#!/usr/bin/env python2
# coding=utf-8
#
# Copyright © 2013 Intel Corporation
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice (including the next
# paragraph) shall be included in all copies or substantial portions of the
# Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
# DEALINGS IN THE SOFTWARE.

import os
import os.path
from mako.template import Template
from textwrap import dedent

sampler_type_to_coord_type = {
	'sampler1D':              'float',
	'isampler1D':             'float',
	'usampler1D':             'float',

	'sampler2D':              'vec2',
	'isampler2D':             'vec2',
	'usampler2D':             'vec2',

	'sampler3D':              'vec3',
	'isampler3D':             'vec3',
	'usampler3D':             'vec3',

	'samplerCube':            'vec3',
	'isamplerCube':           'vec3',
	'usamplerCube':           'vec3',

	'sampler1DArray':         'float',
	'isampler1DArray':        'float',
	'usampler1DArray':        'float',

	'sampler2DArray':         'vec2',
	'isampler2DArray':        'vec2',
	'usampler2DArray':        'vec2',

	'samplerCubeArray':       'vec3',
	'isamplerCubeArray':      'vec3',
	'usamplerCubeArray':      'vec3',

	'sampler1DShadow':        'float',
	'sampler2DShadow':        'vec2',
	'samplerCubeShadow':      'vec3',
	'sampler1DArrayShadow':   'float',
	'sampler2DArrayShadow':   'vec2',
	'samplerCubeArrayShadow': 'vec3',
}

requirements = {
	'ARB_texture_query_lod': {
		'version': '1.30',
		'extension': 'GL_ARB_texture_query_lod'
	},
	'glsl-4.00': {
		'version': '4.00',
		'extension': ''
	}
}

template = Template(dedent("""\
	/* [config]
	% if execution_stage == 'fs':
	 * expect_result: pass
	% else:
	 * expect_result: fail
	% endif
	 * glsl_version: ${version}
	% if extensions:
	 * required_extensions: ${" ".join(extensions)}
	% endif
	 * [end config]
	 */

	#version ${version.translate(None, '.')}
	% for extension in extensions:
	#extension ${extension} : enable
	% endfor

	uniform ${sampler_type} s;
	% if execution_stage == 'fs':
	varying ${coord_type} coord;
	% else:
	uniform ${coord_type} coord;
	% endif

	void main()
	{
		% if execution_stage == 'fs':
		gl_FragColor.xy = textureQuery${Lod}(s, coord);
		% else:
		gl_Position.xy = textureQuery${Lod}(s, coord);
		% endif
	}
"""))

for api, requirement in requirements.iteritems():
	for sampler_type, coord_type in sampler_type_to_coord_type.iteritems():
		for execution_stage in ("vs", "fs"):
			file_extension = 'frag' if execution_stage == 'fs' else 'vert'
			filename = os.path.join("spec",
						api,
						"compiler",
						"built-in-functions",
						"{0}.{1}"\
						.format(sampler_type,
							file_extension))
			print filename

			dirname = os.path.dirname(filename)
			if not os.path.exists(dirname):
				os.makedirs(dirname)

			version = requirement['version']
			extensions = [requirement['extension']]

			# samplerCubeArray types are part GLSL 4.00
			# or GL_ARB_texture_cube_map_array.
			if api == "ARB_texture_query_lod" and \
			   sampler_type in ['samplerCubeArray', \
					    'isamplerCubeArray', \
					    'usamplerCubeArray', \
					    'samplerCubeArrayShadow']:
				extensions += ['GL_ARB_texture_cube_map_array']

			Lod = 'Lod' if api == 'glsl-4.00' else 'LOD';

			f = open(filename, "w")
			f.write(template.render(version = version,
						extensions = extensions,
						execution_stage = execution_stage,
						sampler_type = sampler_type,
						coord_type = coord_type,
						Lod = Lod))
			f.close()