GDI+.md

GDI+

Gdiplus Namespace

GDI+ identifiers are defined inside Gdiplus namespace.

If compiler said "undefined identifier" error message, Check identifier's namespace, or consider to use using directive.

GdiplusStartup and GdiplusShutdown

Must call Gdiplus::GdiplusStartup before using GDI+. Otherwise, GDI+ methods will draw nothing. Also, should call Gdiplus::GdiplusShutdown on exit.

Gdiplus::GdiplusStartupInput gdiplusInput;
ULONG_PTR gdiplusToken;
Gdiplus::GdiplusStartup(&gdiplusToken, &gdiplusInput, NULL);
...
Gdiplus::GdiplusShutdown(gdiplusToken);

https://msdn.microsoft.com/en-us/library/windows/desktop/ms534077(v=vs.85).aspx

Angle Unit (IN DEGREE!)

Generally GDI uses radian, but GDI+ uses degree as follows:

• FillPie
• RotateTransform

GDI+_api_exploration.md

Matrix (3x3)

https://msdn.microsoft.com/en-us/library/ms534475(v=vs.85).aspx

A Matrix object stores only 6 of 9 numbers in 3 x 3 matrix. Because all 3 x 3 matrices that represent affine transformations have the same third column |0, 0, 1|

Matrix::Matrix(REAL, REAL, REAL, REAL, REAL, REAL)

• => Graphics.SetTransform(Matrix*)
• => Graphics.DrawImage(Image*, RECTF*, Matrix*, ...

Brushes

Brush base class
  |- SolidBrush
  |- HatchBrush
  |- LinearGradientBrush
  |- PathGradientBrush
  `- TextureBrush

• SolidBrush
• HatchBrush
• LinearGradientBrush
• PathGradientBrush
• TextureBrush

Pen

GdiplusBase base class
  `- Pen class

Pen

Note that Pen can be created from Brush.

Pen::Pen(Color&, REAL)
Pen::Pen(const Brush*, REAL)

Path

https://msdn.microsoft.com/en-us/library/ms534456(v=vs.85).aspx

GraphicsPath => Graphics::DrawPath

Font

https://msdn.microsoft.com/en-us/library/ms534438(v=vs.85).aspx

FontCollection base class
  |- InstalledFontCollection
  `- PrivateFontCollection

GraphicContainer

Graphics containers are used to retain graphics state, such as transformations, clipping regions, and various rendering properties.

• Graphics::BeginContainer
• Graphics::EndContainer

Note that, new container will reset compositing quality, smoothing mode, and etc.

g.SetSmootingMode(Gdiplus::SmoothingMode::SmoothingModeHighQuality);
// Smoothing mode is activated.
g.BeginContainer(...);
  // Inside new container, smoothing mode is reset and deactivated.
  // Draws shapes without antialiasing.
g.EndContainer();
// Smoothing mode is restored and actived. (maybe, not tested)

Shapes

• Arc
  • Graphics::DrawArc
• Bezier
  • Graphics::DrawBezier
• Curve
  • Graphics::DrawCurve
  • Graphics::FillClosedCurve
• Ellipse
  • Graphics::DrawEllipse
  • Graphics::FillEllipse
• Line
  • Graphics::DrawLine
• Path
  • Graphics::DrawPath
  • Graphics::FillPath
• Pie
  • Graphics::DrawPie
  • Graphics::FillPie
• Polygon
  • Graphics::DrawPolygon
  • Graphics::FillPolygon
• Rectanle
  • Graphics::DrawRectangle
  • Graphics::FillRectangle
  • Graphics::FillRectangles
• Region
  • Graphics::FillRegion
  • Regions can also be created from the interiors of rectangles, paths, or a combination of these. Regions are used in clipping and hit-testing operations.

Image & Bitmap & Metafile

Image class provides methods for loading and saving raster images and vector images: BMP, ICON, GIF, JPEG, Exif, PNG, TIFF, WMF, and EMF.

Image base class
  |- Bitmap
  `- Metafile

GdiplusBase
  `- CachedBitmap (NOTE: Not inherited class from Image)

Drawing

• Graphics::DrawImage

Caching

• Graphics::DrawCachedBitmap
• Graphics::CachedBitmap

Metafile (*.EMF: Sequence of graphics API calls)

The Metafile class defines a graphic metafile. A metafile contains records that describe a sequence of graphics API calls. Metafiles can be recorded (constructed) and played back (displayed).

• Graphics::EnumerateMetafile
• Metafile::PlayRecord

Metafile is stored as EMF Metafile: Enhanced Metafile

BOOL CALLBACK metaCallback(
   EmfPlusRecordType recordType, 
   unsigned int flags, 
   unsigned int dataSize, 
   const unsigned char* pStr, 
   void* callbackData)
{ 
   // Play only EmfPlusRecordTypeFillEllipse records.
   if (recordType == EmfPlusRecordTypeFillEllipse)
   {
   // Explicitly cast callbackData as a metafile pointer, and use it to call
   // the PlayRecord method.
   static_cast < Metafile* > (callbackData)->PlayRecord(recordType, flags, dataSize, pStr);
   }
   return TRUE; 
}

VOID Example_EnumerateMetafile(HDC hdc)
{
   Graphics graphics(hdc);
   // Create a Metafile object from an existing disk metafile.
   Metafile* pMeta = new Metafile(L"SampleMetafile.emf", hdc);
   {
      // Fill a rectangle and an ellipse in pMeta.
      Graphics metaGraphics(pMeta);
      SolidBrush blackBrush(Color(255, 0, 0, 0));
      SolidBrush redBrush(Color(255, 255, 0, 0));
      metaGraphics.FillRectangle(&blackBrush 0, 0, 100, 100);
  metaGraphics.FillEllipse(&redBrush 100, 0, 200, 100);
   }
   // Enumerate pMeta, passing pMeta as the callback data. 
   graphics.EnumerateMetafile(pMeta, Point(0, 0), metaCallback, pMeta);
   graphics.DrawImage(pMeta, Point(0, 150));
}

Text

Drawing

• [Graphics::DrawDriverString(https://msdn.microsoft.com/en-us/library/ms535683(v=vs.85).aspx)

Mesurement

• Graphics::MeasureCharacterRanges
• Graphics::MeasureDriverString
• Graphics::MeasureString

Antialiasing

• Graphics::SetTextContrast
• Graphics::SetTextRenderingHint * Does not confuse with SetSmoothingMode

Bitmap Effects

https://msdn.microsoft.com/en-us/library/ms534433(v=vs.85).aspx

Effect base class => Bitmap::ApplyEffect, Graphics::DrawImage
 |- Blur
 |- Sharpen
 |- Tint
 |- RedEyeCorrection
 |- ColorMatrixEffect
 |- ColorLUT
 |- BrightnessContrast
 |- HueSaturationLightness
 |- ColorBalance
 |- Levels
 `- ColorCurve