1 /* libs/graphics/sgl/SkMask.cpp
2 **
3 ** Copyright 2007, The Android Open Source Project
4 **
5 ** Licensed under the Apache License, Version 2.0 (the "License");
6 ** you may not use this file except in compliance with the License.
7 ** You may obtain a copy of the License at
8 **
9 ** http://www.apache.org/licenses/LICENSE-2.0
10 **
11 ** Unless required by applicable law or agreed to in writing, software
12 ** distributed under the License is distributed on an "AS IS" BASIS,
13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 ** See the License for the specific language governing permissions and
15 ** limitations under the License.
16 */
17
18 #include "Sk64.h"
19 #include "SkMask.h"
20
21 /** returns the product if it is positive and fits in 31 bits. Otherwise this
22 returns 0.
23 */
safeMul32(int32_t a,int32_t b)24 static int32_t safeMul32(int32_t a, int32_t b) {
25 Sk64 size;
26 size.setMul(a, b);
27 if (size.is32() && size.isPos()) {
28 return size.get32();
29 }
30 return 0;
31 }
32
computeImageSize() const33 size_t SkMask::computeImageSize() const {
34 return safeMul32(fBounds.height(), fRowBytes);
35 }
36
computeTotalImageSize() const37 size_t SkMask::computeTotalImageSize() const {
38 size_t size = this->computeImageSize();
39 if (fFormat == SkMask::k3D_Format) {
40 size = safeMul32(size, 3);
41 }
42 return size;
43 }
44
45 /** We explicitly use this allocator for SkBimap pixels, so that we can
46 freely assign memory allocated by one class to the other.
47 */
AllocImage(size_t size)48 uint8_t* SkMask::AllocImage(size_t size)
49 {
50 return (uint8_t*)sk_malloc_throw(SkAlign4(size));
51 }
52
53 /** We explicitly use this allocator for SkBimap pixels, so that we can
54 freely assign memory allocated by one class to the other.
55 */
FreeImage(void * image)56 void SkMask::FreeImage(void* image)
57 {
58 sk_free(image);
59 }
60
61