diff options
| -rw-r--r-- | src/gallium/auxiliary/draw/draw_pipe_clip.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/src/gallium/auxiliary/draw/draw_pipe_clip.c b/src/gallium/auxiliary/draw/draw_pipe_clip.c index 0f90bfdff08..dbb67575843 100644 --- a/src/gallium/auxiliary/draw/draw_pipe_clip.c +++ b/src/gallium/auxiliary/draw/draw_pipe_clip.c @@ -209,6 +209,29 @@ static void interp( const struct clip_stage *clip, } } +/** + * Checks whether the specifed triangle is empty and if it is returns + * true, otherwise returns false. + * Triangle is considered null/empty if it's area is qual to zero. + */ +static INLINE boolean +is_tri_null(struct draw_context *draw, const struct prim_header *header) +{ + const unsigned pos_attr = draw_current_shader_position_output(draw); + float x1 = header->v[1]->data[pos_attr][0] - header->v[0]->data[pos_attr][0]; + float y1 = header->v[1]->data[pos_attr][1] - header->v[0]->data[pos_attr][1]; + float z1 = header->v[1]->data[pos_attr][2] - header->v[0]->data[pos_attr][2]; + + float x2 = header->v[2]->data[pos_attr][0] - header->v[0]->data[pos_attr][0]; + float y2 = header->v[2]->data[pos_attr][1] - header->v[0]->data[pos_attr][1]; + float z2 = header->v[2]->data[pos_attr][2] - header->v[0]->data[pos_attr][2]; + + float vx = y1 * z2 - z1 * y2; + float vy = x1 * z2 - z1 * x2; + float vz = x1 * y2 - y1 * x2; + + return (vx*vx + vy*vy + vz*vz) == 0.f; +} /** * Emit a post-clip polygon to the next pipeline stage. The polygon @@ -223,6 +246,8 @@ static void emit_poly( struct draw_stage *stage, struct prim_header header; unsigned i; ushort edge_first, edge_middle, edge_last; + boolean last_tri_was_null = FALSE; + boolean tri_was_not_null = FALSE; if (stage->draw->rasterizer->flatshade_first) { edge_first = DRAW_PIPE_EDGE_FLAG_0; @@ -244,6 +269,7 @@ static void emit_poly( struct draw_stage *stage, header.pad = 0; for (i = 2; i < n; i++, header.flags = edge_middle) { + boolean tri_null; /* order the triangle verts to respect the provoking vertex mode */ if (stage->draw->rasterizer->flatshade_first) { header.v[0] = inlist[0]; /* the provoking vertex */ @@ -256,6 +282,19 @@ static void emit_poly( struct draw_stage *stage, header.v[2] = inlist[0]; /* the provoking vertex */ } + tri_null = is_tri_null(stage->draw, &header); + /* If we generated a triangle with an area, aka. non-null triangle, + * or if the previous triangle was also null then skip all subsequent + * null triangles */ + if ((tri_was_not_null && tri_null) || (last_tri_was_null && tri_null)) { + last_tri_was_null = tri_null; + continue; + } + last_tri_was_null = tri_null; + if (!tri_null) { + tri_was_not_null = TRUE; + } + if (!edgeflags[i-1]) { header.flags &= ~edge_middle; } |