From f87dccdc19416fd8d47b995f9b0f0c54534bfd16 Mon Sep 17 00:00:00 2001 From: Chia-I Wu Date: Thu, 2 May 2013 14:28:12 +0800 Subject: util/prim: add u_reduced_prims_for_vertices() The function returns the number of reduced/tessellated primitives for the given vertex count. Signed-off-by: Chia-I Wu Acked-by: Zack Rusin --- src/gallium/auxiliary/util/u_prim.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'src') diff --git a/src/gallium/auxiliary/util/u_prim.h b/src/gallium/auxiliary/util/u_prim.h index 624a508c42c..8f444a30529 100644 --- a/src/gallium/auxiliary/util/u_prim.h +++ b/src/gallium/auxiliary/util/u_prim.h @@ -243,6 +243,26 @@ u_decomposed_prims_for_vertices(int primitive, int vertices) } } +/** + * Returns the number of reduced/tessellated primitives for the given vertex + * count. Each quad is treated as two triangles. Polygons are treated as + * triangle fans. + */ +static INLINE unsigned +u_reduced_prims_for_vertices(int primitive, int vertices) +{ + switch (primitive) { + case PIPE_PRIM_QUADS: + case PIPE_PRIM_QUAD_STRIP: + return u_decomposed_prims_for_vertices(primitive, vertices) * 2; + case PIPE_PRIM_POLYGON: + primitive = PIPE_PRIM_TRIANGLE_FAN; + /* fall through */ + default: + return u_decomposed_prims_for_vertices(primitive, vertices); + } +} + const char *u_prim_name( unsigned pipe_prim ); #endif -- cgit v1.2.3