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
19static float brightM = 0.f;
20static float brightC = 0.f;
21
22void setBright(float v) {
23    brightM = pow(2.f, v / 100.f);
24    brightC = 127.f - brightM * 127.f;
25}
26
27void contrast(const uchar4 *in, uchar4 *out)
28{
29#if 0
30    out->r = rsClamp((int)(brightM * in->r + brightC), 0, 255);
31    out->g = rsClamp((int)(brightM * in->g + brightC), 0, 255);
32    out->b = rsClamp((int)(brightM * in->b + brightC), 0, 255);
33#else
34    float3 v = convert_float3(in->rgb) * brightM + brightC;
35    out->rgb = convert_uchar3(clamp(v, 0.f, 255.f));
36#endif
37}
38