From a45275b779d461894c705496aab06993de8d5495 Mon Sep 17 00:00:00 2001
From: Hermet Park <hermetpark@gmail.com>
Date: Mon, 10 Apr 2023 22:19:13 +0900
Subject: [PATCH] sw_engine renderer: add clip() interface.

As there are multiple types of painting tasks,
the clip() interface has been newly designed to handle clipping behavior
according to each task's role when requested."

Now Scene clipper could implement clipping behavior on it.
---
 src/lib/sw_engine/tvgSwRenderer.cpp | 42 ++++++++++++++++-------------
 1 file changed, 23 insertions(+), 19 deletions(-)

diff --git a/src/lib/sw_engine/tvgSwRenderer.cpp b/src/lib/sw_engine/tvgSwRenderer.cpp
index e589d618..b4131eac 100644
--- a/src/lib/sw_engine/tvgSwRenderer.cpp
+++ b/src/lib/sw_engine/tvgSwRenderer.cpp
@@ -61,6 +61,7 @@ struct SwTask : Task
     }
 
     virtual bool dispose() = 0;
+    virtual bool clip(SwRleData* target) = 0;
 
     virtual ~SwTask()
     {
@@ -76,6 +77,15 @@ struct SwShapeTask : SwTask
     bool cmpStroking = false;
     bool clipper = false;
 
+    bool clip(SwRleData* target) override
+    {
+        if (shape.fastTrack) rleClipRect(target, &bbox);
+        else if (shape.rle) rleClipPath(target, shape.rle);
+        else return false;
+
+        return true;
+    }
+
     void run(unsigned tid) override
     {    
         if (opacity == 0 && !clipper) return;  //Invisible
@@ -150,22 +160,13 @@ struct SwShapeTask : SwTask
 
         //Clip Path
         for (auto clip = clips.data; clip < (clips.data + clips.count); ++clip) {
+            auto clipper = static_cast<SwTask*>(*clip);
             //Guarantee composition targets get ready.
-            static_cast<SwShapeTask*>(*clip)->done(tid);
-
-            auto clipper = &static_cast<SwShapeTask*>(*clip)->shape;
+            clipper->done(tid);
             //Clip shape rle
-            if (shape.rle) {
-                if (clipper->fastTrack) rleClipRect(shape.rle, &clipper->bbox);
-                else if (clipper->rle) rleClipPath(shape.rle, clipper->rle);
-                else goto err;
-            }
+            if (shape.rle && !clipper->clip(shape.rle)) goto err;
             //Clip stroke rle
-            if (shape.strokeRle) {
-                if (clipper->fastTrack) rleClipRect(shape.strokeRle, &clipper->bbox);
-                else if (clipper->rle) rleClipPath(shape.strokeRle, clipper->rle);
-                else goto err;
-            }
+            if (shape.strokeRle && !clipper->clip(shape.strokeRle)) goto err;
         }
         goto end;
 
@@ -189,6 +190,12 @@ struct SwImageTask : SwTask
     Polygon* triangles;
     uint32_t triangleCnt;
 
+    bool clip(SwRleData* target) override
+    {
+        TVGERR("SW_ENGINE", "Image is used as ClipPath?");
+        return true;
+    }
+
     void run(unsigned tid) override
     {
         auto clipRegion = bbox;
@@ -205,13 +212,10 @@ struct SwImageTask : SwTask
                 if (!imageGenRle(&image, bbox, false)) goto end;
                 if (image.rle) {
                     for (auto clip = clips.data; clip < (clips.data + clips.count); ++clip) {
+                        auto clipper = static_cast<SwTask*>(*clip);
                         //Guarantee composition targets get ready.
-                        static_cast<SwShapeTask*>(*clip)->done(tid);
-
-                        auto clipper = &static_cast<SwShapeTask*>(*clip)->shape;
-                        if (clipper->fastTrack) rleClipRect(image.rle, &clipper->bbox);
-                        else if (clipper->rle) rleClipPath(image.rle, clipper->rle);
-                        else goto err;
+                        clipper->done(tid);
+                        if (!clipper->clip(image.rle)) goto err;
                     }
                 }
             }