asahi: Skip draws if the scissor culls everything

We can't pack the scissor descriptor for these, and there would be no rendering
anyway, so detect this condition and skip the draw.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11084>

diff --git a/src/gallium/drivers/asahi/agx_state.c b/src/gallium/drivers/asahi/agx_state.c
index d1158e2..d11cddb 100644 (file)
--- a/src/gallium/drivers/asahi/agx_state.c
+++ b/src/gallium/drivers/asahi/agx_state.c
@@ -1190,6 +1190,15 @@ agx_index_buffer_ptr(struct agx_batch *batch,
    }
 }
 
+static bool
+agx_scissor_culls_everything(struct agx_context *ctx)
+{
+        const struct pipe_scissor_state ss = ctx->scissor;
+
+        return ctx->rast->base.scissor &&
+               ((ss.minx == ss.maxx) || (ss.miny == ss.maxy));
+}
+
 static void
 agx_draw_vbo(struct pipe_context *pctx, const struct pipe_draw_info *info,
              unsigned drawid_offset,
@@ -1210,6 +1219,9 @@ agx_draw_vbo(struct pipe_context *pctx, const struct pipe_draw_info *info,
    struct agx_context *ctx = agx_context(pctx);
    struct agx_batch *batch = ctx->batch;
 
+   if (agx_scissor_culls_everything(ctx))
+          return;
+
    /* TODO: masks */
    ctx->batch->draw |= ~0;