Drawing Graphics Elements

The graphics routines provided with Visual Fortran set points, draw lines, draw text, change colors, and draw shapes such as circles, rectangles, and arcs. This section assumes you have read the overview in Using QuickWin.

This section uses the following terms:

• The origin (point 0, 0) is the upper-left corner of the screen or the client area (defined user area) of the child window being written to. The x-axis and y-axis start at the origin. You can change the origin in some coordinate systems.
• The horizontal direction is represented by the x-axis, increasing to the right.
• The vertical direction is represented by the y-axis, increasing down.
• Some graphics adapters offer a color palette that can be changed.
• Some graphics adapters (VGA and SVGA) allow you to change the color that a color index refers to by providing a color value that describes a new color. The color value indicates the mix of red, green, and blue in a screen color. A color value is always an INTEGER(4) number.

The sections on drawing graphics are organized as follows:

• Working with Graphics Modes
• Adding Color
• Understanding Coordinate Systems
• Advanced Graphics Using OpenGL