--- /dev/null
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "ktx.h"
+#include "SkBitmap.h"
+#include "SkStream.h"
+#include "SkEndian.h"
+
+#include "gl/GrGLDefines.h"
+#include "GrConfig.h"
+
+#include "etc1.h"
+
+static inline uint32_t compressed_fmt_to_gl_define(SkTextureCompressor::Format fmt) {
+ static const uint32_t kGLDefineMap[SkTextureCompressor::kFormatCnt] = {
+ GR_GL_COMPRESSED_LUMINANCE_LATC1, // kLATC_Format
+ GR_GL_COMPRESSED_R11_EAC, // kR11_EAC_Format
+ GR_GL_COMPRESSED_ETC1_RGB8, // kETC1_Format
+ GR_GL_COMPRESSED_RGBA_ASTC_4x4, // kASTC_4x4_Format
+ GR_GL_COMPRESSED_RGBA_ASTC_5x4, // kASTC_5x4_Format
+ GR_GL_COMPRESSED_RGBA_ASTC_5x5, // kASTC_5x5_Format
+ GR_GL_COMPRESSED_RGBA_ASTC_6x5, // kASTC_6x5_Format
+ GR_GL_COMPRESSED_RGBA_ASTC_6x6, // kASTC_6x6_Format
+ GR_GL_COMPRESSED_RGBA_ASTC_8x5, // kASTC_8x5_Format
+ GR_GL_COMPRESSED_RGBA_ASTC_8x6, // kASTC_8x6_Format
+ GR_GL_COMPRESSED_RGBA_ASTC_8x8, // kASTC_8x8_Format
+ GR_GL_COMPRESSED_RGBA_ASTC_10x5, // kASTC_10x5_Format
+ GR_GL_COMPRESSED_RGBA_ASTC_10x6, // kASTC_10x6_Format
+ GR_GL_COMPRESSED_RGBA_ASTC_10x8, // kASTC_10x8_Format
+ GR_GL_COMPRESSED_RGBA_ASTC_10x10, // kASTC_10x10_Format
+ GR_GL_COMPRESSED_RGBA_ASTC_12x10, // kASTC_12x10_Format
+ GR_GL_COMPRESSED_RGBA_ASTC_12x12, // kASTC_12x12_Format
+ };
+
+ GR_STATIC_ASSERT(0 == SkTextureCompressor::kLATC_Format);
+ GR_STATIC_ASSERT(1 == SkTextureCompressor::kR11_EAC_Format);
+ GR_STATIC_ASSERT(2 == SkTextureCompressor::kETC1_Format);
+ GR_STATIC_ASSERT(3 == SkTextureCompressor::kASTC_4x4_Format);
+ GR_STATIC_ASSERT(4 == SkTextureCompressor::kASTC_5x4_Format);
+ GR_STATIC_ASSERT(5 == SkTextureCompressor::kASTC_5x5_Format);
+ GR_STATIC_ASSERT(6 == SkTextureCompressor::kASTC_6x5_Format);
+ GR_STATIC_ASSERT(7 == SkTextureCompressor::kASTC_6x6_Format);
+ GR_STATIC_ASSERT(8 == SkTextureCompressor::kASTC_8x5_Format);
+ GR_STATIC_ASSERT(9 == SkTextureCompressor::kASTC_8x6_Format);
+ GR_STATIC_ASSERT(10 == SkTextureCompressor::kASTC_8x8_Format);
+ GR_STATIC_ASSERT(11 == SkTextureCompressor::kASTC_10x5_Format);
+ GR_STATIC_ASSERT(12 == SkTextureCompressor::kASTC_10x6_Format);
+ GR_STATIC_ASSERT(13 == SkTextureCompressor::kASTC_10x8_Format);
+ GR_STATIC_ASSERT(14 == SkTextureCompressor::kASTC_10x10_Format);
+ GR_STATIC_ASSERT(15 == SkTextureCompressor::kASTC_12x10_Format);
+ GR_STATIC_ASSERT(16 == SkTextureCompressor::kASTC_12x12_Format);
+ GR_STATIC_ASSERT(SK_ARRAY_COUNT(kGLDefineMap) == SkTextureCompressor::kFormatCnt);
+
+ return kGLDefineMap[fmt];
+}
+
+#define KTX_FILE_IDENTIFIER_SIZE 12
+static const uint8_t KTX_FILE_IDENTIFIER[KTX_FILE_IDENTIFIER_SIZE] = {
+ 0xAB, 0x4B, 0x54, 0x58, 0x20, 0x31, 0x31, 0xBB, 0x0D, 0x0A, 0x1A, 0x0A
+};
+
+static const uint32_t kKTX_ENDIANNESS_CODE = 0x04030201;
+
+bool SkKTXFile::KeyValue::readKeyAndValue(const uint8_t* data) {
+ const char *key = reinterpret_cast<const char *>(data);
+ const char *value = key;
+
+ size_t bytesRead = 0;
+ while (*value != '\0' && bytesRead < this->fDataSz) {
+ ++bytesRead;
+ ++value;
+ }
+
+ // Error of some sort..
