From 71fb1ed22615a8ff90330bf3d0cab4d98ccc97a3 Mon Sep 17 00:00:00 2001
From: MacDue <macdue@dueutil.tech>
Date: Sun, 9 Oct 2022 16:30:00 +0100
Subject: [PATCH] PixelPaint: Add InplaceFilter and convert FastBoxBlur to be
 one

This is a simple base class for filters that need to work on the image
in-place.
---
 .../PixelPaint/Filters/FastBoxBlur.cpp        |  9 +-----
 .../PixelPaint/Filters/FastBoxBlur.h          |  8 ++---
 .../PixelPaint/Filters/InplaceFilter.h        | 32 +++++++++++++++++++
 3 files changed, 37 insertions(+), 12 deletions(-)
 create mode 100644 Userland/Applications/PixelPaint/Filters/InplaceFilter.h

diff --git a/Userland/Applications/PixelPaint/Filters/FastBoxBlur.cpp b/Userland/Applications/PixelPaint/Filters/FastBoxBlur.cpp
index 4813a8de10..e12d15bf1a 100644
--- a/Userland/Applications/PixelPaint/Filters/FastBoxBlur.cpp
+++ b/Userland/Applications/PixelPaint/Filters/FastBoxBlur.cpp
@@ -14,15 +14,8 @@
 
 namespace PixelPaint::Filters {
 
-void FastBoxBlur::apply(Gfx::Bitmap& target_bitmap, Gfx::Bitmap const& source_bitmap) const
+void FastBoxBlur::apply(Gfx::Bitmap& target_bitmap) const
 {
-    // This filter only works in-place, so if we have different target and source, we first copy over
-    // the source bitmap to the target one.
-    if (&target_bitmap != &source_bitmap) {
-        VERIFY(source_bitmap.size_in_bytes() == target_bitmap.size_in_bytes());
-        memcpy(target_bitmap.scanline(0), source_bitmap.scanline(0), source_bitmap.size_in_bytes());
-    }
-
     Gfx::FastBoxBlurFilter filter(target_bitmap);
 
     if (m_use_asymmetric_radii) {
diff --git a/Userland/Applications/PixelPaint/Filters/FastBoxBlur.h b/Userland/Applications/PixelPaint/Filters/FastBoxBlur.h
index 85006620ad..c041c2213c 100644
--- a/Userland/Applications/PixelPaint/Filters/FastBoxBlur.h
+++ b/Userland/Applications/PixelPaint/Filters/FastBoxBlur.h
@@ -6,21 +6,21 @@
 
 #pragma once
 
-#include "Filter.h"
+#include "InplaceFilter.h"
 #include <LibGUI/CheckBox.h>
 #include <LibGUI/ValueSlider.h>
 
 namespace PixelPaint::Filters {
 
-class FastBoxBlur final : public Filter {
+class FastBoxBlur final : public InplaceFilter {
 public:
-    virtual void apply(Gfx::Bitmap& target_bitmap, Gfx::Bitmap const& source_bitmap) const override;
+    virtual void apply(Gfx::Bitmap& target_bitmap) const override;
     virtual RefPtr<GUI::Widget> get_settings_widget() override;
 
     virtual StringView filter_name() const override { return "Fast Box Blur (& Gauss)"sv; }
 
     FastBoxBlur(ImageEditor* editor)
-        : Filter(editor) {};
+        : InplaceFilter(editor) {};
 
 private:
     size_t m_radius { 5 };
diff --git a/Userland/Applications/PixelPaint/Filters/InplaceFilter.h b/Userland/Applications/PixelPaint/Filters/InplaceFilter.h
new file mode 100644
index 0000000000..fd9ef94b76
--- /dev/null
+++ b/Userland/Applications/PixelPaint/Filters/InplaceFilter.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2022, MacDue <macdue@dueutil.tech>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include "Filter.h"
+
+namespace PixelPaint {
+
+class InplaceFilter : public Filter {
+public:
+    using Filter::apply;
+    using Filter::Filter;
+
+    virtual void apply(Gfx::Bitmap& target_bitmap) const = 0;
+
+    virtual void apply(Gfx::Bitmap& target_bitmap, Gfx::Bitmap const& source_bitmap) const override
+    {
+        // This filter only works in-place, so if we have different target and source, we first copy over
+        // the source bitmap to the target one.
+        if (&target_bitmap != &source_bitmap) {
+            VERIFY(source_bitmap.size_in_bytes() == target_bitmap.size_in_bytes());
+            memcpy(target_bitmap.scanline(0), source_bitmap.scanline(0), source_bitmap.size_in_bytes());
+        }
+        apply(target_bitmap);
+    }
+};
+
+}