From 2895880fa8354b273b4e2b72e61a5b78d1985fa8 Mon Sep 17 00:00:00 2001
From: Lei Zhang <thestig@chromium.org>
Date: Fri, 29 Jun 2018 18:39:50 +0000
Subject: Better determine if ICC colorspaces can be used for blending.

Implement CPDF_ColorSpace::IsNormal() and check it when rendering. While
IsNormal() is trivial for most colorspaces, it needs to be implemented
separately for ICC colorspaces.

This fixes a rendering regression from commit 1c0de38c.

BUG=chromium:847346

Change-Id: Iaafed3f8ee40b26ac2cbfbdf2251407f7935311b
Reviewed-on: https://pdfium-review.googlesource.com/36571
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
---
 core/fxcodec/codec/ccodec_iccmodule.h |  6 +++++-
 core/fxcodec/codec/fx_codec_icc.cpp   | 20 +++++++++++++++-----
 2 files changed, 20 insertions(+), 6 deletions(-)

(limited to 'core/fxcodec/codec')

diff --git a/core/fxcodec/codec/ccodec_iccmodule.h b/core/fxcodec/codec/ccodec_iccmodule.h
index c304b4bb8e..0d60c3fd4a 100644
--- a/core/fxcodec/codec/ccodec_iccmodule.h
+++ b/core/fxcodec/codec/ccodec_iccmodule.h
@@ -22,12 +22,16 @@
 
 class CLcmsCmm {
  public:
-  CLcmsCmm(int srcComponents, cmsHTRANSFORM transform, bool isLab);
+  CLcmsCmm(int srcComponents,
+           cmsHTRANSFORM transform,
+           bool isLab,
+           bool bNormal);
   ~CLcmsCmm();
 
   cmsHTRANSFORM m_hTransform;
   int m_nSrcComponents;
   bool m_bLab;
+  const bool m_bNormal;
 };
 
 class CCodec_IccModule {
diff --git a/core/fxcodec/codec/fx_codec_icc.cpp b/core/fxcodec/codec/fx_codec_icc.cpp
index bd98a6efab..0aaaf98075 100644
--- a/core/fxcodec/codec/fx_codec_icc.cpp
+++ b/core/fxcodec/codec/fx_codec_icc.cpp
@@ -31,10 +31,14 @@ bool Check3Components(cmsColorSpaceSignature cs, bool bDst) {
 
 }  // namespace
 
-CLcmsCmm::CLcmsCmm(int srcComponents, cmsHTRANSFORM hTransform, bool isLab)
+CLcmsCmm::CLcmsCmm(int srcComponents,
+                   cmsHTRANSFORM hTransform,
+                   bool isLab,
+                   bool bNormal)
     : m_hTransform(hTransform),
       m_nSrcComponents(srcComponents),
-      m_bLab(isLab) {}
+      m_bLab(isLab),
+      m_bNormal(bNormal) {}
 
 CLcmsCmm::~CLcmsCmm() {
   cmsDeleteTransform(m_hTransform);
@@ -60,8 +64,6 @@ std::unique_ptr<CLcmsCmm> CCodec_IccModule::CreateTransform_sRGB(
     cmsCloseProfile(srcProfile);
     return nullptr;
   }
-  int srcFormat;
-  bool bLab = false;
   cmsColorSpaceSignature srcCS = cmsGetColorSpace(srcProfile);
 
   *nSrcComponents = cmsChannelsOf(srcCS);
@@ -72,6 +74,9 @@ std::unique_ptr<CLcmsCmm> CCodec_IccModule::CreateTransform_sRGB(
     return nullptr;
   }
 
+  int srcFormat;
+  bool bLab = false;
+  bool bNormal = false;
   if (srcCS == cmsSigLabData) {
     srcFormat =
         COLORSPACE_SH(PT_Lab) | CHANNELS_SH(*nSrcComponents) | BYTES_SH(0);
@@ -79,6 +84,10 @@ std::unique_ptr<CLcmsCmm> CCodec_IccModule::CreateTransform_sRGB(
   } else {
     srcFormat =
         COLORSPACE_SH(PT_ANY) | CHANNELS_SH(*nSrcComponents) | BYTES_SH(1);
+    // TODO(thestig): Check to see if lcms2 supports more colorspaces that can
+    // be considered normal.
+    bNormal = srcCS == cmsSigGrayData || srcCS == cmsSigRgbData ||
+              srcCS == cmsSigCmykData;
   }
   cmsColorSpaceSignature dstCS = cmsGetColorSpace(dstProfile);
   if (!Check3Components(dstCS, true)) {
@@ -110,7 +119,8 @@ std::unique_ptr<CLcmsCmm> CCodec_IccModule::CreateTransform_sRGB(
     cmsCloseProfile(dstProfile);
     return nullptr;
   }
-  auto pCmm = pdfium::MakeUnique<CLcmsCmm>(*nSrcComponents, hTransform, bLab);
+  auto pCmm =
+      pdfium::MakeUnique<CLcmsCmm>(*nSrcComponents, hTransform, bLab, bNormal);
   cmsCloseProfile(srcProfile);
   cmsCloseProfile(dstProfile);
   return pCmm;
-- 
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