Rename SkGifCodec, SkIcoCodec, SkWbmpCodec

src/codec/SkCodec_wbmp.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 "SkCodec.h"
-#include "SkCodecPriv.h"
-#include "SkColorPriv.h"
-#include "SkColorTable.h"
-#include "SkData.h"
-#include "SkStream.h"
-#include "SkCodec_wbmp.h"
-
-// Each bit represents a pixel, so width is actually a number of bits.
-// A row will always be stored in bytes, so we round width up to the
-// nearest multiple of 8 to get the number of bits actually in the row.
-// We then divide by 8 to convert to bytes.
-static inline size_t get_src_row_bytes(int width) {
-    return SkAlign8(width) >> 3;
-}
-
-static inline void setup_color_table(SkColorType colorType,
-        SkPMColor* colorPtr, int* colorCount) {
-    if (kIndex_8_SkColorType == colorType) {
-        colorPtr[0] = SK_ColorBLACK;
-        colorPtr[1] = SK_ColorWHITE;
-        *colorCount = 2;
-    }
-}
-
-static bool read_byte(SkStream* stream, uint8_t* data)
-{
-    return stream->read(data, 1) == 1;
-}
-
-// http://en.wikipedia.org/wiki/Variable-length_quantity
-static bool read_mbf(SkStream* stream, uint64_t* value) {
-    uint64_t n = 0;
-    uint8_t data;
-    const uint64_t kLimit = 0xFE00000000000000;
-    SkASSERT(kLimit == ~((~static_cast<uint64_t>(0)) >> 7));
-    do {
-        if (n & kLimit) { // Will overflow on shift by 7.
-            return false;
-        }
-        if (stream->read(&data, 1) != 1) {
-            return false;
-        }
-        n = (n << 7) | (data & 0x7F);
-    } while (data & 0x80);
-    *value = n;
-    return true;
-}
-
-static bool read_header(SkStream* stream, SkISize* size) {
-    {
-        uint8_t data;
-        if (!read_byte(stream, &data) || data != 0) { // unknown type
-            return false;
-        }
-        if (!read_byte(stream, &data) || (data & 0x9F)) { // skip fixed header
-            return false;
-        }
-    }
-
-    uint64_t width, height;
-    if (!read_mbf(stream, &width) || width > 0xFFFF || !width) {
-        return false;
-    }
-    if (!read_mbf(stream, &height) || height > 0xFFFF || !height) {
-        return false;
-    }
-    if (size) {
-        *size = SkISize::Make(SkToS32(width), SkToS32(height));
-    }
-    return true;
-}
-
-bool SkWbmpCodec::onRewind() {
-    return read_header(this->stream(), nullptr);
-}
-
-SkSwizzler* SkWbmpCodec::initializeSwizzler(const SkImageInfo& info, const SkPMColor* ctable,
-        const Options& opts) {
-    // Create the swizzler based on the desired color type
-    switch (info.colorType()) {
-        case kIndex_8_SkColorType:
-        case kN32_SkColorType:
-        case kRGB_565_SkColorType:
-        case kGray_8_SkColorType:
-            break;
-        default:
-            return nullptr;
-    }
-    return SkSwizzler::CreateSwizzler(SkSwizzler::kBit, ctable, info, opts);
-}
-
-bool SkWbmpCodec::readRow(uint8_t* row) {
-    return this->stream()->read(row, fSrcRowBytes) == fSrcRowBytes;
-}
-
-SkWbmpCodec::SkWbmpCodec(const SkImageInfo& info, SkStream* stream)
-    : INHERITED(info, stream)
-    , fSrcRowBytes(get_src_row_bytes(this->getInfo().width()))
-    , fSwizzler(nullptr)
-    , fColorTable(nullptr)
-{}
-
-SkEncodedFormat SkWbmpCodec::onGetEncodedFormat() const {
-    return kWBMP_SkEncodedFormat;
-}
-
-SkCodec::Result SkWbmpCodec::onGetPixels(const SkImageInfo& info,
-                                         void* dst,
-                                         size_t rowBytes,
-                                         const Options& options,
-                                         SkPMColor ctable[],
-                                         int* ctableCount,
-                                         int* rowsDecoded) {
-    if (options.fSubset) {
-        // Subsets are not supported.
