Add return value to FPDF_DeviceToPage().

Do the same for FPDF_PageToDevice(). Clean up the internal
implementation as well.

Change-Id: Ia207bfa779d144cb9f0310e768750ab10e603b8f
Reviewed-on: https://pdfium-review.googlesource.com/17370
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

2 files changed, 18 insertions, 30 deletions

diff --git a/core/fpdfapi/page/cpdf_page.cpp b/core/fpdfapi/page/cpdf_page.cpp
index 06043ead35..259e8ce0fb 100644
--- a/core/fpdfapi/page/cpdf_page.cpp
+++ b/core/fpdfapi/page/cpdf_page.cpp
@@ -118,30 +118,21 @@ CFX_FloatRect CPDF_Page::GetBox(const ByteString& name) const {
   return box;
 }
 
-void CPDF_Page::DeviceToPage(const FX_RECT& rect,
-                             int rotate,
-                             const CFX_PointF& device_point,
-                             double* page_x,
-                             double* page_y) const {
+Optional<CFX_PointF> CPDF_Page::DeviceToPage(
+    const FX_RECT& rect,
+    int rotate,
+    const CFX_PointF& device_point) const {
   CFX_Matrix page2device = GetDisplayMatrix(rect, rotate);
-  CFX_PointF pos = page2device.GetInverse().Transform(device_point);
-
-  *page_x = pos.x;
-  *page_y = pos.y;
+  return page2device.GetInverse().Transform(device_point);
 }
 
-void CPDF_Page::PageToDevice(const FX_RECT& rect,
-                             int rotate,
-                             double page_x,
-                             double page_y,
-                             int* device_x,
-                             int* device_y) const {
+Optional<CFX_PointF> CPDF_Page::PageToDevice(const FX_RECT& rect,
+                                             int rotate,
+                                             double page_x,
+                                             double page_y) const {
   CFX_Matrix page2device = GetDisplayMatrix(rect, rotate);
-  CFX_PointF pos = page2device.Transform(
+  return page2device.Transform(
       CFX_PointF(static_cast<float>(page_x), static_cast<float>(page_y)));
-
-  *device_x = FXSYS_round(pos.x);
-  *device_y = FXSYS_round(pos.y);
 }
 
 CFX_Matrix CPDF_Page::GetDisplayMatrix(const FX_RECT& rect, int iRotate) const {
diff --git a/core/fpdfapi/page/cpdf_page.h b/core/fpdfapi/page/cpdf_page.h
index d199ea41db..34c9ef45a8 100644
--- a/core/fpdfapi/page/cpdf_page.h
+++ b/core/fpdfapi/page/cpdf_page.h
@@ -12,6 +12,7 @@
 #include "core/fpdfapi/page/cpdf_pageobjectholder.h"
 #include "core/fxcrt/fx_coordinates.h"
 #include "core/fxcrt/fx_system.h"
+#include "third_party/base/optional.h"
 
 class CPDF_Dictionary;
 class CPDF_Document;
@@ -33,17 +34,13 @@ class CPDF_Page : public CPDF_PageObjectHolder {
 
   void ParseContent();
 
-  void DeviceToPage(const FX_RECT& rect,
-                    int rotate,
-                    const CFX_PointF& device_point,
-                    double* page_x,
-                    double* page_y) const;
-  void PageToDevice(const FX_RECT& rect,
-                    int rotate,
-                    double page_x,
-                    double page_y,
-                    int* device_x,
-                    int* device_y) const;
+  Optional<CFX_PointF> DeviceToPage(const FX_RECT& rect,
+                                    int rotate,
+                                    const CFX_PointF& device_point) const;
+  Optional<CFX_PointF> PageToDevice(const FX_RECT& rect,
+                                    int rotate,
+                                    double page_x,
+                                    double page_y) const;
 
   CFX_Matrix GetDisplayMatrix(const FX_RECT& rect, int iRotate) const;