Revert "Revert of fix for invalid for loop syntax broke build (patchset #1 id:1 of https://codereview.chromium.org/1007373003/)"
This reverts commit d18475854ce232de71c5463e0654f459d4abfd43.
Revert "Revert "Implementation of image decoding for bmp files, in accordance with the new API.""
This reverts commit dfdec78a5d02e8690998741a9fe5b71a08ca3232.
BUG=skia:
TBR=
Review URL: https://codereview.chromium.org/1016443003
diff --git a/src/codec/SkCodec.cpp b/src/codec/SkCodec.cpp
index ec36bc7..d557087 100644
--- a/src/codec/SkCodec.cpp
+++ b/src/codec/SkCodec.cpp
@@ -7,24 +7,34 @@
#include "SkCodec.h"
#include "SkData.h"
+#include "SkCodec_libbmp.h"
#include "SkCodec_libpng.h"
#include "SkStream.h"
+struct DecoderProc {
+ bool (*IsFormat)(SkStream*);
+ SkCodec* (*NewFromStream)(SkStream*);
+};
+
+static const DecoderProc gDecoderProcs[] = {
+ { SkPngCodec::IsPng, SkPngCodec::NewFromStream },
+ { SkBmpCodec::IsBmp, SkBmpCodec::NewFromStream }
+};
+
SkCodec* SkCodec::NewFromStream(SkStream* stream) {
if (!stream) {
return NULL;
}
- SkAutoTDelete<SkStream> streamDeleter(stream);
- const bool isPng = SkPngCodec::IsPng(stream);
- // TODO: Avoid rewinding.
- if (!stream->rewind()) {
- return NULL;
+ for (uint32_t i = 0; i < SK_ARRAY_COUNT(gDecoderProcs); i++) {
+ DecoderProc proc = gDecoderProcs[i];
+ const bool correctFormat = proc.IsFormat(stream);
+ if (!stream->rewind()) {
+ return NULL;
+ }
+ if (correctFormat) {
+ return proc.NewFromStream(stream);
+ }
}
- if (isPng) {
- streamDeleter.detach();
- return SkPngCodec::NewFromStream(stream);
- }
- // TODO: Check other image types.
return NULL;
}
diff --git a/src/codec/SkCodecPriv.h b/src/codec/SkCodecPriv.h
new file mode 100644
index 0000000..a0e5c94
--- /dev/null
+++ b/src/codec/SkCodecPriv.h
@@ -0,0 +1,117 @@
+/*
+ * 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
+
+#include "SkImageInfo.h"
+#include "SkSwizzler.h"
+#include "SkTypes.h"
+
+/*
+ *
+ * Helper routine for alpha result codes
+ *
+ */
+#define INIT_RESULT_ALPHA \
+ uint8_t zeroAlpha = 0; \
+ uint8_t maxAlpha = 0xFF;
+
+#define UPDATE_RESULT_ALPHA(alpha) \
+ zeroAlpha |= (alpha); \
+ maxAlpha &= (alpha);
+
+#define COMPUTE_RESULT_ALPHA \
+ SkSwizzler::GetResult(zeroAlpha, maxAlpha);
+
+/*
+ *
+ * Compute row bytes for an image using pixels per byte
+ *
+ */
+static inline size_t compute_row_bytes_ppb(int width, uint32_t pixelsPerByte) {
+ return (width + pixelsPerByte - 1) / pixelsPerByte;
+}
+
+/*
+ *
+ * Compute row bytes for an image using bytes per pixel
+ *
+ */
+static inline size_t compute_row_bytes_bpp(int width, uint32_t bytesPerPixel) {
+ return width * bytesPerPixel;
+}
+
+/*
+ *
+ * Compute row bytes for an image
+ *
+ */
+static inline size_t compute_row_bytes(int width, uint32_t bitsPerPixel) {
+ if (bitsPerPixel < 16) {
+ SkASSERT(0 == 8 % bitsPerPixel);
+ 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);
+ }
+}
+
+/*
+ *
+ * Checks if alpha types are premul and unpremul
+ *
+ */
+static inline bool premul_and_unpremul(SkAlphaType dst, SkAlphaType src) {
+ return kPremul_SkAlphaType == dst && kUnpremul_SkAlphaType == src;
+}
+
+/*
+ *
+ * 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
+ *
+ */
+static inline uint16_t get_short(uint8_t* buffer, uint32_t i) {
+ uint16_t result;
+ memcpy(&result, &(buffer[i]), 2);
+#ifdef SK_CPU_BENDIAN
+ return SkEndianSwap16(result);
+#else
+ return result;
+#endif
+}
+
+/*
+ *
+ * Get an int from a buffer
+ * This method is unsafe, the caller is responsible for performing a check
+ *
+ */
+static inline uint32_t get_int(uint8_t* buffer, uint32_t i) {
+ uint32_t result;
+ memcpy(&result, &(buffer[i]), 4);
+#ifdef SK_CPU_BENDIAN
+ return SkEndianSwap32(result);
+#else
+ return result;
+#endif
+}
+
+#endif // SkCodecPriv_DEFINED
diff --git a/src/codec/SkCodec_libbmp.cpp b/src/codec/SkCodec_libbmp.cpp
new file mode 100644
index 0000000..5b9691c
--- /dev/null
+++ b/src/codec/SkCodec_libbmp.cpp
@@ -0,0 +1,903 @@
+/*
+ * 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 "SkCodec_libbmp.h"
+#include "SkCodecPriv.h"
+#include "SkColorPriv.h"
+#include "SkStream.h"
+
+/*
+ *
+ * Checks if the conversion between the input image and the requested output
+ * image has been implemented
+ *
+ */
+static bool conversion_possible(const SkImageInfo& dst,
+ const SkImageInfo& src) {
+ // All of the swizzles convert to kN32
+ // TODO: Update this when more swizzles are supported
+ if (kN32_SkColorType != dst.colorType()) {
+ return false;
+ }
+ // Support the swizzle if the requested alpha type is the same as our guess
+ // for the input alpha type
+ if (src.alphaType() == dst.alphaType()) {
+ return true;
+ }
+ // TODO: Support more swizzles, especially premul
+ return false;
+}
+
+/*
+ *
+ * Defines the version and type of the second bitmap header
+ *
+ */
+enum BitmapHeaderType {
+ kInfoV1_BitmapHeaderType,
+ kInfoV2_BitmapHeaderType,
+ kInfoV3_BitmapHeaderType,
+ kInfoV4_BitmapHeaderType,
+ kInfoV5_BitmapHeaderType,
+ kOS2V1_BitmapHeaderType,
+ kOS2VX_BitmapHeaderType,
+ kUnknown_BitmapHeaderType
+};
+
+/*
+ *
+ * Possible bitmap compression types
+ *
+ */
+enum BitmapCompressionMethod {
+ kNone_BitmapCompressionMethod = 0,
+ k8BitRLE_BitmapCompressionMethod = 1,
+ k4BitRLE_BitmapCompressionMethod = 2,
+ kBitMasks_BitmapCompressionMethod = 3,
+ kJpeg_BitmapCompressionMethod = 4,
+ kPng_BitmapCompressionMethod = 5,
+ kAlphaBitMasks_BitmapCompressionMethod = 6,
+ kCMYK_BitmapCompressionMethod = 11,
+ kCMYK8BitRLE_BitmapCompressionMethod = 12,
+ kCMYK4BitRLE_BitmapCompressionMethod = 13
+};
+
+/*
+ *
+ * Checks the start of the stream to see if the image is a bitmap
+ *
+ */
+bool SkBmpCodec::IsBmp(SkStream* stream) {
+ // TODO: Support "IC", "PT", "CI", "CP", "BA"
+ // TODO: ICO files may contain a BMP and need to use this decoder
+ const char bmpSig[] = { 'B', 'M' };
+ char buffer[sizeof(bmpSig)];
+ return stream->read(buffer, sizeof(bmpSig)) == sizeof(bmpSig) &&
+ !memcmp(buffer, bmpSig, sizeof(bmpSig));
+}
+
+/*
+ *
+ * Assumes IsBmp was called and returned true
+ * Creates a bitmap decoder
+ * Reads enough of the stream to determine the image format
+ *
+ */
+SkCodec* SkBmpCodec::NewFromStream(SkStream* stream) {
+ // Header size constants
+ static const uint32_t kBmpHeaderBytes = 14;
+ static const uint32_t kBmpHeaderBytesPlusFour = kBmpHeaderBytes + 4;
+ static const uint32_t kBmpOS2V1Bytes = 12;
+ static const uint32_t kBmpOS2V2Bytes = 64;
+ static const uint32_t kBmpInfoBaseBytes = 16;
+ static const uint32_t kBmpInfoV1Bytes = 40;
+ static const uint32_t kBmpInfoV2Bytes = 52;
+ static const uint32_t kBmpInfoV3Bytes = 56;
+ static const uint32_t kBmpInfoV4Bytes = 108;
+ static const uint32_t kBmpInfoV5Bytes = 124;
+ static const uint32_t kBmpMaskBytes = 12;
+
+ // Read the first header and the size of the second header
+ SkAutoTDeleteArray<uint8_t> hBuffer(
+ SkNEW_ARRAY(uint8_t, kBmpHeaderBytesPlusFour));
+ if (stream->read(hBuffer.get(), kBmpHeaderBytesPlusFour) !=
+ kBmpHeaderBytesPlusFour) {
+ SkDebugf("Error: unable to read first bitmap header.\n");
+ return NULL;
+ }
+
+ // The total bytes in the bmp file
+ // We only need to use this value for RLE decoding, so we will only check
+ // that it is valid in the RLE case.
+ const uint32_t totalBytes = get_int(hBuffer.get(), 2);
+
+ // The offset from the start of the file where the pixel data begins
+ const uint32_t offset = get_int(hBuffer.get(), 10);
+ if (offset < kBmpHeaderBytes + kBmpOS2V1Bytes) {
+ SkDebugf("Error: invalid starting location for pixel data\n");
+ return NULL;
+ }
+
+ // The size of the second (info) header in bytes
+ // The size is the first field of the second header, so we have already
+ // read the first four infoBytes.
