From f97c16f94c34641c330557509e854712a280c4ba Mon Sep 17 00:00:00 2001
From: Sergii Liebodkin <s.lebedkin@gmail.com>
Date: Mon, 17 Jun 2024 11:10:02 +0300
Subject: [PATCH] wg_engine: skip shapes with zero opacity values

Skip shapes rendering, if opacity is 0 and if fill color for shape and strokes also equal to 0
This behavior is used in sw renderer and fix visual artifacts in referenced animations.
Also this rule fix composition results in case of AlphaMask and InvAlphaMask methods
---
 src/renderer/wg_engine/tvgWgRenderData.cpp   | 2 ++
 src/renderer/wg_engine/tvgWgRenderData.h     | 2 ++
 src/renderer/wg_engine/tvgWgRenderTarget.cpp | 2 ++
 src/renderer/wg_engine/tvgWgRenderer.cpp     | 3 +++
 4 files changed, 9 insertions(+)

diff --git a/src/renderer/wg_engine/tvgWgRenderData.cpp b/src/renderer/wg_engine/tvgWgRenderData.cpp
index 1bdd4650..db433f8b 100644
--- a/src/renderer/wg_engine/tvgWgRenderData.cpp
+++ b/src/renderer/wg_engine/tvgWgRenderData.cpp
@@ -236,10 +236,12 @@ void WgRenderSettings::update(WgContext& context, const Fill* fill, const uint8_
             bindGroupRadial.initialize(context.device, context.queue, radialGradient);
             fillType = WgRenderSettingsType::Radial;
         }
+        skip = false;
     } else if ((flags & (RenderUpdateFlag::Color)) && !fill) {
         WgShaderTypeSolidColor solidColor(color);
         bindGroupSolid.initialize(context.device, context.queue, solidColor);
         fillType = WgRenderSettingsType::Solid;
+        skip = (color[3] == 0);
     }
 };
 
diff --git a/src/renderer/wg_engine/tvgWgRenderData.h b/src/renderer/wg_engine/tvgWgRenderData.h
index 1329b5ab..eb80bd88 100644
--- a/src/renderer/wg_engine/tvgWgRenderData.h
+++ b/src/renderer/wg_engine/tvgWgRenderData.h
@@ -77,6 +77,7 @@ struct WgRenderSettings
     WgBindGroupLinearGradient bindGroupLinear{};
     WgBindGroupRadialGradient bindGroupRadial{};
     WgRenderSettingsType fillType{};
+    bool skip{};
 
     void update(WgContext& context, const Fill* fill, const uint8_t* color, const RenderUpdateFlag flags);
     void release(WgContext& context);
@@ -85,6 +86,7 @@ struct WgRenderSettings
 struct WgRenderDataPaint
 {
     WgBindGroupPaint bindGroupPaint{};
+    float opacity{};
 
     virtual ~WgRenderDataPaint() {};
     virtual void release(WgContext& context);
diff --git a/src/renderer/wg_engine/tvgWgRenderTarget.cpp b/src/renderer/wg_engine/tvgWgRenderTarget.cpp
index 5642abff..f39dae0b 100644
--- a/src/renderer/wg_engine/tvgWgRenderTarget.cpp
+++ b/src/renderer/wg_engine/tvgWgRenderTarget.cpp
@@ -111,6 +111,7 @@ void WgRenderStorage::drawShape(WgContext& context, WgRenderDataShape* renderDat
     assert(renderData);
     assert(mRenderPassEncoder);
     assert(renderData->meshGroupShapes.meshes.count == renderData->meshGroupShapesBBox.meshes.count);
+    if (renderData->renderSettingsShape.skip) return;
     // draw shape geometry
     wgpuRenderPassEncoderSetStencilReference(mRenderPassEncoder, 0);
     // setup fill rule
@@ -139,6 +140,7 @@ void WgRenderStorage::drawStroke(WgContext& context, WgRenderDataShape* renderDa
     assert(renderData);
     assert(mRenderPassEncoder);
     assert(renderData->meshGroupStrokes.meshes.count == renderData->meshGroupStrokesBBox.meshes.count);
+    if (renderData->renderSettingsStroke.skip) return;
     // draw stroke geometry
     uint8_t blend = (uint8_t)blendType;
     // draw strokes to stencil (first pass)
diff --git a/src/renderer/wg_engine/tvgWgRenderer.cpp b/src/renderer/wg_engine/tvgWgRenderer.cpp
index e9cb030f..b59327e6 100644
--- a/src/renderer/wg_engine/tvgWgRenderer.cpp
+++ b/src/renderer/wg_engine/tvgWgRenderer.cpp
@@ -89,6 +89,7 @@ RenderData WgRenderer::prepare(const RenderShape& rshape, RenderData data, const
     }
 
     // setup fill settings
+    renderDataShape->opacity = opacity;
     renderDataShape->renderSettingsShape.update(mContext, rshape.fill, rshape.color, flags);
     if (rshape.stroke)
         renderDataShape->renderSettingsStroke.update(mContext, rshape.stroke->fill, rshape.stroke->color, flags);
@@ -111,6 +112,7 @@ RenderData WgRenderer::prepare(Surface* surface, const RenderMesh* mesh, RenderD
         renderDataPicture = new WgRenderDataPicture();
 
     // update paint settings
+    renderDataPicture->opacity = opacity;
     if (flags & (RenderUpdateFlag::Transform | RenderUpdateFlag::Blend)) {
         WgShaderTypeMat4x4f modelMat(transform);
         WgShaderTypeBlendSettings blendSettings(surface->cs, opacity);
@@ -150,6 +152,7 @@ bool WgRenderer::preRender()
 bool WgRenderer::renderShape(RenderData data)
 {
     // get current render storage
+    if (((WgRenderDataShape*)data)->opacity == 0) return 0;
     WgPipelineBlendType blendType = WgPipelines::blendMethodToBlendType(mBlendMethod);
     WgRenderStorage* renderStorage = mRenderStorageStack.last();
     assert(renderStorage);