+ if (bytesRead >= this->fDataSz) {
+ return false;
+ }
+
+ // Read the zero terminator
+ ++bytesRead;
+ ++value;
+
+ size_t bytesLeft = this->fDataSz - bytesRead;
+
+ // We ignore the null terminator when setting the string value.
+ this->fKey.set(key, bytesRead - 1);
+ if (bytesLeft > 0) {
+ this->fValue.set(value, bytesLeft - 1);
+ } else {
+ return false;
+ }
+
+ return true;
+}
+
+bool SkKTXFile::KeyValue::writeKeyAndValueForKTX(SkWStream* strm) {
+ size_t bytesWritten = 0;
+ if (!strm->write(&(this->fDataSz), 4)) {
+ return false;
+ }
+
+ bytesWritten += 4;
+
+ // Here we know that C-strings must end with a null terminating
+ // character, so when we get a c_str(), it will have as many
+ // bytes of data as size() returns plus a zero, so we just
+ // write size() + 1 bytes into the stream.
+
+ size_t keySize = this->fKey.size() + 1;
+ if (!strm->write(this->fKey.c_str(), keySize)) {
+ return false;
+ }
+
+ bytesWritten += keySize;
+
+ size_t valueSize = this->fValue.size() + 1;
+ if (!strm->write(this->fValue.c_str(), valueSize)) {
+ return false;
+ }
+
+ bytesWritten += valueSize;
+
+ size_t bytesWrittenPadFour = (bytesWritten + 3) & ~3;
+ uint8_t nullBuf[4] = { 0, 0, 0, 0 };
+
+ size_t padding = bytesWrittenPadFour - bytesWritten;
+ SkASSERT(padding < 4);
+
+ return strm->write(nullBuf, padding);
+}
+
+uint32_t SkKTXFile::readInt(const uint8_t** buf, size_t* bytesLeft) const {
+ SkASSERT(buf && bytesLeft);
+
+ uint32_t result;
+
+ if (*bytesLeft < 4) {
+ SkASSERT(false);
+ return 0;
+ }
+
+ memcpy(&result, *buf, 4);
+ *buf += 4;
+
+ if (fSwapBytes) {
+ SkEndianSwap32(result);
+ }
+
+ *bytesLeft -= 4;
+
+ return result;
+}
+
+SkString SkKTXFile::getValueForKey(const SkString& key) const {
+ const KeyValue *begin = this->fKeyValuePairs.begin();
+ const KeyValue *end = this->fKeyValuePairs.end();
+ for (const KeyValue *kv = begin; kv != end; ++kv) {
+ if (kv->key() == key) {
+ return kv->value();
+ }
+ }
+ return SkString();
+}
+
+bool SkKTXFile::isCompressedFormat(SkTextureCompressor::Format fmt) const {
+ if (!this->valid()) {
+ return false;
+ }
+
+ // This has many aliases
+ bool isFmt = false;
+ if (fmt == SkTextureCompressor::kLATC_Format) {
+ isFmt = GR_GL_COMPRESSED_RED_RGTC1 == fHeader.fGLInternalFormat ||
+ GR_GL_COMPRESSED_3DC_X == fHeader.fGLInternalFormat;
+ }
+
+ return isFmt || compressed_fmt_to_gl_define(fmt) == fHeader.fGLInternalFormat;
+}
+
+bool SkKTXFile::isRGBA8() const {
+ return this->valid() && GR_GL_RGBA8 == fHeader.fGLInternalFormat;
+}
+
+bool SkKTXFile::isRGB8() const {
+ return this->valid() && GR_GL_RGB8 == fHeader.fGLInternalFormat;
+}
+
+bool SkKTXFile::readKTXFile(const uint8_t* data, size_t dataLen) {
+ const uint8_t *buf = data;
+ size_t bytesLeft = dataLen;
+
+ // Make sure original KTX header is there... this should have been checked
+ // already by a call to is_ktx()
+ SkASSERT(bytesLeft > KTX_FILE_IDENTIFIER_SIZE);
+ SkASSERT(0 == memcmp(KTX_FILE_IDENTIFIER, buf, KTX_FILE_IDENTIFIER_SIZE));
+ buf += KTX_FILE_IDENTIFIER_SIZE;
+ bytesLeft -= KTX_FILE_IDENTIFIER_SIZE;
+
+ // Read header, but first make sure that we have the proper space: we need
+ // two 32-bit ints: 1 for endianness, and another for the mandatory image
+ // size after the header.