+ const uint32_t infoBytes = get_int(hBuffer.get(), 14);
+ if (infoBytes < kBmpOS2V1Bytes) {
+ SkDebugf("Error: invalid second header size.\n");
+ return NULL;
+ }
+ const uint32_t infoBytesRemaining = infoBytes - 4;
+ hBuffer.free();
+
+ // Read the second header
+ SkAutoTDeleteArray<uint8_t> iBuffer(
+ SkNEW_ARRAY(uint8_t, infoBytesRemaining));
+ if (stream->read(iBuffer.get(), infoBytesRemaining) != infoBytesRemaining) {
+ SkDebugf("Error: unable to read second bitmap header.\n");
+ return NULL;
+ }
+
+ // The number of bits used per pixel in the pixel data
+ uint16_t bitsPerPixel;
+
+ // The compression method for the pixel data
+ uint32_t compression = kNone_BitmapCompressionMethod;
+
+ // Number of colors in the color table, defaults to 0 or max (see below)
+ uint32_t numColors = 0;
+
+ // Bytes per color in the color table, early versions use 3, most use 4
+ uint32_t bytesPerColor;
+
+ // The image width and height
+ int width, height;
+
+ // Determine image information depending on second header format
+ BitmapHeaderType headerType;
+ if (infoBytes >= kBmpInfoBaseBytes) {
+ // Check the version of the header
+ switch (infoBytes) {
+ case kBmpInfoV1Bytes:
+ headerType = kInfoV1_BitmapHeaderType;
+ break;
+ case kBmpInfoV2Bytes:
+ headerType = kInfoV2_BitmapHeaderType;
+ break;
+ case kBmpInfoV3Bytes:
+ headerType = kInfoV3_BitmapHeaderType;
+ break;
+ case kBmpInfoV4Bytes:
+ headerType = kInfoV4_BitmapHeaderType;
+ break;
+ case kBmpInfoV5Bytes:
+ headerType = kInfoV5_BitmapHeaderType;
+ break;
+ case 16:
+ case 20:
+ case 24:
+ case 28:
+ case 32:
+ case 36:
+ case 42:
+ case 46:
+ case 48:
+ case 60:
+ case kBmpOS2V2Bytes:
+ headerType = kOS2VX_BitmapHeaderType;
+ break;
+ default:
+ // We do not signal an error here because there is the
+ // possibility of new or undocumented bmp header types. Most
+ // of the newer versions of bmp headers are similar to and
+ // build off of the older versions, so we may still be able to
+ // decode the bmp.
+ SkDebugf("Warning: unknown bmp header format.\n");
+ headerType = kUnknown_BitmapHeaderType;
+ break;
+ }
+ // We check the size of the header before entering the if statement.
+ // We should not reach this point unless the size is large enough for
+ // these required fields.
+ SkASSERT(infoBytesRemaining >= 12);
+ width = get_int(iBuffer.get(), 0);
+ height = get_int(iBuffer.get(), 4);
+ bitsPerPixel = get_short(iBuffer.get(), 10);
+
+ // Some versions do not have these fields, so we check before
+ // overwriting the default value.
+ if (infoBytesRemaining >= 16) {
+ compression = get_int(iBuffer.get(), 12);
+ if (infoBytesRemaining >= 32) {
+ numColors = get_int(iBuffer.get(), 28);
+ }
+ }
+
+ // All of the headers that reach this point, store color table entries
+ // using 4 bytes per pixel.
+ bytesPerColor = 4;
+ } else if (infoBytes >= kBmpOS2V1Bytes) {
+ // The OS2V1 is treated separately because it has a unique format
+ headerType = kOS2V1_BitmapHeaderType;
+ width = (int) get_short(iBuffer.get(), 0);
+ height = (int) get_short(iBuffer.get(), 2);
+ bitsPerPixel = get_short(iBuffer.get(), 6);
+ bytesPerColor = 3;
+ } else {
+ // There are no valid bmp headers
+ SkDebugf("Error: second bitmap header size is invalid.\n");
+ return NULL;
+ }
+
+ // Check for valid dimensions from header
+ RowOrder rowOrder = kBottomUp_RowOrder;
+ if (height < 0) {
+ height = -height;
+ rowOrder = kTopDown_RowOrder;
+ }
+ static const int kBmpMaxDim = 1 << 16;
+ if (width < 0 || width >= kBmpMaxDim || height >= kBmpMaxDim) {
+ // TODO: Decide if we want to support really large bmps.
+ SkDebugf("Error: invalid bitmap dimensions.\n");
+ return NULL;
+ }
+
+ // Create mask struct
+ SkMasks::InputMasks inputMasks;
+ memset(&inputMasks, 0, 4*sizeof(uint32_t));
+
+ // Determine the input compression format and set bit masks if necessary
+ uint32_t maskBytes = 0;
+ BitmapInputFormat inputFormat = kUnknown_BitmapInputFormat;
+ switch (compression) {
+ case kNone_BitmapCompressionMethod:
+ inputFormat = kStandard_BitmapInputFormat;
+ break;
+ case k8BitRLE_BitmapCompressionMethod:
+ if (bitsPerPixel != 8) {
+ SkDebugf("Warning: correcting invalid bitmap format.\n");
+ bitsPerPixel = 8;
+ }
+ inputFormat = kRLE_BitmapInputFormat;
+ break;
+ case k4BitRLE_BitmapCompressionMethod:
+ if (bitsPerPixel != 4) {
+ SkDebugf("Warning: correcting invalid bitmap format.\n");
+ bitsPerPixel = 4;
+ }
+ inputFormat = kRLE_BitmapInputFormat;
+ break;
+ case kAlphaBitMasks_BitmapCompressionMethod:
+ case kBitMasks_BitmapCompressionMethod:
+ // Load the masks
+ inputFormat = kBitMask_BitmapInputFormat;
+ switch (headerType) {
+ case kInfoV1_BitmapHeaderType: {
+ // The V1 header stores the bit masks after the header
+ SkAutoTDeleteArray<uint8_t> mBuffer(
+ SkNEW_ARRAY(uint8_t, kBmpMaskBytes));
+ if (stream->read(mBuffer.get(), kBmpMaskBytes) !=
+ kBmpMaskBytes) {
+ SkDebugf("Error: unable to read bit inputMasks.\n");
+ return NULL;
+ }
+ maskBytes = kBmpMaskBytes;
+ inputMasks.red = get_int(mBuffer.get(), 0);
+ inputMasks.green = get_int(mBuffer.get(), 4);
+ inputMasks.blue = get_int(mBuffer.get(), 8);
+ break;
+ }
+ case kInfoV2_BitmapHeaderType:
+ case kInfoV3_BitmapHeaderType:
+ case kInfoV4_BitmapHeaderType:
+ case kInfoV5_BitmapHeaderType:
+ // Header types are matched based on size. If the header
+ // is V2+, we are guaranteed to be able to read at least
+ // this size.
+ SkASSERT(infoBytesRemaining >= 48);
+ inputMasks.red = get_int(iBuffer.get(), 36);
+ inputMasks.green = get_int(iBuffer.get(), 40);
+ inputMasks.blue = get_int(iBuffer.get(), 44);
+ break;
+ case kOS2VX_BitmapHeaderType:
+ // TODO: Decide if we intend to support this.
+ // It is unsupported in the previous version and
+ // in chromium. I have not come across a test case
+ // that uses this format.
+ SkDebugf("Error: huffman format unsupported.\n");
+ return NULL;
+ default:
+ SkDebugf("Error: invalid bmp bit masks header.\n");
+ return NULL;
+ }
+ break;
+ case kJpeg_BitmapCompressionMethod:
+ if (24 == bitsPerPixel) {
+ inputFormat = kRLE_BitmapInputFormat;
+ break;
+ }
+ // Fall through
+ case kPng_BitmapCompressionMethod:
+ // TODO: Decide if we intend to support this.
+ // It is unsupported in the previous version and
+ // in chromium. I think it is used mostly for printers.
+ SkDebugf("Error: compression format not supported.\n");
+ return NULL;
+ case kCMYK_BitmapCompressionMethod:
+ case kCMYK8BitRLE_BitmapCompressionMethod:
+ case kCMYK4BitRLE_BitmapCompressionMethod:
+ // TODO: Same as above.
+ SkDebugf("Error: CMYK not supported for bitmap decoding.\n");
+ return NULL;
+ default:
+ SkDebugf("Error: invalid format for bitmap decoding.\n");
+ return NULL;
+ }
+
+ // Most versions of bmps should be rendered as opaque. Either they do
+ // not have an alpha channel, or they expect the alpha channel to be
+ // ignored. V4+ bmp files introduce an alpha mask and allow the creator
+ // of the image to use the alpha channels. However, many of these images
+ // leave the alpha channel blank and expect to be rendered as opaque. For
+ // this reason, we set the alpha type to kUnknown for V4+ bmps and figure
+ // out the alpha type during the decode.
+ SkAlphaType alphaType = kOpaque_SkAlphaType;
+ if (kInfoV4_BitmapHeaderType == headerType ||
+ kInfoV5_BitmapHeaderType == headerType) {
+ // Header types are matched based on size. If the header is
+ // V4+, we are guaranteed to be able to read at least this size.
+ SkASSERT(infoBytesRemaining > 52);
+ inputMasks.alpha = get_int(iBuffer.get(), 48);
+ if (inputMasks.alpha != 0) {
+ alphaType = kUnpremul_SkAlphaType;
+ }
+ }
+ iBuffer.free();
+
+ // Check for valid bits per pixel input
+ switch (bitsPerPixel) {
+ // In addition to more standard pixel compression formats, bmp supports
+ // the use of bit masks to determine pixel components. The standard
+ // format for representing 16-bit colors is 555 (XRRRRRGGGGGBBBBB),
+ // which does not map well to any Skia color formats. For this reason,
+ // we will always enable mask mode with 16 bits per pixel.
+ case 16:
+ if (kBitMask_BitmapInputFormat != inputFormat) {
+ inputMasks.red = 0x7C00;
+ inputMasks.green = 0x03E0;
+ inputMasks.blue = 0x001F;
+ inputFormat = kBitMask_BitmapInputFormat;
+ }
+ break;
+ case 1:
+ case 2:
+ case 4:
+ case 8:
+ case 24:
+ case 32:
+ break;
+ default:
+ SkDebugf("Error: invalid input value for bits per pixel.\n");
+ return NULL;
+ }
+
+ // Check that input bit masks are valid and create the masks object
+ SkAutoTDelete<SkMasks>
+ masks(SkMasks::CreateMasks(inputMasks, bitsPerPixel));
+ if (NULL == masks) {
+ SkDebugf("Error: invalid input masks.\n");
+ return NULL;
+ }
+
+ // Process the color table
+ uint32_t colorBytes = 0;
+ SkPMColor* colorTable = NULL;
+ if (bitsPerPixel < 16) {
+ // Verify the number of colors for the color table
+ const uint32_t maxColors = 1 << bitsPerPixel;
+ // Zero is a default for maxColors
+ // Also set numColors to maxColors when input is too large
+ if (numColors <= 0 || numColors > maxColors) {
+ numColors = maxColors;
+ }
+ colorTable = SkNEW_ARRAY(SkPMColor, maxColors);
+
+ // Construct the color table
+ colorBytes = numColors * bytesPerColor;
+ SkAutoTDeleteArray<uint8_t> cBuffer(SkNEW_ARRAY(uint8_t, colorBytes));
+ if (stream->read(cBuffer.get(), colorBytes) != colorBytes) {
+ SkDebugf("Error: unable to read color table.\n");
+ return NULL;
+ }
+
+ // Fill in the color table (colors are stored unpremultiplied)
+ uint32_t i = 0;
+ for (; i < numColors; i++) {
+ uint8_t blue = get_byte(cBuffer.get(), i*bytesPerColor);
+ uint8_t green = get_byte(cBuffer.get(), i*bytesPerColor + 1);
+ uint8_t red = get_byte(cBuffer.get(), i*bytesPerColor + 2);
+ uint8_t alpha = 0xFF;
+ if (kOpaque_SkAlphaType != alphaType) {
+ alpha = (inputMasks.alpha >> 24) &
+ get_byte(cBuffer.get(), i*bytesPerColor + 3);
+ }
+ // Store the unpremultiplied color
+ colorTable[i] = SkPackARGB32NoCheck(alpha, red, green, blue);
+ }
+
+ // To avoid segmentation faults on bad pixel data, fill the end of the
+ // color table with black. This is the same the behavior as the
+ // chromium decoder.
