/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8                               :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney                              │
│                                                                              │
│ Permission to use, copy, modify, and/or distribute this software for         │
│ any purpose with or without fee is hereby granted, provided that the         │
│ above copyright notice and this permission notice appear in all copies.      │
│                                                                              │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
│ PERFORMANCE OF THIS SOFTWARE.                                                │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "dsp/core/core.h"
#include "libc/limits.h"
#include "libc/log/check.h"
#include "libc/macros.h"
#include "libc/nexgen32e/x86feature.h"
#include "libc/stdio/rand.h"
#include "libc/testlib/ezbench.h"
#include "libc/testlib/testlib.h"

short pcm[8][8];

TEST(scalevolume, testIncreaseVolumeByOneIncrement) {
  pcm[0][0] = INT16_MIN;
  pcm[0][1] = INT16_MIN / 2;
  pcm[0][2] = -2;
  pcm[0][3] = -1;
  pcm[0][4] = 0;
  pcm[0][5] = 1;
  pcm[0][6] = 2;
  pcm[0][7] = INT16_MAX / 2;
  pcm[1][0] = INT16_MAX;
  scalevolume(ARRAYLEN(pcm), pcm, 1);
  EXPECT_EQ(INT16_MIN, pcm[0][0]);
  EXPECT_EQ(INT16_MIN, pcm[0][1]);
  EXPECT_EQ(-4, pcm[0][2]);
  EXPECT_EQ(-2, pcm[0][3]);
  EXPECT_EQ(0, pcm[0][4]);
  EXPECT_EQ(2, pcm[0][5]);
  EXPECT_EQ(4, pcm[0][6]);
  EXPECT_EQ(INT16_MAX - 1, pcm[0][7]);
  EXPECT_EQ(INT16_MAX, pcm[1][0]);
}

TEST(scalevolume, testDecreaseVolumeByOneIncrement) {
  pcm[0][0] = INT16_MIN;
  pcm[0][1] = INT16_MIN / 2;
  pcm[0][2] = -2;
  pcm[0][3] = -1;
  pcm[0][4] = 0;
  pcm[0][5] = 1;
  pcm[0][6] = 2;
  pcm[0][7] = INT16_MAX / 2;
  pcm[1][0] = INT16_MAX;
  scalevolume(ARRAYLEN(pcm), pcm, -1);
  EXPECT_EQ(INT16_MIN / 2, pcm[0][0]);
  EXPECT_EQ(INT16_MIN / 4, pcm[0][1]);
  EXPECT_EQ(-1, pcm[0][2]);
  EXPECT_EQ(-1, pcm[0][3]);
  EXPECT_EQ(0, pcm[0][4]);
  EXPECT_EQ(0, pcm[0][5]);
  EXPECT_EQ(1, pcm[0][6]);
  EXPECT_EQ(INT16_MAX / 4, pcm[0][7]);
  EXPECT_EQ(INT16_MAX / 2, pcm[1][0]);
}

TEST(scalevolume, testScaleByZero_doesNothing) {
  pcm[0][0] = INT16_MIN;
  pcm[0][1] = INT16_MIN / 2;
  pcm[0][2] = -2;
  pcm[0][3] = -1;
  pcm[0][4] = 0;
  pcm[0][5] = 1;
  pcm[0][6] = 2;
  pcm[0][7] = INT16_MAX / 2;
  pcm[1][0] = INT16_MAX;
  scalevolume(ARRAYLEN(pcm), pcm, 0);
  EXPECT_EQ(INT16_MIN, pcm[0][0]);
  EXPECT_EQ(INT16_MIN / 2, pcm[0][1]);
  EXPECT_EQ(-2, pcm[0][2]);
  EXPECT_EQ(-1, pcm[0][3]);
  EXPECT_EQ(0, pcm[0][4]);
  EXPECT_EQ(1, pcm[0][5]);
  EXPECT_EQ(2, pcm[0][6]);
  EXPECT_EQ(INT16_MAX / 2, pcm[0][7]);
  EXPECT_EQ(INT16_MAX, pcm[1][0]);
}

TEST(scalevolume, testBiggestScale_justSaturates) {
  pcm[0][0] = INT16_MIN;
  pcm[0][1] = INT16_MIN / 2;
  pcm[0][2] = -2;
  pcm[0][3] = -1;
  pcm[0][4] = 0;
  pcm[0][5] = 1;
  pcm[0][6] = 2;
  pcm[0][7] = INT16_MAX / 2;
  pcm[1][0] = INT16_MAX;
  scalevolume(ARRAYLEN(pcm), pcm, 123);
  EXPECT_EQ(INT16_MIN, pcm[0][0]);
  EXPECT_EQ(INT16_MIN, pcm[0][1]);
  EXPECT_EQ(INT16_MIN, pcm[0][2]);
  EXPECT_EQ(INT16_MIN, pcm[0][3]);
  EXPECT_EQ(0, pcm[0][4]);
  EXPECT_EQ(INT16_MAX, pcm[0][5]);
  EXPECT_EQ(INT16_MAX, pcm[0][6]);
  EXPECT_EQ(INT16_MAX, pcm[0][7]);
  EXPECT_EQ(INT16_MAX, pcm[1][0]);
}

TEST(scalevolume, testSmallestScale_justSaturates) {
  pcm[0][0] = INT16_MIN;
  pcm[0][1] = INT16_MIN / 2;
  pcm[0][2] = -2;
  pcm[0][3] = -1;
  pcm[0][4] = 0;
  pcm[0][5] = 1;
  pcm[0][6] = 2;
  pcm[0][7] = INT16_MAX / 2;
  pcm[1][0] = INT16_MAX;
  scalevolume(ARRAYLEN(pcm), pcm, -123);
  EXPECT_EQ(-1, pcm[0][0]);
  EXPECT_EQ(-1, pcm[0][1]);
  EXPECT_EQ(-1, pcm[0][2]);
  EXPECT_EQ(-1, pcm[0][3]);
  EXPECT_EQ(0, pcm[0][4]);
  EXPECT_EQ(0, pcm[0][5]);
  EXPECT_EQ(0, pcm[0][6]);
  EXPECT_EQ(0, pcm[0][7]);
  EXPECT_EQ(0, pcm[1][0]);
}

//////////////////////////////////////////////////////////////////////
// audio volume adjustment latency:
//   -   ~1µs w/ -Os
//   - ~500ns w/ -O3
//   - ~200ns w/ -O3 -march=skylake MODE=rel

void randomizeaudio(void) {
  rngset(pcm, sizeof(pcm), _rand64, -1);
}

void scalevolume_pure(int amt) {
  scalevolume(ARRAYLEN(pcm), pcm, amt);
}

BENCH(scalevolume, audioframe) {
  EZBENCH(randomizeaudio(), scalevolume_pure(0));
  EZBENCH(randomizeaudio(), scalevolume_pure(1));
  EZBENCH(randomizeaudio(), scalevolume_pure(15));
}