contrast.rs revision 6749f541c20e86f5deb6fd421ed5849ef43c275c 
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
21static float brightM = 0.f;
22static float brightC = 0.f;
23
24void setBright(float v) {
25    brightM = pow(2.f, v / 100.f);
26    brightC = 127.f - brightM * 127.f;
27}
28
29uchar4 __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}