+ for (; i < maxColors; i++) {
+ colorTable[i] = SkPackARGB32NoCheck(0xFF, 0, 0, 0);
+ }
+ }
+
+ // Ensure that the stream now points to the start of the pixel array
+ uint32_t bytesRead = kBmpHeaderBytes + infoBytes + maskBytes + colorBytes;
+
+ // Check that we have not read past the pixel array offset
+ if(bytesRead > offset) {
+ // This may occur on OS 2.1 and other old versions where the color
+ // table defaults to max size, and the bmp tries to use a smaller color
+ // table. This is invalid, and our decision is to indicate an error,
+ // rather than try to guess the intended size of the color table and
+ // rewind the stream to display the image.
+ SkDebugf("Error: pixel data offset less than header size.\n");
+ return NULL;
+ }
+
+ // Skip to the start of the pixel array
+ if (stream->skip(offset - bytesRead) != offset - bytesRead) {
+ SkDebugf("Error: unable to skip to image data.\n");
+ return NULL;
+ }
+
+ // Remaining bytes is only used for RLE
+ const int remainingBytes = totalBytes - offset;
+ if (remainingBytes <= 0 && kRLE_BitmapInputFormat == inputFormat) {
+ SkDebugf("Error: RLE requires valid input size.\n");
+ return NULL;
+ }
+
+ // Return the codec
+ // We will use ImageInfo to store width, height, and alpha type. We will
+ // choose kN32_SkColorType as the input color type because that is the
+ // expected choice for a destination color type. In reality, the input
+ // color type has many possible formats.
+ const SkImageInfo& imageInfo = SkImageInfo::Make(width, height,
+ kN32_SkColorType, alphaType);
+ return SkNEW_ARGS(SkBmpCodec, (imageInfo, stream, bitsPerPixel,
+ inputFormat, masks.detach(), colorTable,
+ rowOrder, remainingBytes));
+}
+
+/*
+ *
+ * Creates an instance of the decoder
+ * Called only by NewFromStream
+ *
+ */
+SkBmpCodec::SkBmpCodec(const SkImageInfo& info, SkStream* stream,
+ uint16_t bitsPerPixel, BitmapInputFormat inputFormat,
+ SkMasks* masks, SkPMColor* colorTable,
+ RowOrder rowOrder,
+ const uint32_t remainingBytes)
+ : INHERITED(info, stream)
+ , fBitsPerPixel(bitsPerPixel)
+ , fInputFormat(inputFormat)
+ , fMasks(masks)
+ , fColorTable(colorTable)
+ , fRowOrder(rowOrder)
+ , fRemainingBytes(remainingBytes)
+{}
+
+/*
+ *
+ * Initiates the bitmap decode
+ *
+ */
+SkCodec::Result SkBmpCodec::onGetPixels(const SkImageInfo& dstInfo,
+ void* dst, size_t dstRowBytes,
+ SkPMColor*, int*) {
+ if (!this->rewindIfNeeded()) {
+ return kCouldNotRewind;
+ }
+ if (dstInfo.dimensions() != this->getOriginalInfo().dimensions()) {
+ SkDebugf("Error: scaling not supported.\n");
+ return kInvalidScale;
+ }
+ if (!conversion_possible(dstInfo, this->getOriginalInfo())) {
+ SkDebugf("Error: cannot convert input type to output type.\n");
+ return kInvalidConversion;
+ }
+
+ switch (fInputFormat) {
+ case kBitMask_BitmapInputFormat:
+ return decodeMask(dstInfo, dst, dstRowBytes);
+ case kRLE_BitmapInputFormat:
+ return decodeRLE(dstInfo, dst, dstRowBytes);
+ case kStandard_BitmapInputFormat:
+ return decode(dstInfo, dst, dstRowBytes);
+ default:
+ SkASSERT(false);
+ return kInvalidInput;
+ }
+}
+
+/*
+ *
+ * Performs the bitmap decoding for bit masks input format
+ *
+ */
+SkCodec::Result SkBmpCodec::decodeMask(const SkImageInfo& dstInfo,
+ void* dst, size_t dstRowBytes) {
+ // Set constant values
+ const int width = dstInfo.width();
+ const int height = dstInfo.height();
+ const size_t rowBytes = SkAlign4(compute_row_bytes(width, fBitsPerPixel));
+
+ // Allocate space for a row buffer and a source for the swizzler
+ SkAutoTDeleteArray<uint8_t> srcBuffer(SkNEW_ARRAY(uint8_t, rowBytes));
+
+ // Get the destination start row and delta
+ SkPMColor* dstRow;
+ int delta;
+ if (kTopDown_RowOrder == fRowOrder) {
+ dstRow = (SkPMColor*) dst;
+ delta = (int) dstRowBytes;
+ } else {
+ dstRow = (SkPMColor*) SkTAddOffset<void>(dst, (height-1) * dstRowBytes);
+ delta = -((int) dstRowBytes);
+ }
+
+ // Create the swizzler
+ SkMaskSwizzler* swizzler = SkMaskSwizzler::CreateMaskSwizzler(
+ dstInfo, fMasks, fBitsPerPixel);
+
+ // Iterate over rows of the image
+ bool transparent = true;
+ for (int y = 0; y < height; y++) {
+ // Read a row of the input
+ if (stream()->read(srcBuffer.get(), rowBytes) != rowBytes) {
+ SkDebugf("Warning: incomplete input stream.\n");
+ return kIncompleteInput;
+ }
+
+ // Decode the row in destination format
+ SkSwizzler::ResultAlpha r = swizzler->next(dstRow, srcBuffer.get());
+ transparent &= SkSwizzler::IsTransparent(r);
+
+ // Move to the next row
+ dstRow = SkTAddOffset<SkPMColor>(dstRow, delta);
+ }
+
+ // Some fully transparent bmp images are intended to be opaque. Here, we
+ // correct for this possibility.
+ dstRow = (SkPMColor*) dst;
+ if (transparent) {
+ for (int y = 0; y < height; y++) {
+ for (int x = 0; x < width; x++) {
+ dstRow[x] |= 0xFF000000;
+ }
+ dstRow = SkTAddOffset<SkPMColor>(dstRow, dstRowBytes);
+ }
+ }
+
+ // Finished decoding the entire image
+ return kSuccess;
+}
+
+/*
+ *
+ * Set an RLE pixel using the color table
+ *
+ */
+void SkBmpCodec::setRLEPixel(SkPMColor* dst, size_t dstRowBytes, int height,
+ uint32_t x, uint32_t y, uint8_t index) {
+ if (kBottomUp_RowOrder == fRowOrder) {
+ y = height - y - 1;
+ }
+ SkPMColor* dstRow = SkTAddOffset<SkPMColor>(dst, y * dstRowBytes);
+ dstRow[x] = fColorTable.get()[index];
+}
+
+/*
+ *
+ * Performs the bitmap decoding for RLE input format
+ * RLE decoding is performed all at once, rather than a one row at a time
+ *
+ */
+SkCodec::Result SkBmpCodec::decodeRLE(const SkImageInfo& dstInfo,
+ void* dst, size_t dstRowBytes) {
+ // Set RLE flags
+ static const uint8_t RLE_ESCAPE = 0;
+ static const uint8_t RLE_EOL = 0;
+ static const uint8_t RLE_EOF = 1;
+ static const uint8_t RLE_DELTA = 2;
+
+ // Set constant values
+ const int width = dstInfo.width();
+ const int height = dstInfo.height();
+
+ // Input buffer parameters
+ uint32_t currByte = 0;
+ SkAutoTDeleteArray<uint8_t> buffer(SkNEW_ARRAY(uint8_t, fRemainingBytes));
+ size_t totalBytes = stream()->read(buffer.get(), fRemainingBytes);
+ if ((uint32_t) totalBytes < fRemainingBytes) {
+ SkDebugf("Warning: incomplete RLE file.\n");
+ } else if (totalBytes <= 0) {
+ SkDebugf("Error: could not read RLE image data.\n");
+ return kInvalidInput;
+ }
+
+ // Destination parameters
+ int x = 0;
+ int y = 0;
+ // If the code skips pixels, remaining pixels are transparent or black
+ // TODO: Skip this if memory was already zeroed.
+ memset(dst, 0, dstRowBytes * height);
+ SkPMColor* dstPtr = (SkPMColor*) dst;
+
+ while (true) {
+ // Every entry takes at least two bytes
+ if ((int) totalBytes - currByte < 2) {
+ SkDebugf("Warning: incomplete RLE input.\n");
+ return kIncompleteInput;
+ }
+
+ // Read the next two bytes. These bytes have different meanings
+ // depending on their values. In the first interpretation, the first
+ // byte is an escape flag and the second byte indicates what special
+ // task to perform.
+ const uint8_t flag = buffer.get()[currByte++];
+ const uint8_t task = buffer.get()[currByte++];
+
+ // If we have reached a row that is beyond the image size, and the RLE
+ // code does not indicate end of file, abort and signal a warning.