+ if (bytesLeft < 8 + sizeof(Header)) {
+ return false;
+ }
+
+ uint32_t endianness = this->readInt(&buf, &bytesLeft);
+ fSwapBytes = kKTX_ENDIANNESS_CODE != endianness;
+
+ // Read header values
+ fHeader.fGLType = this->readInt(&buf, &bytesLeft);
+ fHeader.fGLTypeSize = this->readInt(&buf, &bytesLeft);
+ fHeader.fGLFormat = this->readInt(&buf, &bytesLeft);
+ fHeader.fGLInternalFormat = this->readInt(&buf, &bytesLeft);
+ fHeader.fGLBaseInternalFormat = this->readInt(&buf, &bytesLeft);
+ fHeader.fPixelWidth = this->readInt(&buf, &bytesLeft);
+ fHeader.fPixelHeight = this->readInt(&buf, &bytesLeft);
+ fHeader.fPixelDepth = this->readInt(&buf, &bytesLeft);
+ fHeader.fNumberOfArrayElements = this->readInt(&buf, &bytesLeft);
+ fHeader.fNumberOfFaces = this->readInt(&buf, &bytesLeft);
+ fHeader.fNumberOfMipmapLevels = this->readInt(&buf, &bytesLeft);
+ fHeader.fBytesOfKeyValueData = this->readInt(&buf, &bytesLeft);
+
+ // Check for things that we understand...
+ {
+ // First, we only support compressed formats and single byte
+ // representations at the moment. If the internal format is
+ // compressed, the the GLType field in the header must be zero.
+ // In the future, we may support additional data types (such
+ // as GL_UNSIGNED_SHORT_5_6_5)
+ if (fHeader.fGLType != 0 && fHeader.fGLType != GR_GL_UNSIGNED_BYTE) {
+ return false;
+ }
+
+ // This means that for well-formatted KTX files, the glTypeSize
+ // field must be one...
+ if (fHeader.fGLTypeSize != 1) {
+ return false;
+ }
+
+ // We don't support 3D textures.
+ if (fHeader.fPixelDepth > 1) {
+ return false;
+ }
+
+ // We don't support texture arrays
+ if (fHeader.fNumberOfArrayElements > 1) {
+ return false;
+ }
+
+ // We don't support cube maps
+ if (fHeader.fNumberOfFaces > 1) {
+ return false;
+ }
+
+ // We don't support width and/or height <= 0
+ if (fHeader.fPixelWidth <= 0 || fHeader.fPixelHeight <= 0) {
+ return false;
+ }
+ }
+
+ // Make sure that we have enough bytes left for the key/value
+ // data according to what was said in the header.
+ if (bytesLeft < fHeader.fBytesOfKeyValueData) {
+ return false;
+ }
+
+ // Next read the key value pairs
+ size_t keyValueBytesRead = 0;
+ while (keyValueBytesRead < fHeader.fBytesOfKeyValueData) {
+ uint32_t keyValueBytes = this->readInt(&buf, &bytesLeft);
+ keyValueBytesRead += 4;
+
+ if (keyValueBytes > bytesLeft) {
+ return false;
+ }
+
+ KeyValue kv(keyValueBytes);
+ if (!kv.readKeyAndValue(buf)) {
+ return false;
+ }
+
+ fKeyValuePairs.push_back(kv);
+
+ uint32_t keyValueBytesPadded = (keyValueBytes + 3) & ~3;
+ buf += keyValueBytesPadded;
+ keyValueBytesRead += keyValueBytesPadded;
+ bytesLeft -= keyValueBytesPadded;
+ }
+
+ // Read the pixel data...
