Some optimizations (#880)

include/utils/ImageData.h

@@ -0,0 +1,180 @@
+#pragma once
+
+// STL includes
+#include <vector>
+#include <cstdint>
+#include <cstring>
+#include <algorithm>
+#include <cassert>
+#include <type_traits>
+#include <utils/ColorRgb.h>
+
+// QT includes
+#include <QSharedData>
+
+// https://docs.microsoft.com/en-us/windows/win32/winprog/windows-data-types#ssize-t
+#if defined(_MSC_VER)
+#include <BaseTsd.h>
+typedef SSIZE_T ssize_t;
+#endif
+
+template <typename Pixel_T>
+class ImageData : public QSharedData
+{
+public:
+	typedef Pixel_T pixel_type;
+
+	ImageData(const unsigned width, const unsigned height, const Pixel_T background) :
+		_width(width),
+		_height(height),
+		_pixels(new Pixel_T[width * height + 1])
+	{
+		std::fill(_pixels, _pixels + width * height, background);
+	}
+
+	ImageData(const ImageData & other) :
+		QSharedData(other),
+		_width(other._width),
+		_height(other._height),
+		_pixels(new Pixel_T[other._width * other._height + 1])
+	{
+		memcpy(_pixels, other._pixels, (long) other._width * other._height * sizeof(Pixel_T));
+	}
+
+	ImageData& operator=(ImageData rhs)
+	{
+		rhs.swap(*this);
+		return *this;
+	}
+
+	void swap(ImageData& s) noexcept
+	{
+		using std::swap;
+		swap(this->_width, s._width);
+		swap(this->_height, s._height);
+		swap(this->_pixels, s._pixels);
+	}
+
+	ImageData(ImageData&& src) noexcept
+		: _width(0)
+		, _height(0)
+		, _pixels(NULL)
+	{
+		src.swap(*this);
+	}
+
+	ImageData& operator=(ImageData&& src) noexcept
+	{
+		src.swap(*this);
+		return *this;
+	}
+
+	~ImageData()
+	{
+		delete[] _pixels;
+	}
+
+	inline unsigned width() const
+	{
+		return _width;
+	}
+
+	inline unsigned height() const
+	{
+		return _height;
+	}
+
+	uint8_t red(const unsigned pixel) const
+	{
+		return (_pixels + pixel)->red;
+	}
+
+	uint8_t green(const unsigned pixel) const
+	{
+		return (_pixels + pixel)->green;
+	}
+
+	uint8_t blue(const unsigned pixel) const
+	{
+		return (_pixels + pixel)->blue;
+	}
+
+	const Pixel_T& operator()(const unsigned x, const unsigned y) const
+	{
+		return _pixels[toIndex(x,y)];
+	}
+
+	Pixel_T& operator()(const unsigned x, const unsigned y)
+	{
+		return _pixels[toIndex(x,y)];
+	}
+
+	void resize(const unsigned width, const unsigned height)
+	{
+		if (width == _width && height == _height)
+			return;
+
+		if ((width * height) > unsigned((_width * _height)))
+		{
+			delete[] _pixels;
+			_pixels = new Pixel_T[width*height + 1];
+		}
+
+		_width = width;
+		_height = height;
+	}
+
+	Pixel_T* memptr()
+	{
+		return _pixels;
+	}
+
+	const Pixel_T* memptr() const
+	{
+		return _pixels;
+	}
+
+	void toRgb(ImageData<ColorRgb>& image)
+	{
+		image.resize(_width, _height);
+		const unsigned imageSize = _width * _height;
+
+		for (unsigned idx = 0; idx < imageSize; idx++)
+		{
+			const Pixel_T & color = _pixels[idx];
+			image.memptr()[idx] = ColorRgb{color.red, color.green, color.blue};
+		}
+	}
+
+	ssize_t size() const
+	{
+		return  (ssize_t) _width * _height * sizeof(Pixel_T);
+	}
+
+	void clear()
+	{
+		if (_width != 1 || _height != 1)
+		{
+			_width = 1;
+			_height = 1;
+			delete[] _pixels;
+			_pixels = new Pixel_T[2];
+		}
+
+		memset(_pixels, 0, (unsigned long) _width * _height * sizeof(Pixel_T));
+	}
+
+private:
+	inline unsigned toIndex(const unsigned x, const unsigned y) const
+	{
+		return y * _width + x;
+	}
+
+private:
+	/// The width of the image
+	unsigned _width;
+	/// The height of the image
+	unsigned _height;
+	/// The pixels of the image
+	Pixel_T* _pixels;
+};