+ if (y >= height && (flag != RLE_ESCAPE || (task != RLE_EOF))) {
+ SkDebugf("Warning: invalid RLE input.\n");
+ return kIncompleteInput;
+ }
+
+ // Perform decoding
+ if (RLE_ESCAPE == flag) {
+ switch (task) {
+ case RLE_EOL:
+ x = 0;
+ y++;
+ break;
+ case RLE_EOF:
+ return kSuccess;
+ case RLE_DELTA: {
+ // Two bytes are needed to specify delta
+ if ((int) totalBytes - currByte < 2) {
+ SkDebugf("Warning: incomplete RLE input\n");
+ return kIncompleteInput;
+ }
+ // Modify x and y
+ const uint8_t dx = buffer.get()[currByte++];
+ const uint8_t dy = buffer.get()[currByte++];
+ x += dx;
+ y += dy;
+ if (x > width || y > height) {
+ SkDebugf("Warning: invalid RLE input.\n");
+ return kIncompleteInput;
+ }
+ break;
+ }
+ default: {
+ // If task does not match any of the above signals, it
+ // indicates that we have a sequence of non-RLE pixels.
+ // Furthermore, the value of task is equal to the number
+ // of pixels to interpret.
+ uint8_t numPixels = task;
+ const size_t rowBytes = compute_row_bytes(numPixels,
+ fBitsPerPixel);
+ // Abort if setting numPixels moves us off the edge of the
+ // image. Also abort if there are not enough bytes
+ // remaining in the stream to set numPixels.
+ if (x + numPixels > width ||
+ (int) totalBytes - currByte < SkAlign2(rowBytes)) {
+ SkDebugf("Warning: invalid RLE input.\n");
+ return kIncompleteInput;
+ }
+ // Set numPixels number of pixels
+ SkPMColor* dstRow = SkTAddOffset<SkPMColor>(
+ dstPtr, y * dstRowBytes);
+ while (numPixels > 0) {
+ switch(fBitsPerPixel) {
+ case 4: {
+ SkASSERT(currByte < totalBytes);
+ uint8_t val = buffer.get()[currByte++];
+ setRLEPixel(dstPtr, dstRowBytes, height, x++, y,
+ val >> 4);
+ numPixels--;
+ if (numPixels != 0) {
+ setRLEPixel(dstPtr, dstRowBytes, height,
+ x++, y, val & 0xF);
+ numPixels--;
+ }
+ break;
+ }
+ case 8:
+ SkASSERT(currByte < totalBytes);
+ setRLEPixel(dstPtr, dstRowBytes, height, x++, y,
+ buffer.get()[currByte++]);
+ numPixels--;
+ break;
+ case 24: {
+ SkASSERT(currByte + 2 < totalBytes);
+ uint8_t blue = buffer.get()[currByte++];
+ uint8_t green = buffer.get()[currByte++];
+ uint8_t red = buffer.get()[currByte++];
+ SkPMColor color = SkPackARGB32NoCheck(
+ 0xFF, red, green, blue);
+ dstRow[x++] = color;
+ numPixels--;
+ }
+ default:
+ SkASSERT(false);
+ return kInvalidInput;
+ }
+ }
+ // Skip a byte if necessary to maintain alignment
+ if (!SkIsAlign2(rowBytes)) {
+ currByte++;
+ }
+ break;
+ }
+ }
+ } else {
+ // If the first byte read is not a flag, it indicates the number of
+ // pixels to set in RLE mode.
+ const uint8_t numPixels = flag;
+ const int endX = SkTMin<int>(x + numPixels, width);
+
+ if (24 == fBitsPerPixel) {
+ // In RLE24, the second byte read is part of the pixel color.
+ // There are two more required bytes to finish encoding the
+ // color.
+ if ((int) totalBytes - currByte < 2) {
+ SkDebugf("Warning: incomplete RLE input\n");
+ return kIncompleteInput;
+ }
+
+ // Fill the pixels up to endX with the specified color
+ uint8_t blue = task;
+ uint8_t green = buffer.get()[currByte++];
+ uint8_t red = buffer.get()[currByte++];
+ SkPMColor color = SkPackARGB32NoCheck(0xFF, red, green, blue);
+ SkPMColor* dstRow =
+ SkTAddOffset<SkPMColor>(dstPtr, y * dstRowBytes);
+ while (x < endX) {
+ dstRow[x++] = color;
+ }
+ } else {
+ // In RLE8 or RLE4, the second byte read gives the index in the
+ // color table to look up the pixel color.
+ // RLE8 has one color index that gets repeated
+ // RLE4 has two color indexes in the upper and lower 4 bits of
+ // the bytes, which are alternated
+ uint8_t indices[2] = { task, task };
+ if (4 == fBitsPerPixel) {
+ indices[0] >>= 4;
+ indices[1] &= 0xf;
+ }
+
+ // Set the indicated number of pixels
+ for (int which = 0; x < endX; x++) {
+ setRLEPixel(dstPtr, dstRowBytes, height, x, y,
+ indices[which]);
+ which = !which;
+ }
+ }
+ }
+ }
+}
+
+/*
+ *
+ * Performs the bitmap decoding for standard input format
+ *
+ */
+SkCodec::Result SkBmpCodec::decode(const SkImageInfo& dstInfo,
+ void* dst, size_t dstRowBytes) {
+ // Set constant values
+ const int width = dstInfo.width();
+ const int height = dstInfo.height();
+ const size_t rowBytes = SkAlign4(compute_row_bytes(width, fBitsPerPixel));
+ const uint32_t alphaMask = fMasks->getAlphaMask();
+
+ // Get swizzler configuration
+ SkSwizzler::SrcConfig config;
+ switch (fBitsPerPixel) {
+ case 1:
+ config = SkSwizzler::kIndex1;
+ break;
+ case 2:
+ config = SkSwizzler::kIndex2;
+ break;
+ case 4:
+ config = SkSwizzler::kIndex4;
+ break;
+ case 8:
+ config = SkSwizzler::kIndex;
+ break;
+ case 24:
+ config = SkSwizzler::kBGR;
+ break;
+ case 32:
+ if (0 == alphaMask) {
+ config = SkSwizzler::kBGRX;
+ } else {
+ config = SkSwizzler::kBGRA;
+ }
+ break;
+ default:
+ SkASSERT(false);
+ return kInvalidInput;
+ }
+
+ // Create swizzler
+ SkSwizzler* swizzler = SkSwizzler::CreateSwizzler(config, fColorTable.get(),
+ dstInfo, dst, dstRowBytes, false);
+
+ // Allocate space for a row buffer and a source for the swizzler
+ SkAutoTDeleteArray<uint8_t> srcBuffer(SkNEW_ARRAY(uint8_t, rowBytes));
+
+ // Iterate over rows of the image
+ // FIXME: bool transparent = true;
+ for (int y = 0; y < height; y++) {
+ // Read a row of the input
+ if (stream()->read(srcBuffer.get(), rowBytes) != rowBytes) {
+ SkDebugf("Warning: incomplete input stream.\n");
+ return kIncompleteInput;
+ }
+
+ // Decode the row in destination format
+ uint32_t row;
+ if (kTopDown_RowOrder == fRowOrder) {
+ row = y;
+ } else {
+ row = height - 1 - y;
+ }
+
+ swizzler->next(srcBuffer.get(), row);
+ // FIXME: SkSwizzler::ResultAlpha r =
+ // swizzler->next(srcBuffer.get(), row);
+ // FIXME: transparent &= SkSwizzler::IsTransparent(r);
+ }
+
+ // FIXME: This code exists to match the behavior in the chromium decoder
+ // and to follow the bmp specification as it relates to alpha masks. It is
+ // commented out because we have yet to discover a test image that provides
+ // an alpha mask and uses this decode mode.
+
+ // Now we adjust the output image with some additional behavior that
+ // SkSwizzler does not support. Firstly, all bmp images that contain
+ // alpha are masked by the alpha mask. Secondly, many fully transparent
+ // bmp images are intended to be opaque. Here, we make those corrections.
+ // Modifying alpha is safe because colors are stored unpremultiplied.
+ /*
+ SkPMColor* dstRow = (SkPMColor*) dst;
+ if (SkSwizzler::kBGRA == config) {
+ for (int y = 0; y < height; y++) {
+ for (int x = 0; x < width; x++) {
+ if (transparent) {
+ dstRow[x] |= 0xFF000000;
+ } else {
+ dstRow[x] &= alphaMask;
+ }
+ dstRow = SkTAddOffset<SkPMColor>(dstRow, dstRowBytes);
+ }
+ }
+ }
+ */
+
+ // Finished decoding the entire image
+ return kSuccess;
+}
diff --git a/src/codec/SkCodec_libbmp.h b/src/codec/SkCodec_libbmp.h
new file mode 100644
index 0000000..f35b88d
--- /dev/null
+++ b/src/codec/SkCodec_libbmp.h
@@ -0,0 +1,142 @@
+/*
+ * 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 "SkCodec.h"
+#include "SkImageInfo.h"
+#include "SkMaskSwizzler.h"
+#include "SkStream.h"
+#include "SkSwizzler.h"
+#include "SkTypes.h"
+
+// TODO: rename SkCodec_libbmp files to SkBmpCodec
+// TODO: define a wrapper for SkDebugf that doesn't always print
+/*
+ *
+ * This class implements the decoding for bmp images
+ *
+ */
+class SkBmpCodec : public SkCodec {
+public:
+
+ /*
+ *
+ * Describes if rows of the input start at the top or bottom of the image
+ *
+ */
+ enum RowOrder {
+ kTopDown_RowOrder,
+ kBottomUp_RowOrder
+ };
+
+ /*
+ *
+ * Checks the start of the stream to see if the image is a bitmap
+ *
+ */
+ static bool IsBmp(SkStream*);
+
+ /*
+ *
+ * Assumes IsBmp was called and returned true
+ * Creates a bitmap decoder
+ * Reads enough of the stream to determine the image format
+ *
+ */
+ static SkCodec* NewFromStream(SkStream*);
+
+protected:
+
+ /*
+ *
+ * Initiates the bitmap decode
+ *
+ */
+ virtual Result onGetPixels(const SkImageInfo& dstInfo, void* dst,
+ size_t dstRowBytes, SkPMColor*,
+ int*) SK_OVERRIDE;
+
+private:
+
+ /*
+ *
+ * Used to define the input format of the bitmap
+ *
+ */
+ enum BitmapInputFormat {
+ kStandard_BitmapInputFormat,
+ kRLE_BitmapInputFormat,
+ kBitMask_BitmapInputFormat,
+ kUnknown_BitmapInputFormat
+ };
+
+ /*
+ *
+ * Performs the bitmap decoding for bit masks input format
+ *
+ */
+ Result decodeMask(const SkImageInfo& dstInfo, void* dst,
+ size_t dstRowBytes);
+
+ /*
+ *
+ * Set an RLE pixel using the color table
+ *
+ */
+ void setRLEPixel(SkPMColor* dst, size_t dstRowBytes, int height,
+ uint32_t x, uint32_t y, uint8_t index);
+
+ /*
+ *
+ * Performs the bitmap decoding for RLE input format
+ *
+ */
+ Result decodeRLE(const SkImageInfo& dstInfo, void* dst,
+ size_t dstRowBytes);
+
+ /*
+ *
+ * Performs the bitmap decoding for standard input format
+ *
+ */
+ Result decode(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes);
+
+ /*
+ *
+ * Creates an instance of the decoder
+ * Called only by NewFromStream
+ *
+ * @param srcInfo contains the source width and height
+ * @param stream the stream of image data
+ * @param bitsPerPixel the number of bits used to store each pixel
+ * @param format the format of the bmp file
+ * @param masks optional color masks for certain bmp formats, passes
+ ownership to SkBmpCodec
+ * @param colorTable array representing the color table for index-based bmp
+ * formats, colors are unpremultiplied, passes ownership
+ * to SkBmpCodec
+ * @param rowOrder indicates whether rows are ordered top-down or bottom-up
+ * @param remainingBytes used only for RLE decodes, as we must decode all
+ * of the data at once rather than row by row
+ * it indicates the amount of data left in the stream
+ * after decoding the headers
+ *
+ */
+ SkBmpCodec(const SkImageInfo& srcInfo, SkStream* stream,
+ uint16_t bitsPerPixel, BitmapInputFormat format,
+ SkMasks* masks, SkPMColor* colorTable,
+ RowOrder rowOrder, uint32_t remainingBytes);
+
+ // Fields
+ const uint16_t fBitsPerPixel;
+ const BitmapInputFormat fInputFormat;
+ SkAutoTDelete<SkMasks> fMasks; // owned
+ const SkAutoTDeleteArray<SkPMColor> fColorTable; // owned, unpremul
+ const RowOrder fRowOrder;
+ const uint32_t fRemainingBytes;
+
+ typedef SkCodec INHERITED;
+};
diff --git a/src/codec/SkCodec_libpng.cpp b/src/codec/SkCodec_libpng.cpp
index 8e7ee33..f42af38 100644
--- a/src/codec/SkCodec_libpng.cpp
+++ b/src/codec/SkCodec_libpng.cpp
@@ -6,6 +6,7 @@
*/
#include "SkCodec_libpng.h"
+#include "SkCodecPriv.h"
#include "SkColorPriv.h"
#include "SkColorTable.h"
#include "SkBitmap.h"
@@ -346,10 +347,6 @@
// Getting the pixels
///////////////////////////////////////////////////////////////////////////////
-static bool premul_and_unpremul(SkAlphaType A, SkAlphaType B) {
- return kPremul_SkAlphaType == A && kUnpremul_SkAlphaType == B;
-}
-
static bool conversion_possible(const SkImageInfo& A, const SkImageInfo& B) {
// TODO: Support other conversions
if (A.colorType() != B.colorType()) {
@@ -466,7 +463,7 @@
// Now swizzle it.
