panfrost: Implement instanced rendering

We implement GLES3.0 instanced rendering with full support for instanced
arrays (via instance divisors). To do so, we use the new invocation
helpers to invoke a triplet of (1, vertex_count, instance_count), rather
than simply (1, vertex_count, 1). We rewrite the attribute handling code
into a new pan_instancing.c file which handles both the simple LINEAR
case for non-instanced as well as each of the new instancing cases:
MODULO (for per-vertex attributes), POT and NPOT divisors.

As a side effect, we rework how vertex buffers are handled, duplicating
them to be 1:1 with vertex descriptors to simplify instancing code paths
dramatically. This might be a performance regression, but this remains
to be seen; if so, we can always deduplicate later with some added logic
in pan_instancing.c

Signed-off-by: Alyssa Rosenzweig <[email protected]>

1 files changed, 4 insertions, 0 deletions

diff --git a/src/gallium/drivers/panfrost/pan_screen.c b/src/gallium/drivers/panfrost/pan_screen.c
index f8463d2b3f8..d6b1bc89fc1 100644
--- a/src/gallium/drivers/panfrost/pan_screen.c
+++ b/src/gallium/drivers/panfrost/pan_screen.c
@@ -118,6 +118,10 @@ panfrost_get_param(struct pipe_screen *screen, enum pipe_cap param)
         case PIPE_CAP_VERTEX_ELEMENT_INSTANCE_DIVISOR:
                 return 1;
 
+        /* TODO: Where does this req come from in practice? */
+        case PIPE_CAP_VERTEX_BUFFER_STRIDE_4BYTE_ALIGNED_ONLY:
+                return 1;
+
         case PIPE_CAP_MAX_TEXTURE_2D_SIZE:
                 return 4096;
         case PIPE_CAP_MAX_TEXTURE_3D_LEVELS: