Drawing a 2D rectangle with SharpDX

Question

How to draw a plain red 2D rectangle with SharpDX?

• I have a SharpDX.Direct3D9.Device available from a library that sets up a Direct3D v9 device for me, so I'm hoping to be able to use that?

• Found a tutorial on how to use Direct2D1 to draw a basic rectangle, but the code seems to be dependent on a Direct3D11 device, which I don't have - I need to be able to get the job done without Direct3D11 and without Direct3D10

  unsafe int PresentHook(IntPtr devicePtr, SharpDX.Rectangle* pSourceRect, SharpDX.Rectangle* pDestRect, IntPtr hDestWindowOverride, IntPtr pDirtyRegion)
  {
      _isUsingPresent = true;
  
      SharpDX.Direct3D9.Device device = (SharpDX.Direct3D9.Device)devicePtr;
  
      // How to draw rectangle here?
  
      if (pSourceRect == null || *pSourceRect == SharpDX.Rectangle.Empty)
          device.Present();
      else
      {
          if (hDestWindowOverride != IntPtr.Zero)
              device.Present(*pSourceRect, *pDestRect, hDestWindowOverride);
          else
              device.Present(*pSourceRect, *pDestRect);
      }
      return SharpDX.Result.Ok.Code;
  }
  

Answer 1

Could draw a sprite using something like the following:

// Be sure to only initialise these only once (or as needed)
// not every frame.

//use relative path
string dir = System.IO.Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);
string filename = dir + @"\image.bmp";
var _mytext = SharpDX.Direct3D9.Texture.FromFile(device, filename);
var _sprite = new SharpDX.Direct3D9.Sprite(device);

float posLeft = 10f;
float posTop = 10f;
var pos = new SharpDX.Vector3(posLeft, posTop, 0);
var color = new SharpDX.ColorBGRA(0xffffffff);
_sprite.Begin(SharpDX.Direct3D9.SpriteFlags.AlphaBlend);
_sprite.Draw(_myText, color, null, null, pos);
_sprite.End();

Loading a texture this way will create a square texture, if the device capabilities support it then you can specify the dimensions when you load the texture, e.g.

var _myText = SharpDX.Direct3D9.Texture.FromFile(device, filename, imageSize.Width, imageSize.Height, 0, Usage.None, Format.A8B8G8R8, Pool.Default, Filter.Default, Filter.Default, 0);

Otherwise you can scale the X and Y appropriately within the transform:

// Get image dimensions
Size imageSize;
using (var img = Image.FromFile(filename))
{
    imageSize = img.Size;
}
// Calculate scale to get correct image size
var transform = SharpDX.Matrix.AffineTransformation2D(1f, 0f, Vector2.Zero);
// Calculate width scale
if (imageSize.Width <= 128)
{
    transform.M11 = (float)imageSize.Width / 128f; // scale x
}
else if (imageSize.Width <= 256)
{
    transform.M11 = (float)imageSize.Width / 256f; // scale x
}
else if (imageSize.Width <= 512)
{
    transform.M11 = (float)imageSize.Width / 512f; // scale x
}
else if (imageSize.Width <= 1024)
{
    transform.M11 = (float)imageSize.Width / 1024f; // scale x
}
// Calculate height scale
if (imageSize.Height <= 128)
{
    transform.M22 = (float)imageSize.Height / 128f; // scale y
}
else if (imageSize.Height <= 256)
{
    transform.M22 = (float)imageSize.Height / 256f; // scale y
}
else if (imageSize.Height <= 512)
{
    transform.M22 = (float)imageSize.Height / 512f; // scale y
}
else if (imageSize.Height <= 1024)
{
    transform.M22 = (float)imageSize.Height / 1024f; // scale y
}

_sprite.Transform = transform;