Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(794)

Unified Diff: src/images/SkImageDecoder_pkm.cpp

Issue 292663011: Simple PKM image decoder. (Closed) Base URL: https://skia.googlesource.com/skia.git@master
Patch Set: Resync Created 6 years, 7 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« no previous file with comments | « src/images/SkImageDecoder.cpp ('k') | tests/ImageDecodingTest.cpp » ('j') | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: src/images/SkImageDecoder_pkm.cpp
diff --git a/src/images/SkImageDecoder_pkm.cpp b/src/images/SkImageDecoder_pkm.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..9a925083876534f325d41233c5b4be1c2315bed5
--- /dev/null
+++ b/src/images/SkImageDecoder_pkm.cpp
@@ -0,0 +1,122 @@
+/*
+ * 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 "SkColorPriv.h"
+#include "SkImageDecoder.h"
+#include "SkStream.h"
+#include "SkStreamHelpers.h"
+#include "SkTypes.h"
+
+#include "etc1.h"
+
+class SkPKMImageDecoder : public SkImageDecoder {
+public:
+ SkPKMImageDecoder() { }
+
+ virtual Format getFormat() const SK_OVERRIDE {
+ return kPKM_Format;
+ }
+
+protected:
+ virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode) SK_OVERRIDE;
+
+private:
+ typedef SkImageDecoder INHERITED;
+};
+
+/////////////////////////////////////////////////////////////////////////////////////////
+
+bool SkPKMImageDecoder::onDecode(SkStream* stream, SkBitmap* bm, Mode mode) {
+ SkAutoMalloc autoMal;
+ const size_t length = CopyStreamToStorage(&autoMal, stream);
+ if (0 == length) {
+ return false;
+ }
+
+ unsigned char* buf = (unsigned char*)autoMal.get();
+
+ // Make sure original PKM header is there...
+ SkASSERT(etc1_pkm_is_valid(buf));
+
+ const unsigned short width = etc1_pkm_get_width(buf);
+ const unsigned short height = etc1_pkm_get_height(buf);
+
+ // should we allow the Chooser (if present) to pick a config for us???
+ if (!this->chooseFromOneChoice(SkBitmap::kARGB_8888_Config, width, height)) {
+ return false;
+ }
+
+ bm->setConfig(SkBitmap::kARGB_8888_Config, width, height, 0, kOpaque_SkAlphaType);
+ if (SkImageDecoder::kDecodeBounds_Mode == mode) {
+ return true;
+ }
+
+ if (!this->allocPixelRef(bm, NULL)) {
+ return false;
+ }
+
+ // Lock the pixels, since we're about to write to them...
+ SkAutoLockPixels alp(*bm);
+
+ // Advance buffer past the header
+ buf += ETC_PKM_HEADER_SIZE;
+
+ // ETC1 Data is encoded as RGB pixels, so we should extract it as such
+ int nPixels = width * height;
+ SkAutoMalloc outRGBData(nPixels * 3);
+ etc1_byte *outRGBDataPtr = reinterpret_cast<etc1_byte *>(outRGBData.get());
+
+ // Decode ETC1
+ if (etc1_decode_image(buf, outRGBDataPtr, width, height, 3, width*3)) {
+ return false;
+ }
+
+ // Set each of the pixels...
+ const uint8_t *src = reinterpret_cast<uint8_t *>(outRGBDataPtr);
+ uint8_t *dst = reinterpret_cast<uint8_t *>(bm->getPixels());
+ for (int i = 0; i < width*height; ++i) {
+ *dst++ = src[2]; // B
+ *dst++ = src[1]; // G
+ *dst++ = src[0]; // R
+ *dst++ = 0xFF; // Opaque alpha...
+ src += 3;
+ }
+
+ return true;
+}
+
+/////////////////////////////////////////////////////////////////////////////////////////
+DEFINE_DECODER_CREATOR(PKMImageDecoder);
+/////////////////////////////////////////////////////////////////////////////////////////
+
+static bool is_pkm(SkStreamRewindable* stream) {
+ // Read the PKM header and make sure it's valid.
+ unsigned char buf[ETC_PKM_HEADER_SIZE];
+ if (stream->read((void*)buf, ETC_PKM_HEADER_SIZE) != ETC_PKM_HEADER_SIZE) {
+ return false;
+ }
+
+ return etc1_pkm_is_valid(buf);
+}
+
+static SkImageDecoder* sk_libpkm_dfactory(SkStreamRewindable* stream) {
+ if (is_pkm(stream)) {
+ return SkNEW(SkPKMImageDecoder);
+ }
+ return NULL;
+}
+
+static SkImageDecoder_DecodeReg gReg(sk_libpkm_dfactory);
+
+static SkImageDecoder::Format get_format_pkm(SkStreamRewindable* stream) {
+ if (is_pkm(stream)) {
+ return SkImageDecoder::kPKM_Format;
+ }
+ return SkImageDecoder::kUnknown_Format;
+}
+
+static SkImageDecoder_FormatReg gFormatReg(get_format_pkm);
« no previous file with comments | « src/images/SkImageDecoder.cpp ('k') | tests/ImageDecodingTest.cpp » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698