uint8_t* row = base;
for (int y = 0; y < height; y++) {
- reallyHasAlpha |= swizzler->next(row);
+ reallyHasAlpha |= !SkSwizzler::IsOpaque(swizzler->next(row));
row += rowBytes;
}
} else {
@@ -474,7 +471,7 @@
uint8_t* srcRow = static_cast<uint8_t*>(storage.get());
for (int y = 0; y < requestedInfo.height(); y++) {
png_read_rows(fPng_ptr, &srcRow, png_bytepp_NULL, 1);
- reallyHasAlpha |= swizzler->next(srcRow);
+ reallyHasAlpha |= !SkSwizzler::IsOpaque(swizzler->next(srcRow));
}
}
diff --git a/src/codec/SkMaskSwizzler.cpp b/src/codec/SkMaskSwizzler.cpp
new file mode 100644
index 0000000..8d9f6c6
--- /dev/null
+++ b/src/codec/SkMaskSwizzler.cpp
@@ -0,0 +1,205 @@
+/*
+ * 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 "SkCodecPriv.h"
+#include "SkColorPriv.h"
+#include "SkMaskSwizzler.h"
+
+/*
+ *
+ * Row procedure for masked color components with 16 bits per pixel
+ *
+ */
+static SkSwizzler::ResultAlpha swizzle_mask16_to_n32(
+ void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks) {
+
+ // Use the masks to decode to the destination
+ uint16_t* srcPtr = (uint16_t*) srcRow;
+ SkPMColor* dstPtr = (SkPMColor*) dstRow;
+ for (int i = 0; i < width; i++) {
+ uint16_t p = srcPtr[i];
+ uint8_t red = masks->getRed(p);
+ uint8_t green = masks->getGreen(p);
+ uint8_t blue = masks->getBlue(p);
+ dstPtr[i] = SkPackARGB32NoCheck(0xFF, red, green, blue);
+ }
+ return SkSwizzler::kOpaque_ResultAlpha;
+}
+
+/*
+ *
+ * Row procedure for masked color components with 16 bits per pixel with alpha
+ *
+ */
+static SkSwizzler::ResultAlpha swizzle_mask16_alpha_to_n32(
+ void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks) {
+
+ // Use the masks to decode to the destination
+ uint16_t* srcPtr = (uint16_t*) srcRow;
+ SkPMColor* dstPtr = (SkPMColor*) dstRow;
+ INIT_RESULT_ALPHA;
+ for (int i = 0; i < width; i++) {
+ uint16_t p = srcPtr[i];
+ uint8_t red = masks->getRed(p);
+ uint8_t green = masks->getGreen(p);
+ uint8_t blue = masks->getBlue(p);
+ uint8_t alpha = masks->getAlpha(p);
+ UPDATE_RESULT_ALPHA(alpha);
+ dstPtr[i] = SkPackARGB32NoCheck(alpha, red, green, blue);
+ }
+ return COMPUTE_RESULT_ALPHA;
+}
+
+/*
+ *
+ * Row procedure for masked color components with 24 bits per pixel
+ *
+ */
+static SkSwizzler::ResultAlpha swizzle_mask24_to_n32(
+ void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks) {
+
+ // Use the masks to decode to the destination
+ SkPMColor* dstPtr = (SkPMColor*) dstRow;
+ for (int i = 0; i < 3*width; i += 3) {
+ uint32_t p = srcRow[i] | (srcRow[i + 1] << 8) | srcRow[i + 2] << 16;
+ uint8_t red = masks->getRed(p);
+ uint8_t green = masks->getGreen(p);
+ uint8_t blue = masks->getBlue(p);
+ dstPtr[i/3] = SkPackARGB32NoCheck(0xFF, red, green, blue);
+ }
+ return SkSwizzler::kOpaque_ResultAlpha;
+}
+
+/*
+ *
+ * Row procedure for masked color components with 24 bits per pixel with alpha
+ *
+ */
+static SkSwizzler::ResultAlpha swizzle_mask24_alpha_to_n32(
+ void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks) {
+
+ // Use the masks to decode to the destination
+ SkPMColor* dstPtr = (SkPMColor*) dstRow;
+ INIT_RESULT_ALPHA;
+ for (int i = 0; i < 3*width; i += 3) {
+ uint32_t p = srcRow[i] | (srcRow[i + 1] << 8) | srcRow[i + 2] << 16;
+ uint8_t red = masks->getRed(p);
+ uint8_t green = masks->getGreen(p);
+ uint8_t blue = masks->getBlue(p);
+ uint8_t alpha = masks->getAlpha(p);
+ UPDATE_RESULT_ALPHA(alpha);
+ dstPtr[i/3] = SkPackARGB32NoCheck(alpha, red, green, blue);
+ }
+ return COMPUTE_RESULT_ALPHA;
+}
+
+/*
+ *
+ * Row procedure for masked color components with 32 bits per pixel
+ *
+ */
+static SkSwizzler::ResultAlpha swizzle_mask32_to_n32(
+ void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks) {
+
+ // Use the masks to decode to the destination
+ uint32_t* srcPtr = (uint32_t*) srcRow;
+ SkPMColor* dstPtr = (SkPMColor*) dstRow;
+ for (int i = 0; i < width; i++) {
+ uint32_t p = srcPtr[i];
+ uint8_t red = masks->getRed(p);
+ uint8_t green = masks->getGreen(p);
+ uint8_t blue = masks->getBlue(p);
+ dstPtr[i] = SkPackARGB32NoCheck(0xFF, red, green, blue);
+ }
+ return SkSwizzler::kOpaque_ResultAlpha;
+}
+
+/*
+ *
+ * Row procedure for masked color components with 32 bits per pixel
+ *
+ */
+static SkSwizzler::ResultAlpha swizzle_mask32_alpha_to_n32(
+ void* dstRow, const uint8_t* srcRow, int width, SkMasks* masks) {
+
+ // Use the masks to decode to the destination
+ uint32_t* srcPtr = (uint32_t*) srcRow;
+ SkPMColor* dstPtr = (SkPMColor*) dstRow;
+ INIT_RESULT_ALPHA;
+ for (int i = 0; i < width; i++) {
+ uint32_t p = srcPtr[i];
+ uint8_t red = masks->getRed(p);
+ uint8_t green = masks->getGreen(p);
+ uint8_t blue = masks->getBlue(p);
+ uint8_t alpha = masks->getAlpha(p);
+ UPDATE_RESULT_ALPHA(alpha);
+ dstPtr[i] = SkPackARGB32NoCheck(alpha, red, green, blue);
+ }
+ return COMPUTE_RESULT_ALPHA;
+}
+
+/*
+ *
+ * Create a new mask swizzler
+ *
+ */
+SkMaskSwizzler* SkMaskSwizzler::CreateMaskSwizzler(
+ const SkImageInfo& imageInfo, SkMasks* masks, uint32_t bitsPerPixel) {
+
+ // Choose the appropriate row procedure
+ RowProc proc = NULL;
+ uint32_t alphaMask = masks->getAlphaMask();
+ switch (bitsPerPixel) {
+ case 16:
+ if (0 == alphaMask) {
+ proc = &swizzle_mask16_to_n32;
+ } else {
+ proc = &swizzle_mask16_alpha_to_n32;
+ }
+ break;
+ case 24:
+ if (0 == alphaMask) {
+ proc = &swizzle_mask24_to_n32;
+ } else {
+ proc = &swizzle_mask24_alpha_to_n32;
+ }
+ break;
+ case 32:
+ if (0 == alphaMask) {
+ proc = &swizzle_mask32_to_n32;
+ } else {
+ proc = &swizzle_mask32_alpha_to_n32;
+ }
+ break;
+ default:
+ SkASSERT(false);
+ return NULL;
+ }
+ return SkNEW_ARGS(SkMaskSwizzler, (imageInfo, masks, proc));
+}
+
+/*
+ *
+ * Constructor for mask swizzler
+ *
+ */
+SkMaskSwizzler::SkMaskSwizzler(const SkImageInfo& imageInfo,
+ SkMasks* masks, RowProc proc)
+ : fImageInfo(imageInfo)
+ , fMasks(masks)
+ , fRowProc(proc)
+{}
+
+/*
+ *
+ * Swizzle the next row
+ *
+ */
+SkSwizzler::ResultAlpha SkMaskSwizzler::next(void* dst,
+ const uint8_t* src) {
+ return fRowProc(dst, src, fImageInfo.width(), fMasks);
+}
diff --git a/src/codec/SkMaskSwizzler.h b/src/codec/SkMaskSwizzler.h
new file mode 100644
index 0000000..9351f02
--- /dev/null
+++ b/src/codec/SkMaskSwizzler.h
@@ -0,0 +1,60 @@
+/*
+ * 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 "SkMasks.h"
+#include "SkSwizzler.h"
+#include "SkTypes.h"
+
+/*
+ *
+ * Used to swizzle images whose pixel components are extracted by bit masks
+ * Currently only used by bmp
+ *
+ */
+class SkMaskSwizzler {
+public:
+
+ /*
+ *
+ * Create a new swizzler
+ * @param masks Unowned pointer to helper class
+ *
+ */
+ static SkMaskSwizzler* CreateMaskSwizzler(const SkImageInfo& imageInfo,
+ SkMasks* masks,
+ uint32_t bitsPerPixel);
