Implement FPDFImageObj_GetMatrix().

BUG=pdfium:1183

Change-Id: I5b1051d8924264aa12534466ee51b2718b3eca67
Reviewed-on: https://pdfium-review.googlesource.com/c/44514
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>

5 files changed, 187 insertions, 1 deletions

diff --git a/fpdfsdk/fpdf_edit_embeddertest.cpp b/fpdfsdk/fpdf_edit_embeddertest.cpp
index 9cd7dbf86b..ae6e444a4e 100644
--- a/fpdfsdk/fpdf_edit_embeddertest.cpp
+++ b/fpdfsdk/fpdf_edit_embeddertest.cpp
@@ -2963,6 +2963,83 @@ TEST_F(FPDFEditEmbeddertest, GetImageData) {
   UnloadPage(page);
 }
 
+TEST_F(FPDFEditEmbeddertest, GetImageMatrix) {
+  ASSERT_TRUE(OpenDocument("embedded_images.pdf"));
+  FPDF_PAGE page = LoadPage(0);
+  ASSERT_TRUE(page);
+  ASSERT_EQ(39, FPDFPage_CountObjects(page));
+
+  FPDF_PAGEOBJECT obj;
+  double a;
+  double b;
+  double c;
+  double d;
+  double e;
+  double f;
+
+  obj = FPDFPage_GetObject(page, 33);
+  ASSERT_EQ(FPDF_PAGEOBJ_IMAGE, FPDFPageObj_GetType(obj));
+  EXPECT_TRUE(FPDFImageObj_GetMatrix(obj, &a, &b, &c, &d, &e, &f));
+  EXPECT_DOUBLE_EQ(53.0, a);
+  EXPECT_DOUBLE_EQ(0.0, b);
+  EXPECT_DOUBLE_EQ(0.0, c);
+  EXPECT_DOUBLE_EQ(43.0, d);
+  EXPECT_DOUBLE_EQ(72.0, e);
+  EXPECT_DOUBLE_EQ(646.510009765625, f);
+
+  obj = FPDFPage_GetObject(page, 34);
+  ASSERT_EQ(FPDF_PAGEOBJ_IMAGE, FPDFPageObj_GetType(obj));
+  EXPECT_TRUE(FPDFImageObj_GetMatrix(obj, &a, &b, &c, &d, &e, &f));
+  EXPECT_DOUBLE_EQ(70.0, a);
+  EXPECT_DOUBLE_EQ(0.0, b);
+  EXPECT_DOUBLE_EQ(0.0, c);
+  EXPECT_DOUBLE_EQ(51.0, d);
+  EXPECT_DOUBLE_EQ(216.0, e);
+  EXPECT_DOUBLE_EQ(646.510009765625, f);
+
+  obj = FPDFPage_GetObject(page, 35);
+  ASSERT_EQ(FPDF_PAGEOBJ_IMAGE, FPDFPageObj_GetType(obj));
+  EXPECT_TRUE(FPDFImageObj_GetMatrix(obj, &a, &b, &c, &d, &e, &f));
+  EXPECT_DOUBLE_EQ(69.0, a);
+  EXPECT_DOUBLE_EQ(0.0, b);
+  EXPECT_DOUBLE_EQ(0.0, c);
+  EXPECT_DOUBLE_EQ(51.0, d);
+  EXPECT_DOUBLE_EQ(360.0, e);
+  EXPECT_DOUBLE_EQ(646.510009765625, f);
+
+  obj = FPDFPage_GetObject(page, 36);
+  ASSERT_EQ(FPDF_PAGEOBJ_IMAGE, FPDFPageObj_GetType(obj));
+  EXPECT_TRUE(FPDFImageObj_GetMatrix(obj, &a, &b, &c, &d, &e, &f));
+  EXPECT_DOUBLE_EQ(59.0, a);
+  EXPECT_DOUBLE_EQ(0.0, b);
+  EXPECT_DOUBLE_EQ(0.0, c);
+  EXPECT_DOUBLE_EQ(45.0, d);
+  EXPECT_DOUBLE_EQ(72.0, e);
+  EXPECT_DOUBLE_EQ(553.510009765625, f);
+
+  obj = FPDFPage_GetObject(page, 37);
+  ASSERT_EQ(FPDF_PAGEOBJ_IMAGE, FPDFPageObj_GetType(obj));
+  EXPECT_TRUE(FPDFImageObj_GetMatrix(obj, &a, &b, &c, &d, &e, &f));
+  EXPECT_DOUBLE_EQ(55.94000244140625, a);
+  EXPECT_DOUBLE_EQ(0.0, b);
+  EXPECT_DOUBLE_EQ(0.0, c);
+  EXPECT_DOUBLE_EQ(46.950000762939453, d);
+  EXPECT_DOUBLE_EQ(216.0, e);
+  EXPECT_DOUBLE_EQ(552.510009765625, f);
+
+  obj = FPDFPage_GetObject(page, 38);
+  ASSERT_EQ(FPDF_PAGEOBJ_IMAGE, FPDFPageObj_GetType(obj));
+  EXPECT_TRUE(FPDFImageObj_GetMatrix(obj, &a, &b, &c, &d, &e, &f));
+  EXPECT_DOUBLE_EQ(70.528999328613281, a);
+  EXPECT_DOUBLE_EQ(0.0, b);
+  EXPECT_DOUBLE_EQ(0.0, c);
+  EXPECT_DOUBLE_EQ(43.149997711181641, d);
+  EXPECT_DOUBLE_EQ(360.0, e);
+  EXPECT_DOUBLE_EQ(553.3599853515625, f);
+
+  UnloadPage(page);
+}
+
 TEST_F(FPDFEditEmbeddertest, DestroyPageObject) {
   FPDF_PAGEOBJECT rect = FPDFPageObj_CreateNewRect(10, 10, 20, 20);
   ASSERT_TRUE(rect);
diff --git a/fpdfsdk/fpdf_editimg.cpp b/fpdfsdk/fpdf_editimg.cpp
index af4d125db0..21ed434d7f 100644
--- a/fpdfsdk/fpdf_editimg.cpp
+++ b/fpdfsdk/fpdf_editimg.cpp
@@ -118,6 +118,28 @@ FPDFImageObj_LoadJpegFileInline(FPDF_PAGE* pages,
 }
 
 FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV
+FPDFImageObj_GetMatrix(FPDF_PAGEOBJECT image_object,
+                       double* a,
+                       double* b,
+                       double* c,
+                       double* d,
+                       double* e,
+                       double* f) {
+  CPDF_ImageObject* pImgObj = CPDFImageObjectFromFPDFPageObject(image_object);
+  if (!pImgObj || !a || !b || !c || !d || !e || !f)
+    return false;
+
+  const CFX_Matrix& matrix = pImgObj->matrix();
+  *a = matrix.a;
+  *b = matrix.b;
+  *c = matrix.c;
+  *d = matrix.d;
+  *e = matrix.e;
+  *f = matrix.f;
+  return true;
+}
+
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV
 FPDFImageObj_SetMatrix(FPDF_PAGEOBJECT image_object,
                        double a,
                        double b,
diff --git a/fpdfsdk/fpdf_editimg_unittest.cpp b/fpdfsdk/fpdf_editimg_unittest.cpp
index 48bd7f146b..16e464d549 100644
--- a/fpdfsdk/fpdf_editimg_unittest.cpp
+++ b/fpdfsdk/fpdf_editimg_unittest.cpp
@@ -69,3 +69,64 @@ TEST_F(PDFEditImgTest, NewImageObjGenerateContent) {
   FPDF_ClosePage(page);
   FPDF_CloseDocument(doc);
 }
+
+TEST_F(PDFEditImgTest, GetSetImageMatrix) {
+  FPDF_DOCUMENT doc = FPDF_CreateNewDocument();
+  FPDF_PAGEOBJECT image = FPDFPageObj_NewImageObj(doc);
+
+  double a;
+  double b;
+  double c;
+  double d;
+  double e;
+  double f;
+  EXPECT_FALSE(FPDFImageObj_GetMatrix(nullptr, nullptr, nullptr, nullptr,
+                                      nullptr, nullptr, nullptr));
+  EXPECT_FALSE(FPDFImageObj_GetMatrix(nullptr, &a, nullptr, nullptr, nullptr,
+                                      nullptr, nullptr));
+  EXPECT_FALSE(FPDFImageObj_GetMatrix(nullptr, &a, &b, nullptr, nullptr,
+                                      nullptr, nullptr));
+  EXPECT_FALSE(
+      FPDFImageObj_GetMatrix(nullptr, &a, &b, &c, nullptr, nullptr, nullptr));
+  EXPECT_FALSE(
+      FPDFImageObj_GetMatrix(nullptr, &a, &b, &c, nullptr, nullptr, nullptr));
+  EXPECT_FALSE(
+      FPDFImageObj_GetMatrix(nullptr, &a, &b, &c, &d, nullptr, nullptr));
+  EXPECT_FALSE(FPDFImageObj_GetMatrix(nullptr, &a, &b, &c, &d, &e, nullptr));
+  EXPECT_FALSE(FPDFImageObj_GetMatrix(nullptr, &a, &b, &c, &d, &e, &f));
+  EXPECT_FALSE(FPDFImageObj_GetMatrix(nullptr, &a, nullptr, &c, &d, &e, &f));
+
+  EXPECT_FALSE(FPDFImageObj_GetMatrix(image, nullptr, nullptr, nullptr, nullptr,
+                                      nullptr, nullptr));
+  EXPECT_FALSE(FPDFImageObj_GetMatrix(image, &a, nullptr, nullptr, nullptr,
+                                      nullptr, nullptr));
+  EXPECT_FALSE(FPDFImageObj_GetMatrix(image, &a, &b, nullptr, nullptr, nullptr,
+                                      nullptr));
+  EXPECT_FALSE(
+      FPDFImageObj_GetMatrix(image, &a, &b, &c, nullptr, nullptr, nullptr));
+  EXPECT_FALSE(
+      FPDFImageObj_GetMatrix(image, &a, &b, &c, nullptr, nullptr, nullptr));
