vello/piet-gpu/shader/setup.h
Elias Naur 07e07c7544 ensure consistent path segment transformation
As described in #62, the non-deterministic scene monoid may result in
slightly different transformations for path segments in an otherwise
closed path.

This change ensures consistent transformation across paths in three steps.

First, absolute transformations computed by the scene monoid is stored
along with path segments and annotated elements.

Second, elements.comp no longer transforms path segments. Instead, each
segment is stored untransformed along with a reference to its absolute
transformation.

Finally, path_coarse performs the transformation of path segments.
Because all segments in a path share a single transformation reference,
the inconsistency in #62 is avoided.

Fixes #62

Signed-off-by: Elias Naur <mail@eliasnaur.com>
2021-03-19 12:45:23 +01:00

40 lines
1.2 KiB
C

// SPDX-License-Identifier: Apache-2.0 OR MIT OR Unlicense
// Various constants for the sizes of groups and tiles.
// Much of this will be made dynamic in various ways, but for now it's easiest
// to hardcode and keep all in one place.
// A LG_WG_FACTOR of n scales workgroup sizes by 2^n. Use 0 for a
// maximum workgroup size of 128, or 1 for a maximum size of 256.
#define LG_WG_FACTOR 1
#define WG_FACTOR (1<<LG_WG_FACTOR)
#define TILE_WIDTH_PX 16
#define TILE_HEIGHT_PX 16
#define PTCL_INITIAL_ALLOC 1024
// These should probably be renamed and/or reworked. In the binning
// kernel, they represent the number of bins. Also, the workgroup size
// of that kernel is equal to the number of bins, but should probably
// be more flexible (it's 512 in the K&L paper).
#define N_TILE_X 16
#define N_TILE_Y (8 * WG_FACTOR)
#define N_TILE (N_TILE_X * N_TILE_Y)
#define LG_N_TILE (7 + LG_WG_FACTOR)
#define N_SLICE (N_TILE / 32)
struct Config {
uint n_elements; // paths
uint n_pathseg;
uint width_in_tiles;
uint height_in_tiles;
Alloc tile_alloc;
Alloc bin_alloc;
Alloc ptcl_alloc;
Alloc pathseg_alloc;
Alloc anno_alloc;
Alloc trans_alloc;
};