Run scripts with added vulkan layers

vklayer

#!/usr/bin/env python
"""
    Run programs with added vulkan layers.
    
    Author: Henri Tuhola <henri.tuhola@gmail.com>
    License: MIT
    Date: 2016-2-20
"""
import argparse, json, os, sys

parser = argparse.ArgumentParser(description="Run programs with added vulkan layers")
parser.add_argument("names", metavar="NAME", nargs='*',
    help="Appropos for the vulkan layer to add")
parser.add_argument("-c", dest="cmd", metavar="COMMAND", nargs='+',
    help="Command to execute")
parser.add_argument("-l", "--list", dest="ls", action="store_true",
    help="List available layers")

args = parser.parse_args()

instance_layers = os.environ.get("VK_INSTANCE_LAYERS", "").split(":")
device_layers = os.environ.get("VK_DEVICE_LAYERS", "").split(":")
instance_layers = filter(bool, instance_layers)
device_layers = filter(bool, device_layers)

paths = [
    "/usr/share/vulkan/implicit_layer.d",
    "/usr/share/vulkan/explicit_layer.d",
    "/etc/vulkan/implicit_layer.d",
    "/etc/vulkan/explicit_layer.d",
]

manifests = []
for path in paths:
    try:
        manifests.extend(os.path.join(path, name)
            for name in os.listdir(path)
            if name.endswith(".json"))
    except OSError as _:
        pass

layers = []
for path in manifests:
    with open(path) as fd:
        manifest = json.load(fd)
        layers.append( manifest["layer"]["name"] )

# I did not find the alias layers defined anywhere. So here it is.
aliases = {
    "VK_LAYER_LUNARG_standard_validation": [
        "VK_LAYER_LUNARG_threading",
        "VK_LAYER_LUNARG_param_checker",
        "VK_LAYER_LUNARG_device_limits",
        "VK_LAYER_LUNARG_object_tracker",
        "VK_LAYER_LUNARG_image",
        "VK_LAYER_LUNARG_mem_tracker",
        "VK_LAYER_LUNARG_draw_state",
        "VK_LAYER_LUNARG_swapchain",
        "VK_LAYER_GOOGLE_unique_objects",
    ]
}
layers.extend(aliases)

for arg in args.names:
    for name in layers:
        if name.find(arg) >= 0:
            instance_layers.append(name)
            device_layers.append(name)

if args.ls:
    for name in sorted(layers):
        active = "[ ]"
        if name in instance_layers and name in device_layers:
            active = "[*]"
        elif name in instance_layers:
            active = "[I]"
        elif name in device_layers:
            active = "[D]"
        sys.stdout.write("{:<40}{}\n".format(name, active))
elif not args.cmd:
    sys.stdout.write("\n    ".join(["VK_INSTANCE_LAYERS="] + instance_layers) + "\n")
    sys.stdout.write("\n    ".join(["VK_DEVICE_LAYERS="] + device_layers) + "\n")
if args.cmd:
    os.environ["VK_INSTANCE_LAYERS"] = ":".join(instance_layers)
    os.environ["VK_DEVICE_LAYERS"] = ":".join(device_layers)
    os.execvp(args.cmd[0], args.cmd)