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Diffstat (limited to 'tools/aapt2/compile/NinePatch.cpp')
| -rw-r--r-- | tools/aapt2/compile/NinePatch.cpp | 671 |
1 files changed, 671 insertions, 0 deletions
diff --git a/tools/aapt2/compile/NinePatch.cpp b/tools/aapt2/compile/NinePatch.cpp new file mode 100644 index 000000000000..408ecf71a44f --- /dev/null +++ b/tools/aapt2/compile/NinePatch.cpp @@ -0,0 +1,671 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "compile/Image.h" +#include "util/StringPiece.h" +#include "util/Util.h" + +#include <androidfw/ResourceTypes.h> +#include <sstream> +#include <string> +#include <vector> + +namespace aapt { + +// Colors in the format 0xAARRGGBB (the way 9-patch expects it). +constexpr static const uint32_t kColorOpaqueWhite = 0xffffffffu; +constexpr static const uint32_t kColorOpaqueBlack = 0xff000000u; +constexpr static const uint32_t kColorOpaqueRed = 0xffff0000u; + +constexpr static const uint32_t kPrimaryColor = kColorOpaqueBlack; +constexpr static const uint32_t kSecondaryColor = kColorOpaqueRed; + +/** + * Returns the alpha value encoded in the 0xAARRGBB encoded pixel. + */ +static uint32_t getAlpha(uint32_t color); + +/** + * Determines whether a color on an ImageLine is valid. + * A 9patch image may use a transparent color as neutral, + * or a fully opaque white color as neutral, based on the + * pixel color at (0,0) of the image. One or the other is fine, + * but we need to ensure consistency throughout the image. + */ +class ColorValidator { +public: + virtual ~ColorValidator() = default; + + /** + * Returns true if the color specified is a neutral color + * (no padding, stretching, or optical bounds). + */ + virtual bool isNeutralColor(uint32_t color) const = 0; + + /** + * Returns true if the color is either a neutral color + * or one denoting padding, stretching, or optical bounds. + */ + bool isValidColor(uint32_t color) const { + switch (color) { + case kPrimaryColor: + case kSecondaryColor: + return true; + } + return isNeutralColor(color); + } +}; + +// Walks an ImageLine and records Ranges of primary and secondary colors. +// The primary color is black and is used to denote a padding or stretching range, +// depending on which border we're iterating over. +// The secondary color is red and is used to denote optical bounds. +// +// An ImageLine is a templated-interface that would look something like this if it +// were polymorphic: +// +// class ImageLine { +// public: +// virtual int32_t getLength() const = 0; +// virtual uint32_t getColor(int32_t idx) const = 0; +// }; +// +template <typename ImageLine> +static bool fillRanges(const ImageLine* imageLine, + const ColorValidator* colorValidator, + std::vector<Range>* primaryRanges, + std::vector<Range>* secondaryRanges, + std::string* err) { + const int32_t length = imageLine->getLength(); + + uint32_t lastColor = 0xffffffffu; + for (int32_t idx = 1; idx < length - 1; idx++) { + const uint32_t color = imageLine->getColor(idx); + if (!colorValidator->isValidColor(color)) { + *err = "found an invalid color"; + return false; + } + + if (color != lastColor) { + // We are ending a range. Which range? + // note: encode the x offset without the final 1 pixel border. + if (lastColor == kPrimaryColor) { + primaryRanges->back().end = idx - 1; + } else if (lastColor == kSecondaryColor) { + secondaryRanges->back().end = idx - 1; + } + + // We are starting a range. Which range? + // note: encode the x offset without the final 1 pixel border. + if (color == kPrimaryColor) { + primaryRanges->push_back(Range(idx - 1, length - 2)); + } else if (color == kSecondaryColor) { + secondaryRanges->push_back(Range(idx - 1, length - 2)); + } + lastColor = color; + } + } + return true; +} + +/** + * Iterates over a row in an image. Implements the templated ImageLine interface. + */ +class HorizontalImageLine { +public: + explicit HorizontalImageLine(uint8_t** rows, int32_t xOffset, int32_t yOffset, + int32_t length) : + mRows(rows), mXOffset(xOffset), mYOffset(yOffset), mLength(length) { + } + + inline int32_t getLength() const { + return mLength; + } + + inline uint32_t getColor(int32_t idx) const { + return NinePatch::packRGBA(mRows[mYOffset] + (idx + mXOffset) * 4); + } + +private: + uint8_t** mRows; + int32_t mXOffset, mYOffset, mLength; + + DISALLOW_COPY_AND_ASSIGN(HorizontalImageLine); +}; + +/** + * Iterates over a column in an image. Implements the templated ImageLine interface. + */ +class VerticalImageLine { +public: + explicit VerticalImageLine(uint8_t** rows, int32_t xOffset, int32_t yOffset, + int32_t length) : + mRows(rows), mXOffset(xOffset), mYOffset(yOffset), mLength(length) { + } + + inline int32_t getLength() const { + return mLength; + } + + inline uint32_t getColor(int32_t idx) const { + return NinePatch::packRGBA(mRows[mYOffset + idx] + (mXOffset * 4)); + } + +private: + uint8_t** mRows; + int32_t mXOffset, mYOffset, mLength; + + DISALLOW_COPY_AND_ASSIGN(VerticalImageLine); +}; + +class DiagonalImageLine { +public: + explicit DiagonalImageLine(uint8_t** rows, int32_t xOffset, int32_t yOffset, + int32_t xStep, int32_t yStep, int32_t length) : + mRows(rows), mXOffset(xOffset), mYOffset(yOffset), mXStep(xStep), mYStep(yStep), + mLength(length) { + } + + inline int32_t getLength() const { + return mLength; + } + + inline uint32_t getColor(int32_t idx) const { + return NinePatch::packRGBA( + mRows[mYOffset + (idx * mYStep)] + ((idx + mXOffset) * mXStep) * 4); + } + +private: + uint8_t** mRows; + int32_t mXOffset, mYOffset, mXStep, mYStep, mLength; + + DISALLOW_COPY_AND_ASSIGN(DiagonalImageLine); +}; + +class TransparentNeutralColorValidator : public ColorValidator { +public: + bool isNeutralColor(uint32_t color) const override { + return getAlpha(color) == 0; + } +}; + +class WhiteNeutralColorValidator : public ColorValidator { +public: + bool isNeutralColor(uint32_t color) const override { + return color == kColorOpaqueWhite; + } +}; + +inline static uint32_t getAlpha(uint32_t color) { + return (color & 0xff000000u) >> 24; +} + +static bool populateBounds(const std::vector<Range>& padding, + const std::vector<Range>& layoutBounds, + const std::vector<Range>& stretchRegions, + const int32_t length, + int32_t* paddingStart, int32_t* paddingEnd, + int32_t* layoutStart, int32_t* layoutEnd, + const StringPiece& edgeName, + std::string* err) { + if (padding.size() > 1) { + std::stringstream errStream; + errStream << "too many padding sections on " << edgeName << " border"; + *err = errStream.str(); + return false; + } + + *paddingStart = 0; + *paddingEnd = 0; + if (!padding.empty()) { + const Range& range = padding.front(); + *paddingStart = range.start; + *paddingEnd = length - range.end; + } else if (!stretchRegions.empty()) { + // No padding was defined. Compute the padding from the first and last + // stretch regions. + *paddingStart = stretchRegions.front().start; + *paddingEnd = length - stretchRegions.back().end; + } + + if (layoutBounds.size() > 2) { + std::stringstream errStream; + errStream << "too many layout bounds sections on " << edgeName << " border"; + *err = errStream.str(); + return false; + } + + *layoutStart = 0; + *layoutEnd = 0; + if (layoutBounds.size() >= 1) { + const Range& range = layoutBounds.front(); + // If there is only one layout bound segment, it might not start at 0, but then it should + // end at length. + if (range.start != 0 && range.end != length) { + std::stringstream errStream; + errStream << "layout bounds on " << edgeName << " border must start at edge"; + *err = errStream.str(); + return false; + } + *layoutStart = range.end; + + if (layoutBounds.size() >= 2) { + const Range& range = layoutBounds.back(); + if (range.end != length) { + std::stringstream errStream; + errStream << "layout bounds on " << edgeName << " border must start at edge"; + *err = errStream.str(); + return false; + } + *layoutEnd = length - range.start; + } + } + return true; +} + +static int32_t calculateSegmentCount(const std::vector<Range>& stretchRegions, int32_t length) { + if (stretchRegions.size() == 0) { + return 0; + } + + const bool startIsFixed = stretchRegions.front().start != 0; + const bool endIsFixed = stretchRegions.back().end != length; + int32_t modifier = 0; + if (startIsFixed && endIsFixed) { + modifier = 1; + } else if (!startIsFixed && !endIsFixed) { + modifier = -1; + } + return static_cast<int32_t>(stretchRegions.size()) * 2 + modifier; +} + +static uint32_t getRegionColor(uint8_t** rows, const Bounds& region) { + // Sample the first pixel to compare against. + const uint32_t expectedColor = NinePatch::packRGBA(rows[region.top] + region.left * 4); + for (int32_t y = region.top; y < region.bottom; y++) { + const uint8_t* row = rows[y]; + for (int32_t x = region.left; x < region.right; x++) { + const uint32_t color = NinePatch::packRGBA(row + x * 4); + if (getAlpha(color) == 0) { + // The color is transparent. + // If the expectedColor is not transparent, NO_COLOR. + if (getAlpha(expectedColor) != 0) { + return android::Res_png_9patch::NO_COLOR; + } + } else if (color != expectedColor) { + return android::Res_png_9patch::NO_COLOR; + } + } + } + + if (getAlpha(expectedColor) == 0) { + return android::Res_png_9patch::TRANSPARENT_COLOR; + } + return expectedColor; +} + +// Fills outColors with each 9-patch section's colour. If the whole section is transparent, +// it gets the special TRANSPARENT colour. If the whole section is the same colour, it is assigned +// that colour. Otherwise it gets the special NO_COLOR colour. +// +// Note that the rows contain the 9-patch 1px border, and the indices in the stretch regions are +// already offset to exclude the border. This means that each time the rows are accessed, +// the indices must be offset by 1. +// +// width and height also include the 9-patch 1px border. +static void calculateRegionColors(uint8_t** rows, + const std::vector<Range>& horizontalStretchRegions, + const std::vector<Range>& verticalStretchRegions, + const int32_t width, const int32_t height, + std::vector<uint32_t>* outColors) { + int32_t nextTop = 0; + Bounds bounds; + auto rowIter = verticalStretchRegions.begin(); + while (nextTop != height) { + if (rowIter != verticalStretchRegions.end()) { + if (nextTop != rowIter->start) { + // This is a fixed segment. + // Offset the bounds by 1 to accommodate the border. + bounds.top = nextTop + 1; + bounds.bottom = rowIter->start + 1; + nextTop = rowIter->start; + } else { + // This is a stretchy segment. + // Offset the bounds by 1 to accommodate the border. + bounds.top = rowIter->start + 1; + bounds.bottom = rowIter->end + 1; + nextTop = rowIter->end; + ++rowIter; + } + } else { + // This is the end, fixed section. + // Offset the bounds by 1 to accommodate the border. + bounds.top = nextTop + 1; + bounds.bottom = height + 1; + nextTop = height; + } + + int32_t nextLeft = 0; + auto colIter = horizontalStretchRegions.begin(); + while (nextLeft != width) { + if (colIter != horizontalStretchRegions.end()) { + if (nextLeft != colIter->start) { + // This is a fixed segment. + // Offset the bounds by 1 to accommodate the border. + bounds.left = nextLeft + 1; + bounds.right = colIter->start + 1; + nextLeft = colIter->start; + } else { + // This is a stretchy segment. + // Offset the bounds by 1 to accommodate the border. + bounds.left = colIter->start + 1; + bounds.right = colIter->end + 1; + nextLeft = colIter->end; + ++colIter; + } + } else { + // This is the end, fixed section. + // Offset the bounds by 1 to accommodate the border. + bounds.left = nextLeft + 1; + bounds.right = width + 1; + nextLeft = width; + } + outColors->push_back(getRegionColor(rows, bounds)); + } + } +} + +// Calculates the insets of a row/column of pixels based on where the largest alpha value begins +// (on both sides). +template <typename ImageLine> +static void findOutlineInsets(const ImageLine* imageLine, int32_t* outStart, int32_t* outEnd) { + *outStart = 0; + *outEnd = 0; + + const int32_t length = imageLine->getLength(); + if (length < 3) { + return; + } + + // If the length is odd, we want both sides to process the center pixel, + // so we use two different midpoints (to account for < and <= in the different loops). + const int32_t mid2 = length / 2; + const int32_t mid1 = mid2 + (length % 2); + + uint32_t maxAlpha = 0; + for (int32_t i = 0; i < mid1 && maxAlpha != 0xff; i++) { + uint32_t alpha = getAlpha(imageLine->getColor(i)); + if (alpha > maxAlpha) { + maxAlpha = alpha; + *outStart = i; + } + } + + maxAlpha = 0; + for (int32_t i = length - 1; i >= mid2 && maxAlpha != 0xff; i--) { + uint32_t alpha = getAlpha(imageLine->getColor(i)); + if (alpha > maxAlpha) { + maxAlpha = alpha; + *outEnd = length - (i + 1); + } + } + return; +} + +template <typename ImageLine> +static uint32_t findMaxAlpha(const ImageLine* imageLine) { + const int32_t length = imageLine->getLength(); + uint32_t maxAlpha = 0; + for (int32_t idx = 0; idx < length && maxAlpha != 0xff; idx++) { + uint32_t alpha = getAlpha(imageLine->getColor(idx)); + if (alpha > maxAlpha) { + maxAlpha = alpha; + } + } + return maxAlpha; +} + +// Pack the pixels in as 0xAARRGGBB (as 9-patch expects it). +uint32_t NinePatch::packRGBA(const uint8_t* pixel) { + return (pixel[3] << 24) | (pixel[0] << 16) | (pixel[1] << 8) | pixel[2]; +} + +std::unique_ptr<NinePatch> NinePatch::create(uint8_t** rows, + const int32_t width, const int32_t height, + std::string* err) { + if (width < 3 || height < 3) { + *err = "image must be at least 3x3 (1x1 image with 1 pixel border)"; + return {}; + } + + std::vector<Range> horizontalPadding; + std::vector<Range> horizontalOpticalBounds; + std::vector<Range> verticalPadding; + std::vector<Range> verticalOpticalBounds; + std::vector<Range> unexpectedRanges; + std::unique_ptr<ColorValidator> colorValidator; + + if (rows[0][3] == 0) { + colorValidator = util::make_unique<TransparentNeutralColorValidator>(); + } else if (packRGBA(rows[0]) == kColorOpaqueWhite) { + colorValidator = util::make_unique<WhiteNeutralColorValidator>(); + } else { + *err = "top-left corner pixel must be either opaque white or transparent"; + return {}; + } + + // Private constructor, can't use