Add FPDFPath_GetMatrix() and FPDFPath_SetMatrix() APIs

This is similar to the existing FPDFImageObj_SetMatrix(), but this
exposes the matrix of CPDF_PathObject and provides both a getter and a
setter.

Change-Id: Ib90a64929dae1b2be3889eca57e4af822d7823be
Reviewed-on: https://pdfium-review.googlesource.com/33670
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>

4 files changed, 131 insertions, 0 deletions

diff --git a/fpdfsdk/fpdf_edit_embeddertest.cpp b/fpdfsdk/fpdf_edit_embeddertest.cpp
index f9b165c28d..7ca2174440 100644
--- a/fpdfsdk/fpdf_edit_embeddertest.cpp
+++ b/fpdfsdk/fpdf_edit_embeddertest.cpp
@@ -248,6 +248,36 @@ TEST_F(FPDFEditEmbeddertest, AddPaths) {
   EXPECT_EQ(FPDF_FILLMODE_ALTERNATE, fillmode);
   EXPECT_FALSE(stroke);
 
+  double matrix_a = 1;
+  double matrix_b = 2;
+  double matrix_c = 3;
+  double matrix_d = 4;
+  double matrix_e = 5;
+  double matrix_f = 6;
+  EXPECT_FALSE(FPDFPath_SetMatrix(nullptr, matrix_a, matrix_b, matrix_c,
+                                  matrix_d, matrix_e, matrix_f));
+  EXPECT_TRUE(FPDFPath_SetMatrix(red_rect, matrix_a, matrix_b, matrix_c,
+                                 matrix_d, matrix_e, matrix_f));
+  EXPECT_FALSE(FPDFPath_GetMatrix(nullptr, &matrix_a, &matrix_b, &matrix_c,
+                                  &matrix_d, &matrix_e, &matrix_f));
+  EXPECT_TRUE(FPDFPath_GetMatrix(red_rect, &matrix_a, &matrix_b, &matrix_c,
+                                 &matrix_d, &matrix_e, &matrix_f));
+  EXPECT_EQ(1, static_cast<int>(matrix_a));
+  EXPECT_EQ(2, static_cast<int>(matrix_b));
+  EXPECT_EQ(3, static_cast<int>(matrix_c));
+  EXPECT_EQ(4, static_cast<int>(matrix_d));
+  EXPECT_EQ(5, static_cast<int>(matrix_e));
+  EXPECT_EQ(6, static_cast<int>(matrix_f));
+  // Set back the default
+  matrix_a = 1;
+  matrix_b = 0;
+  matrix_c = 0;
+  matrix_d = 1;
+  matrix_e = 0;
+  matrix_f = 0;
+  EXPECT_TRUE(FPDFPath_SetMatrix(red_rect, matrix_a, matrix_b, matrix_c,
+                                 matrix_d, matrix_e, matrix_f));
+
   FPDFPage_InsertObject(page, red_rect);
   {
     ScopedFPDFBitmap page_bitmap = RenderPageWithFlags(page, nullptr, 0);
diff --git a/fpdfsdk/fpdf_editpath.cpp b/fpdfsdk/fpdf_editpath.cpp
index 7f00b85d7b..70a558d2f1 100644
--- a/fpdfsdk/fpdf_editpath.cpp
+++ b/fpdfsdk/fpdf_editpath.cpp
@@ -236,6 +236,55 @@ FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFPath_GetDrawMode(FPDF_PAGEOBJECT path,
   return true;
 }
 
