1 files changed, 36 insertions, 0 deletions
diff --git a/core/SkScalar.cpp b/core/SkScalar.cpp
new file mode 100644
index 00000000..c48d3890
--- /dev/null
+++ b/core/SkScalar.cpp
@@ -0,0 +1,36 @@
+
+/*
+ * Copyright 2010 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#include "SkMath.h"
+#include "SkScalar.h"
+
+SkScalar SkScalarInterpFunc(SkScalar searchKey, const SkScalar keys[],
+                            const SkScalar values[], int length) {
+    SkASSERT(length > 0);
+    SkASSERT(keys != NULL);
+    SkASSERT(values != NULL);
+#ifdef SK_DEBUG
+    for (int i = 1; i < length; i++)
+        SkASSERT(keys[i] >= keys[i-1]);
+#endif
+    int right = 0;
+    while (right < length && searchKey > keys[right])
+        right++;
+    // Could use sentinel values to eliminate conditionals, but since the
+    // tables are taken as input, a simpler format is better.
+    if (length == right)
+        return values[length-1];
+    if (0 == right)
+        return values[0];
+    // Otherwise, interpolate between right - 1 and right.
+    SkScalar rightKey = keys[right];
+    SkScalar leftKey = keys[right-1];
+    SkScalar fract = SkScalarDiv(searchKey-leftKey,rightKey-leftKey);
+    return SkScalarInterp(values[right-1], values[right], fract);
+}