[Mesa-dev] [PATCH] freedreno/a3xx: add basic clip plane support

[Ilia Mirkin]

The hardware is capable of dealing with GL1-style user clip planes.
No clip vertex, no clip distances. Fixes a number of ucp tests, as well
as neverball.

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
---
 src/gallium/drivers/freedreno/a3xx/fd3_emit.c     | 18 ++++++++++++++++++
 src/gallium/drivers/freedreno/freedreno_context.h |  2 ++
 src/gallium/drivers/freedreno/freedreno_state.c   |  4 +++-
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/gallium/drivers/freedreno/a3xx/fd3_emit.c b/src/gallium/drivers/freedreno/a3xx/fd3_emit.c
index 7a6ddc1..114d5c8 100644
--- a/src/gallium/drivers/freedreno/a3xx/fd3_emit.c
+++ b/src/gallium/drivers/freedreno/a3xx/fd3_emit.c
@@ -575,10 +575,28 @@ fd3_emit_state(struct fd_context *ctx, struct fd_ringbuffer *ring,
 		val |= COND(fp->writes_pos, A3XX_GRAS_CL_CLIP_CNTL_ZCLIP_DISABLE);
 		val |= COND(fp->frag_coord, A3XX_GRAS_CL_CLIP_CNTL_ZCOORD |
 				A3XX_GRAS_CL_CLIP_CNTL_WCOORD);
+		/* TODO only use if prog doesn't use clipvertex/clipdist */
+		val |= MIN2(util_bitcount(ctx->rasterizer->clip_plane_enable), 6) << 26;
 		OUT_PKT0(ring, REG_A3XX_GRAS_CL_CLIP_CNTL, 1);
 		OUT_RING(ring, val);
 	}
 
+	if (dirty & (FD_DIRTY_RASTERIZER | FD_DIRTY_UCP)) {
+		uint32_t planes = ctx->rasterizer->clip_plane_enable;
+		int count = 0;
+
+		fd_wfi(ctx, ring);
+		while (planes && count < 6) {
+			int i = ffs(planes) - 1;
+			planes &= ~(1U << i);
+			OUT_PKT0(ring, REG_A3XX_GRAS_CL_USER_PLANE(count++), 4);
+			OUT_RING(ring, fui(ctx->ucp.ucp[i][0]));
+			OUT_RING(ring, fui(ctx->ucp.ucp[i][1]));
+			OUT_RING(ring, fui(ctx->ucp.ucp[i][2]));
+			OUT_RING(ring, fui(ctx->ucp.ucp[i][3]));
+		}
+	}
+
 	/* NOTE: since primitive_restart is not actually part of any
 	 * state object, we need to make sure that we always emit
 	 * PRIM_VTX_CNTL.. either that or be more clever and detect
diff --git a/src/gallium/drivers/freedreno/freedreno_context.h b/src/gallium/drivers/freedreno/freedreno_context.h
index 509a90f..3486c2f 100644
--- a/src/gallium/drivers/freedreno/freedreno_context.h
+++ b/src/gallium/drivers/freedreno/freedreno_context.h
@@ -334,6 +334,7 @@ struct fd_context {
 		FD_DIRTY_INDEXBUF    = (1 << 16),
 		FD_DIRTY_SCISSOR     = (1 << 17),
 		FD_DIRTY_STREAMOUT   = (1 << 18),
+		FD_DIRTY_UCP         = (1 << 19),
 	} dirty;
 
 	struct pipe_blend_state *blend;
@@ -355,6 +356,7 @@ struct fd_context {
 	struct fd_constbuf_stateobj constbuf[PIPE_SHADER_TYPES];
 	struct pipe_index_buffer indexbuf;
 	struct fd_streamout_stateobj streamout;
+	struct pipe_clip_state ucp;
 
 	/* GMEM/tile handling fxns: */
 	void (*emit_tile_init)(struct fd_context *ctx);
diff --git a/src/gallium/drivers/freedreno/freedreno_state.c b/src/gallium/drivers/freedreno/freedreno_state.c
index 7bf8bdb..e75865a 100644
--- a/src/gallium/drivers/freedreno/freedreno_state.c
+++ b/src/gallium/drivers/freedreno/freedreno_state.c
@@ -65,7 +65,9 @@ static void
 fd_set_clip_state(struct pipe_context *pctx,
 		const struct pipe_clip_state *clip)
 {
-	DBG("TODO: ");
+	struct fd_context *ctx = fd_context(pctx);
+	ctx->ucp = *clip;
+	ctx->dirty |= FD_DIRTY_UCP;
 }
 
 static void
-- 
2.4.6