tests/java_api/ScriptGroupTest/src/com/android/rs/sgtest/contrast_f.rs

/*
 * 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 = 1.4142136f;
static float brightC = -50.948268f;

/*
void setBright(float v) {
    brightM = pow(2.f, v / 100.f);
    brightC = 127.f - brightM * 127.f;
}
*/

float4 RS_KERNEL contrast(float4 in) {
    return in * brightM + brightC;
}