TRIANGLES_NORMAL 
Draw a triangle with 'GL_TRIANGLES' mode.
Treats each triplet of vertices as an independent triangle. Vertices 3n  2, 3n  1, and 3n define triangle n.

TRIANGLES_STRIP 
Draw a triangle with 'GL_TRIANGLE_STRIP' mode.
Draws a connected group of triangles. One triangle is defined for each vertex presented after the first two vertices. For odd n, vertices n, n + 1, and n + 2 define triangle n. For even n, vertices n + 1, n, and n + 2 define triangle n. N  2 triangles are drawn.

TRIANGLES_FAN 
Draw a triangle with 'GL_TRIANGLE_FAN' mode.
Draws a connected group of triangles. One triangle is defined for each vertex presented after the first two vertices. Vertices 1, n + 1, and n + 2 define triangle n. N  2 triangles are drawn.

QUADS_NORMAL 
Draw a quad with 'GL_QUADS' mode.
Treats each group of four vertices as an independent quadrilateral. Vertices 4n  3, 4n  2, 4n  1, and 4n define quadrilateral n. N / 4 quadrilaterals are drawn.

QUADS_STRIP 
Draw a quad with 'GL_QUAD_STRIP' mode.
Draws a connected group of quadrilaterals. One quadrilateral is defined for each pair of vertices presented after the first pair. Vertices 2n  1, 2n, 2n + 2, and 2n + 1 define quadrilateral n. N / 2  1 quadrilaterals are drawn. Note that the order in which vertices are used to construct a quadrilateral from strip data is different from that used with independent data.

LINES_NORMAL 
Draw a line object with 'GL_LINES' mode.
Treats each pair of vertices as an independent line segment. Vertices 2n  1 and 2n define line n. N/2 lines are drawn.

LINES_STRIP 
Draw a line object with 'GL_LINE_STRIP' mode.
Draws a connected group of line segments from the first vertex to the last. Vertices n and n + 1 define line n.

LINES_LOOP 
Draw a line object with 'GL_LINE_LOOP' mode.
Draws a connected group of line segments from the first vertex to the last, then back to the first. Vertices n and n+1 define line n. The last line, however, is defined by vertices N and 1. N lines are drawn.

POLYGON_NORMAL 
Draw a polygon object with 'GL_POLYGON' mode.
Draws a single, convex polygon. Vertices 1 through N define this polygon. 