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