work in progress for shape operations

A    experimental/Intersection
A    experimental/Intersection/Intersections.h
A    experimental/Intersection/DataTypes.cpp
A    experimental/Intersection/QuadraticReduceOrder.cpp
A    experimental/Intersection/IntersectionUtilities.cpp
A    experimental/Intersection/CubicIntersection_Tests.h
A    experimental/Intersection/LineParameteters_Test.cpp
A    experimental/Intersection/ReduceOrder.cpp
A    experimental/Intersection/QuadraticIntersection.cpp
A    experimental/Intersection/Extrema.h
A    experimental/Intersection/CubicIntersection_TestData.h
A    experimental/Intersection/QuadraticParameterization_Test.cpp
A    experimental/Intersection/TestUtilities.cpp
A    experimental/Intersection/CubicRoots.cpp
A    experimental/Intersection/QuadraticParameterization.cpp
A    experimental/Intersection/QuadraticSubDivide.cpp
A    experimental/Intersection/LineIntersection_Test.cpp
A    experimental/Intersection/LineIntersection.cpp
A    experimental/Intersection/CubicParameterizationCode.cpp
A    experimental/Intersection/LineParameters.h
A    experimental/Intersection/CubicIntersection.h
A    experimental/Intersection/CubeRoot.cpp
A    experimental/Intersection/SkAntiEdge.h
A    experimental/Intersection/ConvexHull_Test.cpp
A    experimental/Intersection/CubicBezierClip_Test.cpp
A    experimental/Intersection/CubicIntersection_Tests.cpp
A    experimental/Intersection/CubicBezierClip.cpp
A    experimental/Intersection/CubicIntersectionT.cpp
A    experimental/Intersection/Inline_Tests.cpp
A    experimental/Intersection/ReduceOrder_Test.cpp
A    experimental/Intersection/QuadraticIntersection_TestData.h
A    experimental/Intersection/DataTypes.h
A    experimental/Intersection/Extrema.cpp
A    experimental/Intersection/EdgeApp.cpp
A    experimental/Intersection/CubicIntersection_TestData.cpp
A    experimental/Intersection/IntersectionUtilities.h
A    experimental/Intersection/CubicReduceOrder.cpp
A    experimental/Intersection/CubicCoincidence.cpp
A    experimental/Intersection/CubicIntersection_Test.cpp
A    experimental/Intersection/CubicIntersection.cpp
A    experimental/Intersection/QuadraticUtilities.h
A    experimental/Intersection/SkAntiEdge.cpp
A    experimental/Intersection/TestUtilities.h
A    experimental/Intersection/CubicParameterization_Test.cpp
A    experimental/Intersection/LineIntersection.h
A    experimental/Intersection/CubicSubDivide.cpp
A    experimental/Intersection/CubicParameterization.cpp
A    experimental/Intersection/QuadraticBezierClip_Test.cpp
A    experimental/Intersection/QuadraticBezierClip.cpp
A    experimental/Intersection/BezierClip_Test.cpp
A    experimental/Intersection/ConvexHull.cpp
A    experimental/Intersection/BezierClip.cpp
A    experimental/Intersection/QuadraticIntersection_TestData.cpp



git-svn-id: http://skia.googlecode.com/svn/trunk@3005 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 40 insertions, 0 deletions

diff --git a/experimental/Intersection/IntersectionUtilities.cpp b/experimental/Intersection/IntersectionUtilities.cpp
new file mode 100644
index 0000000000..d05afdf947
--- /dev/null
+++ b/experimental/Intersection/IntersectionUtilities.cpp
@@ -0,0 +1,40 @@
+
+// snippets that one day may be useful, unused for now...
+
+// get sign, exponent, mantissa from double
+// Translate the double into sign, exponent and mantissa.
+    long bits = BitConverter.DoubleToInt64Bits(d);
+    // Note that the shift is sign-extended, hence the test against -1 not 1
+    bool negative = (bits < 0);
+    int exponent = (int) ((bits >> 52) & 0x7ffL);
+    long mantissa = bits & 0xfffffffffffffL;
+
+    // Subnormal numbers; exponent is effectively one higher,
+    // but there's no extra normalisation bit in the mantissa
+    if (exponent==0)
+    {
+        exponent++;
+    }
+    // Normal numbers; leave exponent as it is but add extra
+    // bit to the front of the mantissa
+    else
+    {
+        mantissa = mantissa | (1L<<52);
+    }
+
+    // Bias the exponent. It's actually biased by 1023, but we're
+    // treating the mantissa as m.0 rather than 0.m, so we need
+    // to subtract another 52 from it.
+    exponent -= 1075;
+
+    if (mantissa == 0) 
+    {
+        return "0";
+    }
+
+    /* Normalize */
+    while((mantissa & 1) == 0) 
+    {    /*  i.e., Mantissa is even */
+        mantissa >>= 1;
+        exponent++;
+    }
\ No newline at end of file