+ int mipmaps = SkMax32(fHeader.fNumberOfMipmapLevels, 1);
+ SkASSERT(mipmaps == 1);
+
+ int arrayElements = SkMax32(fHeader.fNumberOfArrayElements, 1);
+ SkASSERT(arrayElements == 1);
+
+ int faces = SkMax32(fHeader.fNumberOfFaces, 1);
+ SkASSERT(faces == 1);
+
+ int depth = SkMax32(fHeader.fPixelDepth, 1);
+ SkASSERT(depth == 1);
+
+ for (int mipmap = 0; mipmap < mipmaps; ++mipmap) {
+ // Make sure that we have at least 4 more bytes for the first image size
+ if (bytesLeft < 4) {
+ return false;
+ }
+
+ uint32_t imgSize = this->readInt(&buf, &bytesLeft);
+
+ // Truncated file.
+ if (bytesLeft < imgSize) {
+ return false;
+ }
+
+ // !FIXME! If support is ever added for cube maps then the padding
+ // needs to be taken into account here.
+ for (int arrayElement = 0; arrayElement < arrayElements; ++arrayElement) {
+ for (int face = 0; face < faces; ++face) {
+ for (int z = 0; z < depth; ++z) {
+ PixelData pd(buf, imgSize);
+ fPixelData.append(1, &pd);
+ }
+ }
+ }
+
+ uint32_t imgSizePadded = (imgSize + 3) & ~3;
+ buf += imgSizePadded;
+ bytesLeft -= imgSizePadded;
+ }
+
+ return bytesLeft == 0;
+}
+
+bool SkKTXFile::is_ktx(const uint8_t data[], size_t size) {
+ return size >= KTX_FILE_IDENTIFIER_SIZE &&
+ 0 == memcmp(KTX_FILE_IDENTIFIER, data, KTX_FILE_IDENTIFIER_SIZE);
+}
+
+bool SkKTXFile::is_ktx(SkStreamRewindable* stream) {
+ // Read the KTX header and make sure it's valid.
+ unsigned char buf[KTX_FILE_IDENTIFIER_SIZE];
+ bool largeEnough =
+ stream->read((void*)buf, KTX_FILE_IDENTIFIER_SIZE) == KTX_FILE_IDENTIFIER_SIZE;
+ stream->rewind();
+ if (!largeEnough) {
+ return false;
+ }
+ return is_ktx(buf, KTX_FILE_IDENTIFIER_SIZE);
+}
+
+SkKTXFile::KeyValue SkKTXFile::CreateKeyValue(const char *cstrKey, const char *cstrValue) {
+ SkString key(cstrKey);
+ SkString value(cstrValue);
+
+ // Size of buffer is length of string plus the null terminators...
+ size_t size = key.size() + 1 + value.size() + 1;
+
+ SkAutoSMalloc<256> buf(size);
+ uint8_t* kvBuf = reinterpret_cast<uint8_t*>(buf.get());
+ memcpy(kvBuf, key.c_str(), key.size() + 1);
+ memcpy(kvBuf + key.size() + 1, value.c_str(), value.size() + 1);
+
+ KeyValue kv(size);
+ SkAssertResult(kv.readKeyAndValue(kvBuf));
+ return kv;
+}
+
+bool SkKTXFile::WriteETC1ToKTX(SkWStream* stream, const uint8_t *etc1Data,
+ uint32_t width, uint32_t height) {
+ // First thing's first, write out the magic identifier and endianness...
