CMeshFast.h

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2020, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */

#pragma once

#include <mrpt/img/CImage.h>
#include <mrpt/img/color_maps.h>
#include <mrpt/math/CMatrixF.h>
#include <mrpt/opengl/CRenderizableShaderPoints.h>

namespace mrpt::opengl
{
/** A planar (XY) grid where each cell has an associated height and, optionally,
 * a texture map.
 * To make it faster to render, instead of drawing lines and triangles it draws
 * a point at each
 * gridcell.
 *  A typical usage example would be an elevation map or a 3D model of a
 * terrain.
 *  \sa opengl::COpenGLScene
 *
 *  <div align="center">
 *  <table border="0" cellspan="4" cellspacing="4" style="border-width: 1px;
 * border-style: solid;">
 *   <tr> <td> mrpt::opengl::CMeshFast </td> <td> \image html
 * preview_CMeshFast.png </td> </tr>
 *  </table>
 *  </div>
 *
 * \ingroup mrpt_opengl_grp
 */
class CMeshFast : public CRenderizableShaderPoints
{
    DEFINE_SERIALIZABLE(CMeshFast, mrpt::opengl)

   public:
    /** @name Renderizable shader API virtual methods
     * @{ */
    void onUpdateBuffers_Points() override;
    /** @} */

    /** Constructor
     */
    CMeshFast(
        bool enableTransparency = false, float xMin_p = -1.0f,
        float xMax_p = 1.0f, float yMin_p = -1.0f, float yMax_p = 1.0f)
        : m_textureImage(0, 0),
          m_enableTransparency(enableTransparency),
          X(0, 0),
          Y(0, 0),
          Z(0, 0),
          C(0, 0),
          C_r(0, 0),
          C_g(0, 0),
          C_b(0, 0),
          xMin(xMin_p),
          xMax(xMax_p),
          yMin(yMin_p),
          yMax(yMax_p)
    {
        m_color.A = 255;
        m_color.R = 0;
        m_color.G = 0;
        m_color.B = 150;
    }
    virtual ~CMeshFast() override = default;

    void setGridLimits(float xmin, float xmax, float ymin, float ymax)
    {
        xMin = xmin;
        xMax = xmax;
        yMin = ymin;
        yMax = ymax;
        CRenderizable::notifyChange();
    }

    void getGridLimits(float& xmin, float& xmax, float& ymin, float& ymax) const
    {
        xmin = xMin;
        xmax = xMax;
        ymin = yMin;
        ymax = yMax;
    }

    void enableTransparency(bool v)
    {
        m_enableTransparency = v;
        CRenderizable::notifyChange();
    }
    void enableColorFromZ(
        bool v, mrpt::img::TColormap colorMap = mrpt::img::cmJET)
    {
        m_colorFromZ = v;
        m_colorMap = colorMap;
        CRenderizable::notifyChange();
    }

    /** This method sets the matrix of heights for each position (cell) in the
     * mesh grid */
    void setZ(const mrpt::math::CMatrixDynamic<float>& in_Z);

    /** Returns a reference to the internal Z matrix, allowing changing it
     * efficiently */
    inline void getZ(mrpt::math::CMatrixFloat& out) const { out = Z; }
    inline float getXMin() const { return xMin; }
    inline float getXMax() const { return xMax; }
    inline float getYMin() const { return yMin; }
    inline float getYMax() const { return yMax; }
    inline void setXMin(float nxm)
    {
        xMin = nxm;
        pointsUpToDate = false;
        CRenderizable::notifyChange();
    }
    inline void setXMax(float nxm)
    {
        xMax = nxm;
        pointsUpToDate = false;
        CRenderizable::notifyChange();
    }
    inline void setYMin(float nym)
    {
        yMin = nym;
        pointsUpToDate = false;
        CRenderizable::notifyChange();
    }
    inline void setYMax(float nym)
    {
        yMax = nym;
        pointsUpToDate = false;
        CRenderizable::notifyChange();
    }
    inline void getXBounds(float& min, float& max) const
    {
        min = xMin;
        max = xMax;
    }
    inline void getYBounds(float& min, float& max) const
    {
        min = yMin;
        max = yMax;
    }
    inline void setXBounds(float min, float max)
    {
        xMin = min;
        xMax = max;
        pointsUpToDate = false;
        CRenderizable::notifyChange();
    }
    inline void setYBounds(float min, float max)
    {
        yMin = min;
        yMax = max;
        pointsUpToDate = false;
        CRenderizable::notifyChange();
    }

    void getBoundingBox(
        mrpt::math::TPoint3D& bb_min,
        mrpt::math::TPoint3D& bb_max) const override;

    /** Assigns a texture image, and disable transparency.
     */
    void assignImage(const mrpt::img::CImage& img);

    /** Assigns a texture image and Z simultaneously, and disable transparency.
     */
    void assignImageAndZ(
        const mrpt::img::CImage& img,
        const mrpt::math::CMatrixDynamic<float>& in_Z);

    /** Adjust grid limits according to the image aspect ratio, maintaining the
     * X limits and resizing in the Y direction.
     */
    inline void adjustGridToImageAR()
    {
        ASSERT_(m_isImage);
        const float ycenter = 0.5f * (yMin + yMax);
        const float xwidth = xMax - xMin;
        const float newratio = float(m_textureImage.getWidth()) /
                               float(m_textureImage.getHeight());
        yMax = ycenter + 0.5f * newratio * xwidth;
        yMin = ycenter - 0.5f * newratio * xwidth;
        CRenderizable::notifyChange();
    }

   protected:
    mrpt::img::CImage m_textureImage;

    bool m_enableTransparency;
    bool m_colorFromZ{false};
    bool m_isImage{false};

    /** X(x,y): X-coordinate of the point (x,y) */
    mutable math::CMatrixF X;
    /** Y(x,y): Y-coordinate of the point (x,y) */
    mutable math::CMatrixF Y;
    /** Z(x,y): Z-coordinate of the point (x,y) */
    mutable math::CMatrixF Z;

    /** Grayscale or RGB components [0,255] for each cell, updated by
     * updateColorsMatrix */
    mutable math::CMatrix_u8 C, C_r, C_g, C_b;

    /** Used when m_colorFromZ is true */
    mrpt::img::TColormap m_colorMap{mrpt::img::cmJET};

    /** Whether C is not up-to-date wrt to Z */
    mutable bool m_modified_Z{true};
    /** Whether C is not up-to-date wrt to the texture image */
    mutable bool m_modified_Image{false};

    /** Called internally to assure C is updated. */
    void updateColorsMatrix() const;
    void updatePoints() const;

    /** Mesh bounds */
    float xMin, xMax, yMin, yMax;

    /**Whether the coordinates of the points needs to be recalculated */
    mutable bool pointsUpToDate{false};
};

}  // namespace mrpt::opengl