| /* |
| * Copyright (C) 2012 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "ip.rsh" |
| #pragma rs_fp_relaxed |
| |
| static float brightM = 0.f; |
| static float brightC = 0.f; |
| |
| void setBright(float v) { |
| brightM = pow(2.f, v / 100.f); |
| brightC = 127.f - brightM * 127.f; |
| } |
| |
| uchar4 RS_KERNEL contrast(uchar4 in) { |
| float3 v = convert_float3(in.rgb) * brightM + brightC; |
| uchar4 o; |
| o.rgb = convert_uchar3(clamp(v, 0.f, 255.f)); |
| o.a = 0xff; |
| return o; |
| } |