+ if (!stream->write(KTX_FILE_IDENTIFIER, KTX_FILE_IDENTIFIER_SIZE)) {
+ return false;
+ }
+
+ if (!stream->write(&kKTX_ENDIANNESS_CODE, 4)) {
+ return false;
+ }
+
+ Header hdr;
+ hdr.fGLType = 0;
+ hdr.fGLTypeSize = 1;
+ hdr.fGLFormat = 0;
+ hdr.fGLInternalFormat = GR_GL_COMPRESSED_ETC1_RGB8;
+ hdr.fGLBaseInternalFormat = GR_GL_RGB;
+ hdr.fPixelWidth = width;
+ hdr.fPixelHeight = height;
+ hdr.fNumberOfArrayElements = 0;
+ hdr.fNumberOfFaces = 1;
+ hdr.fNumberOfMipmapLevels = 1;
+
+ // !FIXME! The spec suggests that we put KTXOrientation as a
+ // key value pair in the header, but that means that we'd have to
+ // pipe through the pixmap's orientation to properly do that.
+ hdr.fBytesOfKeyValueData = 0;
+
+ // Write the header
+ if (!stream->write(&hdr, sizeof(hdr))) {
+ return false;
+ }
+
+ // Write the size of the image data
+ etc1_uint32 dataSize = etc1_get_encoded_data_size(width, height);
+ if (!stream->write(&dataSize, 4)) {
+ return false;
+ }
+
+ // Write the actual image data
+ if (!stream->write(etc1Data, dataSize)) {
+ return false;
+ }
+
+ return true;
+}
+
+bool SkKTXFile::WritePixmapToKTX(SkWStream* stream, const SkPixmap& pixmap) {
+ const SkColorType ct = pixmap.colorType();
+
+ const int width = pixmap.width();
+ const int height = pixmap.height();
+ const uint8_t* src = reinterpret_cast<const uint8_t*>(pixmap.addr());
+ if (!src) {
+ return false;
+ }
+ const size_t rowBytes = pixmap.rowBytes();
+ const int bytesPerPixel = pixmap.info().bytesPerPixel();
+
+ // First thing's first, write out the magic identifier and endianness...
+ if (!stream->write(KTX_FILE_IDENTIFIER, KTX_FILE_IDENTIFIER_SIZE) ||
+ !stream->write(&kKTX_ENDIANNESS_CODE, 4)) {
+ return false;
+ }
+
+ // Collect our key/value pairs...
+ SkTArray<KeyValue> kvPairs;
+
+ // Next, write the header based on the pixmap's config.
+ Header hdr;
+ switch (ct) {
+ case kIndex_8_SkColorType:
+ // There is a compressed format for this, but we don't support it yet.
+ SkDebugf("Writing indexed pixmap to KTX unsupported.\n");
+ // VVV fall through VVV
+ default:
+ case kUnknown_SkColorType:
+ // Pixmap hasn't been configured.
+ return false;
+
+ case kAlpha_8_SkColorType:
+ hdr.fGLType = GR_GL_UNSIGNED_BYTE;
+ hdr.fGLTypeSize = 1;
+ hdr.fGLFormat = GR_GL_RED;
+ hdr.fGLInternalFormat = GR_GL_R8;
+ hdr.fGLBaseInternalFormat = GR_GL_RED;
+ break;
+
+ case kRGB_565_SkColorType:
+ hdr.fGLType = GR_GL_UNSIGNED_SHORT_5_6_5;
+ hdr.fGLTypeSize = 2;
+ hdr.fGLFormat = GR_GL_RGB;
+ hdr.fGLInternalFormat = GR_GL_RGB;
+ hdr.fGLBaseInternalFormat = GR_GL_RGB;
+ break;
+
+ case kARGB_4444_SkColorType:
+ hdr.fGLType = GR_GL_UNSIGNED_SHORT_4_4_4_4;
+ hdr.fGLTypeSize = 2;
+ hdr.fGLFormat = GR_GL_RGBA;
+ hdr.fGLInternalFormat = GR_GL_RGBA4;
+ hdr.fGLBaseInternalFormat = GR_GL_RGBA;
+ kvPairs.push_back(CreateKeyValue("KTXPremultipliedAlpha", "True"));
+ break;
+
+ case kN32_SkColorType:
+ hdr.fGLType = GR_GL_UNSIGNED_BYTE;
+ hdr.fGLTypeSize = 1;
+ hdr.fGLFormat = GR_GL_RGBA;
+ hdr.fGLInternalFormat = GR_GL_RGBA8;
+ hdr.fGLBaseInternalFormat = GR_GL_RGBA;
+ kvPairs.push_back(CreateKeyValue("KTXPremultipliedAlpha", "True"));
+ break;
+ }
+
+ // Everything else in the header is shared.