+
+ /*
+ *
+ * Swizzle the next row
+ *
+ */
+ SkSwizzler::ResultAlpha next(void* dst, const uint8_t* src);
+
+private:
+
+ /*
+ *
+ * Row procedure used for swizzle
+ *
+ */
+ typedef SkSwizzler::ResultAlpha (*RowProc)(
+ void* dstRow, const uint8_t* srcRow, int width,
+ SkMasks* masks);
+
+ /*
+ *
+ * Constructor for mask swizzler
+ *
+ */
+ SkMaskSwizzler(const SkImageInfo& info, SkMasks* masks, RowProc proc);
+
+ // Fields
+ const SkImageInfo& fImageInfo;
+ SkMasks* fMasks; // unowned
+ const RowProc fRowProc;
+};
diff --git a/src/codec/SkMasks.cpp b/src/codec/SkMasks.cpp
new file mode 100644
index 0000000..1c542ce
--- /dev/null
+++ b/src/codec/SkMasks.cpp
@@ -0,0 +1,160 @@
+/*
+ * 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 "SkMasks.h"
+#include "SkTypes.h"
+
+/*
+ *
+ * Used to convert 1-7 bit color components into 8-bit color components
+ *
+ */
+const static uint8_t n_bit_to_8_bit_lookup_table[] = {
+ // 1 bit
+ 0, 255,
+ // 2 bits
+ 0, 85, 170, 255,
+ // 3 bits
+ 0, 36, 73, 109, 146, 182, 219, 255,
+ // 4 bits
+ 0, 17, 34, 51, 68, 85, 102, 119, 136, 153, 170, 187, 204, 221, 238, 255,
+ // 5 bits
+ 0, 8, 16, 25, 33, 41, 49, 58, 66, 74, 82, 90, 99, 107, 115, 123, 132, 140,
+ 148, 156, 165, 173, 181, 189, 197, 206, 214, 222, 230, 239, 247, 255,
+ // 6 bits
+ 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 45, 49, 53, 57, 61, 65, 69, 73,
+ 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125, 130, 134, 138,
+ 142, 146, 150, 154, 158, 162, 166, 170, 174, 178, 182, 186, 190, 194, 198,
+ 202, 206, 210, 215, 219, 223, 227, 231, 235, 239, 243, 247, 251, 255,
+ // 7 bits
+ 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38,
+ 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76,
+ 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110,
+ 112, 114, 116, 118, 120, 122, 124, 126, 129, 131, 133, 135, 137, 139, 141,
+ 143, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 165, 167, 169, 171,
+ 173, 175, 177, 179, 181, 183, 185, 187, 189, 191, 193, 195, 197, 199, 201,
+ 203, 205, 207, 209, 211, 213, 215, 217, 219, 221, 223, 225, 227, 229, 231,
+ 233, 235, 237, 239, 241, 243, 245, 247, 249, 251, 253, 255
+};
+
+/*
+ *
+ * Convert an n bit component to an 8-bit component
+ *
+ */
+static uint8_t convert_to_8(uint32_t component, uint32_t n) {
+ if (0 == n) {
+ return 0;
+ } else if (8 > n) {
+ return n_bit_to_8_bit_lookup_table[(1 << n) - 2 + component];
+ } else {
+ SkASSERT(8 == n);
+ return component;
+ }
+}
+
+static uint8_t get_comp(uint32_t pixel, uint32_t mask, uint32_t shift,
+ uint32_t size) {
+ return convert_to_8((pixel & mask) >> shift, size);
+}
+
+/*
+ *
+ * Get a color component
+ *
+ */
+uint8_t SkMasks::getRed(uint32_t pixel) {
+ return get_comp(pixel, fRed.mask, fRed.shift, fRed.size);
+}
+uint8_t SkMasks::getGreen(uint32_t pixel) {
+ return get_comp(pixel, fGreen.mask, fGreen.shift, fGreen.size);
+}
+uint8_t SkMasks::getBlue(uint32_t pixel) {
+ return get_comp(pixel, fBlue.mask, fBlue.shift, fBlue.size);
+}
+uint8_t SkMasks::getAlpha(uint32_t pixel) {
+ return get_comp(pixel, fAlpha.mask, fAlpha.shift, fAlpha.size);
+}
+
+/*
+ *
+ * Process an input mask to obtain the necessary information
+ *
+ */
+const SkMasks::MaskInfo process_mask(uint32_t mask, uint32_t bpp) {
+ // Trim the masks to the allowed number of bits
+ if (bpp < 32) {
+ mask &= (1 << bpp) - 1;
+ }
+
+ // Determine properties of the mask
+ uint32_t tempMask = mask;
+ uint32_t shift = 0;
+ uint32_t size = 0;
+ if (tempMask != 0) {
+ // Count trailing zeros on masks
+ for (; (tempMask & 1) == 0; tempMask >>= 1) {
+ shift++;
+ }
+ // Count the size of the mask
+ for (; tempMask & 1; tempMask >>= 1) {
+ size++;
+ }
+ // Check that the mask is continuous
+ if (tempMask != 0) {
+ SkDebugf("Warning: Bit masks is not continuous.\n");
+ }
+ // Truncate masks greater than 8 bits
+ if (size > 8) {
+ shift += size - 8;
+ size = 8;
+ }
+ }
+
+ // Save the calculated values
+ const SkMasks::MaskInfo info = { mask, shift, size };
+ return info;
+}
+
+/*
+ *
+ * Create the masks object
+ *
+ */
+SkMasks* SkMasks::CreateMasks(InputMasks masks, uint32_t bitsPerPixel) {
+ // Trim the input masks according to bitsPerPixel
+ if (bitsPerPixel < 32) {
+ masks.red &= (1 << bitsPerPixel) - 1;
+ masks.green &= (1 << bitsPerPixel) - 1;
+ masks.blue &= (1 << bitsPerPixel) - 1;
+ masks.alpha &= (1 << bitsPerPixel) - 1;
+ }
+
+ // Check that masks do not overlap
+ if (((masks.red & masks.green) | (masks.red & masks.blue) |
+ (masks.red & masks.alpha) | (masks.green & masks.blue) |
+ (masks.green & masks.alpha) | (masks.blue & masks.alpha)) != 0) {
+ return NULL;
+ }
+
+ // Collect information about the masks
+ const MaskInfo red = process_mask(masks.red, bitsPerPixel);
+ const MaskInfo green = process_mask(masks.green, bitsPerPixel);
+ const MaskInfo blue = process_mask(masks.blue, bitsPerPixel);
+ const MaskInfo alpha = process_mask(masks.alpha, bitsPerPixel);
+
+ return SkNEW_ARGS(SkMasks, (red, green, blue, alpha));
+}
+
+
+SkMasks::SkMasks(const MaskInfo red, const MaskInfo green,
+ const MaskInfo blue, const MaskInfo alpha)
+ : fRed(red)
+ , fGreen(green)
+ , fBlue(blue)
+ , fAlpha(alpha)
+{}
diff --git a/src/codec/SkMasks.h b/src/codec/SkMasks.h
new file mode 100644
index 0000000..31c6849
--- /dev/null
+++ b/src/codec/SkMasks.h
@@ -0,0 +1,81 @@
+/*
+ * 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 "SkTypes.h"
+
+/*
+ *
+ * Contains useful mask routines for SkMaskSwizzler
+ *
+ */
+class SkMasks {
+public:
+
+ /*
+ *
+ * Input bit masks format
+ *
+ */
+ struct InputMasks {
+ uint32_t red;
+ uint32_t green;
+ uint32_t blue;
+ uint32_t alpha;
+ };
+
+ /*
+ *
+ * Contains all of the information for a single mask
+ *
+ */
+ struct MaskInfo {
+ uint32_t mask;
+ uint32_t shift;
+ uint32_t size;
+ };
+
+ /*
+ *
+ * Create the masks object
+ *
+ */
+ static SkMasks* CreateMasks(InputMasks masks, uint32_t bpp);
+
+ /*
+ *
+ * Get a color component
+ *
+ */
+ uint8_t getRed(uint32_t pixel);
+ uint8_t getGreen(uint32_t pixel);
+ uint8_t getBlue(uint32_t pixel);
+ uint8_t getAlpha(uint32_t pixel);
+
+ /*
+ *
+ * Getter for the alpha mask
+ * The alpha mask may be used in other decoding modes
+ *
+ */
+ uint32_t getAlphaMask() {
+ return fAlpha.mask;
+ }
+
+private:
+
+ /*
+ *
+ * Constrcutor
+ *
+ */
+ SkMasks(const MaskInfo red, const MaskInfo green, const MaskInfo blue,
+ const MaskInfo alpha);
+
+ const MaskInfo fRed;
+ const MaskInfo fGreen;
+ const MaskInfo fBlue;
+ const MaskInfo fAlpha;
+};
diff --git a/src/codec/SkSwizzler.cpp b/src/codec/SkSwizzler.cpp
index 563933f..0668db6 100644
--- a/src/codec/SkSwizzler.cpp
+++ b/src/codec/SkSwizzler.cpp
@@ -5,105 +5,168 @@
* found in the LICENSE file.
