Add skia to the repository.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@16 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 178 insertions, 0 deletions

diff --git a/skia/effects/SkDashPathEffect.cpp b/skia/effects/SkDashPathEffect.cpp
new file mode 100644
index 0000000..2c29009
--- /dev/null
+++ b/skia/effects/SkDashPathEffect.cpp
@@ -0,0 +1,178 @@
+/* libs/graphics/effects/SkDashPathEffect.cpp
+**
+** Copyright 2006, Google Inc.
+**
+** 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 "SkDashPathEffect.h"
+#include "SkBuffer.h"
+#include "SkPathMeasure.h"
+
+static inline int is_even(int x)
+{
+    return (~x) << 31;
+}
+
+static SkScalar FindFirstInterval(const SkScalar intervals[], SkScalar phase, int32_t* index)
+{
+    int i;
+
+    for (i = 0; phase > intervals[i]; i++)
+        phase -= intervals[i];
+    *index = i;
+    return intervals[i] - phase;
+}
+
+SkDashPathEffect::SkDashPathEffect(const SkScalar intervals[], int count, SkScalar phase, bool scaleToFit)
+    : fScaleToFit(scaleToFit)
+{
+    SkASSERT(intervals);
+    SkASSERT(count > 1 && SkAlign2(count) == count);
+
+    fIntervals = (SkScalar*)sk_malloc_throw(sizeof(SkScalar) * count);
+    fCount = count;
+
+    SkScalar len = 0;
+    for (int i = 0; i < count; i++)
+    {
+        SkASSERT(intervals[i] >= 0);
+        fIntervals[i] = intervals[i];
+        len += intervals[i];
+    }
+    fIntervalLength = len;
+
+    if (len > 0)    // we don't handle 0 length dash arrays
+    {
+        if (phase < 0)
+        {
+            phase = -phase;
+            if (phase > len)
+                phase = SkScalarMod(phase, len);
+            phase = len - phase;
+        }
+        else if (phase >= len)
+            phase = SkScalarMod(phase, len);
+
+        SkASSERT(phase >= 0 && phase < len);
+        fInitialDashLength = FindFirstInterval(intervals, phase, &fInitialDashIndex);
+
+        SkASSERT(fInitialDashLength >= 0);
+        SkASSERT(fInitialDashIndex >= 0 && fInitialDashIndex < fCount);
+    }
+    else
+        fInitialDashLength = -1;    // signal bad dash intervals
+}
+
+SkDashPathEffect::~SkDashPathEffect()
+{
+    sk_free(fIntervals);
+}
+
+bool SkDashPathEffect::filterPath(SkPath* dst, const SkPath& src, SkScalar* width)
+{
+    // we do nothing if the src wants to be filled, or if our dashlength is 0
+    if (*width < 0 || fInitialDashLength < 0)
+        return false;
+
+    SkPathMeasure   meas(src, false);
+    const SkScalar* intervals = fIntervals;
+
+    do {
+        bool        skipFirstSegment = meas.isClosed();
+        bool        addedSegment = false;
+        SkScalar    length = meas.getLength();
+        int         index = fInitialDashIndex;
+        SkScalar    scale = SK_Scalar1;
+
+        if (fScaleToFit)
+        {
+            if (fIntervalLength >= length)
+                scale = SkScalarDiv(length, fIntervalLength);
+            else
+            {
+                SkScalar div = SkScalarDiv(length, fIntervalLength);
+                int n = SkScalarFloor(div);
+                scale = SkScalarDiv(length, n * fIntervalLength);
+            }
+        }
+
+        SkScalar    distance = 0;
+        SkScalar    dlen = SkScalarMul(fInitialDashLength, scale);
+
+        while (distance < length)
+        {
+            SkASSERT(dlen >= 0);
+            addedSegment = false;
+            if (is_even(index) && dlen > 0 && !skipFirstSegment)
+            {
+                addedSegment = true;
+                meas.getSegment(distance, distance + dlen, dst, true);
+            }
+            distance += dlen;
+
+            // clear this so we only respect it the first time around
+            skipFirstSegment = false;
+
+            // wrap around our intervals array if necessary
+            index += 1;
+            SkASSERT(index <= fCount);
+            if (index == fCount)
+                index = 0;
+
+            // fetch our next dlen
+            dlen = SkScalarMul(intervals[index], scale);
+        }
+
+        // extend if we ended on a segment and we need to join up with the (skipped) initial segment
+        if (meas.isClosed() && is_even(fInitialDashIndex) && fInitialDashLength > 0)
+            meas.getSegment(0, SkScalarMul(fInitialDashLength, scale), dst, !addedSegment);
+    } while (meas.nextContour());
+    return true;
+}
+
+SkFlattenable::Factory SkDashPathEffect::getFactory()
+{
+    return fInitialDashLength < 0 ? NULL : CreateProc;
+}
+
+void SkDashPathEffect::flatten(SkFlattenableWriteBuffer& buffer)
+{
+    SkASSERT(fInitialDashLength >= 0);
+
+    buffer.write32(fCount);
+    buffer.write32(fInitialDashIndex);
+    buffer.writeScalar(fInitialDashLength);
+    buffer.writeScalar(fIntervalLength);
+    buffer.write32(fScaleToFit);
+    buffer.writeMul4(fIntervals, fCount * sizeof(fIntervals[0]));
+}
+
+SkFlattenable* SkDashPathEffect::CreateProc(SkFlattenableReadBuffer& buffer)
+{
+    return SkNEW_ARGS(SkDashPathEffect, (buffer));
+}
+
+SkDashPathEffect::SkDashPathEffect(SkFlattenableReadBuffer& buffer)
+{
+    fCount = buffer.readS32();
+    fInitialDashIndex = buffer.readS32();
+    fInitialDashLength = buffer.readScalar();
+    fIntervalLength = buffer.readScalar();
+    fScaleToFit = (buffer.readS32() != 0);
+    
+    fIntervals = (SkScalar*)sk_malloc_throw(sizeof(SkScalar) * fCount);
+    buffer.read(fIntervals, fCount * sizeof(fIntervals[0]));
+}
+
+