Cleanup CPDF_MeshStream

This CL converts the MeshVertex to a point and the TransformPoint to the
CFX_PointF override.

Change-Id: I3faa5c14cedcf5af6aafca1c566acbc68577cca7
Reviewed-on: https://pdfium-review.googlesource.com/2610
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: Nicolás Peña <npm@chromium.org>

3 files changed, 63 insertions, 41 deletions

diff --git a/core/fpdfapi/page/cpdf_meshstream.cpp b/core/fpdfapi/page/cpdf_meshstream.cpp
index b852901794..75069cab7f 100644
--- a/core/fpdfapi/page/cpdf_meshstream.cpp
+++ b/core/fpdfapi/page/cpdf_meshstream.cpp
@@ -83,6 +83,12 @@ bool IsValidBitsPerFlag(uint32_t x) {
 
 }  // namespace
 
+CPDF_MeshVertex::CPDF_MeshVertex() = default;
+
+CPDF_MeshVertex::CPDF_MeshVertex(const CPDF_MeshVertex&) = default;
+
+CPDF_MeshVertex::~CPDF_MeshVertex() = default;
+
 CPDF_MeshStream::CPDF_MeshStream(
     ShadingType type,
     const std::vector<std::unique_ptr<CPDF_Function>>& funcs,
@@ -148,37 +154,47 @@ bool CPDF_MeshStream::Load() {
   return true;
 }
 
-uint32_t CPDF_MeshStream::GetFlag() {
+uint32_t CPDF_MeshStream::ReadFlag() {
   ASSERT(ShouldCheckBitsPerFlag(m_type));
   return m_BitStream.GetBits(m_nFlagBits) & 0x03;
 }
 
-void CPDF_MeshStream::GetCoords(FX_FLOAT& x, FX_FLOAT& y) {
+CFX_PointF CPDF_MeshStream::ReadCoords() {
   ASSERT(ShouldCheckBPC(m_type));
+
+  CFX_PointF pos;
   if (m_nCoordBits == 32) {
-    x = m_xmin + (FX_FLOAT)(m_BitStream.GetBits(m_nCoordBits) *
-                            (m_xmax - m_xmin) / (double)m_CoordMax);
-    y = m_ymin + (FX_FLOAT)(m_BitStream.GetBits(m_nCoordBits) *
-                            (m_ymax - m_ymin) / (double)m_CoordMax);
+    pos.x = m_xmin +
+            m_BitStream.GetBits(m_nCoordBits) * (m_xmax - m_xmin) /
+                static_cast<double>(m_CoordMax);
+    pos.y = m_ymin +
+            m_BitStream.GetBits(m_nCoordBits) * (m_ymax - m_ymin) /
+                static_cast<double>(m_CoordMax);
   } else {
-    x = m_xmin +
-        m_BitStream.GetBits(m_nCoordBits) * (m_xmax - m_xmin) / m_CoordMax;
-    y = m_ymin +
-        m_BitStream.GetBits(m_nCoordBits) * (m_ymax - m_ymin) / m_CoordMax;
+    pos.x = m_xmin +
+            m_BitStream.GetBits(m_nCoordBits) * (m_xmax - m_xmin) / m_CoordMax;
+    pos.y = m_ymin +
+            m_BitStream.GetBits(m_nCoordBits) * (m_ymax - m_ymin) / m_CoordMax;
   }
+  return pos;
 }
 
-void CPDF_MeshStream::GetColor(FX_FLOAT& r, FX_FLOAT& g, FX_FLOAT& b) {
+std::tuple<FX_FLOAT, FX_FLOAT, FX_FLOAT> CPDF_MeshStream::ReadColor() {
   ASSERT(ShouldCheckBPC(m_type));
+
   FX_FLOAT color_value[kMaxComponents];
   for (uint32_t i = 0; i < m_nComponents; ++i) {
     color_value[i] = m_ColorMin[i] +
                      m_BitStream.GetBits(m_nComponentBits) *
                          (m_ColorMax[i] - m_ColorMin[i]) / m_ComponentMax;
   }
+
+  FX_FLOAT r;
+  FX_FLOAT g;
+  FX_FLOAT b;
   if (m_funcs.empty()) {
     m_pCS->GetRGB(color_value, r, g, b);
-    return;
+    return std::tuple<FX_FLOAT, FX_FLOAT, FX_FLOAT>(r, g, b);
   }
 
   FX_FLOAT result[kMaxComponents];
@@ -188,29 +204,32 @@ void CPDF_MeshStream::GetColor(FX_FLOAT& r, FX_FLOAT& g, FX_FLOAT& b) {
     if (func && func->CountOutputs() <= kMaxComponents)
       func->Call(color_value, 1, result, nResults);
   }
+
   m_pCS->GetRGB(result, r, g, b);
+  return std::tuple<FX_FLOAT, FX_FLOAT, FX_FLOAT>(r, g, b);
 }
 
-uint32_t CPDF_MeshStream::GetVertex(CPDF_MeshVertex& vertex,
-                                    CFX_Matrix* pObject2Bitmap) {
-  uint32_t flag = GetFlag();
-  GetCoords(vertex.x, vertex.y);
-  pObject2Bitmap->TransformPoint(vertex.x, vertex.y);
-  GetColor(vertex.r, vertex.g, vertex.b);
+CPDF_MeshVertex CPDF_MeshStream::ReadVertex(const CFX_Matrix& pObject2Bitmap,
+                                            uint32_t* flag) {
+  *flag = ReadFlag();
+
+  CPDF_MeshVertex vertex;
+  vertex.position = pObject2Bitmap.Transform(ReadCoords());
+  std::tie(vertex.r, vertex.g, vertex.b) = ReadColor();
   m_BitStream.ByteAlign();
-  return flag;
+
+  return vertex;
 }
 
-bool CPDF_MeshStream::GetVertexRow(CPDF_MeshVertex* vertex,
-                                   int count,
-                                   CFX_Matrix* pObject2Bitmap) {
+bool CPDF_MeshStream::ReadVertexRow(const CFX_Matrix& pObject2Bitmap,
+                                    int count,
+                                    CPDF_MeshVertex* vertex) {
   for (int i = 0; i < count; i++) {
     if (m_BitStream.IsEOF())
       return false;
 
-    GetCoords(vertex[i].x, vertex[i].y);
-    pObject2Bitmap->TransformPoint(vertex[i].x, vertex[i].y);
-    GetColor(vertex[i].r, vertex[i].g, vertex[i].b);
+    vertex[i].position = pObject2Bitmap.Transform(ReadCoords());
+    std::tie(vertex[i].r, vertex[i].g, vertex[i].b) = ReadColor();
     m_BitStream.ByteAlign();
   }
   return true;
diff --git a/core/fpdfapi/page/cpdf_meshstream.h b/core/fpdfapi/page/cpdf_meshstream.h
index 21a6c2fa8c..24f1d66cfd 100644
--- a/core/fpdfapi/page/cpdf_meshstream.h
+++ b/core/fpdfapi/page/cpdf_meshstream.h
@@ -8,6 +8,7 @@
 #define CORE_FPDFAPI_PAGE_CPDF_MESHSTREAM_H_
 
 #include <memory>
+#include <tuple>
 #include <vector>
 
 #include "core/fpdfapi/page/cpdf_shadingpattern.h"
@@ -15,9 +16,13 @@
 #include "core/fxcrt/fx_basic.h"
 #include "core/fxcrt/fx_system.h"
 
-struct CPDF_MeshVertex {
-  FX_FLOAT x;
-  FX_FLOAT y;
+class CPDF_MeshVertex {
+ public:
+  CPDF_MeshVertex();
+  CPDF_MeshVertex(const CPDF_MeshVertex&);
+  ~CPDF_MeshVertex();
+
+  CFX_PointF position;
   FX_FLOAT r;
   FX_FLOAT g;
   FX_FLOAT b;
@@ -37,14 +42,14 @@ class CPDF_MeshStream {
 
   bool Load();
 
-  uint32_t GetFlag();
-  void GetCoords(FX_FLOAT& x, FX_FLOAT& y);
-  void GetColor(FX_FLOAT& r, FX_FLOAT& g, FX_FLOAT& b);
+  uint32_t ReadFlag();
+  CFX_PointF ReadCoords();
+  std::tuple<FX_FLOAT, FX_FLOAT, FX_FLOAT> ReadColor();
 
-  uint32_t GetVertex(CPDF_MeshVertex& vertex, CFX_Matrix* pObject2Bitmap);
-  bool GetVertexRow(CPDF_MeshVertex* vertex,
-                    int count,
-                    CFX_Matrix* pObject2Bitmap);
+  CPDF_MeshVertex ReadVertex(const CFX_Matrix& pObject2Bitmap, uint32_t* flag);
+  bool ReadVertexRow(const CFX_Matrix& pObject2Bitmap,
+                     int count,
+                     CPDF_MeshVertex* vertex);
 
   CFX_BitStream* BitStream() { return &m_BitStream; }
   uint32_t ComponentBits() const { return m_nComponentBits; }
diff --git a/core/fpdfapi/page/cpdf_streamcontentparser.cpp b/core/fpdfapi/page/cpdf_streamcontentparser.cpp
index 21b13772c5..af5b88fead 100644
--- a/core/fpdfapi/page/cpdf_streamcontentparser.cpp
+++ b/core/fpdfapi/page/cpdf_streamcontentparser.cpp
@@ -99,7 +99,7 @@ CFX_FloatRect GetShadingBBox(CPDF_ShadingPattern* pShading,
   while (!stream.BitStream()->IsEOF()) {
     uint32_t flag = 0;
     if (type != kLatticeFormGouraudTriangleMeshShading)
-      flag = stream.GetFlag();
+      flag = stream.ReadFlag();
 
     if (!bGouraud && flag) {
       point_count -= 4;
@@ -107,13 +107,11 @@ CFX_FloatRect GetShadingBBox(CPDF_ShadingPattern* pShading,
     }
 
     for (int i = 0; i < point_count; i++) {
-      FX_FLOAT x;
-      FX_FLOAT y;
-      stream.GetCoords(x, y);
+      CFX_PointF origin = stream.ReadCoords();
       if (bStarted) {
-        rect.UpdateRect(x, y);
+        rect.UpdateRect(origin.x, origin.y);
       } else {
-        rect.InitRect(x, y);
+        rect.InitRect(origin.x, origin.y);
         bStarted = true;
       }
     }