#include <windows.h>
#include <gdiplus.h>
using namespace Gdiplus;


void DrawMarks(Graphics* graphics, Pen* greenPen, Pen* redPen, const Rect& r)
{
  graphics->DrawRectangle(redPen, r);
  graphics->DrawLine(greenPen, r.X+r.Width-1, r.Y-5, r.X+r.Width-1, r.Y+5); // end markers
  graphics->DrawLine(greenPen, r.X-5, r.Y+r.Height-1, r.X+5, r.Y+r.Height-1);
}

extern "C" void SimpleImageTest(HWND hWnd)
{
  int x, y;
  Graphics* graphics = new Graphics(hWnd);
  graphics->Clear(Color(255, 255, 255)); // white background

  Bitmap image(16, 16, PixelFormat24bppRGB);
  image.SetResolution(graphics->GetDpiX(), graphics->GetDpiX());

  /* black pixel border */
  for (y = 0; y < 16; y++)
    image.SetPixel(0, y, Color(0, 0, 0));
  for (y = 0; y < 16; y++)
    image.SetPixel(15, y, Color(0, 0, 0));
  for (x = 1; x < 15; x++)
    image.SetPixel(x, 0, Color(0, 0, 0));
  for (x = 1; x < 15; x++)
    image.SetPixel(x, 15, Color(0, 0, 0));

  /* light yellow contents */
  for (y = 1; y < 15; y++)
    for (x = 1; x < 15; x++)
      image.SetPixel(x, y, Color(192, 192, 0));

  Pen redPen(Color(255, 0, 0), 1);
  redPen.SetDashStyle(DashStyleDash);
  Pen greenPen(Color(0, 255, 0), 1);
  greenPen.SetDashStyle(DashStyleDash);



  // Standard Usage

  // NO zoom
  {
  Rect actualRect(10, 10, 16, 16);
  graphics->DrawImage(&image, 10, 10);  
  DrawMarks(graphics, &greenPen, &redPen, actualRect);
  }

  // zoom using Bilinear Interpolation
  {
  Rect zoomRect(50, 10, 160, 160);
  graphics->SetInterpolationMode(InterpolationModeBilinear);
  graphics->DrawImage(&image, zoomRect);
  DrawMarks(graphics, &greenPen, &redPen, zoomRect);
  }

  // zoom using Nearest Neighborhood
  {
  Rect zoomRect(250, 10, 160, 160);
  graphics->SetInterpolationMode(InterpolationModeNearestNeighbor);
  graphics->DrawImage(&image, zoomRect);
  DrawMarks(graphics, &greenPen, &redPen, zoomRect);
  }




  // Experiment using a source image size, greater than actual
  // The image is resized down!!!


  // NO zoom
  {
  Rect actualRect(10, 200, 16, 16);
  graphics->DrawImage(&image, actualRect);
  DrawMarks(graphics, &greenPen, &redPen, actualRect);
  }

  // zoom using Bilinear Interpolation
  {
  Rect zoomRect(50, 200, 160, 160);
  graphics->SetInterpolationMode(InterpolationModeBilinear);
  graphics->DrawImage(&image, zoomRect, 0, 0, 20, 20, UnitPixel, NULL, NULL);
  DrawMarks(graphics, &greenPen, &redPen, zoomRect);
  }

  // zoom using Nearest Neighborhood
  {
  Rect zoomRect(250, 200, 160, 160);
  graphics->SetInterpolationMode(InterpolationModeNearestNeighbor);
  graphics->DrawImage(&image, zoomRect, 0, 0, 20, 20, UnitPixel, NULL, NULL);
  DrawMarks(graphics, &greenPen, &redPen, zoomRect);
  }


  // Use the Experiment results to try a solution
  // Using a source image size, smaller than actual


  // NO zoom
  {
  Rect actualRect(10, 400, 16, 16);
  graphics->SetInterpolationMode(InterpolationModeNearestNeighbor);
  graphics->DrawImage(&image, actualRect, 0, 0, 16-1, 16-1, UnitPixel, NULL, NULL);
  DrawMarks(graphics, &greenPen, &redPen, actualRect);
  }