+ hdr.fPixelWidth = width;
+ hdr.fPixelHeight = height;
+ hdr.fNumberOfArrayElements = 0;
+ hdr.fNumberOfFaces = 1;
+ hdr.fNumberOfMipmapLevels = 1;
+
+ // Calculate the key value data size
+ hdr.fBytesOfKeyValueData = 0;
+ for (KeyValue *kv = kvPairs.begin(); kv != kvPairs.end(); ++kv) {
+ // Key value size is the size of the key value data,
+ // four bytes for saying how big the key value size is
+ // and then additional bytes for padding to four byte boundary
+ size_t kvsize = kv->size();
+ kvsize += 4;
+ kvsize = (kvsize + 3) & ~3;
+ hdr.fBytesOfKeyValueData = SkToU32(hdr.fBytesOfKeyValueData + kvsize);
+ }
+
+ // Write the header
+ if (!stream->write(&hdr, sizeof(hdr))) {
+ return false;
+ }
+
+ // Write out each key value pair
+ for (KeyValue *kv = kvPairs.begin(); kv != kvPairs.end(); ++kv) {
+ if (!kv->writeKeyAndValueForKTX(stream)) {
+ return false;
+ }
+ }
+
+ // Calculate the size of the data
+ uint32_t dataSz = bytesPerPixel * width * height;
+
+ if (0 >= bytesPerPixel) {
+ return false;
+ }
+
+ // Write it into the buffer
+ if (!stream->write(&dataSz, 4)) {
+ return false;
+ }
+
+ // Write the pixel data...
+ const uint8_t* rowPtr = src;
+ if (kN32_SkColorType == ct) {
+ for (int j = 0; j < height; ++j) {
+ const uint32_t* pixelsPtr = reinterpret_cast<const uint32_t*>(rowPtr);
+ for (int i = 0; i < width; ++i) {
+ uint32_t pixel = pixelsPtr[i];
+ uint8_t dstPixel[4];
+ dstPixel[0] = pixel >> SK_R32_SHIFT;
+ dstPixel[1] = pixel >> SK_G32_SHIFT;
+ dstPixel[2] = pixel >> SK_B32_SHIFT;
+ dstPixel[3] = pixel >> SK_A32_SHIFT;
+ if (!stream->write(dstPixel, 4)) {
+ return false;
+ }
+ }
+ rowPtr += rowBytes;
+ }
+ } else {
+ for (int i = 0; i < height; ++i) {
+ if (!stream->write(rowPtr, bytesPerPixel * width)) {
+ return false;
+ }
+ rowPtr += rowBytes;
+ }
+ }
+
+ return true;
+}
+
+bool SkKTXFile::WriteBitmapToKTX(SkWStream* stream, const SkBitmap& bitmap) {
+ SkAutoLockPixels autoLockPixels(bitmap);
+ SkPixmap pixmap;
+ return bitmap.peekPixels(&pixmap) && SkKTXFile::WritePixmapToKTX(stream, pixmap);
+}
--- /dev/null
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#ifndef SkKTXFile_DEFINED
+#define SkKTXFile_DEFINED
+
+#include "SkData.h"
+#include "SkTextureCompressor.h"
+#include "SkTypes.h"
+#include "SkTDArray.h"
+#include "SkString.h"
+#include "SkRefCnt.h"
+
+class SkBitmap;
+class SkPixmap;
+class SkStreamRewindable;
+class SkWStream;
+
+// KTX Image File
+// ---
+// KTX is a general texture data storage file format ratified by the Khronos Group. As an
+// overview, a KTX file contains all of the appropriate values needed to fully specify a
+// texture in an OpenGL application, including the use of compressed data.
+//
+// A full format specification can be found here:
+// http://www.khronos.org/opengles/sdk/tools/KTX/file_format_spec/
+
+class SkKTXFile {
+public:
+ // The ownership of the data remains with the caller. This class is intended
+ // to be used as a logical wrapper around the data in order to properly
+ // access the pixels.
+ SkKTXFile(SkData* data) : fData(data), fSwapBytes(false) {
+ data->ref();
+ fValid = this->readKTXFile(fData->bytes(), fData->size());
+ }
+
+ bool valid() const { return fValid; }
+
+ int width() const { return static_cast<int>(fHeader.fPixelWidth); }
+ int height() const { return static_cast<int>(fHeader.fPixelHeight); }
+
+ const uint8_t *pixelData(int mipmap = 0) const {
+ SkASSERT(!this->valid() || mipmap < fPixelData.count());
+ return this->valid() ? fPixelData[mipmap].data() : NULL;
+ }
+
+ // If the decoded KTX file has the following key, then it will
+ // return the associated value. If not found, the empty string
+ // is returned.
+ SkString getValueForKey(const SkString& key) const;
+
+ int numMipmaps() const { return static_cast<int>(fHeader.fNumberOfMipmapLevels); }
+
+ bool isCompressedFormat(SkTextureCompressor::Format fmt) const;
+ bool isRGBA8() const;
+ bool isRGB8() const;
+
+ static bool is_ktx(const uint8_t data[], size_t size);
+ static bool is_ktx(SkStreamRewindable* stream);
+
+ static bool WriteETC1ToKTX(SkWStream* stream, const uint8_t *etc1Data,
+ uint32_t width, uint32_t height);
+ static bool WritePixmapToKTX(SkWStream* stream, const SkPixmap& pixmap);
+ static bool WriteBitmapToKTX(SkWStream* stream, const SkBitmap& bitmap);
+
+private:
+
+ // The blob holding the file data.
+ sk_sp<SkData> fData;
+
+ // This header captures all of the data that describes the format
+ // of the image data in a KTX file.
+ struct Header {
+ uint32_t fGLType;
+ uint32_t fGLTypeSize;
+ uint32_t fGLFormat;
+ uint32_t fGLInternalFormat;
+ uint32_t fGLBaseInternalFormat;
+ uint32_t fPixelWidth;
+ uint32_t fPixelHeight;
+ uint32_t fPixelDepth;
+ uint32_t fNumberOfArrayElements;
+ uint32_t fNumberOfFaces;
+ uint32_t fNumberOfMipmapLevels;
+ uint32_t fBytesOfKeyValueData;
+
+ Header() { memset(this, 0, sizeof(*this)); }
+ } fHeader;
+
+ // A Key Value pair stored in the KTX file. There may be
+ // arbitrarily many of these.
+ class KeyValue {
+ public:
+ KeyValue(size_t size) : fDataSz(size) { }
+ bool readKeyAndValue(const uint8_t *data);
+ size_t size() const { return fDataSz; }
+ const SkString& key() const { return fKey; }
+ const SkString& value() const { return fValue; }
+ bool writeKeyAndValueForKTX(SkWStream* strm);
+ private:
+ const size_t fDataSz;
+ SkString fKey;
+ SkString fValue;
+ };
+
+ static KeyValue CreateKeyValue(const char *key, const char *value);
+
+ // The pixel data for a single mipmap level in an image. Based on how
+ // the rest of the data is stored, this may be compressed, a cubemap, etc.
+ // The header will describe the format of this data.
+ class PixelData {
+ public:
+ PixelData(const uint8_t *ptr, size_t sz) : fDataSz(sz), fDataPtr(ptr) { }
+ const uint8_t *data() const { return fDataPtr; }
+ size_t dataSize() const { return fDataSz; }
+ private:
+ const size_t fDataSz;
+ const uint8_t *fDataPtr;
+ };
+
+ // This function is only called once from the constructor. It loads the data
+ // and populates the appropriate fields of this class
+ // (fKeyValuePairs, fPixelData, fSwapBytes)
+ bool readKTXFile(const uint8_t *data, size_t dataLen);
+
+ SkTArray<KeyValue> fKeyValuePairs;
+ SkTDArray<PixelData> fPixelData;
+ bool fValid;
+
+ // If the endianness of the platform is different than the file,
+ // then we need to do proper byte swapping.
+ bool fSwapBytes;
+
+ // Read an integer from a buffer, advance the buffer, and swap
+ // bytes if fSwapBytes is set
+ uint32_t readInt(const uint8_t** buf, size_t* bytesLeft) const;
+};
+
+#endif // SkKTXFile_DEFINED