Move SkPackBits to src/effects.

src/core/SkPackBits.cpp

-/*
- * Copyright 2011 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-#include "SkPackBits.h"
-
-size_t SkPackBits::ComputeMaxSize8(int count) {
-    // worst case is the number of 8bit values + 1 byte per (up to) 128 entries.
-    return ((count + 127) >> 7) + count;
-}
-
-static uint8_t* flush_same8(uint8_t dst[], uint8_t value, size_t count) {
-    while (count > 0) {
-        int n = count > 128 ? 128 : count;
-        *dst++ = (uint8_t)(n - 1);
-        *dst++ = (uint8_t)value;
-        count -= n;
-    }
-    return dst;
-}
-
-static uint8_t* flush_diff8(uint8_t* SK_RESTRICT dst,
-                            const uint8_t* SK_RESTRICT src, size_t count) {
-    while (count > 0) {
-        int n = count > 128 ? 128 : count;
-        *dst++ = (uint8_t)(n + 127);
-        memcpy(dst, src, n);
-        src += n;
-        dst += n;
-        count -= n;
-    }
-    return dst;
-}
-
-size_t SkPackBits::Pack8(const uint8_t* SK_RESTRICT src, size_t srcSize,
-                         uint8_t* SK_RESTRICT dst, size_t dstSize) {
-    if (dstSize < ComputeMaxSize8(srcSize)) {
-        return 0;
-    }
-
-    uint8_t* const origDst = dst;
-    const uint8_t* stop = src + srcSize;
-
-    for (intptr_t count = stop - src; count > 0; count = stop - src) {
-        if (1 == count) {
-            *dst++ = 0;
-            *dst++ = *src;
-            break;
-        }
-
-        unsigned value = *src;
-        const uint8_t* s = src + 1;
-
-        if (*s == value) { // accumulate same values...
-            do {
-                s++;
-                if (s == stop) {
-                    break;
-                }
-            } while (*s == value);
-            dst = flush_same8(dst, value, SkToInt(s - src));
-        } else {    // accumulate diff values...
-            do {
-                if (++s == stop) {
-                    goto FLUSH_DIFF;
-                }
-                // only stop if we hit 3 in a row,
-                // otherwise we get bigger than compuatemax
-            } while (*s != s[-1] || s[-1] != s[-2]);
-            s -= 2; // back up so we don't grab the "same" values that follow
-        FLUSH_DIFF:
-            dst = flush_diff8(dst, src, SkToInt(s - src));
-        }
-        src = s;
-    }
-    return dst - origDst;
-}
-
-#include "SkUtils.h"
-
-int SkPackBits::Unpack8(const uint8_t* SK_RESTRICT src, size_t srcSize,
-                        uint8_t* SK_RESTRICT dst, size_t dstSize) {
-    uint8_t* const origDst = dst;
-    uint8_t* const endDst = dst + dstSize;
-    const uint8_t* stop = src + srcSize;
-
-    while (src < stop) {
-        unsigned n = *src++;
-        if (n <= 127) {   // repeat count (n + 1)
-            n += 1;
-            if (dst >(endDst - n)) {
-                return 0;
-            }
-            memset(dst, *src++, n);
-        } else {    // same count (n - 127)
-            n -= 127;
-            if (dst > (endDst - n)) {
-                return 0;
-            }
-            memcpy(dst, src, n);
-            src += n;
-        }
-        dst += n;
-    }
-    SkASSERT(src <= stop);
-    return SkToInt(dst - origDst);
-}