1 /*
2 * Copyright 2017 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #ifndef SkEncodedOrigin_DEFINED
9 #define SkEncodedOrigin_DEFINED
10
11 #include "include/core/SkMatrix.h"
12
13 // These values match the orientation www.exif.org/Exif2-2.PDF.
14 enum SkEncodedOrigin {
15 kTopLeft_SkEncodedOrigin = 1, // Default
16 kTopRight_SkEncodedOrigin = 2, // Reflected across y-axis
17 kBottomRight_SkEncodedOrigin = 3, // Rotated 180
18 kBottomLeft_SkEncodedOrigin = 4, // Reflected across x-axis
19 kLeftTop_SkEncodedOrigin = 5, // Reflected across x-axis, Rotated 90 CCW
20 kRightTop_SkEncodedOrigin = 6, // Rotated 90 CW
21 kRightBottom_SkEncodedOrigin = 7, // Reflected across x-axis, Rotated 90 CW
22 kLeftBottom_SkEncodedOrigin = 8, // Rotated 90 CCW
23 kDefault_SkEncodedOrigin = kTopLeft_SkEncodedOrigin,
24 kLast_SkEncodedOrigin = kLeftBottom_SkEncodedOrigin,
25 };
26
27 /**
28 * Given an encoded origin and the width and height of the source data, returns a matrix
29 * that transforms the source rectangle with upper left corner at [0, 0] and origin to a correctly
30 * oriented destination rectangle of [0, 0, w, h].
31 */
SkEncodedOriginToMatrix(SkEncodedOrigin origin,int w,int h)32 static inline SkMatrix SkEncodedOriginToMatrix(SkEncodedOrigin origin, int w, int h) {
33 switch (origin) {
34 case kTopLeft_SkEncodedOrigin: return SkMatrix::I();
35 case kTopRight_SkEncodedOrigin: return SkMatrix::MakeAll(-1, 0, w, 0, 1, 0, 0, 0, 1);
36 case kBottomRight_SkEncodedOrigin: return SkMatrix::MakeAll(-1, 0, w, 0, -1, h, 0, 0, 1);
37 case kBottomLeft_SkEncodedOrigin: return SkMatrix::MakeAll( 1, 0, 0, 0, -1, h, 0, 0, 1);
38 case kLeftTop_SkEncodedOrigin: return SkMatrix::MakeAll( 0, 1, 0, 1, 0, 0, 0, 0, 1);
39 case kRightTop_SkEncodedOrigin: return SkMatrix::MakeAll( 0, -1, w, 1, 0, 0, 0, 0, 1);
40 case kRightBottom_SkEncodedOrigin: return SkMatrix::MakeAll( 0, -1, w, -1, 0, h, 0, 0, 1);
41 case kLeftBottom_SkEncodedOrigin: return SkMatrix::MakeAll( 0, 1, 0, -1, 0, h, 0, 0, 1);
42 }
43 SK_ABORT("Unexpected origin");
44 }
45
46 /**
47 * Return true if the encoded origin includes a 90 degree rotation, in which case the width
48 * and height of the source data are swapped relative to a correctly oriented destination.
49 */
SkEncodedOriginSwapsWidthHeight(SkEncodedOrigin origin)50 static inline bool SkEncodedOriginSwapsWidthHeight(SkEncodedOrigin origin) {
51 return origin >= kLeftTop_SkEncodedOrigin;
52 }
53
54 #endif // SkEncodedOrigin_DEFINED
55