CEnhancedMetaFile.h

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2018, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */
#pragma once

#include <mrpt/img/CCanvas.h>
#include <mrpt/core/safe_pointers.h>

namespace mrpt::img
{
/** This class represents a Windows Enhanced Meta File (EMF) for generating and
 * saving graphics.
 *  If used under Linux, a ".png", non-vectorial, file will be generated
 * instead.
 * \ingroup mrpt_img_grp
 */
class CEnhancedMetaFile : public CCanvas
{
   private:
    void_ptr_noncopy m_hdc;
    int m_scale;
    void_ptr_noncopy m_hFont{nullptr};
    std::string m_targetFile;

   public:
    /** In Linux, the size of the bitmap image that emulates the EMF
     * (Default:800) */
    static void LINUX_IMG_WIDTH(int value);
    static int LINUX_IMG_WIDTH();
    /** In Linux, the size of the bitmap image that emulates the EMF
     * (Default:600) */
    static void LINUX_IMG_HEIGHT(int value);
    static int LINUX_IMG_HEIGHT();

    /** Constructor
     *  \param targetFileName This file will be created and the EMF saved
     * there.
     *  \param scaleFactor All coordinates in draw commands will be internally
     * multiplied by this scale, to provide a way of obtaining "subpixel"
     * drawing.
     */
    CEnhancedMetaFile(const std::string& targetFileName, int scaleFactor = 1);

    /** Destructor */
    virtual ~CEnhancedMetaFile();

    /** Changes the value of the pixel (x,y).
     *  Pixel coordinates starts at the left-top corner of the image, and start
     * in (0,0).
     *  The meaning of the parameter "color" depends on the implementation: it
     * will usually
     *   be a 24bit RGB value (0x00RRGGBB), but it can also be just a 8bit gray
     * level.
     *  This method must support (x,y) values OUT of the actual image size
     * without neither
     *   raising exceptions, nor leading to memory access errors.
     */
    void setPixel(int x, int y, size_t color) override;

    /** Returns the width of the image in pixels (this currently has no
     * applicability for a EMF file...) */
    size_t getWidth() const override { return 640; }
    /** Returns the height of the image in pixels (this currently has no
     * applicability for a EMF file...) */
    size_t getHeight() const override { return 480; }
    /** Draws an image as a bitmap at a given position.
     * \param x0 The top-left corner x coordinates on this canvas where the
     * image is to be drawn
     * \param y0 The top-left corner y coordinates on this canvas where the
     * image is to be drawn
     * \param img The image to be drawn in this canvas
     *  This method may be redefined in some classes implementing this
     * interface in a more appropiate manner.
     */
    void drawImage(int x, int y, const mrpt::img::CImage& img) override;

    /** Draws a line.
     * \param x0 The starting point x coordinate
     * \param y0 The starting point y coordinate
     * \param x1 The end point x coordinate
     * \param y1 The end point y coordinate
     * \param color The color of the line
     * \param width The desired width of the line (this is IGNORED in this
     * virtual class)
     *  This method may be redefined in some classes implementing this
     * interface in a more appropiate manner.
     */
    void line(
        int x0, int y0, int x1, int y1, const mrpt::img::TColor color,
        unsigned int width = 1, TPenStyle penStyle = psSolid) override;

    /** Places a text label.
     * \param x0 The x coordinates
     * \param y0 The y coordinates
     * \param str The string to put
     * \param color The text color
     * \param fontSize The font size, in "points"
     *  This method may be redefined in some classes implementing this
     * interface in a more appropiate manner.
     * \sa rectangle
     */
    void textOut(
        int x0, int y0, const std::string& str,
        const mrpt::img::TColor color) override;

    /** Select the current font used when drawing text.
     * \param fontName The face name of a font (e.g. "Arial","System",...)
     * \param fontSize The size of the font in pts.
     * \param bold Whether the font is bold
     * \param italic Whether the font is italic
     * \sa textOut, CCanvas::selectTextFont
     */
    virtual void selectVectorTextFont(
        const std::string& fontName, int fontSize, bool bold = false,
        bool italic = false);

    /** Draws an image as a bitmap at a given position, with some custom scale
     * and rotation changes.
     * \param x0 The top-left corner x coordinates on this canvas where the
     * image is to be drawn
     * \param y0 The top-left corner y coordinates on this canvas where the
     * image is to be drawn
     * \param rotation The rotation in radians, positive values being
     * anti-clockwise direction, 0 is the normal position.
     * \param scale The scale factor, e.g. 2 means twice the original size.
     * \param img The image to be drawn in this canvas
     *  This method may be redefined in some classes implementing this
     * interface in a more appropiate manner.
     */
    void drawImage(
        int x, int y, const mrpt::img::CImage& img, float rotation,
        float scale) override
    {
        CCanvas::drawImage(x, y, img, rotation, scale);
    }

    /** Draws a rectangle (an empty rectangle, without filling)
     * \param x0 The top-left x coordinate
     * \param y0 The top-left y coordinate
     * \param x1 The right-bottom x coordinate
     * \param y1 The right-bottom y coordinate
     * \param color The color of the line
     * \param width The desired width of the line.
     * \sa filledRectangle
     */
    virtual void rectangle(
        int x0, int y0, int x1, int y1, const mrpt::img::TColor color,
        unsigned int width = 1);

    /** Draws an ellipse representing a given confidence interval of a 2D
     * Gaussian distribution.
     * \param mean_x The x coordinate of the center point of the ellipse.
     * \param mean_y The y coordinate of the center point of the ellipse.
     * \param cov2D A 2x2 covariance matrix.
     * \param confIntervalStds How many "sigmas" for the confidence level (i.e.
     * 2->95%, 3=99.97%,...)
     * \param color The color of the ellipse
     * \param width The desired width of the line (this is IGNORED in this
     * virtual class)
     * \param nEllipsePoints The number of points to generate to approximate
     * the ellipse shape.
     * \exception std::exception On an invalid matrix.
     */
    template <class T>
    void ellipseGaussian(
        math::CMatrixTemplateNumeric<T>* cov2D, T mean_x, T mean_y,
        float confIntervalStds = 2,
        const mrpt::img::TColor& color = mrpt::img::TColor(255, 255, 255),
        unsigned int width = 1, int nEllipsePoints = 20)
    {
        MRPT_START
        int x1 = 0, y1 = 0, x2 = 0, y2 = 0;
        double ang;
        math::CMatrixTemplateNumeric<T> eigVal, eigVec;
        int i;

        // Compute the eigen-vectors & values:
        cov2D->eigenVectors(eigVec, eigVal);

        eigVal.Sqrt();
        math::CMatrixTemplateNumeric<T> M(eigVal * (~eigVec));

        // Compute the points of the 2D ellipse:
        for (i = 0, ang = 0; i < nEllipsePoints;
             i++, ang += (M_2PI / (nEllipsePoints - 1)))
        {
            float ccos = cos(ang);
            float ssin = sin(ang);

            x2 = round(
                mean_x + confIntervalStds * (ccos * M(0, 0) + ssin * M(1, 0)));
            y2 = round(
                mean_y + confIntervalStds * (ccos * M(0, 1) + ssin * M(1, 1)));

            if (i > 0) line(x1, y1, x2, y2, color, width);

            x1 = x2;
            y1 = y2;
        }  // end for points on ellipse

        MRPT_END_WITH_CLEAN_UP(
            std::cout << "Covariance matrix leading to error is:" << std::endl
                      << *cov2D << std::endl;);
    }
};  // End of class def.
}