Scanline decoding for bmp

src/codec/SkBmpStandardCodec.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBmpStandardCodec.h"
 #include "SkCodecPriv.h"
 #include "SkColorPriv.h"
@@ skipping 27 matching lines @@
         default:
             return false;
     }
 }
 
 /*
  * Creates an instance of the decoder
  * Called only by NewFromStream
  */
 SkBmpStandardCodec::SkBmpStandardCodec(const SkImageInfo& info, SkStream* stream,
+                                       SkBmpCodec::BmpInputFormat inputFormat,
                                        uint16_t bitsPerPixel, uint32_t numColors,
                                        uint32_t bytesPerColor, uint32_t offset,
                                        SkBmpCodec::RowOrder rowOrder, bool inIco)
-    : INHERITED(info, stream, bitsPerPixel, rowOrder)
+    : INHERITED(info, stream, inputFormat, bitsPerPixel, rowOrder)
     , fColorTable(NULL)
     , fNumColors(this->computeNumColors(numColors))
     , fBytesPerColor(bytesPerColor)
     , fOffset(offset)
     , fSwizzler(NULL)
     , fSrcBuffer(NULL)
     , fInIco(inIco)
 {}
 
 /*
@@ skipping 211 matching lines @@
             SkASSERT(false);
             return 0;
     }
     return fillColorOrIndex;
 }
 
 /*
  * Performs the bitmap decoding for standard input format
  */
 SkCodec::Result SkBmpStandardCodec::decode(const SkImageInfo& dstInfo,
-                                   void* dst, size_t dstRowBytes,
-                                   const Options& opts) {
+                                           void* dst, size_t dstRowBytes,
+                                           const Options& opts) {
     // Set constant values
     const int width = dstInfo.width();
     const int height = dstInfo.height();
     const size_t rowBytes = SkAlign4(compute_row_bytes(width, this->bitsPerPixel()));
 
     // Iterate over rows of the image
     for (int y = 0; y < height; y++) {
         // Read a row of the input
         if (this->stream()->read(fSrcBuffer.get(), rowBytes) != rowBytes) {
             SkCodecPrintf("Warning: incomplete input stream.\n");
@@ skipping 57 matching lines @@
                 uint32_t alphaBit =
                         (fSrcBuffer.get()[quotient] >> shift) & 0x1;
                 dstRow[x] &= alphaBit - 1;
             }
         }
     }
 
     // Finished decoding the entire image
     return kSuccess;
 }
+
+SkCodec::Result SkBmpStandardCodec::onStart(const SkImageInfo& dstInfo,
+        const SkCodec::Options& options, SkPMColor inputColorPtr[], int* inputColorCount) {
+    // Create the color table if necessary and prepare the stream for decode
+    // Note that if it is non-NULL, inputColorCount will be modified
+    if (!this->createColorTable(dstInfo.alphaType(), inputColorCount)) {
+        SkCodecPrintf("Error: could not create color table.\n");
+        return SkCodec::kInvalidInput;
+    }
+
+    // Copy the color table to the client if necessary
+    copy_color_table(dstInfo, this->fColorTable, inputColorPtr, inputColorCount);
+
+    // Initialize a swizzler if necessary
+    if (!this->initializeSwizzler(dstInfo, options)) {
+        SkCodecPrintf("Error: cannot initialize swizzler.\n");
+        return SkCodec::kInvalidConversion;
+    }
+
+    return SkCodec::kSuccess;
+}