engines: manage the update with the precise update flags

this also fixes one broken clipping issue.

issue: https://github.com/thorvg/thorvg/issues/3448

src/renderer/gl_engine/tvgGlRenderer.cpp

@@ -1329,7 +1329,7 @@ RenderData GlRenderer::prepare(RenderSurface* image, RenderData data, const Matr
 
     sdata->geometry->tesselate(image, flags);
 
-    if (!clips.empty()) {
+    if (flags & RenderUpdateFlag::Clip) {
         sdata->clips.clear();
         sdata->clips.push(clips);
     }
@@ -1340,6 +1340,8 @@ RenderData GlRenderer::prepare(RenderSurface* image, RenderData data, const Matr
 
 RenderData GlRenderer::prepare(const RenderShape& rshape, RenderData data, const Matrix& transform, Array<RenderData>& clips, uint8_t opacity, RenderUpdateFlag flags, bool clipper)
 {
+    if (flags == RenderUpdateFlag::None) return data;
+
     // If prepare for clip, only path is meaningful.
     if (clipper) flags = RenderUpdateFlag::Path;
 
@@ -1353,7 +1355,6 @@ RenderData GlRenderer::prepare(const RenderShape& rshape, RenderData data, const
     sdata->viewWd = static_cast<float>(surface.w);
     sdata->viewHt = static_cast<float>(surface.h);
     sdata->updateFlag = RenderUpdateFlag::None;
-
     sdata->geometry = make_unique<GlGeometry>();
     sdata->opacity = opacity;
 
@@ -1362,10 +1363,7 @@ RenderData GlRenderer::prepare(const RenderShape& rshape, RenderData data, const
     rshape.fillColor(nullptr, nullptr, nullptr, &alphaF);
     rshape.strokeColor(nullptr, nullptr, nullptr, &alphaS);
 
-    if ( ((flags & RenderUpdateFlag::Gradient) == 0) &&
+    if ((flags & RenderUpdateFlag::Gradient) == 0 && ((flags & RenderUpdateFlag::Color) && alphaF == 0) && ((flags & RenderUpdateFlag::Stroke) && alphaS == 0)) {
-         ((flags & RenderUpdateFlag::Color) && alphaF == 0) &&
-         ((flags & RenderUpdateFlag::Stroke) && alphaS == 0) )
-    {
         return sdata;
     }
 
@@ -1383,12 +1381,11 @@ RenderData GlRenderer::prepare(const RenderShape& rshape, RenderData data, const
     sdata->geometry->updateTransform(transform);
     sdata->geometry->setViewport(mViewport);
 
-    if (sdata->updateFlag & (RenderUpdateFlag::Color | RenderUpdateFlag::Stroke | RenderUpdateFlag::Gradient | RenderUpdateFlag::GradientStroke | RenderUpdateFlag::Transform | RenderUpdateFlag::Path))
+    if (sdata->updateFlag & (RenderUpdateFlag::Color | RenderUpdateFlag::Stroke | RenderUpdateFlag::Gradient | RenderUpdateFlag::GradientStroke | RenderUpdateFlag::Transform | RenderUpdateFlag::Path)) {
-    {
         if (!sdata->geometry->tesselate(rshape, sdata->updateFlag)) return sdata;
     }
 
-    if (!clipper && !clips.empty()) {
+    if (flags & RenderUpdateFlag::Clip) {
         sdata->clips.clear();
         sdata->clips.push(clips);
     }

src/renderer/sw_engine/tvgSwRenderer.cpp

@@ -750,8 +750,7 @@ void SwRenderer::dispose(RenderData data)
 
 void* SwRenderer::prepareCommon(SwTask* task, const Matrix& transform, const Array<RenderData>& clips, uint8_t opacity, RenderUpdateFlag flags)
 {
-    if (!surface) return task;
+    if (!surface || (transform.e11 == 0.0f && transform.e12 == 0.0f) || (transform.e21 == 0.0f && transform.e22 == 0.0f)) return task;  //invalid
-    if (flags == RenderUpdateFlag::None) return task;
 
