(C++) SurfacePlotterTImage

 

Simple class to make a surface plot of a 2D std::vector.

 

The tool SurfacePlotter demonstrates the use of this class.

 

The class SurfacePlotter needs a Extctrls::TImage to work on, but does not manage the deletion of it.

 

• View the VCL code for 'SurfacePlotter' in plain text
• (obsolete) View the CLX code for 'SurfacePlotter' in plain text

 

---

//--------------------------------------------------------------------------- /*   SurfacePlotter, plot a user-defined 2D function   Copyright 2010  Richèl Bilderbeek   This program is free software: you can redistribute it and/or modify   it under the terms of the GNU General Public License as published by   the Free Software Foundation, either version 3 of the License, or   (at your option) any later version.   This program is distributed in the hope that it will be useful,   but WITHOUT ANY WARRANTY; without even the implied warranty of   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the   GNU General Public License for more details.   You should have received a copy of the GNU General Public License   along with this program.  If not, see <http://www.gnu.org/licenses/>. */ //--------------------------------------------------------------------------- // From http://www.richelbilderbeek.nl //--------------------------------------------------------------------------- #ifndef UnitSurfacePlotterH #define UnitSurfacePlotterH //--------------------------------------------------------------------------- #include <vector> #include <algorithm> #include <cassert> #include <Graphics.hpp> //VCL specific #include <ExtCtrls.hpp> //VCL specific //--------------------------------------------------------------------------- // From http://www.richelbilderbeek.nl //--------------------------------------------------------------------------- struct SurfacePlotter {   SurfacePlotter(Extctrls::TImage * const image)   : mImage(image)   {     assert(mImage);     assert(mImage->Picture->Bitmap!=0);     assert(mImage->Picture->Bitmap->PixelFormat == pf24bit);   }   //Sets the image of the surface plot to the values of the vector   //The doubles can be in any range   void SetSurfaceGrey(const std::vector<std::vector<double> >& surface)   {     //Get the size     const int maxx = surface.size();     const int maxy = surface[0].size();     //Resize Image to the correct size     mImage->Picture->Bitmap->Width  = maxx;     mImage->Picture->Bitmap->Height = maxy;     //Minimum and maximum are not given, so these need to be calculated     double minVal = *(std::min_element(surface[0].begin(),surface[0].end()));     double maxVal = *(std::max_element(surface[0].begin(),surface[0].end()));     for (int x=1; x!=maxx; ++x) //1, because 0 gets know the lines above     {       const double localMinVal = *(std::min_element(surface[x].begin(),surface[x].end()));       const double localMaxVal = *(std::max_element(surface[x].begin(),surface[x].end()));       if (localMinVal < minVal) minVal = localMinVal;       if (localMaxVal > maxVal) maxVal = localMaxVal;     }     if (minVal == maxVal)     {       //Draw black       for (int y=0; y!=maxy; ++y)       {         unsigned char * const line           = static_cast<unsigned char *>(mImage->Picture->Bitmap->ScanLine[y]);         for (int x=0; x!=maxx; ++x)         {           line[x*3+0] = 0; //Blue           line[x*3+1] = 0; //Green           line[x*3+2] = 0; //Red         }       }       return;     }     //Draw the pixels     for (int y=0; y!=maxy; ++y)     {       unsigned char * const line         = static_cast<unsigned char *>(mImage->Picture->Bitmap->ScanLine[y]);       for (int x=0; x!=maxx; ++x)       {         assert(minVal != maxVal);         assert(minVal < maxVal);         const double greyValueDouble = (surface[x][y] - minVal) / (maxVal - minVal);         assert(greyValueDouble >= 0.0 && greyValueDouble <= 1.0);         const char greyValue = greyValueDouble * 255.0;         line[x*3+0] = greyValue; //Blue         line[x*3+1] = greyValue; //Green         line[x*3+2] = greyValue; //Red       }     }   }   //Sets the image of the surface plot to the values of the vector   //Assumes that the chars are in the range [0,255] (a char's range)   //If the chars are in a shorter range, they will NOT be rescaled to [0,255]   void SetSurfaceGrey(const std::vector<std::vector<char> >& surface)   {     const int maxx = surface.size();     const int maxy = surface[0].size();     mImage->Picture->Bitmap->Width = maxx;     mImage->Picture->Bitmap->Height = maxy;     for (int y=0; y!=maxy; ++y)     {       unsigned char * const line         = static_cast<unsigned char *>(mImage->Picture->Bitmap->ScanLine[y]);       for (int x=0; x!=maxx; ++x)       {         const char greyValue = surface[x][y];         line[x*3+0] = greyValue; //Blue         line[x*3+1] = greyValue; //Green         line[x*3+2] = greyValue; //Red       }     }   }   private:   Extctrls::TImage * const mImage; }; //--------------------------------------------------------------------------- #endif