From 24eadb4810be963e0a4473e071548313686ad5cb Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Fri, 13 May 2016 16:45:25 -0600 Subject: [PATCH] util/indices: improve comments in u_indices.h Reviewed-by: Roland Scheidegger --- src/gallium/auxiliary/indices/u_indices.h | 32 ++++++++++++++++++++--- 1 file changed, 29 insertions(+), 3 deletions(-) diff --git a/src/gallium/auxiliary/indices/u_indices.h b/src/gallium/auxiliary/indices/u_indices.h index 4483eb81337..7f696ab0663 100644 --- a/src/gallium/auxiliary/indices/u_indices.h +++ b/src/gallium/auxiliary/indices/u_indices.h @@ -27,6 +27,7 @@ #include "pipe/p_compiler.h" +/* First/last provoking vertex */ #define PV_FIRST 0 #define PV_LAST 1 #define PV_COUNT 2 @@ -35,13 +36,15 @@ #define PR_DISABLE 0 #define PR_ENABLE 1 #define PR_COUNT 2 + + /** * Index translator function (for glDrawElements() case) * * \param in the input index buffer * \param start the index of the first vertex (pipe_draw_info::start) * \param nr the number of vertices (pipe_draw_info::count) - * \param out output buffer big enough or nr vertices (of + * \param out output buffer big enough for nr vertices (of * @out_index_size bytes each) */ typedef void (*u_translate_func)( const void *in, @@ -56,7 +59,7 @@ typedef void (*u_translate_func)( const void *in, * * \param start the index of the first vertex (pipe_draw_info::start) * \param nr the number of vertices (pipe_draw_info::count) - * \param out output buffer big enough or nr vertices (of + * \param out output buffer big enough for nr vertices (of * @out_index_size bytes each) */ typedef void (*u_generate_func)( unsigned start, @@ -78,6 +81,15 @@ enum indices_mode { void u_index_init( void ); + +/** + * For indexed drawing, this function determines what kind of primitive + * transformation is needed (if any) for handling: + * - unsupported primitive types (such as PIPE_PRIM_POLYGON) + * - changing the provoking vertex + * - primitive restart + * - index size (1 byte, 2 byte or 4 byte indexes) + */ enum indices_mode u_index_translator(unsigned hw_mask, unsigned prim, @@ -91,7 +103,12 @@ u_index_translator(unsigned hw_mask, unsigned *out_nr, u_translate_func *out_translate); -/* Note that even when generating it is necessary to know what the + +/** + * For non-indexed drawing, this function determines what kind of primitive + * transformation is needed (see above). + * + * Note that even when generating it is necessary to know what the * API's PV is, as the indices generated will depend on whether it is * the same as hardware or not, and in the case of triangle strips, * whether it is first or last. @@ -111,6 +128,12 @@ u_index_generator(unsigned hw_mask, void u_unfilled_init( void ); +/** + * If the driver can't handle "unfilled" primitives (i.e. drawing triangle + * primitives as 3 lines or 3 points) this function can be used to translate + * an indexed primitive into a new indexed primitive to draw as lines or + * points. + */ enum indices_mode u_unfilled_translator(unsigned prim, unsigned in_index_size, @@ -121,6 +144,9 @@ u_unfilled_translator(unsigned prim, unsigned *out_nr, u_translate_func *out_translate); +/** + * As above, but for non-indexed (array) primitives. + */ enum indices_mode u_unfilled_generator(unsigned prim, unsigned start, -- 2.30.2