make_unique. + auto ninePatch = std::unique_ptr<NinePatch>(new NinePatch()); + + HorizontalImageLine topRow(rows, 0, 0, width); + if (!fillRanges(&topRow, colorValidator.get(), &ninePatch->horizontalStretchRegions, + &unexpectedRanges, err)) { + return {}; + } + + if (!unexpectedRanges.empty()) { + const Range& range = unexpectedRanges[0]; + std::stringstream errStream; + errStream << "found unexpected optical bounds (red pixel) on top border " + << "at x=" << range.start + 1; + *err = errStream.str(); + return {}; + } + + VerticalImageLine leftCol(rows, 0, 0, height); + if (!fillRanges(&leftCol, colorValidator.get(), &ninePatch->verticalStretchRegions, + &unexpectedRanges, err)) { + return {}; + } + + if (!unexpectedRanges.empty()) { + const Range& range = unexpectedRanges[0]; + std::stringstream errStream; + errStream << "found unexpected optical bounds (red pixel) on left border " + << "at y=" << range.start + 1; + return {}; + } + + HorizontalImageLine bottomRow(rows, 0, height - 1, width); + if (!fillRanges(&bottomRow, colorValidator.get(), &horizontalPadding, + &horizontalOpticalBounds, err)) { + return {}; + } + + if (!populateBounds(horizontalPadding, horizontalOpticalBounds, + ninePatch->horizontalStretchRegions, width - 2, + &ninePatch->padding.left, &ninePatch->padding.right, + &ninePatch->layoutBounds.left, &ninePatch->layoutBounds.right, + "bottom", err)) { + return {}; + } + + VerticalImageLine rightCol(rows, width - 1, 0, height); + if (!fillRanges(&rightCol, colorValidator.get(), &verticalPadding, + &verticalOpticalBounds, err)) { + return {}; + } + + if (!populateBounds(verticalPadding, verticalOpticalBounds, + ninePatch->verticalStretchRegions, height - 2, + &ninePatch->padding.top, &ninePatch->padding.bottom, + &ninePatch->layoutBounds.top, &ninePatch->layoutBounds.bottom, + "right", err)) { + return {}; + } + + // Fill the region colors of the 9-patch. + const int32_t numRows = calculateSegmentCount(ninePatch->horizontalStretchRegions, width - 2); + const int32_t numCols = calculateSegmentCount(ninePatch->verticalStretchRegions, height - 2); + if ((int64_t) numRows * (int64_t) numCols > 0x7f) { + *err = "too many regions in 9-patch"; + return {}; + } + + ninePatch->regionColors.reserve(numRows * numCols); + calculateRegionColors(rows, ninePatch->horizontalStretchRegions, + ninePatch->verticalStretchRegions, + width - 2, height - 2, + &ninePatch->regionColors); + + // Compute the outline based on opacity. + + // Find left and right extent of 9-patch content on center row. + HorizontalImageLine midRow(rows, 1, height / 2, width - 2); + findOutlineInsets(&midRow, &ninePatch->outline.left, &ninePatch->outline.right); + + // Find top and bottom extent of 9-patch content on center column. + VerticalImageLine midCol(rows, width / 2, 1, height - 2); + findOutlineInsets(&midCol, &ninePatch->outline.top, &ninePatch->outline.bottom); + + const int32_t outlineWidth = (width - 2) - ninePatch->outline.left - ninePatch->outline.right; + const int32_t outlineHeight = (height - 2) - ninePatch->outline.top - ninePatch->outline.bottom; + + // Find the largest alpha value within the outline area. + HorizontalImageLine outlineMidRow(rows, + 1 + ninePatch->outline.left, + 1 + ninePatch->outline.top + (outlineHeight / 2), + outlineWidth); + VerticalImageLine outlineMidCol(rows, + 1 + ninePatch->outline.left + (outlineWidth / 2), + 1 + ninePatch->outline.top, + outlineHeight); + ninePatch->outlineAlpha = std::max(findMaxAlpha(&outlineMidRow), findMaxAlpha(&outlineMidCol)); + + // Assuming