Break out CFX_ImageTransformer mask calculations.

Change-Id: Iab7ff29c2ce9ed56715b5897e89da2d9d693583c
Reviewed-on: https://pdfium-review.googlesource.com/20252
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

2 files changed, 82 insertions, 70 deletions

diff --git a/core/fxge/dib/cfx_imagetransformer.cpp b/core/fxge/dib/cfx_imagetransformer.cpp
index 3be1dbe463..7d3d0a2a37 100644
--- a/core/fxge/dib/cfx_imagetransformer.cpp
+++ b/core/fxge/dib/cfx_imagetransformer.cpp
@@ -289,76 +289,11 @@ bool CFX_ImageTransformer::Continue(IFX_PauseIndicator* pPause) {
   if (!stretch_buf_mask && pTransformed->m_pAlphaMask) {
     pTransformed->m_pAlphaMask->Clear(0xff000000);
   } else if (pTransformed->m_pAlphaMask) {
-    int stretch_pitch_mask = m_Storer.GetBitmap()->m_pAlphaMask->GetPitch();
-    if (IsBilinear()) {
-      CFX_BilinearMatrix result2stretch_fix(result2stretch, 8);
-      for (int row = 0; row < m_result.Height(); row++) {
-        uint8_t* dest_pos_mask =
-            (uint8_t*)pTransformed->m_pAlphaMask->GetScanline(row);
-        for (int col = 0; col < m_result.Width(); col++) {
-          int src_col_l = 0;
-          int src_row_l = 0;
-          int res_x = 0;
-          int res_y = 0;
-          result2stretch_fix.Transform(col, row, &src_col_l, &src_row_l, &res_x,
-                                       &res_y);
-          if (InStretchBounds(src_col_l, src_row_l)) {
-            AdjustCoords(&src_col_l, &src_row_l);
-            int src_col_r = src_col_l + 1;
-            int src_row_r = src_row_l + 1;
-            AdjustCoords(&src_col_r, &src_row_r);
-            int row_offset_l = src_row_l * stretch_pitch_mask;
-            int row_offset_r = src_row_r * stretch_pitch_mask;
-            *dest_pos_mask =
-                bilinear_interpol(stretch_buf_mask, row_offset_l, row_offset_r,
-                                  src_col_l, src_col_r, res_x, res_y, 1, 0);
-          }
-          dest_pos_mask++;
-        }
-      }
-    } else if (IsBiCubic()) {
-      CFX_BilinearMatrix result2stretch_fix(result2stretch, 8);
-      for (int row = 0; row < m_result.Height(); row++) {
-        uint8_t* dest_pos_mask =
-            (uint8_t*)pTransformed->m_pAlphaMask->GetScanline(row);
-        for (int col = 0; col < m_result.Width(); col++) {
-          int src_col_l = 0;
-          int src_row_l = 0;
-          int res_x = 0;
-          int res_y = 0;
-          result2stretch_fix.Transform(col, row, &src_col_l, &src_row_l, &res_x,
-                                       &res_y);
-          if (InStretchBounds(src_col_l, src_row_l)) {
-            int pos_pixel[8];
-            int u_w[4], v_w[4];
-            AdjustCoords(&src_col_l, &src_row_l);
-            bicubic_get_pos_weight(pos_pixel, u_w, v_w, src_col_l, src_row_l,
-                                   res_x, res_y, stretch_width, stretch_height);
-            *dest_pos_mask =
-                bicubic_interpol(stretch_buf_mask, stretch_pitch_mask,
-                                 pos_pixel, u_w, v_w, res_x, res_y, 1, 0);
-          }
-          dest_pos_mask++;
-        }
-      }
-    } else {
-      CPDF_FixedMatrix result2stretch_fix(result2stretch, 8);
-      for (int row = 0; row < m_result.Height(); row++) {
-        uint8_t* dest_pos_mask =
-            (uint8_t*)pTransformed->m_pAlphaMask->GetScanline(row);
-        for (int col = 0; col < m_result.Width(); col++) {
-          int src_col = 0;
-          int src_row = 0;
-          result2stretch_fix.Transform(col, row, &src_col, &src_row);
-          if (InStretchBounds(src_col, src_row)) {
-            AdjustCoords(&src_col, &src_row);
-            *dest_pos_mask =
-                stretch_buf_mask[src_row * stretch_pitch_mask + src_col];
-          }
-          dest_pos_mask++;
-        }
-      }
-    }
+    CalcData cdata = {
+        pTransformed->m_pAlphaMask.Get(), result2stretch, stretch_buf_mask,
+        m_Storer.GetBitmap()->m_pAlphaMask->GetPitch(),
+    };
+    CalcMask(cdata);
   }
   if (m_Storer.GetBitmap()->IsAlphaMask()) {
     if (IsBilinear()) {
@@ -727,6 +662,74 @@ RetainPtr<CFX_DIBitmap> CFX_ImageTransformer::DetachBitmap() {
   return m_Storer.Detach();
 }
 
