13.003 Computational Geometry and Visualization

OpenGL Geometric Primitives

Geometry is drawn by specifying the geometric type and a sequence of vertices.

    glBegin(type);
    glVertex2f(x, y);
    glVertex2f(x, y);
    ...
    glEnd();

The geometric types include points, lines, and polygons:

• GL_POINTS
• GL_LINES
• GL_LINE_STRIP
• GL_LINE_LOOP
• GL_POLYGON
• GL_QUADS
• GL_QUAD_STRIP
• GL_TRIANGLES
• GL_TRIANGLE_STRIP
• GL_TRIANGLE_FAN

Several forms of the vertex function are available for different dimensionality and argument types:

    glVertex{234}{sifd}(x, y [, z [, w]]);

where the curly braces { and } indicate the selection of one character from the list of alternatives, and the square brackets [ and ] indicate optional arguments.