| /* |
| * Copyright (C) 2013 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" |
| |
| rs_allocation gSrc; |
| rs_allocation gDest; |
| rs_allocation gSums; |
| rs_allocation gSum; |
| |
| int gWidth; |
| int gHeight; |
| int gStep; |
| int gSteps; |
| |
| void RS_KERNEL pass1(uint x) { |
| for (int i=0; i < (256); i++) { |
| rsSetElementAt_int(gSums, 0, i, x); |
| } |
| |
| for (int i = 0; i < gStep; i++) { |
| int py = x * gStep + i; |
| if (py >= gHeight) return; |
| |
| for (int px=0; px < gWidth; px++) { |
| uchar4 c = rsGetElementAt_uchar4(gSrc, px, py); |
| int lum = (77 * c.r + 150 * c.g + 29 * c.b) >> 8; |
| |
| int old = rsGetElementAt_int(gSums, lum, x); |
| rsSetElementAt_int(gSums, old+1, lum, x); |
| } |
| } |
| } |
| |
| int RS_KERNEL pass2(uint x) { |
| int sum = 0; |
| for (int i=0; i < gSteps; i++) { |
| sum += rsGetElementAt_int(gSums, x, i); |
| } |
| return sum; |
| } |
| |
| void rescale() { |
| int maxv = 0; |
| |
| for (int i=0; i < 256; i++) { |
| maxv = max(maxv, rsGetElementAt_int(gSum, i)); |
| } |
| float overMax = (1.f / maxv) * gHeight; |
| |
| for (int i=0; i < 256; i++) { |
| int t = rsGetElementAt_int(gSum, i); |
| t = gHeight - (overMax * rsGetElementAt_int(gSum, i)); |
| t = max(0, t); |
| rsSetElementAt_int(gSum, t, i); |
| } |
| } |
| |
| static const uchar4 gClear = {0, 0, 0, 0xff}; |
| |
| uchar4 RS_KERNEL clear() { |
| return gClear; |
| } |
| |
| uchar4 RS_KERNEL draw(uint x, uint y) { |
| int l = rsGetElementAt_int(gSum, x >> 2); |
| if (y > l) { |
| return 0xff; |
| } |
| return gClear; |
| } |