grab from latest android
git-svn-id: http://skia.googlecode.com/svn/trunk@27 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/images/SkImageDecoder_wbmp.cpp b/src/images/SkImageDecoder_wbmp.cpp
new file mode 100644
index 0000000..9d188f6
--- /dev/null
+++ b/src/images/SkImageDecoder_wbmp.cpp
@@ -0,0 +1,167 @@
+/**
+** Copyright 2006, 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 "SkImageDecoder.h"
+#include "SkColor.h"
+#include "SkColorPriv.h"
+#include "SkMath.h"
+#include "SkStream.h"
+#include "SkTemplates.h"
+#include "SkUtils.h"
+
+class SkWBMPImageDecoder : public SkImageDecoder {
+public:
+ virtual Format getFormat() const {
+ return kWBMP_Format;
+ }
+
+protected:
+ virtual bool onDecode(SkStream* stream, SkBitmap* bm,
+ SkBitmap::Config pref, Mode);
+};
+
+static bool read_byte(SkStream* stream, uint8_t* data)
+{
+ return stream->read(data, 1) == 1;
+}
+
+static bool read_mbf(SkStream* stream, int* value)
+{
+ int n = 0;
+ uint8_t data;
+ do {
+ if (!read_byte(stream, &data)) {
+ return false;
+ }
+ n = (n << 7) | (data & 0x7F);
+ } while (data & 0x80);
+
+ *value = n;
+ return true;
+}
+
+struct wbmp_head {
+ int fWidth;
+ int fHeight;
+
+ bool init(SkStream* stream)
+ {
+ 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;
+ }
+ if (!read_mbf(stream, &fWidth) || (unsigned)fWidth > 0xFFFF) {
+ return false;
+ }
+ if (!read_mbf(stream, &fHeight) || (unsigned)fHeight > 0xFFFF) {
+ return false;
+ }
+ return fWidth != 0 && fHeight != 0;
+ }
+};
+
+SkImageDecoder* SkImageDecoder_WBMP_Factory(SkStream* stream)
+{
+ wbmp_head head;
+
+ if (head.init(stream)) {
+ return SkNEW(SkWBMPImageDecoder);
+ }
+ return NULL;
+}
+
+static void expand_bits_to_bytes(uint8_t dst[], const uint8_t src[], int bits)
+{
+ int bytes = bits >> 3;
+
+ for (int i = 0; i < bytes; i++) {
+ unsigned mask = *src++;
+ dst[0] = (mask >> 7) & 1;
+ dst[1] = (mask >> 6) & 1;
+ dst[2] = (mask >> 5) & 1;
+ dst[3] = (mask >> 4) & 1;
+ dst[4] = (mask >> 3) & 1;
+ dst[5] = (mask >> 2) & 1;
+ dst[6] = (mask >> 1) & 1;
+ dst[7] = (mask >> 0) & 1;
+ dst += 8;
+ }
+
+ bits &= 7;
+ if (bits > 0) {
+ unsigned mask = *src;
+ do {
+ *dst++ = (mask >> 7) & 1;;
+ mask <<= 1;
+ } while (--bits != 0);
+ }
+}
+
+#define SkAlign8(x) (((x) + 7) & ~7)
+
+bool SkWBMPImageDecoder::onDecode(SkStream* stream, SkBitmap* decodedBitmap,
+ SkBitmap::Config prefConfig, Mode mode)
+{
+ wbmp_head head;
+
+ if (!head.init(stream)) {
+ return false;
+ }
+
+ int width = head.fWidth;
+ int height = head.fHeight;
+
+ // assign these directly, in case we return kDimensions_Result
+ decodedBitmap->setConfig(SkBitmap::kIndex8_Config, width, height);
+ decodedBitmap->setIsOpaque(true);
+
+ if (SkImageDecoder::kDecodeBounds_Mode == mode)
+ return true;
+
+ const SkPMColor colors[] = { SK_ColorBLACK, SK_ColorWHITE };
+ SkColorTable* ct = SkNEW_ARGS(SkColorTable, (colors, 2));
+ SkAutoUnref aur(ct);
+
+ if (!this->allocPixelRef(decodedBitmap, ct)) {
+ return false;
+ }
+
+ SkAutoLockPixels alp(*decodedBitmap);
+
+ uint8_t* dst = decodedBitmap->getAddr8(0, 0);
+ // store the 1-bit valuess at the end of our pixels, so we won't stomp
+ // on them before we're read them. Just trying to avoid a temp allocation
+ size_t srcRB = SkAlign8(width) >> 3;
+ size_t srcSize = height * srcRB;
+ uint8_t* src = dst + decodedBitmap->getSize() - srcSize;
+ if (stream->read(src, srcSize) != srcSize) {
+ return false;
+ }
+
+ for (int y = 0; y < height; y++)
+ {
+ expand_bits_to_bytes(dst, src, width);
+ dst += decodedBitmap->rowBytes();
+ src += srcRB;
+ }
+
+ return true;
+}
+