initializer: add reference counting for the engines initialization.

Introduced the reference counting for the backend engines so that
tvg prevents unpaired engine initialization/termination calls by user mistake.

@Issues: 296

src/lib/gl_engine/tvgGlRenderer.cpp

@@ -28,8 +28,8 @@
 /************************************************************************/
 /* Internal Class Implementation                                        */
 /************************************************************************/
-static bool initEngine = false;
+static int32_t initEngineCnt = false;
-static uint32_t rendererCnt = 0;
+static int32_t rendererCnt = 0;
 
 
 static void _termEngine()
@@ -236,22 +236,19 @@ RenderData GlRenderer::prepare(const Shape& shape, RenderData data, const Render
 
 int GlRenderer::init(uint32_t threads)
 {
-    if (rendererCnt > 0) return false;
+    if ((initEngineCnt++) > 0) return true;
-    if (initEngine) return true;
 
     //TODO:
 
-    initEngine = true;
-
     return true;
 }
 
 
 int GlRenderer::term()
 {
-    if (!initEngine) return true;
+    if ((--initEngineCnt) > 0) return true;
 
-    initEngine = false;
+    initEngineCnt = 0;
 
    _termEngine();
 
@@ -270,7 +267,8 @@ GlRenderer::~GlRenderer()
     mRenderTasks.clear();
 
     --rendererCnt;
-    if (!initEngine) _termEngine();
+
+    if (rendererCnt == 0 && initEngineCnt == 0) _termEngine();
 }
 
 
@@ -308,13 +306,11 @@ void GlRenderer::drawPrimitive(GlShape& sdata, const Fill* fill, uint32_t primit
 {
     const Fill::ColorStop* stops = nullptr;
     auto stopCnt = fill->colorStops(&stops);
-    if (stopCnt < 2)
+    if (stopCnt < 2) return;
-    {
+
-        return;
-    }
     GlGradientRenderTask* rTask = nullptr;
-    GlSize size = sdata.geometry->getPrimitiveSize(primitiveIndex);
+    auto size = sdata.geometry->getPrimitiveSize(primitiveIndex);
-    float* matrix = sdata.geometry->getTransforMatrix();
+    auto matrix = sdata.geometry->getTransforMatrix();
 
     switch (fill->id()) {
         case FILL_ID_LINEAR: {
@@ -344,16 +340,15 @@ void GlRenderer::drawPrimitive(GlShape& sdata, const Fill* fill, uint32_t primit
             break;
         }
     }
-    if (rTask)
+    if (rTask) {
-    {
+        auto vertexLoc = rTask->getLocationPropertyId();
-        int32_t vertexLoc = rTask->getLocationPropertyId();
         rTask->setPrimitveSize(size.x, size.y);
         rTask->setCanvasSize(sdata.viewWd, sdata.viewHt);
         rTask->setNoise(NOISE_LEVEL);
         rTask->setStopCount((int)stopCnt);
         rTask->setTransform(FORMAT_SIZE_MAT_4x4, matrix);
-        for (uint32_t i = 0; i < stopCnt; ++i)
+
-        {
+        for (uint32_t i = 0; i < stopCnt; ++i) {
             rTask->setStopColor(i, stops[i].offset, stops[i].r, stops[i].g, stops[i].b, stops[i].a);
         }
 

src/lib/sw_engine/tvgSwRenderer.cpp

@@ -27,8 +27,8 @@
 /************************************************************************/
 /* Internal Class Implementation                                        */
 /************************************************************************/
-static bool initEngine = false;
+static int32_t initEngineCnt = false;
-static uint32_t rendererCnt = 0;
+static int32_t rendererCnt = 0;
 
 
 struct SwTask : Task
@@ -229,7 +229,8 @@ SwRenderer::~SwRenderer()
     if (surface) delete(surface);
 
     --rendererCnt;
-    if (!initEngine) _termEngine();
+
+    if (rendererCnt == 0 && initEngineCnt == 0) _termEngine();
 }
 
 
@@ -546,22 +547,19 @@ RenderData SwRenderer::prepare(const Shape& sdata, RenderData data, const Render
 
 bool SwRenderer::init(uint32_t threads)
 {
-    if (rendererCnt > 0) return false;
+    if ((initEngineCnt++) > 0) return true;
-    if (initEngine) return true;
 
     if (!mpoolInit(threads)) return false;
 
-    initEngine = true;
-
     return true;
 }
 
 
 bool SwRenderer::term()
 {
-    if (!initEngine) return true;
+    if ((--initEngineCnt) > 0) return true;
 
-    initEngine = false;
+    initEngineCnt = 0;
 
    _termEngine();
 

src/lib/tvgInitializer.cpp

@@ -35,7 +35,7 @@
 /************************************************************************/
 /* Internal Class Implementation                                        */
 /************************************************************************/
-static bool initialized = false;
+
 
 /************************************************************************/
 /* External Class Implementation                                        */
@@ -43,8 +43,6 @@ static bool initialized = false;
 
 Result Initializer::init(CanvasEngine engine, uint32_t threads) noexcept
 {
-    if (initialized) return Result::InsufficientCondition;
-
     auto nonSupport = true;
 
     if (static_cast<uint32_t>(engine) & static_cast<uint32_t>(CanvasEngine::Sw)) {
@@ -67,16 +65,12 @@ Result Initializer::init(CanvasEngine engine, uint32_t threads) noexcept
 
     TaskScheduler::init(threads);
 
-    initialized = true;
-
     return Result::Success;
 }
 
 
 Result Initializer::term(CanvasEngine engine) noexcept
 {
-    if (!initialized) return Result::InsufficientCondition;
-
     auto nonSupport = true;
 
     if (static_cast<uint32_t>(engine) & static_cast<uint32_t>(CanvasEngine::Sw)) {
@@ -99,7 +93,5 @@ Result Initializer::term(CanvasEngine engine) noexcept
 
     if (!LoaderMgr::term()) return Result::Unknown;
 
-    initialized = false;
-
     return Result::Success;
 }