Revert "remove unused TableMaskFilter"

This reverts commit d72b55b32cf6b3bf7b8d7b4c08045597652285cf.

Reason for revert: used by android

Original change's description:
> remove unused TableMaskFilter
> 
> will revert if its needed in android
> 
> Bug: skia:
> Change-Id: I2ef777d31de4bbed6556d013054083ff6ff2cb8c
> Reviewed-on: https://skia-review.googlesource.com/20206
> Reviewed-by: Mike Reed <reed@google.com>
> Commit-Queue: Mike Reed <reed@google.com>

TBR=djsollen@google.com,reed@google.com,stani@google.com

Change-Id: I8ea36a912496e12c9fbfb73587d11e002252e8b8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/20212
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>

1 files changed, 66 insertions, 0 deletions

diff --git a/include/effects/SkTableMaskFilter.h b/include/effects/SkTableMaskFilter.h
new file mode 100644
index 0000000000..f226dd1760
--- /dev/null
+++ b/include/effects/SkTableMaskFilter.h
@@ -0,0 +1,66 @@
+/*
+ * Copyright 2006 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.
+ */
+
+#ifndef SkTableMaskFilter_DEFINED
+#define SkTableMaskFilter_DEFINED
+
+#include "SkMaskFilter.h"
+#include "SkScalar.h"
+
+/** \class SkTableMaskFilter
+
+    Applies a table lookup on each of the alpha values in the mask.
+    Helper methods create some common tables (e.g. gamma, clipping)
+ */
+class SK_API SkTableMaskFilter : public SkMaskFilter {
+public:
+    /** Utility that sets the gamma table
+     */
+    static void MakeGammaTable(uint8_t table[256], SkScalar gamma);
+
+    /** Utility that creates a clipping table: clamps values below min to 0
+        and above max to 255, and rescales the remaining into 0..255
+     */
+    static void MakeClipTable(uint8_t table[256], uint8_t min, uint8_t max);
+
+    static SkMaskFilter* Create(const uint8_t table[256]) {
+        return new SkTableMaskFilter(table);
+    }
+
+    static SkMaskFilter* CreateGamma(SkScalar gamma) {
+        uint8_t table[256];
+        MakeGammaTable(table, gamma);
+        return new SkTableMaskFilter(table);
+    }
+
+    static SkMaskFilter* CreateClip(uint8_t min, uint8_t max) {
+        uint8_t table[256];
+        MakeClipTable(table, min, max);
+        return new SkTableMaskFilter(table);
+    }
+
+    SkMask::Format getFormat() const override;
+    bool filterMask(SkMask*, const SkMask&, const SkMatrix&, SkIPoint*) const override;
+
+    SK_TO_STRING_OVERRIDE()
+    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkTableMaskFilter)
+
+protected:
+    ~SkTableMaskFilter() override;
+
+    void flatten(SkWriteBuffer&) const override;
+
+private:
+    SkTableMaskFilter();
+    explicit SkTableMaskFilter(const uint8_t table[256]);
+
+    uint8_t fTable[256];
+
+    typedef SkMaskFilter INHERITED;
+};
+
+#endif