*/
+#include "SkCodecPriv.h"
#include "SkColorPriv.h"
#include "SkSwizzler.h"
#include "SkTemplates.h"
-// index
-
-#define A32_MASK_IN_PLACE (SkPMColor)(SK_A32_MASK << SK_A32_SHIFT)
-
-static bool swizzle_index_to_n32(void* SK_RESTRICT dstRow,
- const uint8_t* SK_RESTRICT src,
- int width, int deltaSrc, int, const SkPMColor ctable[]) {
-
- SkPMColor* SK_RESTRICT dst = (SkPMColor*)dstRow;
- SkPMColor cc = A32_MASK_IN_PLACE;
- for (int x = 0; x < width; x++) {
- SkPMColor c = ctable[*src];
- cc &= c;
- dst[x] = c;
- src += deltaSrc;
- }
- return cc != A32_MASK_IN_PLACE;
+SkSwizzler::ResultAlpha SkSwizzler::GetResult(uint8_t zeroAlpha,
+ uint8_t maxAlpha) {
+ // In the transparent case, this returns 0x0000
+ // In the opaque case, this returns 0xFFFF
+ // If the row is neither transparent nor opaque, returns something else
+ return (((uint16_t) maxAlpha) << 8) | zeroAlpha;
}
-static bool swizzle_index_to_n32_skipZ(void* SK_RESTRICT dstRow,
- const uint8_t* SK_RESTRICT src,
- int width, int deltaSrc, int,
- const SkPMColor ctable[]) {
+// kIndex1, kIndex2, kIndex4
+
+static SkSwizzler::ResultAlpha swizzle_small_index_to_n32(
+ void* SK_RESTRICT dstRow, const uint8_t* SK_RESTRICT src, int width,
+ int bitsPerPixel, int y, const SkPMColor ctable[]) {
+
+ SkPMColor* SK_RESTRICT dst = (SkPMColor*) dstRow;
+ INIT_RESULT_ALPHA;
+ const uint32_t pixelsPerByte = 8 / bitsPerPixel;
+ const size_t rowBytes = compute_row_bytes_ppb(width, pixelsPerByte);
+ const uint8_t mask = (1 << bitsPerPixel) - 1;
+ int x = 0;
+ for (uint32_t byte = 0; byte < rowBytes; byte++) {
+ uint8_t pixelData = src[byte];
+ for (uint32_t p = 0; p < pixelsPerByte && x < width; p++) {
+ uint8_t index = (pixelData >> (8 - bitsPerPixel)) & mask;
+ SkPMColor c = ctable[index];
+ UPDATE_RESULT_ALPHA(c >> SK_A32_SHIFT);
+ dst[x] = c;
+ pixelData <<= bitsPerPixel;
+ x++;
+ }
+ }
+ return COMPUTE_RESULT_ALPHA;
+}
+
+// kIndex
+
+static SkSwizzler::ResultAlpha swizzle_index_to_n32(
+ void* SK_RESTRICT dstRow, const uint8_t* SK_RESTRICT src, int width,
+ int bytesPerPixel, int y, const SkPMColor ctable[]) {
SkPMColor* SK_RESTRICT dst = (SkPMColor*)dstRow;
- SkPMColor cc = A32_MASK_IN_PLACE;
+ INIT_RESULT_ALPHA;
for (int x = 0; x < width; x++) {
SkPMColor c = ctable[*src];
- cc &= c;
+ UPDATE_RESULT_ALPHA(c >> SK_A32_SHIFT);
+ dst[x] = c;
+ src++;
+ }
+ return COMPUTE_RESULT_ALPHA;
+}
+
+static SkSwizzler::ResultAlpha swizzle_index_to_n32_skipZ(
+ void* SK_RESTRICT dstRow, const uint8_t* SK_RESTRICT src, int width,
+ int bytesPerPixel, int y, const SkPMColor ctable[]) {
+
+ SkPMColor* SK_RESTRICT dst = (SkPMColor*)dstRow;
+ INIT_RESULT_ALPHA;
+ for (int x = 0; x < width; x++) {
+ SkPMColor c = ctable[*src];
+ UPDATE_RESULT_ALPHA(c >> SK_A32_SHIFT);
if (c != 0) {
dst[x] = c;
}
- src += deltaSrc;
+ src++;
}
- return cc != A32_MASK_IN_PLACE;
+ return COMPUTE_RESULT_ALPHA;
}
#undef A32_MASK_IN_PLACE
+static SkSwizzler::ResultAlpha swizzle_bgrx_to_n32(
+ void* SK_RESTRICT dstRow, const uint8_t* SK_RESTRICT src, int width,
+ int bytesPerPixel, int y, const SkPMColor ctable[]) {
+
+ SkPMColor* SK_RESTRICT dst = (SkPMColor*)dstRow;
+ for (int x = 0; x < width; x++) {
+ dst[x] = SkPackARGB32NoCheck(0xFF, src[2], src[1], src[0]);
+ src += bytesPerPixel;
+ }
+ return SkSwizzler::kOpaque_ResultAlpha;
+}
+
+// kBGRA
+
+static SkSwizzler::ResultAlpha swizzle_bgra_to_n32(
+ void* SK_RESTRICT dstRow, const uint8_t* SK_RESTRICT src, int width,
+ int bytesPerPixel, int y, const SkPMColor ctable[]) {
+
+ SkPMColor* SK_RESTRICT dst = (SkPMColor*)dstRow;
+ INIT_RESULT_ALPHA;
+ for (int x = 0; x < width; x++) {
+ uint8_t alpha = src[3];
+ UPDATE_RESULT_ALPHA(alpha);
+ dst[x] = SkPackARGB32NoCheck(alpha, src[2], src[1], src[0]);
+ src += bytesPerPixel;
+ }
+ return COMPUTE_RESULT_ALPHA;
+}
+
// n32
-static bool swizzle_rgbx_to_n32(void* SK_RESTRICT dstRow,
- const uint8_t* SK_RESTRICT src,
- int width, int deltaSrc, int, const SkPMColor[]) {
+static SkSwizzler::ResultAlpha swizzle_rgbx_to_n32(
+ void* SK_RESTRICT dstRow, const uint8_t* SK_RESTRICT src, int width,
+ int bytesPerPixel, int y, const SkPMColor ctable[]) {
+
SkPMColor* SK_RESTRICT dst = (SkPMColor*)dstRow;
for (int x = 0; x < width; x++) {
dst[x] = SkPackARGB32(0xFF, src[0], src[1], src[2]);
- src += deltaSrc;
+ src += bytesPerPixel;
}
- return false;
+ return SkSwizzler::kOpaque_ResultAlpha;
}
-static bool swizzle_rgba_to_n32_premul(void* SK_RESTRICT dstRow,
- const uint8_t* SK_RESTRICT src,
- int width, int deltaSrc, int, const SkPMColor[]) {
+static SkSwizzler::ResultAlpha swizzle_rgba_to_n32_premul(
+ void* SK_RESTRICT dstRow, const uint8_t* SK_RESTRICT src, int width,
+ int bytesPerPixel, int y, const SkPMColor ctable[]) {
+
SkPMColor* SK_RESTRICT dst = (SkPMColor*)dstRow;
- unsigned alphaMask = 0xFF;
+ INIT_RESULT_ALPHA;
for (int x = 0; x < width; x++) {
unsigned alpha = src[3];
+ UPDATE_RESULT_ALPHA(alpha);
dst[x] = SkPreMultiplyARGB(alpha, src[0], src[1], src[2]);
- src += deltaSrc;
- alphaMask &= alpha;
+ src += bytesPerPixel;
}
- return alphaMask != 0xFF;
+ return COMPUTE_RESULT_ALPHA;
}
-static bool swizzle_rgba_to_n32_unpremul(void* SK_RESTRICT dstRow,
- const uint8_t* SK_RESTRICT src,
- int width, int deltaSrc, int,
- const SkPMColor[]) {
+static SkSwizzler::ResultAlpha swizzle_rgba_to_n32_unpremul(
+ void* SK_RESTRICT dstRow, const uint8_t* SK_RESTRICT src, int width,
+ int bytesPerPixel, int y, const SkPMColor ctable[]) {
+
uint32_t* SK_RESTRICT dst = reinterpret_cast<uint32_t*>(dstRow);
- unsigned alphaMask = 0xFF;
+ INIT_RESULT_ALPHA;
for (int x = 0; x < width; x++) {
unsigned alpha = src[3];
+ UPDATE_RESULT_ALPHA(alpha);
dst[x] = SkPackARGB32NoCheck(alpha, src[0], src[1], src[2]);
- src += deltaSrc;
- alphaMask &= alpha;
+ src += bytesPerPixel;
}
- return alphaMask != 0xFF;
+ return COMPUTE_RESULT_ALPHA;
}
-static bool swizzle_rgba_to_n32_premul_skipZ(void* SK_RESTRICT dstRow,
- const uint8_t* SK_RESTRICT src,
- int width, int deltaSrc, int,
- const SkPMColor[]) {
+static SkSwizzler::ResultAlpha swizzle_rgba_to_n32_premul_skipZ(
+ void* SK_RESTRICT dstRow, const uint8_t* SK_RESTRICT src, int width,
+ int bytesPerPixel, int y, const SkPMColor ctable[]) {
+
SkPMColor* SK_RESTRICT dst = (SkPMColor*)dstRow;
- unsigned alphaMask = 0xFF;
+ INIT_RESULT_ALPHA;
for (int x = 0; x < width; x++) {
unsigned alpha = src[3];
+ UPDATE_RESULT_ALPHA(alpha);
if (0 != alpha) {
dst[x] = SkPreMultiplyARGB(alpha, src[0], src[1], src[2]);
}
- src += deltaSrc;
- alphaMask &= alpha;
+ src += bytesPerPixel;
}
- return alphaMask != 0xFF;
+ return COMPUTE_RESULT_ALPHA;
}
/**
@@ -114,7 +177,7 @@
decide whether to switch to unpremul default.
static bool swizzle_rgba_to_n32_unpremul_skipZ(void* SK_RESTRICT dstRow,
const uint8_t* SK_RESTRICT src,
- int width, int deltaSrc, int,
+ int width, int bitsPerPixel,
const SkPMColor[]) {
SkPMColor* SK_RESTRICT dst = (SkPMColor*)dstRow;
unsigned alphaMask = 0xFF;
@@ -133,31 +196,61 @@
}
*/
-SkSwizzler* SkSwizzler::CreateSwizzler(SkSwizzler::SrcConfig sc, const SkPMColor* ctable,
+SkSwizzler* SkSwizzler::CreateSwizzler(SkSwizzler::SrcConfig sc,
+ const SkPMColor* ctable,
const SkImageInfo& info, void* dst,
size_t dstRowBytes, bool skipZeroes) {
- if (info.colorType() == kUnknown_SkColorType) {
+ if (kUnknown_SkColorType == info.colorType()) {
return NULL;
}
if (info.minRowBytes() > dstRowBytes) {
return NULL;
}
- if (kIndex == sc && NULL == ctable) {
+ if ((kIndex == sc || kIndex4 == sc || kIndex2 == sc || kIndex1 == sc)
+ && NULL == ctable) {
return NULL;
}
RowProc proc = NULL;
switch (sc) {
+ case kIndex1:
+ case kIndex2:
+ case kIndex4:
+ switch (info.colorType()) {
+ case kN32_SkColorType:
+ proc = &swizzle_small_index_to_n32;
+ break;
+ default:
+ break;
+ }
+ break;
case kIndex:
switch (info.colorType()) {
case kN32_SkColorType:
- // We assume the color premultiplied ctable (or not) as desired.
