2D Drawing Functions

Statements and procedures for working with 2D graphics.

Description
   The statements and procedures listed here provide ways of drawing to the 
   screen. Image buffers can be created and blitted to the screen using a 
   variety of blending methods. Palette colors can be retrieved or set in 
   graphics modes that support them.

Working with Color
   Procedures that control the color used by other drawing procedures.
Drawing to Image Buffers
   Procedures that draw shapes and text onto image buffers or to the 
   screen.
Image Buffer Creation
   Procedures that create, free and save image buffers.
Blitting Image Buffers
   Procedures that draw image buffers onto other image buffers or to the 
   screen.

Working with Color
   Color
      Sets the foreground and background color to use with the drawing 
      procedures.
   Palette
      Gets or sets color table information in paletted modes.
   RGB
      Returns a color value for hi/truecolor modes.
   RGBA
      Returns a color value including alpha (transparency) for hi/truecolor 
      modes.
   Point
      Gets a pixel value from an image buffer or screen.

Drawing to Image Buffers
   PSet and PReset
      Plots a single pixel on an image buffer or screen.
   Line (Graphics)
      Plots a line of pixels on an image buffer or screen.
   Circle
      Plots circles and ellipses on an image buffer or screen.
   Draw
      Draws in a sequence of commands on an image buffer or screen.
   Draw String
      Writes text to an image buffer or screen.
   Paint
      Fills an area with color on an image buffer or screen.

Image Buffer Creation
   Get (Graphics)
      Creates an image buffer from a portion of another image buffer or 
      screen.
   ImageCreate
      Creates an image buffer of a certain size and pixel depth.
   ImageDestroy
      Frees an image buffer resource.
   ImageConvertRow
      Converts a row of pixels in an image buffer to a different color 
      depth.
   ImageInfo
      Retrieves useful information about an image buffer
   BLoad
      Creates an image buffer from a file.
   BSave
      Saves an image buffer to a file.
Blitting Image Buffers
   Put (Graphics)
      Blits an image buffer to another image buffer or screen.

   Blending Methods
      Add
         Saturated addition of the source and target components.
      Alpha
         Blend using a uniform transparency or the image buffer's alpha 
         channel.
      And
         Combine the source and target components using a bitwise And
      Or
         Combine the source and target components using a bitwise Or
      PSet
         Directly copy pixel colors from the source to the destination.
      Trans
         Pixels matching the transparent mask color are not blitted.
      Custom
         Allows a custom blending procedure to be used.
      Xor
         Combine the source and target components using a bitwise Xor