  // zoom using Bilinear Interpolation
  {
  Rect zoomRect(50, 400, 160, 160);
  graphics->SetInterpolationMode(InterpolationModeBilinear);
  graphics->DrawImage(&image, zoomRect, 0, 0, 16-1, 16-1, UnitPixel, NULL, NULL);
  DrawMarks(graphics, &greenPen, &redPen, zoomRect);
  }

  // zoom using Nearest Neighborhood
  {
  Rect zoomRect(250, 400, 160, 160);
  graphics->SetInterpolationMode(InterpolationModeNearestNeighbor);
  graphics->DrawImage(&image, zoomRect, 0, 0, 16-1, 16-1, UnitPixel, NULL, NULL);
  DrawMarks(graphics, &greenPen, &redPen, zoomRect);
  }





  // First Solution
  {
  Rect zoomRect(600, 10, 160, 160);
  graphics->SetInterpolationMode(InterpolationModeBilinear);

  int errorBand = 10; // zoomRect.Width / actualRect.Width;
  Rect zoomRectClip(600-1, 10-1, 160+2, 160+2);
  Rect zoomRectError(600, 10, 160 + errorBand, 160 + errorBand);
  graphics->SetClip(zoomRectClip);
  graphics->DrawImage(&image, zoomRectError);
  graphics->ResetClip();

  DrawMarks(graphics, &greenPen, &redPen, zoomRect);
  }


  // Solution suggested by Michael Phillips, Jr.
  {
  Rect zoomRect(600, 200, 160, 160);
  graphics->SetInterpolationMode(InterpolationModeNearestNeighbor);
  graphics->SetPixelOffsetMode(PixelOffsetModeHalf); // pixel center is (.5,.5) instead of (0, 0)

  graphics->SetClip(zoomRect); // clip out the badly interpolated pixels
  zoomRect.Width += 4; // force gdi+ to scale to a slightly wider area, the dropped pixels will be clipped out
  graphics->DrawImage(&image, zoomRect, 0, 0, 16, 16, UnitPixel, NULL, NULL, NULL);
  graphics->ResetClip();
  zoomRect.Width -= 4;

  graphics->SetPixelOffsetMode(PixelOffsetModeNone);
  DrawMarks(graphics, &greenPen, &redPen, zoomRect);
  }



  // Final Solution
  // Use PixelOffsetModeHalf and        [pixel center is (.5,.5) instead of (0, 0)]
  // WrapModeTileFlipXY  (suggested by Vlad Grachov)

  ImageAttributes imAtt;
  imAtt.SetWrapMode(WrapModeTileFlipXY); // set wrapping mode to get rid of gray lines at sides

  // NO zoom
  {
  Rect actualRect(10, 400, 16, 16);
  graphics->DrawImage(&image, 10, 400);  
  DrawMarks(graphics, &greenPen, &redPen, actualRect);
  }

  // zoom using Bilinear Interpolation
  {
  Rect zoomRect(50, 400, 160, 160);
  graphics->SetInterpolationMode(InterpolationModeBilinear);
  graphics->SetPixelOffsetMode(PixelOffsetModeHalf); 
  graphics->DrawImage(&image, zoomRect, 0, 0, image.GetWidth(), image.GetHeight(), UnitPixel, &imAtt, NULL, NULL);
  graphics->SetPixelOffsetMode(PixelOffsetModeNone);
  DrawMarks(graphics, &greenPen, &redPen, zoomRect);
  }

  // zoom using Nearest Neighborhood
  {
  Rect zoomRect(250, 400, 160, 160);
  graphics->SetInterpolationMode(InterpolationModeNearestNeighbor);
  graphics->SetPixelOffsetMode(PixelOffsetModeHalf);
  graphics->DrawImage(&image, zoomRect, 0, 0, image.GetWidth(), image.GetHeight(), UnitPixel, &imAtt, NULL, NULL);
  graphics->SetPixelOffsetMode(PixelOffsetModeNone);
  DrawMarks(graphics, &greenPen, &redPen, zoomRect);
  }

  delete graphics;
}