Maybe avoid a copy in CPDF_RenderStatus::SelectClipPath

core/fpdfapi/fpdf_render/fpdf_render.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "core/fpdfapi/fpdf_render/render_int.h"
 
 #include <memory>
 
@@ skipping 635 matching lines @@
     m_pDevice->DrawPath(pPathData, pObj2Device, &stroke_state, 0, 0xffff0000,
                         fill_mode);
   }
 }
 FX_BOOL CPDF_RenderStatus::SelectClipPath(const CPDF_PathObject* pPathObj,
                                           const CFX_Matrix* pObj2Device,
                                           FX_BOOL bStroke) {
   CFX_Matrix path_matrix = pPathObj->m_Matrix;
   path_matrix.Concat(*pObj2Device);
   if (bStroke) {
-    CFX_GraphStateData graphState(*pPathObj->m_GraphState.GetObject());
-    if (m_Options.m_Flags & RENDER_THINLINE) {
-      graphState.m_LineWidth = 0;
-    }
+    CFX_GraphState graphState = pPathObj->m_GraphState;
+    if (m_Options.m_Flags & RENDER_THINLINE)
+      graphState.SetLineWidth(0);
     return m_pDevice->SetClip_PathStroke(pPathObj->m_Path.GetObject(),
-                                         &path_matrix, &graphState);
+                                         &path_matrix, graphState.GetObject());

[dsinclair, 2016/09/07 12:55:40]

Is this copy needed or can the CFX_GraphState be passed through here as well?

[Tom Sepez, 2016/09/07 16:35:11]

I'll get to that eventually.  Turns out the m_pDevice methods don't modify the
object, but having it peek at the internals isn't desirable.

   }
   int fill_mode = pPathObj->m_FillType;
   if (m_Options.m_Flags & RENDER_NOPATHSMOOTH) {
     fill_mode |= FXFILL_NOPATHSMOOTH;
   }
   return m_pDevice->SetClip_PathFill(pPathObj->m_Path.GetObject(), &path_matrix,
                                      fill_mode);
 }
 FX_BOOL CPDF_RenderStatus::ProcessTransparency(CPDF_PageObject* pPageObj,
                                                const CFX_Matrix* pObj2Device) {
@@ skipping 605 matching lines @@
     m_pDevice->StretchDIBits(m_pBitmapDevice->GetBitmap(), m_Rect.left,
                              m_Rect.top, m_Rect.Width(), m_Rect.Height());
   }
 }
 
 #if defined _SKIA_SUPPORT_
 void CPDF_RenderStatus::DebugVerifyDeviceIsPreMultiplied() const {
   m_pDevice->DebugVerifyBitmapIsPreMultiplied();
 }
 #endif