1 /*
2 * Copyright 2016 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 #include "GrColorSpaceXform.h"
9 #include "SkColorSpace.h"
10 #include "SkColorSpace_Base.h"
11 #include "SkMatrix44.h"
12
sk_float_almost_equals(float x,float y,float tol)13 static inline bool sk_float_almost_equals(float x, float y, float tol) {
14 return sk_float_abs(x - y) <= tol;
15 }
16
matrix_is_almost_identity(const SkMatrix44 & m,SkMScalar tol=SK_MScalar1/(1<<12))17 static inline bool matrix_is_almost_identity(const SkMatrix44& m,
18 SkMScalar tol = SK_MScalar1 / (1 << 12)) {
19 return
20 sk_float_almost_equals(m.getFloat(0, 0), 1.0f, tol) &&
21 sk_float_almost_equals(m.getFloat(0, 1), 0.0f, tol) &&
22 sk_float_almost_equals(m.getFloat(0, 2), 0.0f, tol) &&
23 sk_float_almost_equals(m.getFloat(0, 3), 0.0f, tol) &&
24 sk_float_almost_equals(m.getFloat(1, 0), 0.0f, tol) &&
25 sk_float_almost_equals(m.getFloat(1, 1), 1.0f, tol) &&
26 sk_float_almost_equals(m.getFloat(1, 2), 0.0f, tol) &&
27 sk_float_almost_equals(m.getFloat(1, 3), 0.0f, tol) &&
28 sk_float_almost_equals(m.getFloat(2, 0), 0.0f, tol) &&
29 sk_float_almost_equals(m.getFloat(2, 1), 0.0f, tol) &&
30 sk_float_almost_equals(m.getFloat(2, 2), 1.0f, tol) &&
31 sk_float_almost_equals(m.getFloat(2, 3), 0.0f, tol) &&
32 sk_float_almost_equals(m.getFloat(3, 0), 0.0f, tol) &&
33 sk_float_almost_equals(m.getFloat(3, 1), 0.0f, tol) &&
34 sk_float_almost_equals(m.getFloat(3, 2), 0.0f, tol) &&
35 sk_float_almost_equals(m.getFloat(3, 3), 1.0f, tol);
36 }
37
GrColorSpaceXform(const SkMatrix44 & srcToDst)38 GrColorSpaceXform::GrColorSpaceXform(const SkMatrix44& srcToDst)
39 : fSrcToDst(srcToDst) {}
40
Make(SkColorSpace * src,SkColorSpace * dst)41 sk_sp<GrColorSpaceXform> GrColorSpaceXform::Make(SkColorSpace* src, SkColorSpace* dst) {
42 if (!src || !dst) {
43 // Invalid
44 return nullptr;
45 }
46
47 if (src == dst) {
48 // Quick equality check - no conversion needed in this case
49 return nullptr;
50 }
51
52 SkMatrix44 srcToDst(SkMatrix44::kUninitialized_Constructor);
53 srcToDst.setConcat(as_CSB(dst)->fromXYZD50(), as_CSB(src)->toXYZD50());
54
55 if (matrix_is_almost_identity(srcToDst)) {
56 return nullptr;
57 }
58
59 return sk_make_sp<GrColorSpaceXform>(srcToDst);
60 }
61
Equals(const GrColorSpaceXform * a,const GrColorSpaceXform * b)62 bool GrColorSpaceXform::Equals(const GrColorSpaceXform* a, const GrColorSpaceXform* b) {
63 if (a == b) {
64 return true;
65 }
66
67 if (!a || !b) {
68 return false;
69 }
70
71 return a->fSrcToDst == b->fSrcToDst;
72 }
73
apply(const GrColor4f & srcColor)74 GrColor4f GrColorSpaceXform::apply(const GrColor4f& srcColor) {
75 GrColor4f result;
76 fSrcToDst.mapScalars(srcColor.fRGBA, result.fRGBA);
77 return result;
78 }
79