Initial implementation of a SkColorSpace_A2B xform

src/core/SkColorLookUpTable.h

+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkColorLookUpTable_DEFINED
+#define SkColorLookUpTable_DEFINED
+
+#include "SkRefCnt.h"
+#include "SkTemplates.h"
+
+class SkColorLookUpTable : public SkRefCnt {
+public:
+    static constexpr uint8_t kOutputChannels = 3;
+
+    SkColorLookUpTable(uint8_t inputChannels, const uint8_t gridPoints[3])
+        : fInputChannels(inputChannels) {
+        SkASSERT(3 == inputChannels);
+        memcpy(fGridPoints, gridPoints, 3 * sizeof(uint8_t));
+    }
+
+    void interp3D(float dst[3], float src[3]) const;
+
+private:
+    const float* table() const {
+        return SkTAddOffset<const float>(this, sizeof(SkColorLookUpTable));
+    }
+
+    uint8_t                  fInputChannels;
+    uint8_t                  fGridPoints[3];
+
+public:
+    // Objects of this type are created in a custom fashion using sk_malloc_throw
+    // and therefore must be sk_freed.
+    void* operator new(size_t size) = delete;
+    void* operator new(size_t, void* p) { return p; }
+    void operator delete(void* p) { sk_free(p); }
+};
+
+#endif