1 /*
2 * Copyright 2021 Google LLC
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 "include/core/SkBlender.h"
9 #include "include/core/SkRefCnt.h"
10 #include "include/core/SkTypes.h"
11 #include "include/effects/SkBlenders.h"
12
13 #include "include/core/SkBlendMode.h"
14 #include "include/core/SkData.h"
15 #include "include/core/SkScalar.h"
16 #include "include/effects/SkRuntimeEffect.h"
17 #include "include/private/base/SkFloatingPoint.h"
18 #include "src/core/SkKnownRuntimeEffects.h"
19
Arithmetic(float k1,float k2,float k3,float k4,bool enforcePremul)20 sk_sp<SkBlender> SkBlenders::Arithmetic(float k1, float k2, float k3, float k4,
21 bool enforcePremul) {
22 using namespace SkKnownRuntimeEffects;
23
24 if (!SkIsFinite(k1, k2, k3, k4)) {
25 return nullptr;
26 }
27
28 // Are we nearly a SkBlendMode?
29 const struct {
30 float k1, k2, k3, k4;
31 SkBlendMode mode;
32 } table[] = {
33 { 0, 1, 0, 0, SkBlendMode::kSrc },
34 { 0, 0, 1, 0, SkBlendMode::kDst },
35 { 0, 0, 0, 0, SkBlendMode::kClear },
36 };
37 for (const auto& t : table) {
38 if (SkScalarNearlyEqual(k1, t.k1) &&
39 SkScalarNearlyEqual(k2, t.k2) &&
40 SkScalarNearlyEqual(k3, t.k3) &&
41 SkScalarNearlyEqual(k4, t.k4)) {
42 return SkBlender::Mode(t.mode);
43 }
44 }
45
46 // If we get here, we need the actual blender effect.
47 const SkRuntimeEffect* arithmeticEffect = GetKnownRuntimeEffect(StableKey::kArithmetic);
48
49 const float array[] = {
50 k1, k2, k3, k4,
51 enforcePremul ? 0.0f : 1.0f,
52 };
53 return arithmeticEffect->makeBlender(SkData::MakeWithCopy(array, sizeof(array)));
54 }
55