+void CFX_ImageTransformer::CalcMask(const CalcData& cdata) {
+  if (IsBilinear()) {
+    CFX_BilinearMatrix result2stretch_fix(cdata.matrix, 8);
+    for (int row = 0; row < m_result.Height(); row++) {
+      uint8_t* dest_pos_mask = (uint8_t*)cdata.bitmap->GetScanline(row);
+      for (int col = 0; col < m_result.Width(); col++) {
+        int src_col_l = 0;
+        int src_row_l = 0;
+        int res_x = 0;
+        int res_y = 0;
+        result2stretch_fix.Transform(col, row, &src_col_l, &src_row_l, &res_x,
+                                     &res_y);
+        if (InStretchBounds(src_col_l, src_row_l)) {
+          AdjustCoords(&src_col_l, &src_row_l);
+          int src_col_r = src_col_l + 1;
+          int src_row_r = src_row_l + 1;
+          AdjustCoords(&src_col_r, &src_row_r);
+          int row_offset_l = src_row_l * cdata.pitch;
+          int row_offset_r = src_row_r * cdata.pitch;
+          *dest_pos_mask =
+              bilinear_interpol(cdata.buf, row_offset_l, row_offset_r,
+                                src_col_l, src_col_r, res_x, res_y, 1, 0);
+        }
+        dest_pos_mask++;
+      }
+    }
+  } else if (IsBiCubic()) {
+    CFX_BilinearMatrix result2stretch_fix(cdata.matrix, 8);
+    for (int row = 0; row < m_result.Height(); row++) {
+      uint8_t* dest_pos_mask = (uint8_t*)cdata.bitmap->GetScanline(row);
+      for (int col = 0; col < m_result.Width(); col++) {
+        int src_col_l = 0;
+        int src_row_l = 0;
+        int res_x = 0;
+        int res_y = 0;
+        result2stretch_fix.Transform(col, row, &src_col_l, &src_row_l, &res_x,
+                                     &res_y);
+        if (InStretchBounds(src_col_l, src_row_l)) {
+          int pos_pixel[8];
+          int u_w[4], v_w[4];
+          AdjustCoords(&src_col_l, &src_row_l);
+          bicubic_get_pos_weight(pos_pixel, u_w, v_w, src_col_l, src_row_l,
+                                 res_x, res_y, stretch_width(),
+                                 stretch_height());
+          *dest_pos_mask = bicubic_interpol(cdata.buf, cdata.pitch, pos_pixel,
+                                            u_w, v_w, res_x, res_y, 1, 0);
+        }
+        dest_pos_mask++;
+      }
+    }
+  } else {
+    CPDF_FixedMatrix result2stretch_fix(cdata.matrix, 8);
+    for (int row = 0; row < m_result.Height(); row++) {
+      uint8_t* dest_pos_mask = (uint8_t*)cdata.bitmap->GetScanline(row);
+      for (int col = 0; col < m_result.Width(); col++) {
+        int src_col = 0;
+        int src_row = 0;
+        result2stretch_fix.Transform(col, row, &src_col, &src_row);
+        if (InStretchBounds(src_col, src_row)) {
+          AdjustCoords(&src_col, &src_row);
+          *dest_pos_mask = cdata.buf[src_row * cdata.pitch + src_col];
+        }
+        dest_pos_mask++;
+      }
+    }
+  }
+}
+
 void CFX_ImageTransformer::AdjustCoords(int* col, int* row) const {
   int& src_col = *col;
   int& src_row = *row;
diff --git a/core/fxge/dib/cfx_imagetransformer.h b/core/fxge/dib/cfx_imagetransformer.h
index dcda687d42..47b1513499 100644
--- a/core/fxge/dib/cfx_imagetransformer.h
+++ b/core/fxge/dib/cfx_imagetransformer.h
@@ -32,6 +32,15 @@ class CFX_ImageTransformer {
   RetainPtr<CFX_DIBitmap> DetachBitmap();
 
  private:
+  struct CalcData {
+    const CFX_DIBitmap* bitmap;
+    const CFX_Matrix& matrix;
+    const uint8_t* buf;
+    int pitch;
+  };
+
+  void CalcMask(const CalcData& cdata);
+
   bool IsBilinear() const {
     return !(m_Flags & FXDIB_DOWNSAMPLE) && !IsBiCubic();
   }