From 20b11a0fd3d43832a8ab93fc2a1c45dacaaf1747 Mon Sep 17 00:00:00 2001
From: David Capello <david@igara.com>
Date: Mon, 23 Dec 2024 16:37:05 -0300
Subject: [PATCH] Add image_benchmark

---
 src/doc/image_benchmark.cpp | 170 ++++++++++++++++++++++++++++++++++++
 1 file changed, 170 insertions(+)
 create mode 100644 src/doc/image_benchmark.cpp

diff --git a/src/doc/image_benchmark.cpp b/src/doc/image_benchmark.cpp
new file mode 100644
index 000000000..a7ede8fb0
--- /dev/null
+++ b/src/doc/image_benchmark.cpp
@@ -0,0 +1,170 @@
+// Aseprite Document Library
+// Copyright (c) 2024 Igara Studio S.A.
+//
+// This file is released under the terms of the MIT license.
+// Read LICENSE.txt for more information.
+
+#ifdef HAVE_CONFIG_H
+  #include "config.h"
+#endif
+
+#include "doc/algorithm/random_image.h"
+#include "doc/image.h"
+#include "doc/image_ref.h"
+
+#include <benchmark/benchmark.h>
+
+using namespace doc;
+
+void BM_ForXYGetPixel(benchmark::State& state)
+{
+  const auto pf = (PixelFormat)state.range(0);
+  const int w = state.range(1);
+  const int h = state.range(2);
+  ImageRef img(Image::create(pf, w, h));
+  doc::algorithm::random_image(img.get());
+  for (auto _ : state) {
+    color_t c = 0;
+    for (int y = 0; y < h; ++y) {
+      for (int x = 0; x < w; ++x) {
+        c += img->getPixel(x, y);
+      }
+    }
+    benchmark::DoNotOptimize(c);
+  }
+}
+
+void BM_ForEachPixel(benchmark::State& state)
+{
+  const auto pf = (PixelFormat)state.range(0);
+  const int w = state.range(1);
+  const int h = state.range(2);
+  ImageRef img(Image::create(pf, w, h));
+  doc::algorithm::random_image(img.get());
+  for (auto _ : state) {
+    color_t c = 0;
+    auto func = [&c](color_t u) { c += u; };
+    switch (pf) {
+      case IMAGE_RGB:       for_each_pixel<RgbTraits>(img.get(), func); break;
+      case IMAGE_GRAYSCALE: for_each_pixel<GrayscaleTraits>(img.get(), func); break;
+      case IMAGE_INDEXED:   for_each_pixel<IndexedTraits>(img.get(), func); break;
+      case IMAGE_BITMAP:    for_each_pixel<BitmapTraits>(img.get(), func); break;
+      case IMAGE_TILEMAP:   for_each_pixel<TilemapTraits>(img.get(), func); break;
+    }
+    benchmark::DoNotOptimize(c);
+  }
+}
+
+void BM_ForXYGetPixelFast(benchmark::State& state)
+{
+  const auto pf = (PixelFormat)state.range(0);
+  const int w = state.range(1);
+  const int h = state.range(2);
+  ImageRef img(Image::create(pf, w, h));
+  doc::algorithm::random_image(img.get());
+  for (auto _ : state) {
+    color_t c = 0;
+    switch (pf) {
+      case IMAGE_RGB:
+        for (int y = 0; y < h; ++y) {
+          for (int x = 0; x < w; ++x) {
+            c += get_pixel_fast<RgbTraits>(img.get(), x, y);
+          }
+        }
+        break;
+      case IMAGE_GRAYSCALE:
+        for (int y = 0; y < h; ++y) {
+          for (int x = 0; x < w; ++x) {
+            c += get_pixel_fast<GrayscaleTraits>(img.get(), x, y);
+          }
+        }
+        break;
+      case IMAGE_INDEXED:
+        for (int y = 0; y < h; ++y) {
+          for (int x = 0; x < w; ++x) {
+            c += get_pixel_fast<IndexedTraits>(img.get(), x, y);
+          }
+        }
+        break;
+      case IMAGE_BITMAP:
+        for (int y = 0; y < h; ++y) {
+          for (int x = 0; x < w; ++x) {
+            c += get_pixel_fast<BitmapTraits>(img.get(), x, y);
+          }
+        }
+        break;
+    }
+    benchmark::DoNotOptimize(c);
+  }
+}
+
+template<typename Func>
+void dispatch_by_pixel_format(Image* image, const ReadIterator& it, Func func)
+{
+  switch (image->pixelFormat()) {
+    case IMAGE_RGB:       func(it.addr32()); break;
+    case IMAGE_GRAYSCALE: func(it.addr16()); break;
+    case IMAGE_INDEXED:   func(it.addr8()); break;
+#if !DOC_USE_BITMAP_AS_1BPP
+    case IMAGE_BITMAP: func(it.addr8()); break;
+#endif
+    case IMAGE_TILEMAP: func(it.addr32()); break;
+  }
+}
+
+void BM_ReadIterator(benchmark::State& state)
+{
+  const auto pf = (PixelFormat)state.range(0);
+  const int w = state.range(1);
+  const int h = state.range(2);
+  ImageRef img(Image::create(pf, w, h));
+  doc::algorithm::random_image(img.get());
+  for (auto _ : state) {
+    auto it = img->readArea(img->bounds());
+    while (it.nextLine()) {
+      dispatch_by_pixel_format(img.get(), it, [w](auto addr) {
+        color_t c = 0;
+        for (int x = 0; x < w; ++x, ++addr) {
+          c += *addr;
+        }
+        benchmark::DoNotOptimize(c);
+      });
+    }
+  }
+}
+
+#define DEFARGS()                                                                                  \
+  ->Args({ IMAGE_RGB, 1024, 1024 })                                                                \
+    ->Args({ IMAGE_GRAYSCALE, 1024, 1024 })                                                        \
+    ->Args({ IMAGE_INDEXED, 1024, 1024 })                                                          \
+    ->Args({ IMAGE_BITMAP, 1024, 1024 })
+
+#if DOC_USE_BITMAP_AS_1BPP
+
+  // In this case we avoid IMAGE_BITMAP as its iterator goes through
+  // bits instead of bytes, i.e. a pixel cannot be addressed with a
+  // memory pointer.
+  #define DEFARGS_ADDRESSABLE_ONLY()                                                               \
+    ->Args({ IMAGE_RGB, 1024, 1024 })                                                              \
+      ->Args({ IMAGE_GRAYSCALE, 1024, 1024 })                                                      \
+      ->Args({ IMAGE_INDEXED, 1024, 1024 })
+
+#else
+
+  #define DEFARGS_ADDRESSABLE_ONLY DEFARGS
+
+#endif
+
+BENCHMARK(BM_ForXYGetPixel)
+DEFARGS()->UseRealTime();
+
+BENCHMARK(BM_ForEachPixel)
+DEFARGS()->UseRealTime();
+
+BENCHMARK(BM_ForXYGetPixelFast)
+DEFARGS()->UseRealTime();
+
+BENCHMARK(BM_ReadIterator)
+DEFARGS_ADDRESSABLE_ONLY()->UseRealTime();
+
+BENCHMARK_MAIN();