diff --git a/ArchitectureColoredPainting/res/Shaders/element.comp b/ArchitectureColoredPainting/res/Shaders/element.comp
index 67700fa..f50abd8 100644
--- a/ArchitectureColoredPainting/res/Shaders/element.comp
+++ b/ArchitectureColoredPainting/res/Shaders/element.comp
@@ -1110,8 +1110,6 @@ void main()
             bool onVeryEnd = false;
             vec2 tangentEndLast = vec2(0);
             vec2 tangentFirstBegin = vec2(0);
-            uint lastHitIndex = 0;
-            bool lastHitElement = false;
             hitElement = false;
             for (uint pathIndex = 0; pathIndex < pathSize; pathIndex++)
             {
@@ -1182,9 +1180,6 @@ void main()
                 float localWidth = strokeWidth; // * mix(lengthRate.x, lengthRate.y, t);
                 if (d <= localWidth)
                 {
-                    // bool onBegin = true;
-                    // bool onEnd = true;
-
                     bool hit = d < minDistance;
                     hit = hit && shouldFillBeginCap(localUV, onVeryBegin, endType, p[0], tangentBegin, tangentEndLast,
                                                     localWidth);
@@ -1205,8 +1200,6 @@ void main()
                         if (lineType == 2 || (intTest % 2 == int(lineType)))
                         {
                             minDistance = min(minDistance, d);
-                            lastHitElement = hitElement;
-                            lastHitIndex = pathIndex;
                             hitElement = true;
                             // elementColor = vec4(1, 1, 0, 1);
                             vec2 metallicRoughness;
diff --git a/ArchitectureColoredPainting/res/Shaders/painting.comp b/ArchitectureColoredPainting/res/Shaders/painting.comp
index 150321d..6c79a8b 100644
--- a/ArchitectureColoredPainting/res/Shaders/painting.comp
+++ b/ArchitectureColoredPainting/res/Shaders/painting.comp
@@ -1156,6 +1156,27 @@ vec2 getLineTangentEnd(uint contourIterator, uint linesOffset, uint pointsOffset
         return normalize(p[3] - p[1]);
 }
 
+mat4x2 getPointsByContourIterator(uint contourIterator, uint linesOffset, uint pointsOffset)
+{
+    uint lineIndex = elementIndexs[contourIterator];
+    uint pLocation = linesOffset + 3 * lineIndex;
+    vec2 percent = unpackUnorm2x16(elementIndexs[pLocation + 2]);
+    uvec4 pxIndex =
+        uvec4(pointsOffset) + 2 * uvec4(elementIndexs[pLocation] >> 16, elementIndexs[pLocation] & 0xFFFF,
+                                        elementIndexs[pLocation + 1] >> 16, elementIndexs[pLocation + 1] & 0xFFFF);
+    uvec4 pyIndex = uvec4(1) + pxIndex;
+
+    mat4x2 p =
+        mat4x2(elementData[pxIndex[0]], elementData[pyIndex[0]], elementData[pxIndex[1]], elementData[pyIndex[1]],
+               elementData[pxIndex[2]], elementData[pyIndex[2]], elementData[pxIndex[3]], elementData[pyIndex[3]]);
+    if (p[0] == p[1] && p[2] == p[3])
+    {
+        p[1] = (p[0] + p[3]) / 2;
+        p[2] = p[1];
+    }
+    return p;
+}
+
 bool strokeElement(vec2 localUV, uint contourIndex, uint linesOffset, uint pointsOffset, uint styleIndex,
                    inout vec4 elementColor, inout vec2 metallicRoughness)
 {
@@ -1177,64 +1198,21 @@ bool strokeElement(vec2 localUV, uint contourIndex, uint linesOffset, uint point
 
     bool onVeryBegin = false;
     bool onVeryEnd = false;
-    if (endType != 4 /*StrokeEndType::kClosed*/)
-        onVeryBegin = true;
 
     for (uint contourIterator_ = contourIndex + 1; contourIterator_ < contourIndex + 1 + lineCount; contourIterator_++)
     {
         uint contourIterator = contourIterator_;
-        uint lineIndex = elementIndexs[contourIterator];
-        uint pLocation = linesOffset + 3 * lineIndex;
-        vec2 percent = unpackUnorm2x16(elementIndexs[pLocation + 2]);
-        uvec4 pxIndex =
-            uvec4(pointsOffset) + 2 * uvec4(elementIndexs[pLocation] >> 16, elementIndexs[pLocation] & 0xFFFF,
-                                            elementIndexs[pLocation + 1] >> 16, elementIndexs[pLocation + 1] & 0xFFFF);
-        uvec4 pyIndex = uvec4(1) + pxIndex;
+        mat4x2 p = getPointsByContourIterator(contourIterator, linesOffset, pointsOffset);
 
