Fix FPDF_RenderPageBitmapWithMatrix

This CL fixes FPDF_RenderPageBitmapWithMatrix and improves tests.

Bug: pdfium:837
Change-Id: I98f90b667cc9a50fb0e915b8a758603488b44d40
Reviewed-on: https://pdfium-review.googlesource.com/9010
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>

1 files changed, 33 insertions, 9 deletions

diff --git a/fpdfsdk/fpdfview_embeddertest.cpp b/fpdfsdk/fpdfview_embeddertest.cpp
index f36edbc4d6..a986a1cd96 100644
--- a/fpdfsdk/fpdfview_embeddertest.cpp
+++ b/fpdfsdk/fpdfview_embeddertest.cpp
@@ -330,19 +330,21 @@ TEST_F(FPDFViewEmbeddertest, Hang_360) {
 }
 
 TEST_F(FPDFViewEmbeddertest, FPDF_RenderPageBitmapWithMatrix) {
-  const char kAllBlackMd5sum[] = "5708fc5c4a8bd0abde99c8e8f0390615";
-  const char kTopLeftQuarterBlackMd5sum[] = "24e4d1ec06fa0258af758cfc8b2ad50a";
+  const char kOriginalMD5[] = "210157942bcce97b057a1107a1fd62f8";
+  const char kTopLeftQuarterMD5[] = "c54d58dda13e3cd04eb63e1d0db0feda";
+  const char kTrimmedMD5[] = "88225d7951a21d0eef191cfed06c36ce";
+  const char kRotatedMD5[] = "7d38bc58aa50ad271bc432e77256d3de";
 
-  EXPECT_TRUE(OpenDocument("black.pdf"));
+  EXPECT_TRUE(OpenDocument("rectangles.pdf"));
   FPDF_PAGE page = LoadPage(0);
   EXPECT_NE(nullptr, page);
   const int width = static_cast<int>(FPDF_GetPageWidth(page));
   const int height = static_cast<int>(FPDF_GetPageHeight(page));
-  EXPECT_EQ(612, width);
-  EXPECT_EQ(792, height);
+  EXPECT_EQ(200, width);
+  EXPECT_EQ(200, height);
 
   FPDF_BITMAP bitmap = RenderPage(page);
-  CompareBitmap(bitmap, width, height, kAllBlackMd5sum);
+  CompareBitmap(bitmap, width, height, kOriginalMD5);
   FPDFBitmap_Destroy(bitmap);
 
   // Try rendering with an identity matrix. The output should be the same as
@@ -364,17 +366,39 @@ TEST_F(FPDFViewEmbeddertest, FPDF_RenderPageBitmapWithMatrix) {
   bitmap = FPDFBitmap_Create(width, height, 0);
   FPDFBitmap_FillRect(bitmap, 0, 0, width, height, 0xFFFFFFFF);
   FPDF_RenderPageBitmapWithMatrix(bitmap, page, &matrix, &rect, 0);
-  CompareBitmap(bitmap, width, height, kAllBlackMd5sum);
+  CompareBitmap(bitmap, width, height, kOriginalMD5);
   FPDFBitmap_Destroy(bitmap);
 
-  // Now render again with the image scaled.
+  // Now render again with the image scaled smaller.
   matrix.a = 0.5;
   matrix.d = 0.5;
 
   bitmap = FPDFBitmap_Create(width, height, 0);
   FPDFBitmap_FillRect(bitmap, 0, 0, width, height, 0xFFFFFFFF);
   FPDF_RenderPageBitmapWithMatrix(bitmap, page, &matrix, &rect, 0);
-  CompareBitmap(bitmap, width, height, kTopLeftQuarterBlackMd5sum);
+  CompareBitmap(bitmap, width, height, kTopLeftQuarterMD5);
+  FPDFBitmap_Destroy(bitmap);
+
+  // Now render again with the image scaled larger horizontally (will be
+  // trimmed).
+  matrix.a = 2;
+  matrix.d = 1;
+  bitmap = FPDFBitmap_Create(width, height, 0);
+  FPDFBitmap_FillRect(bitmap, 0, 0, width, height, 0xFFFFFFFF);
+  FPDF_RenderPageBitmapWithMatrix(bitmap, page, &matrix, &rect, 0);
+  CompareBitmap(bitmap, width, height, kTrimmedMD5);
+  FPDFBitmap_Destroy(bitmap);
+
+  // Now try a 90 degree rotation
+  matrix.a = 0;
+  matrix.b = 1;
+  matrix.c = -1;
+  matrix.d = 0;
+  matrix.e = width;
+  bitmap = FPDFBitmap_Create(width, height, 0);
+  FPDFBitmap_FillRect(bitmap, 0, 0, width, height, 0xFFFFFFFF);
+  FPDF_RenderPageBitmapWithMatrix(bitmap, page, &matrix, &rect, 0);
+  CompareBitmap(bitmap, width, height, kRotatedMD5);
   FPDFBitmap_Destroy(bitmap);
 
   UnloadPage(page);