if (skipZeroes) {
proc = &swizzle_index_to_n32_skipZ;
} else {
proc = &swizzle_index_to_n32;
}
break;
-
+ default:
+ break;
+ }
+ break;
+ case kBGR:
+ case kBGRX:
+ switch (info.colorType()) {
+ case kN32_SkColorType:
+ proc = &swizzle_bgrx_to_n32;
+ break;
+ default:
+ break;
+ }
+ break;
+ case kBGRA:
+ switch (info.colorType()) {
+ case kN32_SkColorType:
+ proc = &swizzle_bgra_to_n32;
+ break;
default:
break;
}
@@ -190,32 +283,67 @@
break;
}
break;
+ case kRGB:
+ switch (info.colorType()) {
+ case kN32_SkColorType:
+ proc = &swizzle_rgbx_to_n32;
+ break;
+ default:
+ break;
+ }
+ break;
default:
break;
}
if (NULL == proc) {
return NULL;
}
- return SkNEW_ARGS(SkSwizzler, (proc, ctable, BytesPerPixel(sc), info, dst, dstRowBytes));
+
+ // Store deltaSrc in bytes if it is an even multiple, otherwise use bits
+ int deltaSrc = SkIsAlign8(BitsPerPixel(sc)) ? BytesPerPixel(sc) :
+ BitsPerPixel(sc);
+ return SkNEW_ARGS(SkSwizzler, (proc, ctable, deltaSrc, info, dst,
+ dstRowBytes));
}
-SkSwizzler::SkSwizzler(RowProc proc, const SkPMColor* ctable, int srcBpp,
- const SkImageInfo& info, void* dst, size_t rowBytes)
+SkSwizzler::SkSwizzler(RowProc proc, const SkPMColor* ctable,
+ int deltaSrc, const SkImageInfo& info, void* dst,
+ size_t rowBytes)
: fRowProc(proc)
, fColorTable(ctable)
- , fSrcPixelSize(srcBpp)
+ , fDeltaSrc(deltaSrc)
, fDstInfo(info)
, fDstRow(dst)
, fDstRowBytes(rowBytes)
, fCurrY(0)
{
+ SkDEBUGCODE(fNextMode = kUninitialized_NextMode);
}
-bool SkSwizzler::next(const uint8_t* SK_RESTRICT src) {
- SkASSERT(fCurrY < fDstInfo.height());
- const bool hadAlpha = fRowProc(fDstRow, src, fDstInfo.width(), fSrcPixelSize,
- fCurrY, fColorTable);
- fCurrY++;
+SkSwizzler::ResultAlpha SkSwizzler::next(const uint8_t* SK_RESTRICT src) {
+ SkASSERT(0 <= fCurrY && fCurrY < fDstInfo.height());
+ SkASSERT(kDesignateRow_NextMode != fNextMode);
+ SkDEBUGCODE(fNextMode = kConsecutive_NextMode);
+
+ // Decode a row
+ const ResultAlpha result = fRowProc(fDstRow, src, fDstInfo.width(),
+ fDeltaSrc, fCurrY, fColorTable);
+
+ // Move to the next row and return the result
fDstRow = SkTAddOffset<void>(fDstRow, fDstRowBytes);
- return hadAlpha;
+ return result;
+}
+
+SkSwizzler::ResultAlpha SkSwizzler::next(const uint8_t* SK_RESTRICT src,
+ int y) {
+ SkASSERT(0 <= y && y < fDstInfo.height());
+ SkASSERT(kConsecutive_NextMode != fNextMode);
+ SkDEBUGCODE(fNextMode = kDesignateRow_NextMode);
+
+ // Choose the row
+ void* row = SkTAddOffset<void>(fDstRow, y*fDstRowBytes);
+
+ // Decode the row
+ return fRowProc(row, src, fDstInfo.width(), fDeltaSrc, fCurrY,
+ fColorTable);
}
diff --git a/src/codec/SkSwizzler.h b/src/codec/SkSwizzler.h
index 0bf2ee3..e22c05b 100644
--- a/src/codec/SkSwizzler.h
+++ b/src/codec/SkSwizzler.h
@@ -18,32 +18,99 @@
* Enum describing the config of the source data.
*/
enum SrcConfig {
- kGray, // 1 byte per pixel
- kIndex, // 1 byte per pixel
- kRGB, // 3 bytes per pixel
- kRGBX, // 4 byes per pixel (ignore 4th)
- kRGBA, // 4 bytes per pixel
- kRGB_565 // 2 bytes per pixel
+ kGray,
+ kIndex1,
+ kIndex2,
+ kIndex4,
+ kIndex,
+ kRGB,
+ kBGR,
+ kRGBX,
+ kBGRX,
+ kRGBA,
+ kBGRA,
+ kRGB_565,
};
- static int BytesPerPixel(SrcConfig sc) {
+ /*
+ *
+ * Result code for the alpha components of a row.
+ *
+ */
+ typedef uint16_t ResultAlpha;
+ static const ResultAlpha kOpaque_ResultAlpha = 0xFFFF;
+ static const ResultAlpha kTransparent_ResultAlpha = 0x0000;
+
+ /*
+ *
+ * Checks if the result of decoding a row indicates that the row was
+ * transparent.
+ *
+ */
+ static bool IsTransparent(ResultAlpha r) {
+ return kTransparent_ResultAlpha == r;
+ }
+
+ /*
+ *
+ * Checks if the result of decoding a row indicates that the row was
+ * opaque.
+ *
+ */
+ static bool IsOpaque(ResultAlpha r) {
+ return kOpaque_ResultAlpha == r;
+ }
+
+ /*
+ *
+ * Constructs the proper result code based on accumulated alpha masks
+ *
+ */
+ static ResultAlpha GetResult(uint8_t zeroAlpha, uint8_t maxAlpha);
+
+ /*
+ *
+ * Returns bits per pixel for source config
+ *
+ */
+ static int BitsPerPixel(SrcConfig sc) {
switch (sc) {
+ case kIndex1:
+ return 1;
+ case kIndex2:
+ return 2;
+ case kIndex4:
+ return 4;
case kGray:
case kIndex:
- return 1;
+ return 8;
+ case kRGB_565:
+ return 16;
case kRGB:
- return 3;
+ case kBGR:
+ return 24;
case kRGBX:
case kRGBA:
- return 4;
- case kRGB_565:
- return 2;
+ case kBGRX:
+ case kBGRA:
+ return 32;
default:
- SkDebugf("invalid source config passed to BytesPerPixel\n");
- return -1;
+ SkASSERT(false);
+ return 0;
}
}
+ /*
+ *
+ * Returns bytes per pixel for source config
+ * Raises an error if each pixel is not stored in an even number of bytes
+ *
+ */
+ static int BytesPerPixel(SrcConfig sc) {
+ SkASSERT(SkIsAlign8(BitsPerPixel(sc)));
+ return BitsPerPixel(sc) >> 3;
+ }
+
/**
* Create a new SkSwizzler.
* @param sc SrcConfig
@@ -58,36 +125,68 @@
static SkSwizzler* CreateSwizzler(SrcConfig sc, const SkPMColor* ctable,
const SkImageInfo& info, void* dst,
size_t dstRowBytes, bool skipZeroes);
+
/**
* Swizzle the next line. Call height times, once for each row of source.
* @param src The next row of the source data.
- * @return Whether the row had non-opaque alpha.
+ * @return A result code describing if the row was fully opaque, fully
+ * transparent, or neither
*/
- bool next(const uint8_t* SK_RESTRICT src);
+ ResultAlpha next(const uint8_t* SK_RESTRICT src);
+
+ /**
+ *
+ * Alternate version of next that allows the caller to specify the row.
+ * It is very important to only use one version of next. Since the other
+ * version modifies the dst pointer, it will change the behavior of this
+ * function. We will check this in Debug mode.
+ *
+ */
+ ResultAlpha next(const uint8_t* SK_RESTRICT src, int y);
private:
+
+#ifdef SK_DEBUG
+ /*
+ *
+ * Keep track of which version of next the caller is using
+ *
+ */
+ enum NextMode {
+ kUninitialized_NextMode,
+ kConsecutive_NextMode,
+ kDesignateRow_NextMode,
+ };
+
+ NextMode fNextMode;
+#endif
+
/**
* Method for converting raw data to Skia pixels.
* @param dstRow Row in which to write the resulting pixels.
* @param src Row of src data, in format specified by SrcConfig
* @param width Width in pixels
- * @param bpp bytes per pixel of the source.
+ * @param deltaSrc if bitsPerPixel % 8 == 0, deltaSrc is bytesPerPixel
+ * else, deltaSrc is bitsPerPixel
* @param y Line of source.
* @param ctable Colors (used for kIndex source).
*/
- typedef bool (*RowProc)(void* SK_RESTRICT dstRow,
- const uint8_t* SK_RESTRICT src,
- int width, int bpp, int y,
- const SkPMColor ctable[]);
+ typedef ResultAlpha (*RowProc)(void* SK_RESTRICT dstRow,
+ const uint8_t* SK_RESTRICT src,
+ int width, int deltaSrc, int y,
+ const SkPMColor ctable[]);
const RowProc fRowProc;
- const SkPMColor* fColorTable; // Unowned pointer
- const int fSrcPixelSize;
+ const SkPMColor* fColorTable; // Unowned pointer
+ const int fDeltaSrc; // if bitsPerPixel % 8 == 0
+ // deltaSrc is bytesPerPixel
+ // else
+ // deltaSrc is bitsPerPixel
const SkImageInfo fDstInfo;
void* fDstRow;
const size_t fDstRowBytes;
int fCurrY;
- SkSwizzler(RowProc proc, const SkPMColor* ctable, int srcBpp,
+ SkSwizzler(RowProc proc, const SkPMColor* ctable, int deltaSrc,
const SkImageInfo& info, void* dst, size_t rowBytes);
};