     //TODO: Failed threading them. It would be better if it's possible.
     //See: https://github.com/thorvg/thorvg/issues/1409
@@ -781,7 +780,16 @@ void* SwRenderer::prepareCommon(SwTask* task, const Matrix& transform, const Arr
         tasks.push(task);
     }
 
-    TaskScheduler::request(task);
+    //TODO: Failed threading them. It would be better if it's possible.
+    //See: https://github.com/thorvg/thorvg/issues/1409
+    //Guarantee composition targets get ready.
+    if (flags & RenderUpdateFlag::Clip) {
+        for (uint32_t i = 0; i < clips.count; ++i) {
+            static_cast<SwTask*>(clips[i])->done();
+        }
+    }
+
+    if (flags) TaskScheduler::request(task);
 
     return task;
 }
@@ -791,10 +799,11 @@ RenderData SwRenderer::prepare(RenderSurface* surface, RenderData data, const Ma
 {
     //prepare task
     auto task = static_cast<SwImageTask*>(data);
-    if (!task) task = new SwImageTask;
+    if (task) task->done();
-    else task->done();
+    else {
-
+        task = new SwImageTask;
-    task->source = surface;
+        task->source = surface;
+    }
 
     return prepareCommon(task, transform, clips, opacity, flags);
 }
@@ -804,10 +813,12 @@ RenderData SwRenderer::prepare(const RenderShape& rshape, RenderData data, const
 {
     //prepare task
     auto task = static_cast<SwShapeTask*>(data);
-    if (!task) task = new SwShapeTask;
+    if (task) task->done();
-    else task->done();
+    else {
+        task = new SwShapeTask;
+        task->rshape = &rshape;
+    }
 
-    task->rshape = &rshape;
     task->clipper = clipper;
 
     return prepareCommon(task, transform, clips, opacity, flags);

src/renderer/wg_engine/tvgWgRenderer.cpp

@@ -82,13 +82,14 @@ void WgRenderer::disposeObjects()
 
 RenderData WgRenderer::prepare(const RenderShape& rshape, RenderData data, const Matrix& transform, Array<RenderData>& clips, uint8_t opacity, RenderUpdateFlag flags, bool clipper)
 {
-    // get or create render data shape
+    if (flags == RenderUpdateFlag::None) return data;
+
     auto renderDataShape = (WgRenderDataShape*)data;
     if (!renderDataShape)
         renderDataShape = mRenderDataShapePool.allocate(mContext);
 
     // update geometry
-    if ((!data) || (flags & (RenderUpdateFlag::Path | RenderUpdateFlag::Stroke))) {
+    if (!data || (flags & (RenderUpdateFlag::Path | RenderUpdateFlag::Stroke))) {
         renderDataShape->updateMeshes(mContext, rshape, transform);
     }
 
@@ -106,7 +107,7 @@ RenderData WgRenderer::prepare(const RenderShape& rshape, RenderData data, const
         renderDataShape->renderSettingsStroke.update(mContext, rshape.stroke->fill, rshape.stroke->color, flags);
 
     // store clips data
-    renderDataShape->updateClips(clips);
+    if (flags & RenderUpdateFlag::Clip) renderDataShape->updateClips(clips);
 
     return renderDataShape;
 }
@@ -114,6 +115,8 @@ RenderData WgRenderer::prepare(const RenderShape& rshape, RenderData data, const
 
 RenderData WgRenderer::prepare(RenderSurface* surface, RenderData data, const Matrix& transform, Array<RenderData>& clips, uint8_t opacity, RenderUpdateFlag flags)
 {
+    if (flags == RenderUpdateFlag::None) return data;
+
     // get or create render data shape
     auto renderDataPicture = (WgRenderDataPicture*)data;
     if (!renderDataPicture)
@@ -139,8 +142,7 @@ RenderData WgRenderer::prepare(RenderSurface* surface, RenderData data, const Ma
         );
     }
 
-    // store clips data
+    if (flags & RenderUpdateFlag::Clip) renderDataPicture->updateClips(clips);
-    renderDataPicture->updateClips(clips);
 
     return renderDataPicture;
 }