Optimizing Geometry Performance

• Primitive length. Most systems have a characteristic primitive length that the system is optimized for. On RealityEngine systems, multiples of 3 vertices are preferred, and 12 vertices (for example a triangle strip that consists of 10 triangles) result in the best performance.

• Fast mode changes. Changes involving logic op, depth func, alpha func, shade model, cullface, or matrix mode are fast.

• Slow mode changes. Changes involving texture binding, lighting and material changes, line width and point size changes, scissor, or viewport are slow.

• Texture coordinates. Automatic texture coordinate generation with glTexGen() results in a relatively small performance degradation.

• Quads and polygons. When rendering quads, use GL_POLYGON instead of GL_QUADS. The GL_QUADS primitive checks for self-intersecting quads and is therefore slower.