-        mat4x2 p =
-            mat4x2(elementData[pxIndex[0]], elementData[pyIndex[0]], elementData[pxIndex[1]], elementData[pyIndex[1]],
-                   elementData[pxIndex[2]], elementData[pyIndex[2]], elementData[pxIndex[3]], elementData[pyIndex[3]]);
-
-        vec2 tangentBeginNext = vec2(0);
-        if (contourIterator + 1 < contourIndex + 1 + lineCount)
+        if ((contourIterator == contourIndex + 1))
         {
-            uint lineIndex = elementIndexs[contourIterator + 1];
-            uint pLocation = linesOffset + 3 * lineIndex;
-            // vec2 percent = unpackUnorm2x16(elementIndexs[pLocation + 2]);
-            uvec4 pxIndex = uvec4(pointsOffset) +
-                            2 * uvec4(elementIndexs[pLocation] >> 16, elementIndexs[pLocation] & 0xFFFF,
-                                      elementIndexs[pLocation + 1] >> 16, elementIndexs[pLocation + 1] & 0xFFFF);
-            uvec4 pyIndex = uvec4(1) + pxIndex;
-
-            mat4x2 pNext = mat4x2(elementData[pxIndex[0]], elementData[pyIndex[0]], elementData[pxIndex[1]],
-                                  elementData[pyIndex[1]], elementData[pxIndex[2]], elementData[pyIndex[2]],
-                                  elementData[pxIndex[3]], elementData[pyIndex[3]]);
-
-            if (pNext[0] == pNext[1] && pNext[2] == pNext[3])
-            {
-                pNext[1] = (pNext[0] + pNext[3]) / 2;
-                pNext[2] = pNext[1];
-            }
-
-            if (pNext[0] != pNext[1])
-                tangentBeginNext = normalize(pNext[0] - pNext[1]);
-            else
-                tangentBeginNext = normalize(pNext[0] - pNext[2]);
+            if (endType != 4 /*StrokeEndType::kClosed*/)
+                onVeryBegin = true;
         }
-        else
+        else if (p[0] != p3Last)
         {
-            if (endType == 4 /*StrokeEndType::kClosed*/)
-                tangentBeginNext = tangentFirstBegin;
-            else
-                onVeryEnd = true;
+            onVeryBegin = true;
         }
-
-        if (p[0] == p[1] && p[2] == p[3])
-        {
-            p[1] = (p[0] + p[3]) / 2;
-            p[2] = p[1];
-        }
-
         if (distance(localUV, p[0]) <= 0.001)
         {
             if (p3Last == p[0])
@@ -1254,6 +1232,41 @@ bool strokeElement(vec2 localUV, uint contourIndex, uint linesOffset, uint point
         else
             tangentEnd = normalize(p[3] - p[1]);
 
+        vec2 tangentBeginNext = vec2(0);
+        if (contourIterator + 1 < contourIndex + 1 + lineCount)
+        {
+            mat4x2 pNext = getPointsByContourIterator(contourIterator + 1, linesOffset, pointsOffset);
+
+            if (pNext[0] == p[3])
+            {
+                onVeryEnd = false;
+                if (pNext[0] != pNext[1])
+                    tangentBeginNext = normalize(pNext[0] - pNext[1]);
+                else
+                    tangentBeginNext = normalize(pNext[0] - pNext[2]);
+            }
+            else
+            {
+                if (endType == 4 /*StrokeEndType::kClosed*/)
+                {
+                    onVeryEnd = false;
+                    tangentBeginNext = tangentBegin;
+                }
+                else
+                    onVeryEnd = true;
+            }
+        }
+        else
+        {
+            if (endType == 4 /*StrokeEndType::kClosed*/)
+            {
+                onVeryEnd = false;
+                tangentBeginNext = tangentFirstBegin;
+            }
+            else
+                onVeryEnd = true;
+        }
+
         float d = cubic_bezier_dis(localUV, p[0], p[1], p[2], p[3], true);
         if (d <= strokeWidth)
         {
@@ -1263,8 +1276,11 @@ bool strokeElement(vec2 localUV, uint contourIndex, uint linesOffset, uint point
             hit = hit && shouldFillEndCap(localUV, onVeryEnd, endType, p[3], tangentEnd, tangentBeginNext, strokeWidth);
             if (hit)
             {
-
                 bool reverse = p[3].y - p[0].y < 0.;
+                if (tangentBegin.y == 0.)
+                    tangentBegin.y = reverse ? eps : -eps;
+                if (tangentEnd.y == 0.)
+                    tangentEnd.y = reverse ? -eps : eps;
                 int intTest = cubic_bezier_int_test2(localUV, p[0], p[1], p[2], p[3], reverse) +
                               ray_int_test(localUV, p[0], tangentBegin, reverse) +
                               ray_int_test(localUV, p[3], tangentEnd, reverse);