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(rs2spirv)
19 #pragma rs_fp_relaxed
20 
21 static float brightM = 0.f;
22 static float brightC = 0.f;
23 
24 void setBright(float v) {
25     brightM = pow(2.f, v / 100.f);
26     brightC = 127.f - brightM * 127.f;
27 }
28 
29 uchar4 __attribute__((kernel)) contrast(uchar4 in) {
30     float3 v = convert_float3(in.rgb) * brightM + brightC;
31     uchar4 o;
32     o.rgb = convert_uchar3(clamp(v, 0.f, 255.f));
33     o.a = 0xff;
34     return o;
35 }