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFPath_GetMatrix(FPDF_PAGEOBJECT path,
+                                                       double* a,
+                                                       double* b,
+                                                       double* c,
+                                                       double* d,
+                                                       double* e,
+                                                       double* f) {
+  if (!path || !a || !b || !c || !d || !e || !f)
+    return false;
+
+  CPDF_PathObject* pPathObj = CPDFPathObjectFromFPDFPageObject(path);
+  if (!pPathObj)
+    return false;
+
+  *a = pPathObj->m_Matrix.a;
+  *b = pPathObj->m_Matrix.b;
+  *c = pPathObj->m_Matrix.c;
+  *d = pPathObj->m_Matrix.d;
+  *e = pPathObj->m_Matrix.e;
+  *f = pPathObj->m_Matrix.f;
+
+  return true;
+}
+
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFPath_SetMatrix(FPDF_PAGEOBJECT path,
+                                                       double a,
+                                                       double b,
+                                                       double c,
+                                                       double d,
+                                                       double e,
+                                                       double f) {
+  if (!path)
+    return false;
+
+  CPDF_PathObject* pPathObj = CPDFPathObjectFromFPDFPageObject(path);
+  if (!pPathObj)
+    return false;
+
+  pPathObj->m_Matrix.a = a;
+  pPathObj->m_Matrix.b = b;
+  pPathObj->m_Matrix.c = c;
+  pPathObj->m_Matrix.d = d;
+  pPathObj->m_Matrix.e = e;
+  pPathObj->m_Matrix.f = f;
+  pPathObj->SetDirty(true);
+
+  return true;
+}
+
 FPDF_EXPORT void FPDF_CALLCONV FPDFPath_SetLineJoin(FPDF_PAGEOBJECT path,
                                                     int line_join) {
   auto* pPathObj = CPDFPathObjectFromFPDFPageObject(path);
diff --git a/fpdfsdk/fpdf_view_c_api_test.c b/fpdfsdk/fpdf_view_c_api_test.c
index dd97a6e330..34ac5518a3 100644
--- a/fpdfsdk/fpdf_view_c_api_test.c
+++ b/fpdfsdk/fpdf_view_c_api_test.c
@@ -183,6 +183,7 @@ int CheckPDFiumCApi() {
     CHK(FPDFPath_CountSegments);
     CHK(FPDFPath_GetDrawMode);
     CHK(FPDFPath_GetFillColor);
+    CHK(FPDFPath_GetMatrix);
     CHK(FPDFPath_GetPathSegment);
     CHK(FPDFPath_GetStrokeColor);
     CHK(FPDFPath_LineTo);
@@ -191,6 +192,7 @@ int CheckPDFiumCApi() {
     CHK(FPDFPath_SetFillColor);
     CHK(FPDFPath_SetLineCap);
     CHK(FPDFPath_SetLineJoin);
+    CHK(FPDFPath_SetMatrix);
     CHK(FPDFPath_SetStrokeColor);
     CHK(FPDFPath_SetStrokeWidth);
     CHK(FPDFText_LoadFont);
diff --git a/public/fpdf_edit.h b/public/fpdf_edit.h
index 8cb97eed15..338b42b588 100644
--- a/public/fpdf_edit.h
+++ b/public/fpdf_edit.h
@@ -941,6 +941,56 @@ FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFPath_GetDrawMode(FPDF_PAGEOBJECT path,
                                                          int* fillmode,
                                                          FPDF_BOOL* stroke);
 
+// Experimental API.
+// Get the transform matrix of a path.
+//
+//   path - handle to a path.
+//   a    - matrix value.
+//   b    - matrix value.
+//   c    - matrix value.
+//   d    - matrix value.
+//   e    - matrix value.
+//   f    - matrix value.
+//
+// The matrix is composed as:
+//   |a c e|
+//   |b d f|
+// and used to scale, rotate, shear and translate the path.
+//
+// Returns TRUE on success.
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFPath_GetMatrix(FPDF_PAGEOBJECT path,
+                                                       double* a,
+                                                       double* b,
+                                                       double* c,
+                                                       double* d,
+                                                       double* e,
+                                                       double* f);
+
+// Experimental API.
+// Set the transform matrix of a path.
+//
+//   path - handle to a path.
+//   a    - matrix value.
+//   b    - matrix value.
+//   c    - matrix value.
+//   d    - matrix value.
+//   e    - matrix value.
+//   f    - matrix value.
+//
+// The matrix is composed as:
+//   |a c e|
+//   |b d f|
+// and can be used to scale, rotate, shear and translate the path.
+//
+// Returns TRUE on success.
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFPath_SetMatrix(FPDF_PAGEOBJECT path,
+                                                       double a,
+                                                       double b,
+                                                       double c,
+                                                       double d,
+                                                       double e,
+                                                       double f);
+
 // Create a new text object using one of the standard PDF fonts.
 //
 // document   - handle to the document.