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#include "ip.rsh"
18#pragma rs_fp_relaxed
19
20rs_allocation gBlur;
21
22static float gOverWm1;
23static float gOverHm1;
24static uchar gLutR[256];
25static uchar gLutG[256];
26static uchar gLutB[256];
27
28void setup() {
29    int w = rsAllocationGetDimX(gBlur);
30    int h = rsAllocationGetDimY(gBlur);
31    gOverWm1 = 1.f / w;
32    gOverHm1 = 1.f / h;
33
34    for (int x=0; x < 256; x++) {
35        gLutR[x] = x;//255-x;
36        gLutG[x] = x;//255-x;
37        gLutB[x] = x;//255-x;
38    }
39}
40
41uchar4 RS_KERNEL process(uchar4 in, uint32_t x, uint32_t y) {
42    float2 xyDist;
43    xyDist.x = (x * gOverWm1 - 0.5f);
44    xyDist.y = (y * gOverHm1 - 0.5f);
45
46    // color
47    float4 v1 = rsUnpackColor8888(in);
48    float4 v2 = rsUnpackColor8888(rsGetElementAt_uchar4(gBlur, x, y));
49
50    float dist = dot(xyDist, xyDist) * 1.4f;
51    float pdist = native_powr(dist, 2.7f * 0.5f);
52    //float pdist = powr(dist, 2.7f * 0.5f);
53
54    pdist = clamp(pdist, 0.f, 1.f);
55    v1 = mix(v1, v2, dist * 2.f);
56    v1 *= 1.f - pdist;
57
58    // apply curve
59    uchar4 out = rsPackColorTo8888(v1);
60
61    out.r = gLutR[out.r];
62    out.g = gLutG[out.g];
63    out.b = gLutB[out.b];
64    return out;
65}
66
67
68