Add text unit to glyph unit conversion to CPDF_Type3Char.

Use it in type 3 font code.

Change-Id: I8b0eb462cc0308f1700d21a62efc929babae8e20
Reviewed-on: https://pdfium-review.googlesource.com/20215
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

3 files changed, 39 insertions, 24 deletions

diff --git a/core/fpdfapi/font/cpdf_type3char.cpp b/core/fpdfapi/font/cpdf_type3char.cpp
index eea3d9a86e..f1448ab751 100644
--- a/core/fpdfapi/font/cpdf_type3char.cpp
+++ b/core/fpdfapi/font/cpdf_type3char.cpp
@@ -14,11 +14,27 @@
 #include "core/fpdfapi/page/cpdf_pageobject.h"
 #include "core/fxge/fx_dib.h"
 
+namespace {
+
+constexpr float kTextUnitInGlyphUnit = 1000.0f;
+
+}  // namespace
+
 CPDF_Type3Char::CPDF_Type3Char(std::unique_ptr<CPDF_Form> pForm)
     : m_pForm(std::move(pForm)) {}
 
 CPDF_Type3Char::~CPDF_Type3Char() {}
 
+// static
+float CPDF_Type3Char::TextUnitToGlyphUnit(float fTextUnit) {
+  return fTextUnit * kTextUnitInGlyphUnit;
+}
+
+// static
+void CPDF_Type3Char::TextUnitRectToGlyphUnitRect(CFX_FloatRect* pRect) {
+  pRect->Scale(kTextUnitInGlyphUnit);
+}
+
 bool CPDF_Type3Char::LoadBitmap(CPDF_RenderContext* pContext) {
   if (m_pBitmap || !m_pForm)
     return true;
@@ -53,27 +69,25 @@ bool CPDF_Type3Char::LoadBitmap(CPDF_RenderContext* pContext) {
 void CPDF_Type3Char::InitializeFromStreamData(bool bColored,
                                               const float* pData) {
   m_bColored = bColored;
-  m_Width = FXSYS_round(pData[0] * 1000);
-  m_BBox.left = FXSYS_round(pData[2] * 1000);
-  m_BBox.bottom = FXSYS_round(pData[3] * 1000);
-  m_BBox.right = FXSYS_round(pData[4] * 1000);
-  m_BBox.top = FXSYS_round(pData[5] * 1000);
+  m_Width = FXSYS_round(TextUnitToGlyphUnit(pData[0]));
+  m_BBox.left = FXSYS_round(TextUnitToGlyphUnit(pData[2]));
+  m_BBox.bottom = FXSYS_round(TextUnitToGlyphUnit(pData[3]));
+  m_BBox.right = FXSYS_round(TextUnitToGlyphUnit(pData[4]));
+  m_BBox.top = FXSYS_round(TextUnitToGlyphUnit(pData[5]));
 }
 
 void CPDF_Type3Char::Transform(const CFX_Matrix& matrix) {
   m_Width = m_Width * matrix.GetXUnit() + 0.5f;
-  CFX_FloatRect char_rect(static_cast<float>(m_BBox.left) / 1000.0f,
-                          static_cast<float>(m_BBox.bottom) / 1000.0f,
-                          static_cast<float>(m_BBox.right) / 1000.0f,
-                          static_cast<float>(m_BBox.top) / 1000.0f);
-  if (m_BBox.right <= m_BBox.left || m_BBox.bottom >= m_BBox.top)
+
+  CFX_FloatRect char_rect;
+  if (m_BBox.right <= m_BBox.left || m_BBox.bottom >= m_BBox.top) {
     char_rect = form()->CalcBoundingBox();
+    TextUnitRectToGlyphUnitRect(&char_rect);
+  } else {
+    char_rect = CFX_FloatRect(m_BBox);
+  }
 
-  char_rect = matrix.TransformRect(char_rect);
-  m_BBox.left = FXSYS_round(char_rect.left * 1000);
-  m_BBox.right = FXSYS_round(char_rect.right * 1000);
-  m_BBox.top = FXSYS_round(char_rect.top * 1000);
-  m_BBox.bottom = FXSYS_round(char_rect.bottom * 1000);
+  m_BBox = matrix.TransformRect(char_rect).ToRoundedFxRect();
 }
 
 void CPDF_Type3Char::ResetForm() {
diff --git a/core/fpdfapi/font/cpdf_type3char.h b/core/fpdfapi/font/cpdf_type3char.h
index 7661817b1f..2aec16a0eb 100644
--- a/core/fpdfapi/font/cpdf_type3char.h
+++ b/core/fpdfapi/font/cpdf_type3char.h
@@ -22,6 +22,9 @@ class CPDF_Type3Char {
   explicit CPDF_Type3Char(std::unique_ptr<CPDF_Form> pForm);
   ~CPDF_Type3Char();
 
+  static float TextUnitToGlyphUnit(float fTextUnit);
+  static void TextUnitRectToGlyphUnitRect(CFX_FloatRect* pRect);
+
   bool LoadBitmap(CPDF_RenderContext* pContext);
 
   void InitializeFromStreamData(bool bColored, const float* pData);
diff --git a/core/fpdfapi/font/cpdf_type3font.cpp b/core/fpdfapi/font/cpdf_type3font.cpp
index 6588493e16..c328c1020d 100644
--- a/core/fpdfapi/font/cpdf_type3font.cpp
+++ b/core/fpdfapi/font/cpdf_type3font.cpp
@@ -54,14 +54,11 @@ bool CPDF_Type3Font::Load() {
 
   CPDF_Array* pBBox = m_pFontDict->GetArrayFor("FontBBox");
   if (pBBox) {
-    m_FontBBox.left =
-        static_cast<int32_t>(pBBox->GetNumberAt(0) * xscale * 1000);
-    m_FontBBox.bottom =
-        static_cast<int32_t>(pBBox->GetNumberAt(1) * yscale * 1000);
-    m_FontBBox.right =
-        static_cast<int32_t>(pBBox->GetNumberAt(2) * xscale * 1000);
-    m_FontBBox.top =
-        static_cast<int32_t>(pBBox->GetNumberAt(3) * yscale * 1000);
+    CFX_FloatRect box(
+        pBBox->GetNumberAt(0) * xscale, pBBox->GetNumberAt(1) * yscale,
+        pBBox->GetNumberAt(2) * xscale, pBBox->GetNumberAt(3) * yscale);
+    CPDF_Type3Char::TextUnitRectToGlyphUnitRect(&box);
+    m_FontBBox = box.ToFxRect();
   }
 
   static constexpr size_t kCharLimit = FX_ArraySize(m_CharWidthL);
@@ -73,7 +70,8 @@ bool CPDF_Type3Font::Load() {
       count = std::min(count, kCharLimit - StartChar);
       for (size_t i = 0; i < count; i++) {
         m_CharWidthL[StartChar + i] =
-            FXSYS_round(pWidthArray->GetNumberAt(i) * xscale * 1000);
+            FXSYS_round(CPDF_Type3Char::TextUnitToGlyphUnit(
+                pWidthArray->GetNumberAt(i) * xscale));
       }
     }
   }