render/pixel_format: generate tables via kdfs

Leverage go-kdfs [1] to automatically generate tables (basic info
for single-plane formats, YUV list, opaque list). This allows us
to drop our manually written tables and check format info in a kdfs
viewer (the kdfs CLI or pixfmtdb) to ensure it's correct.

Add a new gen-pixel-format ninja target to regenerate tables. Tables
are checked in Git instead of being generated at build-time, so
that the kdfs CLI isn't a build-time dependency.

block_width/block_height are now never zero.

[1]: https://gitlab.freedesktop.org/emersion/go-kdf

render/gen_pixel_format.sh

@@ -0,0 +1,68 @@
+#!/bin/sh -eu
+#
+# usage: gen_pixel_format.sh pixel_format_table.c
+
+KDFS=${KDFS:-kdfs}
+
+output_file="$1"
+
+gen_info() {
+	"$KDFS" show --json 'DRM_FORMAT_*' | jq -r '
+		to_entries[]
+		| select((.value.bytes_plane | length) == 1)
+		|
+			"	{\n" +
+			"		.drm_format = \(.key),\n" +
+			"		.bytes_per_block = \(.value.bytes_plane[0]),\n" +
+			"		.block_width = \(.value.texel_block_dimension[0]),\n" +
+			"		.block_height = \(.value.texel_block_dimension[1]),\n" +
+			"	},"
+	'
+}
+
+gen_opaque() {
+	"$KDFS" show --json 'DRM_FORMAT_*' | jq -r '
+		to_entries[]
+		| select(any(.value.sample_info[]; .channel == "a") | not)
+		| "	case \(.key):"
+	'
+}
+
+gen_ycbcr() {
+	"$KDFS" show --json 'DRM_FORMAT_*' | jq -r '
+		to_entries[]
+		| select(.value.color_model == "yuvsda")
+		| "	case \(.key):"
+	'
+}
+
+cat >"$output_file" << EOF
+// Generated by gen_pixel_formats.sh - DO NOT EDIT
+
+#include <drm_fourcc.h>
+#include "render/pixel_format.h"
+
+const struct wlr_pixel_format_info pixel_format_info[] = {
+$(gen_info)
+};
+
+const size_t pixel_format_info_len = sizeof(pixel_format_info) / sizeof(pixel_format_info[0]);
+
+bool pixel_format_is_opaque(uint32_t format) {
+	switch (format) {
+$(gen_opaque)
+		return true;
+	default:
+		return false;
+	}
+}
+
+bool pixel_format_is_ycbcr(uint32_t format) {
+	switch (format) {
+$(gen_ycbcr)
+		return true;
+	default:
+		return false;
+	}
+}
+EOF