Remove third arg to CFX_DIBitmap::LoadChannel()chromium/3589

It is always passed as FXDIB_Alpha. Rename method to indicate its
new purpose, and remove dead code.

Change-Id: Ifaf4faa6b25d1cbd2ff272309764b49de70dc836
Reviewed-on: https://pdfium-review.googlesource.com/c/44491
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

4 files changed, 15 insertions, 35 deletions

diff --git a/core/fpdfapi/render/cpdf_renderstatus.cpp b/core/fpdfapi/render/cpdf_renderstatus.cpp
index 982f69acf9..6943661cf3 100644
--- a/core/fpdfapi/render/cpdf_renderstatus.cpp
+++ b/core/fpdfapi/render/cpdf_renderstatus.cpp
@@ -2102,7 +2102,7 @@ void CPDF_RenderStatus::DrawShading(const CPDF_ShadingPattern* pPattern,
     } break;
   }
   if (bAlphaMode)
-    pBitmap->LoadChannel(FXDIB_Red, pBitmap, FXDIB_Alpha);
+    pBitmap->LoadChannelFromAlpha(FXDIB_Red, pBitmap);
 
   if (m_Options.ColorModeIs(CPDF_RenderOptions::kGray))
     pBitmap->ConvertColorScale(0, 0xffffff);
diff --git a/core/fxge/dib/cfx_dibbase.cpp b/core/fxge/dib/cfx_dibbase.cpp
index 65b7e5eded..c70aad69b4 100644
--- a/core/fxge/dib/cfx_dibbase.cpp
+++ b/core/fxge/dib/cfx_dibbase.cpp
@@ -1056,7 +1056,7 @@ RetainPtr<CFX_DIBitmap> CFX_DIBBase::CloneConvert(FXDIB_Format dest_format) {
   if (dest_format & 0x0200) {
     bool ret;
     if (dest_format == FXDIB_Argb) {
-      ret = pSrcAlpha ? pClone->LoadChannel(FXDIB_Alpha, pSrcAlpha, FXDIB_Alpha)
+      ret = pSrcAlpha ? pClone->LoadChannelFromAlpha(FXDIB_Alpha, pSrcAlpha)
                       : pClone->LoadChannel(FXDIB_Alpha, 0xff);
     } else {
       ret = pClone->SetAlphaMask(pSrcAlpha, nullptr);
diff --git a/core/fxge/dib/cfx_dibitmap.cpp b/core/fxge/dib/cfx_dibitmap.cpp
index 3a6eca8228..1ab615a172 100644
--- a/core/fxge/dib/cfx_dibitmap.cpp
+++ b/core/fxge/dib/cfx_dibitmap.cpp
@@ -278,41 +278,22 @@ void CFX_DIBitmap::TransferEqualFormatsOneBPP(
   }
 }
 
-bool CFX_DIBitmap::LoadChannel(FXDIB_Channel destChannel,
-                               const RetainPtr<CFX_DIBBase>& pSrcBitmap,
-                               FXDIB_Channel srcChannel) {
+bool CFX_DIBitmap::LoadChannelFromAlpha(
+    FXDIB_Channel destChannel,
+    const RetainPtr<CFX_DIBBase>& pSrcBitmap) {
   if (!m_pBuffer)
     return false;
 
   RetainPtr<CFX_DIBBase> pSrcClone = pSrcBitmap;
-  int srcOffset;
-  if (srcChannel == FXDIB_Alpha) {
-    if (!pSrcBitmap->HasAlpha() && !pSrcBitmap->IsAlphaMask())
-      return false;
+  if (!pSrcBitmap->HasAlpha() && !pSrcBitmap->IsAlphaMask())
+    return false;
 
-    if (pSrcBitmap->GetBPP() == 1) {
-      pSrcClone = pSrcBitmap->CloneConvert(FXDIB_8bppMask);
-      if (!pSrcClone)
-        return false;
-    }
-    srcOffset = pSrcBitmap->GetFormat() == FXDIB_Argb ? 3 : 0;
-  } else {
-    if (pSrcBitmap->IsAlphaMask())
+  if (pSrcBitmap->GetBPP() == 1) {
+    pSrcClone = pSrcBitmap->CloneConvert(FXDIB_8bppMask);
+    if (!pSrcClone)
       return false;
-
-    if (pSrcBitmap->GetBPP() < 24) {
-      if (pSrcBitmap->IsCmykImage()) {
-        pSrcClone = pSrcBitmap->CloneConvert(static_cast<FXDIB_Format>(
-            (pSrcBitmap->GetFormat() & 0xff00) | 0x20));
-      } else {
-        pSrcClone = pSrcBitmap->CloneConvert(static_cast<FXDIB_Format>(
-            (pSrcBitmap->GetFormat() & 0xff00) | 0x18));
-      }
-      if (!pSrcClone)
-        return false;
-    }
-    srcOffset = kChannelOffset[srcChannel];
   }
+  int srcOffset = pSrcBitmap->GetFormat() == FXDIB_Argb ? 3 : 0;
   int destOffset = 0;
   if (destChannel == FXDIB_Alpha) {
     if (IsAlphaMask()) {
@@ -343,7 +324,7 @@ bool CFX_DIBitmap::LoadChannel(FXDIB_Channel destChannel,
     }
     destOffset = kChannelOffset[destChannel];
   }
-  if (srcChannel == FXDIB_Alpha && pSrcClone->m_pAlphaMask) {
+  if (pSrcClone->m_pAlphaMask) {
     RetainPtr<CFX_DIBBase> pAlphaMask = pSrcClone->m_pAlphaMask;
     if (pSrcClone->GetWidth() != m_Width ||
         pSrcClone->GetHeight() != m_Height) {
@@ -451,7 +432,7 @@ bool CFX_DIBitmap::MultiplyAlpha(const RetainPtr<CFX_DIBBase>& pSrcBitmap) {
     return false;
 
   if (!IsAlphaMask() && !HasAlpha())
-    return LoadChannel(FXDIB_Alpha, pSrcBitmap, FXDIB_Alpha);
+    return LoadChannelFromAlpha(FXDIB_Alpha, pSrcBitmap);
 
   RetainPtr<CFX_DIBitmap> pSrcClone = pSrcBitmap.As<CFX_DIBitmap>();
   if (pSrcBitmap->GetWidth() != m_Width ||
diff --git a/core/fxge/dib/cfx_dibitmap.h b/core/fxge/dib/cfx_dibitmap.h
index 63aed7ffc6..8ab83c3eda 100644
--- a/core/fxge/dib/cfx_dibitmap.h
+++ b/core/fxge/dib/cfx_dibitmap.h
@@ -45,9 +45,8 @@ class CFX_DIBitmap : public CFX_DIBBase {
   uint32_t GetPixel(int x, int y) const;
   void SetPixel(int x, int y, uint32_t color);
 
-  bool LoadChannel(FXDIB_Channel destChannel,
-                   const RetainPtr<CFX_DIBBase>& pSrcBitmap,
-                   FXDIB_Channel srcChannel);
+  bool LoadChannelFromAlpha(FXDIB_Channel destChannel,
+                            const RetainPtr<CFX_DIBBase>& pSrcBitmap);
   bool LoadChannel(FXDIB_Channel destChannel, int value);
 
   bool MultiplyAlpha(int alpha);