| /* |
| * 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 "include/core/SkScalar.h" |
| |
| SkScalar SkScalarInterpFunc(SkScalar searchKey, const SkScalar keys[], |
| const SkScalar values[], int length) { |
| SkASSERT(length > 0); |
| SkASSERT(keys != nullptr); |
| SkASSERT(values != nullptr); |
| #ifdef SK_DEBUG |
| for (int i = 1; i < length; i++) { |
| SkASSERT(keys[i-1] <= keys[i]); |
| } |
| #endif |
| int right = 0; |
| while (right < length && keys[right] < searchKey) { |
| ++right; |
| } |
| // Could use sentinel values to eliminate conditionals, but since the |
| // tables are taken as input, a simpler format is better. |
| if (right == length) { |
| return values[length-1]; |
| } |
| if (right == 0) { |
| return values[0]; |
| } |
| // Otherwise, interpolate between right - 1 and right. |
| SkScalar leftKey = keys[right-1]; |
| SkScalar rightKey = keys[right]; |
| SkScalar fract = (searchKey - leftKey) / (rightKey - leftKey); |
| return SkScalarInterp(values[right-1], values[right], fract); |
| } |