thorvg/src/examples/Opacity.cpp

#include "Common.h"

/************************************************************************/
/* Drawing Commands                                                     */
/************************************************************************/

void tvgDrawCmds(tvg::Canvas* canvas)
{
    if (!canvas) return;

    //Prepare Circle
    auto shape1 = tvg::Shape::gen();
    shape1->appendCircle(400, 400, 250, 250);
    shape1->fill(255, 255, 0, 255);
    canvas->push(move(shape1));

    //Create a Scene
    auto scene = tvg::Scene::gen();
    scene->opacity(127);              //Apply opacity to scene (0 - 255)
    scene->reserve(2);

    //Star
    auto shape2 = tvg::Shape::gen();

    //Appends Paths
    shape2->moveTo(199, 34);
    shape2->lineTo(253, 143);
    shape2->lineTo(374, 160);
    shape2->lineTo(287, 244);
    shape2->lineTo(307, 365);
    shape2->lineTo(199, 309);
    shape2->lineTo(97, 365);
    shape2->lineTo(112, 245);
    shape2->lineTo(26, 161);
    shape2->lineTo(146, 143);
    shape2->close();
    shape2->fill(0, 0, 255, 255);
    shape2->stroke(10);
    shape2->stroke(255, 255, 255, 255);
    shape2->opacity(127);

    scene->push(move(shape2));

    //Circle
    auto shape3 = tvg::Shape::gen();

    auto cx = 550.0f;
    auto cy = 550.0f;
    auto radius = 125.0f;
    auto halfRadius = radius * 0.552284f;

    //Append Paths
    shape3->moveTo(cx, cy - radius);
    shape3->cubicTo(cx + halfRadius, cy - radius, cx + radius, cy - halfRadius, cx + radius, cy);
    shape3->cubicTo(cx + radius, cy + halfRadius, cx + halfRadius, cy + radius, cx, cy+ radius);
    shape3->cubicTo(cx - halfRadius, cy + radius, cx - radius, cy + halfRadius, cx - radius, cy);
    shape3->cubicTo(cx - radius, cy - halfRadius, cx - halfRadius, cy - radius, cx, cy - radius);
    shape3->fill(255, 0, 0, 255);
    shape3->stroke(10);
    shape3->stroke(0, 0, 255, 255);
    shape3->opacity(200);
    scene->push(move(shape3));

    //Draw the Scene onto the Canvas
    canvas->push(move(scene));
}


/************************************************************************/
/* 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();

    //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;
}