xref: /aosp_15_r20/external/skia/tests/ColorPrivTest.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
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 #include "include/core/SkColor.h"
9 #include "include/core/SkColorPriv.h"
10 #include "include/core/SkTypes.h"
11 #include "include/private/SkColorData.h"
12 #include "tests/Test.h"
13 
14 #include <cstdint>
15 
16 #define ASSERT(expr) REPORTER_ASSERT(r, expr)
17 
DEF_TEST(Splay,r)18 DEF_TEST(Splay, r) {
19     const SkPMColor color = 0xA1B2C3D4;
20 
21     uint32_t ag, rb;
22     SkSplay(color, &ag, &rb);
23     ASSERT(ag == 0x00A100C3);
24     ASSERT(rb == 0x00B200D4);
25     ASSERT(SkUnsplay(ag << 8, rb << 8) == color);
26 
27     const uint64_t agrb = SkSplay(color);
28     ASSERT(agrb == 0x00A100C300B200D4ULL);
29     ASSERT(SkUnsplay(agrb<<8) == color);
30 }
31 
DEF_TEST(FourByteInterp,r)32 DEF_TEST(FourByteInterp, r) {
33     const SkPMColor src = 0xAB998877, dst = 0x66334455;
34     for (unsigned scale = 0; scale <= 256; scale++) {
35         ASSERT(SkFourByteInterp256(src, dst, scale) == SkFastFourByteInterp256(src, dst, scale));
36     }
37 
38     for (unsigned scale = 0; scale < 256; scale++) {
39         // SkFourByteInterp and SkFastFourByteInterp convert from [0, 255] to [0, 256] differently.
40         // In particular, slow may end up a little too high (weirdly, fast is more accurate).
41         const SkPMColor slow = SkFourByteInterp(src, dst, scale);
42         const SkPMColor fast = SkFastFourByteInterp(src, dst, scale);
43 
44         const int deltaA = SkGetPackedA32(slow) - SkGetPackedA32(fast);
45         const int deltaR = SkGetPackedR32(slow) - SkGetPackedR32(fast);
46         const int deltaG = SkGetPackedG32(slow) - SkGetPackedG32(fast);
47         const int deltaB = SkGetPackedB32(slow) - SkGetPackedB32(fast);
48 
49         ASSERT(deltaA == 0 || deltaA == 1);
50         ASSERT(deltaR == 0 || deltaR == 1);
51         ASSERT(deltaG == 0 || deltaG == 1);
52         ASSERT(deltaB == 0 || deltaB == 1);
53     }
54 }
55