diff options
Diffstat (limited to 'src/gallium/auxiliary')
-rw-r--r-- | src/gallium/auxiliary/util/u_split_prim.h | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/src/gallium/auxiliary/util/u_split_prim.h b/src/gallium/auxiliary/util/u_split_prim.h new file mode 100644 index 0000000000..3c438da0ba --- /dev/null +++ b/src/gallium/auxiliary/util/u_split_prim.h @@ -0,0 +1,102 @@ +/* Originally written by Ben Skeggs for the nv50 driver*/ +#include <pipe/p_defines.h> + +struct u_split_prim { + void *priv; + void (*emit)(void *priv, unsigned start, unsigned count); + void (*edge)(void *priv, boolean enabled); + + unsigned mode; + unsigned start; + unsigned p_start; + unsigned p_end; + + uint repeat_first:1; + uint close_first:1; + uint edgeflag_off:1; +}; + +static INLINE void +u_split_prim_init(struct u_split_prim *s, + unsigned mode, unsigned start, unsigned count) +{ + if (mode == PIPE_PRIM_LINE_LOOP) { + s->mode = PIPE_PRIM_LINE_STRIP; + s->close_first = 1; + } else { + s->mode = mode; + s->close_first = 0; + } + s->start = start; + s->p_start = start; + s->p_end = start + count; + s->edgeflag_off = 0; + s->repeat_first = 0; +} + +static INLINE boolean +u_split_prim_next(struct u_split_prim *s, unsigned max_verts) +{ + int repeat = 0; + + if (s->repeat_first) { + s->emit(s->priv, s->start, 1); + max_verts--; + if (s->edgeflag_off) { + s->edge(s->priv, TRUE); + s->edgeflag_off = FALSE; + } + } + + if (s->p_start + s->close_first + max_verts >= s->p_end) { + s->emit(s->priv, s->p_start, s->p_end - s->p_start); + if (s->close_first) + s->emit(s->priv, s->start, 1); + return TRUE; + } + + switch (s->mode) { + case PIPE_PRIM_LINES: + max_verts &= ~1; + break; + case PIPE_PRIM_LINE_STRIP: + repeat = 1; + break; + case PIPE_PRIM_POLYGON: + max_verts--; + s->emit(s->priv, s->p_start, max_verts); + s->edge(s->priv, FALSE); + s->emit(s->priv, s->p_start + max_verts, 1); + s->p_start += max_verts; + s->repeat_first = TRUE; + s->edgeflag_off = TRUE; + return FALSE; + case PIPE_PRIM_TRIANGLES: + max_verts = max_verts - (max_verts % 3); + break; + case PIPE_PRIM_TRIANGLE_STRIP: + /* to ensure winding stays correct, always split + * on an even number of generated triangles + */ + max_verts = max_verts & ~1; + repeat = 2; + break; + case PIPE_PRIM_TRIANGLE_FAN: + s->repeat_first = TRUE; + repeat = 1; + break; + case PIPE_PRIM_QUADS: + max_verts &= ~3; + break; + case PIPE_PRIM_QUAD_STRIP: + max_verts &= ~1; + repeat = 2; + break; + default: + break; + } + + s->emit (s->priv, s->p_start, max_verts); + s->p_start += (max_verts - repeat); + return FALSE; +} |