aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/core
diff options
context:
space:
mode:
Diffstat (limited to 'src/core')
-rw-r--r--src/core/SkClampRange.cpp166
1 files changed, 0 insertions, 166 deletions
diff --git a/src/core/SkClampRange.cpp b/src/core/SkClampRange.cpp
deleted file mode 100644
index 1f7cce355b..0000000000
--- a/src/core/SkClampRange.cpp
+++ /dev/null
@@ -1,166 +0,0 @@
-
-/*
- * 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 "SkClampRange.h"
-
-/*
- * returns [0..count] for the number of steps (<= count) for which x0 <= edge
- * given each step is followed by x0 += dx
- */
-static int chop(int64_t x0, SkFixed edge, int64_t x1, int64_t dx, int count) {
- SkASSERT(dx > 0);
- SkASSERT(count >= 0);
-
- if (x0 >= edge) {
- return 0;
- }
- if (x1 <= edge) {
- return count;
- }
- int64_t n = (edge - x0 + dx - 1) / dx;
- SkASSERT(n >= 0);
- SkASSERT(n <= count);
- return (int)n;
-}
-
-static bool overflows_fixed(int64_t x) {
- return x < -SK_FixedMax || x > SK_FixedMax;
-}
-
-void SkClampRange::initFor1(SkFixed fx) {
- fCount0 = fCount1 = fCount2 = 0;
- if (fx <= 0) {
- fCount0 = 1;
- } else if (fx < 0xFFFF) {
- fCount1 = 1;
- fFx1 = fx;
- } else {
- fCount2 = 1;
- }
-}
-
-void SkClampRange::init(SkFixed fx0, SkFixed dx0, int count, int v0, int v1) {
- SkASSERT(count > 0);
-
- fV0 = v0;
- fV1 = v1;
- fOverflowed = false;
-
- // special case 1 == count, as it is slightly common for skia
- // and avoids us ever calling divide or 64bit multiply
- if (1 == count) {
- this->initFor1(fx0);
- return;
- }
-
- int64_t fx = fx0;
- int64_t dx = dx0;
- // start with ex equal to the last computed value
- int64_t ex = fx + (count - 1) * dx;
- fOverflowed = overflows_fixed(ex);
-
- if ((uint64_t)(fx | ex) <= 0xFFFF) {
- fCount0 = fCount2 = 0;
- fCount1 = count;
- fFx1 = fx0;
- return;
- }
- if (fx <= 0 && ex <= 0) {
- fCount1 = fCount2 = 0;
- fCount0 = count;
- return;
- }
- if (fx >= 0xFFFF && ex >= 0xFFFF) {
- fCount0 = fCount1 = 0;
- fCount2 = count;
- return;
- }
-
- int extraCount = 0;
-
- // now make ex be 1 past the last computed value
- ex += dx;
- fOverflowed = overflows_fixed(ex);
- // now check for over/under flow
- if (fOverflowed) {
- int originalCount = count;
- int64_t ccount;
- bool swap = dx < 0;
- if (swap) {
- dx = -dx;
- fx = -fx;
- }
- ccount = (SK_FixedMax - fx + dx - 1) / dx;
- if (swap) {
- dx = -dx;
- fx = -fx;
- }
- SkASSERT(ccount > 0 && ccount <= SK_FixedMax);
-
- count = (int)ccount;
- if (0 == count) {
- this->initFor1(fx0);
- if (dx > 0) {
- fCount2 += originalCount - 1;
- } else {
- fCount0 += originalCount - 1;
- }
- return;
- }
- extraCount = originalCount - count;
- ex = fx + dx * count;
- }
-
- bool doSwap = dx < 0;
-
- if (doSwap) {
- ex -= dx;
- fx -= dx;
- SkTSwap(fx, ex);
- dx = -dx;
- }
-
-
- fCount0 = chop(fx, 0, ex, dx, count);
- count -= fCount0;
- fx += fCount0 * dx;
- SkASSERT(fx >= 0);
- SkASSERT(fCount0 == 0 || (fx - dx) < 0);
- fCount1 = chop(fx, 0xFFFF, ex, dx, count);
- count -= fCount1;
- fCount2 = count;
-
-#ifdef SK_DEBUG
- fx += fCount1 * dx;
- SkASSERT(fx <= ex);
- if (fCount2 > 0) {
- SkASSERT(fx >= 0xFFFF);
- if (fCount1 > 0) {
- SkASSERT(fx - dx < 0xFFFF);
- }
- }
-#endif
-
- if (doSwap) {
- SkTSwap(fCount0, fCount2);
- SkTSwap(fV0, fV1);
- dx = -dx;
- }
-
- if (fCount1 > 0) {
- fFx1 = fx0 + fCount0 * (int)dx;
- }
-
- if (dx > 0) {
- fCount2 += extraCount;
- } else {
- fCount0 += extraCount;
- }
-}
-