the image is a round rect, compute the radius by marching + // diagonally from the top left corner towards the center. + DiagonalImageLine diagonal(rows, 1 + ninePatch->outline.left, 1 + ninePatch->outline.top, + 1, 1, std::min(outlineWidth, outlineHeight)); + int32_t topLeft, bottomRight; + findOutlineInsets(&diagonal, &topLeft, &bottomRight); + + /* Determine source radius based upon inset: + * sqrt(r^2 + r^2) = sqrt(i^2 + i^2) + r + * sqrt(2) * r = sqrt(2) * i + r + * (sqrt(2) - 1) * r = sqrt(2) * i + * r = sqrt(2) / (sqrt(2) - 1) * i + */ + ninePatch->outlineRadius = 3.4142f * topLeft; + return ninePatch; +} + +std::unique_ptr<uint8_t[]> NinePatch::serializeBase(size_t* outLen) const { + android::Res_png_9patch data; + data.numXDivs = static_cast<uint8_t>(horizontalStretchRegions.size()) * 2; + data.numYDivs = static_cast<uint8_t>(verticalStretchRegions.size()) * 2; + data.numColors = static_cast<uint8_t>(regionColors.size()); + data.paddingLeft = padding.left; + data.paddingRight = padding.right; + data.paddingTop = padding.top; + data.paddingBottom = padding.bottom; + + auto buffer = std::unique_ptr<uint8_t[]>(new uint8_t[data.serializedSize()]); + android::Res_png_9patch::serialize(data, + (const int32_t*) horizontalStretchRegions.data(), + (const int32_t*) verticalStretchRegions.data(), + regionColors.data(), + buffer.get()); + *outLen = data.serializedSize(); + return buffer; +} + +std::unique_ptr<uint8_t[]> NinePatch::serializeLayoutBounds(size_t* outLen) const { + size_t chunkLen = sizeof(uint32_t) * 4; + auto buffer = std::unique_ptr<uint8_t[]>(new uint8_t[chunkLen]); + uint8_t* cursor = buffer.get(); + + memcpy(cursor, &layoutBounds.left, sizeof(layoutBounds.left)); + cursor += sizeof(layoutBounds.left); + + memcpy(cursor, &layoutBounds.top, sizeof(layoutBounds.top)); + cursor += sizeof(layoutBounds.top); + + memcpy(cursor, &layoutBounds.right, sizeof(layoutBounds.right)); + cursor += sizeof(layoutBounds.right); + + memcpy(cursor, &layoutBounds.bottom, sizeof(layoutBounds.bottom)); + cursor += sizeof(layoutBounds.bottom); + + *outLen = chunkLen; + return buffer; +} + +std::unique_ptr<uint8_t[]> NinePatch::serializeRoundedRectOutline(size_t* outLen) const { + size_t chunkLen = sizeof(uint32_t) * 6; + auto buffer = std::unique_ptr<uint8_t[]>(new uint8_t[chunkLen]); + uint8_t* cursor = buffer.get(); + + memcpy(cursor, &outline.left, sizeof(outline.left)); + cursor += sizeof(outline.left); + + memcpy(cursor, &outline.top, sizeof(outline.top)); + cursor += sizeof(outline.top); + + memcpy(cursor, &outline.right, sizeof(outline.right)); + cursor += sizeof(outline.right); + + memcpy(cursor, &outline.bottom, sizeof(outline.bottom)); + cursor += sizeof(outline.bottom); + + *((float*) cursor) = outlineRadius; + cursor += sizeof(outlineRadius); + + *((uint32_t*) cursor) = outlineAlpha; + + *outLen = chunkLen; + return buffer; +} + +::std::ostream& operator<<(::std::ostream& out, const Range& range) { + return out << "[" << range.start << ", " << range.end << ")"; +} + +::std::ostream& operator<<(::std::ostream& out, const Bounds& bounds) { + return out << "l=" << bounds.left + << " t=" << bounds.top + << " r=" << bounds.right + << " b=" << bounds.bottom; +} + +::std::ostream& operator<<(::std::ostream& out, const NinePatch& ninePatch) { + return out << "padding: " << ninePatch.padding + << ", bounds: " << ninePatch.layoutBounds + << ", outline: " << ninePatch.outline + << " rad=" << ninePatch.outlineRadius + << " alpha=" << ninePatch.outlineAlpha; +} + +} // namespace aapt |