpp',
     'Shape.cpp',
+    'Stacking.cpp',
     'Stress.cpp',
     'Stroke.cpp',
     'StrokeLine.cpp',