Scanline decoding for bmp

src/codec/SkCodecPriv.h

 /*
  * Copyright 2015 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkCodecPriv_DEFINED
 #define SkCodecPriv_DEFINED
 
@@ skipping 114 matching lines @@
         const uint32_t pixelsPerByte = 8 / bitsPerPixel;
         return compute_row_bytes_ppb(width, pixelsPerByte);
     } else {
         SkASSERT(0 == bitsPerPixel % 8);
         const uint32_t bytesPerPixel = bitsPerPixel / 8;
         return compute_row_bytes_bpp(width, bytesPerPixel);
     }
 }
 
 /*
+ * On incomplete images, get the color to fill with
+ */
+static inline SkPMColor get_fill_color_or_index(SkAlphaType alphaType) {
+    // This condition works properly for all supported output color types.
+    // kIndex8: The low 8-bits of both possible return values is 0, which is
+    //          our desired default index.
+    // kGray8:  The low 8-bits of both possible return values is 0, which is
+    //          black, our desired fill value.
+    // kRGB565: The low 16-bits of both possible return values is 0, which is
+    //          black, our desired fill value.
+    // kN32:    Return black for opaque images and transparent for non-opaque
+    //          images.
+    return kOpaque_SkAlphaType == alphaType ?
+            SK_ColorBLACK : SK_ColorTRANSPARENT;
+}
+
+/*
  * Get a byte from a buffer
  * This method is unsafe, the caller is responsible for performing a check
  */
 static inline uint8_t get_byte(uint8_t* buffer, uint32_t i) {
     return buffer[i];
 }
 
 /*
  * Get a short from a buffer
  * This method is unsafe, the caller is responsible for performing a check
@@ skipping 22 matching lines @@
 #endif
 }
 
 #ifdef SK_PRINT_CODEC_MESSAGES
     #define SkCodecPrintf SkDebugf
 #else
     #define SkCodecPrintf(...)
 #endif
 
 #endif // SkCodecPriv_DEFINED