+  EXPECT_FALSE(FPDFImageObj_GetMatrix(image, &a, &b, &c, &d, nullptr, nullptr));
+  EXPECT_FALSE(FPDFImageObj_GetMatrix(image, &a, &b, &c, &d, &e, nullptr));
+  EXPECT_FALSE(FPDFImageObj_GetMatrix(image, &a, nullptr, &c, &d, &e, &f));
+
+  EXPECT_TRUE(FPDFImageObj_GetMatrix(image, &a, &b, &c, &d, &e, &f));
+  EXPECT_DOUBLE_EQ(1.0, a);
+  EXPECT_DOUBLE_EQ(0.0, b);
+  EXPECT_DOUBLE_EQ(0.0, c);
+  EXPECT_DOUBLE_EQ(1.0, d);
+  EXPECT_DOUBLE_EQ(0.0, e);
+  EXPECT_DOUBLE_EQ(0.0, f);
+
+  EXPECT_TRUE(FPDFImageObj_SetMatrix(image, 1, 2, 3, 4, 5, 6));
+  EXPECT_TRUE(FPDFImageObj_GetMatrix(image, &a, &b, &c, &d, &e, &f));
+  EXPECT_DOUBLE_EQ(1.0, a);
+  EXPECT_DOUBLE_EQ(2.0, b);
+  EXPECT_DOUBLE_EQ(3.0, c);
+  EXPECT_DOUBLE_EQ(4.0, d);
+  EXPECT_DOUBLE_EQ(5.0, e);
+  EXPECT_DOUBLE_EQ(6.0, f);
+
+  FPDFPageObj_Destroy(image);
+  FPDF_CloseDocument(doc);
+}
diff --git a/fpdfsdk/fpdf_view_c_api_test.c b/fpdfsdk/fpdf_view_c_api_test.c
index f1a509b3fc..4b52d24247 100644
--- a/fpdfsdk/fpdf_view_c_api_test.c
+++ b/fpdfsdk/fpdf_view_c_api_test.c
@@ -134,6 +134,7 @@ int CheckPDFiumCApi() {
     CHK(FPDFImageObj_GetImageFilter);
     CHK(FPDFImageObj_GetImageFilterCount);
     CHK(FPDFImageObj_GetImageMetadata);
+    CHK(FPDFImageObj_GetMatrix);
     CHK(FPDFImageObj_LoadJpegFile);
     CHK(FPDFImageObj_LoadJpegFileInline);
     CHK(FPDFImageObj_SetBitmap);
diff --git a/public/fpdf_edit.h b/public/fpdf_edit.h
index 42c654c3de..5d654ba305 100644
--- a/public/fpdf_edit.h
+++ b/public/fpdf_edit.h
@@ -565,6 +565,31 @@ FPDFImageObj_LoadJpegFileInline(FPDF_PAGE* pages,
                                 FPDF_PAGEOBJECT image_object,
                                 FPDF_FILEACCESS* fileAccess);
 
+// Experimental API.
+// Get the transform matrix of an image object.
+//
+//   image_object - handle to an image object.
+//   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 image.
+//
+// Returns TRUE on success.
+FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFImageObj_GetMatrix(FPDF_PAGEOBJECT path,
+                                                           double* a,
+                                                           double* b,
+                                                           double* c,
+                                                           double* d,
+                                                           double* e,
+                                                           double* f);
+
 // Set the transform matrix of |image_object|.
 //
 //   image_object - handle to an image object.
@@ -578,7 +603,7 @@ FPDFImageObj_LoadJpegFileInline(FPDF_PAGE* pages,
 // The matrix is composed as:
 //   |a c e|
 //   |b d f|
-// and can be used to scale, rotate, shear and translate the |page| annotations.
+// and can be used to scale, rotate, shear and translate the |image_object|.
 //
 // Returns TRUE on success.
 FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV