Calculate AP for multi-line markup annotations correctly

Currently, when constructing AP for multi-line markup annotations, we
only take into account the first set of quadpoints, resulting in only
the first line of the annotation being displayed if the annotation spans
multiple lines.

This CL, initially written by Jane Liu <janeliulwq@google.com>
(https://pdfium-review.googlesource.com/12010) takes into account all
the quadpoints, so multi-line annotations can be displayed correctly.

BUG=pdfium:876

Change-Id: I8be10ee38e01eb6525ddef556df1b727189455c7
Reviewed-on: https://pdfium-review.googlesource.com/28590
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

1 files changed, 65 insertions, 47 deletions

diff --git a/core/fpdfdoc/cpvt_generateap.cpp b/core/fpdfdoc/cpvt_generateap.cpp
index eb3e22d870..e2fbcc9720 100644
--- a/core/fpdfdoc/cpvt_generateap.cpp
+++ b/core/fpdfdoc/cpvt_generateap.cpp
@@ -519,7 +519,7 @@ void GenerateAndSetAPDict(CPDF_Document* pDoc,
   pStreamDict->SetMatrixFor("Matrix", CFX_Matrix());
 
   CFX_FloatRect rect = bIsTextMarkupAnnotation
-                           ? CPDF_Annot::RectFromQuadPoints(pAnnotDict)
+                           ? CPDF_Annot::BoundingRectFromQuadPoints(pAnnotDict)
                            : pAnnotDict->GetRectFor("Rect");
   pStreamDict->SetRectFor("BBox", rect);
   pStreamDict->SetFor("Resources", std::move(pResourceDict));
@@ -606,13 +606,18 @@ bool GenerateHighlightAP(CPDF_Document* pDoc, CPDF_Dictionary* pAnnotDict) {
                                           CFX_Color(CFX_Color::kRGB, 1, 1, 0),
                                           PaintOperation::FILL);
 
-  CFX_FloatRect rect = CPDF_Annot::RectFromQuadPoints(pAnnotDict);
-  rect.Normalize();
+  CPDF_Array* pArray = pAnnotDict->GetArrayFor("QuadPoints");
+  if (pArray) {
+    size_t nQuadPointCount = CPDF_Annot::QuadPointCount(pArray);
+    for (size_t i = 0; i < nQuadPointCount; ++i) {
+      CFX_FloatRect rect = CPDF_Annot::RectFromQuadPoints(pAnnotDict, i);
+      rect.Normalize();
 
-  sAppStream << rect.left << " " << rect.top << " m " << rect.right << " "
-             << rect.top << " l " << rect.right << " " << rect.bottom << " l "
-             << rect.left << " " << rect.bottom << " l "
-             << "h f\n";
+      sAppStream << rect.left << " " << rect.top << " m " << rect.right << " "
+                 << rect.top << " l " << rect.right << " " << rect.bottom
+                 << " l " << rect.left << " " << rect.bottom << " l h f\n";
+    }
+  }
 
   auto pExtGStateDict =
       GenerateExtGStateDict(*pAnnotDict, sExtGSDictName, "Multiply");
@@ -708,13 +713,18 @@ bool GenerateUnderlineAP(CPDF_Document* pDoc, CPDF_Dictionary* pAnnotDict) {
                                           CFX_Color(CFX_Color::kRGB, 0, 0, 0),
                                           PaintOperation::STROKE);
 
-  CFX_FloatRect rect = CPDF_Annot::RectFromQuadPoints(pAnnotDict);
-  rect.Normalize();
-
-  float fLineWidth = 1.0;
-  sAppStream << fLineWidth << " w " << rect.left << " "
-             << rect.bottom + fLineWidth << " m " << rect.right << " "
-             << rect.bottom + fLineWidth << " l S\n";
+  CPDF_Array* pArray = pAnnotDict->GetArrayFor("QuadPoints");
+  if (pArray) {
+    static constexpr float kLineWidth = 1.0f;
+    sAppStream << kLineWidth << " w ";
+    size_t nQuadPointCount = CPDF_Annot::QuadPointCount(pArray);
+    for (size_t i = 0; i < nQuadPointCount; ++i) {
+      CFX_FloatRect rect = CPDF_Annot::RectFromQuadPoints(pAnnotDict, i);
+      rect.Normalize();
+      sAppStream << rect.left << " " << rect.bottom + kLineWidth << " m "
+                 << rect.right << " " << rect.bottom + kLineWidth << " l S\n";
+    }
+  }
 
   auto pExtGStateDict =
       GenerateExtGStateDict(*pAnnotDict, sExtGSDictName, "Normal");
@@ -817,36 +827,38 @@ bool GenerateSquigglyAP(CPDF_Document* pDoc, CPDF_Dictionary* pAnnotDict) {
                                           CFX_Color(CFX_Color::kRGB, 0, 0, 0),
                                           PaintOperation::STROKE);
 
-  CFX_FloatRect rect = CPDF_Annot::RectFromQuadPoints(pAnnotDict);
-  rect.Normalize();
-
-  float fLineWidth = 1.0;
-  sAppStream << fLineWidth << " w ";
-
-  const float fDelta = 2.0;
-  const float fTop = rect.bottom + fDelta;
-  const float fBottom = rect.bottom;
-
-  sAppStream << rect.left << " " << fTop << " m ";
-
-  float fX = rect.left + fDelta;
-  bool isUpwards = false;
+  CPDF_Array* pArray = pAnnotDict->GetArrayFor("QuadPoints");
+  if (pArray) {
+    static constexpr float kLineWidth = 1.0f;
+    static constexpr float kDelta = 2.0f;
+    sAppStream << kLineWidth << " w ";
+    size_t nQuadPointCount = CPDF_Annot::QuadPointCount(pArray);
+    for (size_t i = 0; i < nQuadPointCount; ++i) {
+      CFX_FloatRect rect = CPDF_Annot::RectFromQuadPoints(pAnnotDict, i);
+      rect.Normalize();
+
+      const float fTop = rect.bottom + kDelta;
+      const float fBottom = rect.bottom;
+      sAppStream << rect.left << " " << fTop << " m ";
+
+      float fX = rect.left + kDelta;
+      bool isUpwards = false;
+      while (fX < rect.right) {
+        sAppStream << fX << " " << (isUpwards ? fTop : fBottom) << " l ";
+        fX += kDelta;
+        isUpwards = !isUpwards;
+      }
 
-  while (fX < rect.right) {
-    sAppStream << fX << " " << (isUpwards ? fTop : fBottom) << " l ";
+      float fRemainder = rect.right - (fX - kDelta);
+      if (isUpwards)
+        sAppStream << rect.right << " " << fBottom + fRemainder << " l ";
+      else
+        sAppStream << rect.right << " " << fTop - fRemainder << " l ";
 
-    fX += fDelta;
-    isUpwards = !isUpwards;
+      sAppStream << "S\n";
+    }
   }
 
-  float fRemainder = rect.right - (fX - fDelta);
-  if (isUpwards)
-    sAppStream << rect.right << " " << fBottom + fRemainder << " l ";
-  else
-    sAppStream << rect.right << " " << fTop - fRemainder << " l ";
-
-  sAppStream << "S\n";
-
   auto pExtGStateDict =
       GenerateExtGStateDict(*pAnnotDict, sExtGSDictName, "Normal");
   auto pResourceDict =
@@ -865,13 +877,19 @@ bool GenerateStrikeOutAP(CPDF_Document* pDoc, CPDF_Dictionary* pAnnotDict) {
                                           CFX_Color(CFX_Color::kRGB, 0, 0, 0),
                                           PaintOperation::STROKE);
 
-  CFX_FloatRect rect = CPDF_Annot::RectFromQuadPoints(pAnnotDict);
-  rect.Normalize();
-
-  float fLineWidth = 1.0;
-  float fY = (rect.top + rect.bottom) / 2;
-  sAppStream << fLineWidth << " w " << rect.left << " " << fY << " m "
-             << rect.right << " " << fY << " l S\n";
+  CPDF_Array* pArray = pAnnotDict->GetArrayFor("QuadPoints");
+  if (pArray) {
+    static constexpr float kLineWidth = 1.0f;
+    size_t nQuadPointCount = CPDF_Annot::QuadPointCount(pArray);
+    for (size_t i = 0; i < nQuadPointCount; ++i) {
+      CFX_FloatRect rect = CPDF_Annot::RectFromQuadPoints(pAnnotDict, i);
+      rect.Normalize();
+
+      float fY = (rect.top + rect.bottom) / 2;
+      sAppStream << kLineWidth << " w " << rect.left << " " << fY << " m "
+                 << rect.right << " " << fY << " l S\n";
+    }
+  }
 
   auto pExtGStateDict =
       GenerateExtGStateDict(*pAnnotDict, sExtGSDictName, "Normal");