1/*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#pragma version(1)
18#pragma rs java_package_name(com.android.rs.image)
19#pragma rs_fp_relaxed
20
21uchar __attribute__((kernel)) genRand() {
22    return (uchar)rsRand(0xff);
23}
24
25/*
26 * Convolution matrix of distance 2 with fixed point of 'kShiftBits' bits
27 * shifted. Thus the sum of this matrix should be 'kShiftValue'. Entries of
28 * small values are not calculated to gain efficiency.
29 * The order ot pixels represented in this matrix is:
30 *  1  2  3
31 *  4  0  5
32 *  6  7  8
33 *  and the matrix should be: {230, 56, 114, 56, 114, 114, 56, 114, 56}.
34 *  However, since most of the valus are identical, we only use the first three
35 *  entries and the entries corresponding to the pixels is:
36 *  1  2  1
37 *  2  0  2
38 *  1  2  1
39 */
40
41int32_t gWMask;
42int32_t gHMask;
43
44rs_allocation gBlendSource;
45uchar __attribute__((kernel)) blend9(uint32_t x, uint32_t y) {
46    uint32_t x1 = (x-1) & gWMask;
47    uint32_t x2 = (x+1) & gWMask;
48    uint32_t y1 = (y-1) & gHMask;
49    uint32_t y2 = (y+1) & gHMask;
50
51    uint p00 = 56 *  rsGetElementAt_uchar(gBlendSource, x1, y1);
52    uint p01 = 114 * rsGetElementAt_uchar(gBlendSource, x, y1);
53    uint p02 = 56 *  rsGetElementAt_uchar(gBlendSource, x2, y1);
54    uint p10 = 114 * rsGetElementAt_uchar(gBlendSource, x1, y);
55    uint p11 = 230 * rsGetElementAt_uchar(gBlendSource, x, y);
56    uint p12 = 114 * rsGetElementAt_uchar(gBlendSource, x2, y);
57    uint p20 = 56 *  rsGetElementAt_uchar(gBlendSource, x1, y2);
58    uint p21 = 114 * rsGetElementAt_uchar(gBlendSource, x, y2);
59    uint p22 = 56 *  rsGetElementAt_uchar(gBlendSource, x2, y2);
60
61    p00 += p01;
62    p02 += p10;
63    p11 += p12;
64    p20 += p21;
65
66    p22 += p00;
67    p02 += p11;
68
69    p20 += p22;
70    p20 += p02;
71
72    p20 = min(p20 >> 10, (uint)255);
73    return (uchar)p20;
74}
75
76float gNoiseStrength;
77
78rs_allocation gNoise;
79uchar4 __attribute__((kernel)) root(uchar4 in, uint32_t x, uint32_t y) {
80    float4 ip = convert_float4(in);
81    float pnoise = (float) rsGetElementAt_uchar(gNoise, x & gWMask, y & gHMask);
82
83    float energy_level = ip.r + ip.g + ip.b;
84    float energy_mask = (28.f - sqrt(energy_level)) * 0.03571f;
85    pnoise = (pnoise - 128.f) * energy_mask;
86
87    ip += pnoise * gNoiseStrength;
88    ip = clamp(ip, 0.f, 255.f);
89
90    uchar4 p = convert_uchar4(ip);
91    p.a = 0xff;
92    return p;
93}
94