GL Driver

This driver represents a basic driver for all system-dependent drivers implemented in the X-Windows system using the OpenGL SDK. The implementation uses the OpenGL, GLU and GLX API functions. For the font support, this driver uses the FTGL API functions, which it was written against the Free Type library.

Behavior of Functions

Control 

• Play: does nothing, returns CD_ERROR.

Coordinate System and Clipping

• UpdateYAxis: does nothing.
• Clipping: only support rectangular areas.
• Complex Regions: not supported.

Primitives

• Begin: CD_PATH is simulated.
• Floating point primitives are supported.

Client Images

• Images are bitmaps, and cannot be directly rotated or scaled.

Attributes

• LineStyle: in CD_CUSTOM, style patterns more than 16 bits are not supported.
• LineCap: does nothing.
• LineJoin: does nothing.
• Stipple: does nothing. There is no support for patterns more than 16 bits.
• Pattern: does nothing.
• FillMode: does nothing.
• NativeFont: also accepts the X-Windows font string format.
• Font: "Courier" is mapped to "Courier New", "Helvetica" is mapped to "Arial", and "Times" is mapped to "Times New Roman". Underline and Strikeout are NOT supported.

Colors

• Palette: does nothing.

Exclusive Attributes

• "ROTATE":  allows the usage of 1 angle and 1 coordinate (x, y), that define a global rotation transformation centered in the specified coordinate. Use 1 real and 2 integer values inside a string ("%g %d %d" = angle x y).

• "GLVERSION": returns a string with the OpenGL version or release number. It is empty if the OpenGL is not available.