gl_engine: fix rendering error caused by viewport and stencil state

Fix some error:
* glViewport not controlled by framebuffer, and need to set manually when
target framebuffer is changed.
* change even-odd stencil operation, so no need to do third draw call to
  clear stencil buffer
* fix the missing `GlCanvas::update` calls in Lottoe and LottieExtension

examples/Lottie.cpp

@@ -217,6 +217,8 @@ void drawGLview(Evas_Object *obj)
     gl->glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
     gl->glClear(GL_COLOR_BUFFER_BIT);
 
+    glCanvas->update();
+
     if (glCanvas->draw() == tvg::Result::Success) {
         glCanvas->sync();
     }

examples/LottieExtension.cpp

@@ -194,6 +194,8 @@ void drawGLview(Evas_Object *obj)
     gl->glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
     gl->glClear(GL_COLOR_BUFFER_BIT);
 
+    glCanvas->update();
+
     if (glCanvas->draw() == tvg::Result::Success) {
         glCanvas->sync();
     }

src/renderer/gl_engine/tvgGlRenderTask.cpp

@@ -128,7 +128,7 @@ void GlStencilCoverTask::run()
 
     if (mStencilMode == GlStencilMode::FillEvenOdd) {
         GL_CHECK(glStencilFunc(GL_EQUAL, 0x01, 0x01));
-        GL_CHECK(glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE));
+        GL_CHECK(glStencilOp(GL_REPLACE, GL_KEEP, GL_REPLACE));
     } else {
         GL_CHECK(glStencilFunc(GL_NOTEQUAL, 0x0, 0xFF));
         GL_CHECK(glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE));
@@ -138,17 +138,6 @@ void GlStencilCoverTask::run()
 
     mCoverTask->run();
 
-    if (mStencilMode == GlStencilMode::FillEvenOdd) {
-        GL_CHECK(glStencilFunc(GL_NOTEQUAL, 0x0, 0xFF));
-        GL_CHECK(glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE));
-
-        GL_CHECK(glColorMask(0, 0, 0, 0));
-
-        mStencilTask->run();
-
-        GL_CHECK(glColorMask(1, 1, 1, 1));
-    }
-
     GL_CHECK(glDisable(GL_STENCIL_TEST));
 }
 
@@ -171,6 +160,7 @@ GlComposeTask::~GlComposeTask()
 void GlComposeTask::run()
 {
     GL_CHECK(glBindFramebuffer(GL_FRAMEBUFFER, getSelfFbo()));
+    GL_CHECK(glViewport(0, 0, mFbo->getWidth(), mFbo->getHeight()));
 
     // clear this fbo
     if (mClearBuffer) {
@@ -216,6 +206,7 @@ void GlBlitTask::run()
     GlComposeTask::run();
 
     GL_CHECK(glBindFramebuffer(GL_FRAMEBUFFER, getTargetFbo()));
+    GL_CHECK(glViewport(mTargetViewport.x, mTargetViewport.y, mTargetViewport.w, mTargetViewport.h));
 
     if (mClearBuffer) {
         GL_CHECK(glClearColor(0, 0, 0, 0));

src/renderer/gl_engine/tvgGlRenderTask.h

@@ -146,8 +146,11 @@ public:
     void run() override;
 
     GLuint getColorTextore() const { return mColorTex; }
+
+    void setTargetViewport(const RenderRegion& vp) { mTargetViewport = vp; }
 private:
     GLuint mColorTex = 0;
+    RenderRegion mTargetViewport = {};
 };
 
 class GlDrawBlitTask : public GlComposeTask

src/renderer/gl_engine/tvgGlRenderer.cpp

@@ -68,11 +68,24 @@ bool GlRenderer::target(int32_t id, uint32_t w, uint32_t h)
     mViewport.w = surface.w;
     mViewport.h = surface.h;
 
+    mTargetViewport.x = 0;
+    mTargetViewport.y = 0;
+    mTargetViewport.w = surface.w;
+    mTargetViewport.h = surface.h;
+
     mTargetFboId = static_cast<GLint>(id);
 
     //TODO: It's not allow to draw onto the main surface. Need to confirm the policy.
     if (mTargetFboId == 0) {
         GL_CHECK(glGetIntegerv(GL_FRAMEBUFFER_BINDING, &mTargetFboId));
+
+        GLint dims[4] = {0};
+
+        GL_CHECK(glGetIntegerv(GL_VIEWPORT, dims));
+        // If targeting on the main framebuffer ,the actual size may by adjusted by the window system.
+        // In case the size is different from logical size, query and set the actual viewport here
+        mTargetViewport.w = dims[2];
+        mTargetViewport.h = dims[3];
     }
 
     mRootTarget = make_unique<GlRenderTarget>(surface.w, surface.h);
@@ -101,6 +114,7 @@ bool GlRenderer::sync()
     prepareBlitTask(task);
 
     task->mClearBuffer = mClearBuffer;
+    task->setTargetViewport(mTargetViewport);
 
     mGpuBuffer->flushToGPU();
     mGpuBuffer->bind();

src/renderer/gl_engine/tvgGlRenderer.h

@@ -98,6 +98,7 @@ private:
 
     GLint mTargetFboId = 0;
     RenderRegion mViewport;
+    RenderRegion mTargetViewport;
     //TODO: remove all unique_ptr / replace the vector with tvg::Array
     unique_ptr<GlStageBuffer> mGpuBuffer;
     vector<std::unique_ptr<GlProgram>> mPrograms;