-        return kUnimplemented;
-    }
-
-    if (!valid_alpha(info.alphaType(), this->getInfo().alphaType())) {
-        return kInvalidConversion;
-    }
-
-    // Prepare a color table if necessary
-    setup_color_table(info.colorType(), ctable, ctableCount);
-
-    // Initialize the swizzler
-    SkAutoTDelete<SkSwizzler> swizzler(this->initializeSwizzler(info, ctable, options));
-    if (nullptr == swizzler.get()) {
-        return kInvalidConversion;
-    }
-
-    // Perform the decode
-    SkISize size = info.dimensions();
-    SkAutoTMalloc<uint8_t> src(fSrcRowBytes);
-    void* dstRow = dst;
-    for (int y = 0; y < size.height(); ++y) {
-        if (!this->readRow(src.get())) {
-            *rowsDecoded = y;
-            return kIncompleteInput;
-        }
-        swizzler->swizzle(dstRow, src.get());
-        dstRow = SkTAddOffset<void>(dstRow, rowBytes);
-    }
-    return kSuccess;
-}
-
-bool SkWbmpCodec::IsWbmp(const void* buffer, size_t bytesRead) {
-    SkAutoTUnref<SkData> data(SkData::NewWithoutCopy(buffer, bytesRead));
-    SkMemoryStream stream(data);
-    return read_header(&stream, nullptr);
-}
-
-SkCodec* SkWbmpCodec::NewFromStream(SkStream* stream) {
-    SkAutoTDelete<SkStream> streamDeleter(stream);
-    SkISize size;
-    if (!read_header(stream, &size)) {
-        return nullptr;
-    }
-    SkImageInfo info = SkImageInfo::Make(size.width(), size.height(),
-            kGray_8_SkColorType, kOpaque_SkAlphaType);
-    return new SkWbmpCodec(info, streamDeleter.detach());
-}
-
-int SkWbmpCodec::onGetScanlines(void* dst, int count, size_t dstRowBytes) {
-    void* dstRow = dst;
-    for (int y = 0; y < count; ++y) {
-        if (!this->readRow(fSrcBuffer.get())) {
-            return y;
-        }
-        fSwizzler->swizzle(dstRow, fSrcBuffer.get());
-        dstRow = SkTAddOffset<void>(dstRow, dstRowBytes);
-    }
-    return count;
-}
-
-SkCodec::Result SkWbmpCodec::onStartScanlineDecode(const SkImageInfo& dstInfo,
-        const Options& options, SkPMColor inputColorTable[], int* inputColorCount) {
-    if (options.fSubset) {
-        // Subsets are not supported.
-        return kUnimplemented;
-    }
-
-    if (!valid_alpha(dstInfo.alphaType(), this->getInfo().alphaType())) {
-        return kInvalidConversion;
-    }
-
-    // Fill in the color table
-    setup_color_table(dstInfo.colorType(), inputColorTable, inputColorCount);
-
-    // Copy the color table to a pointer that can be owned by the scanline decoder
-    if (kIndex_8_SkColorType == dstInfo.colorType()) {
-        fColorTable.reset(new SkColorTable(inputColorTable, 2));
-    }
-
-    // Initialize the swizzler
-    fSwizzler.reset(this->initializeSwizzler(dstInfo, get_color_ptr(fColorTable.get()), options));
-    if (nullptr == fSwizzler.get()) {
-        return kInvalidConversion;
-    }
-
-    fSrcBuffer.reset(fSrcRowBytes);
-
-    return kSuccess;
-}