# Creation of Windows batch files to automate the compilation of
# mental ray shaders for the book "Writing mental ray shaders"
#   http://www.writingshaders.com

import sys, os, string, re

def initial_comment(bits=32, shader=None):
    sys_name = '%d-bit systems using Visual C++ 2008 Express' % (bits)
    if shader == 'components':
        shader_desc = ' for shader components\nREM'
    elif shader:
        shader_desc = ' for shader "%s"\nREM' % (shader)
    else:
        shader_desc = ''
    result = """
REM Microsoft "Windows" batch file for the compilation of the shaders contained
REM in the book "Writing mental ray Shaders: A perceptual introduction".
REM Compilation is described in http://www.writingshaders.com/compilation.html.
REM Also see the subsection "Dynamic Linking of Shaders" in section "Using and
REM Writing Shaders" in the on-line mental ray documentation.

REM Compilation commands%s for %s.
""" % (shader_desc, sys_name)
    return result.strip() + '\n'


# A list of the shader source and component files are used to iterate over all shaders:

shader_inventory_file = 'SHADER_NAMES'
component_inventory_file = 'COMPONENT_NAMES'


# Filename conventions:

extension = 'bat'
all_shaders_filebase = 'all_shaders'
components_filebase = 'components'
variables_filebase = 'set_variables'

# Compilation and linking flags:

C_32 = '/c /O2 /MD /nologo /W3 -DWIN_NT'
C_64 = C_32 + ' -D64'

CPP_32 = '/TP /c /O2 /MD /nologo /W3 /EHsc -DWIN_NT'
CPP_64 = CPP_32 + ' -D64'

INCLUDE_32 = '/I"C:\Program Files\mental images\mental ray nt-x86-vc8\include"'
INCLUDE_64 = '/I"C:\Program Files\mental images\mental ray nt-x64\include"'

LINK = '/nologo /nodefaultlib:LIBC.LIB /OPT:NOREF /INCREMENTAL:NO /DLL'
MT = '-nologo -manifest'


# Defining the batch file variables:

def variables_filename(bits=32):
    if bits == 64:
        suffix = '_64'
    else:
        suffix = ''
    return '%s%s.%s' % (variables_filebase, suffix, extension)

def var_name(s):
    return 'WMRS_' + s.split('_')[0] + '_FLAGS'

def write_set_variables_file(bits=32):
    vars = re.sub('NN', str(bits), 'C_NN CPP_NN INCLUDE_NN LINK MT')
    result = ''
    for var in vars.split():
        result += 'set %s=%s\n' % (var_name(var), eval(var))
    fp = open(variables_filename(bits), 'w')
    fp.write(result)
    fp.close()


# The commands to compile source files:

def var(s):
    return '%%%s%% ' % (var_name(s))

def component_obj_files(shader_name):
    # This breaks the generality of having COMPONENT_NAMES, unfortunately.
    result = 'miaux.obj'
    if shader_name == 'newblocks.cpp':
        result += ' matrix.obj mrpoly.obj'
    return result

def single_shader_commands(shader_name, bits=32, link=True):
    is_cpp = shader_name.endswith('.cpp')
    shader_basename = shader_name.split('.')[0]
    result = '\ncl '
    if bits == 32:
        if is_cpp:
            result += var('CPP_32')
        else:
            result += var('C_32')
        result += var('INCLUDE_32')
    else:
        if is_cpp:
            result += var('CPP_64')
        else:
            result += var('C_64')
        result += var('INCLUDE_64')
    result += shader_name
    if link:
        result += '\nlink %s/OUT:%s.dll %s.obj %s shader.lib\n' % \
                  (var('LINK'), shader_basename, shader_basename,
                   component_obj_files(shader_name))
        result += 'mt %s%s.dll.manifest -outputresource:%s.dll;2' % \
                  (var('MT'), shader_basename, shader_basename)
    return result + '\n'


# Batch file for all shaders:

def all_shader_batchfile(shader_names, component_names, bits=32):
    if bits == 32:
        filename = all_shaders_filebase + '.' + extension
    else:
        filename = all_shaders_filebase + '_64.' + extension

    print 'Making batch file %s' % (filename)

    fp = open(filename, 'w')
    fp.write(initial_comment(bits) + '\n')

    fp.write('call %s\n' % (variables_filename(bits)))

    for component in component_names:
        #fp.write('\nREM Shader component "%s"\n' % (component))
        fp.write(single_shader_commands(component, bits=bits, link=False))

    for shader in shader_names:
        #fp.write('\nREM Shader "%s"\n' % (shader))
        fp.write(single_shader_commands(shader, bits=bits))

    fp.close()


# Batch file for individual shaders:

def individual_shader_batchfiles(shader_names, bits=32):
    for shader in shader_names:
        filebase = shader.split('.')[0]
        if bits == 32:
            filename = filebase + '.' + extension
        else:
            filename = filebase + '_64.' + extension

        print 'Making batch file %s' % (filename)
        fp = open(filename, 'w')
        fp.write(initial_comment(bits, shader) + '\n')
        c_lang = shader.endswith('.c')
        cpp_lang = shader.endswith('.cpp')
        fp.write('call %s\n' % (variables_filename(bits)))
        fp.write(single_shader_commands(shader, bits=bits))
        fp.close()


# Batch file for component files (e.g., miaux.obj):

def component_batchfile(component_names, bits=32):
    if bits == 32:
        filename = components_filebase + '.' + extension
    else:
        filename = components_filebase + '_64.' + extension
    print 'Making batch file %s' % (filename)
    fp = open(filename, 'w')
    fp.write(initial_comment(bits, 'components') + '\n')
    fp.write('call %s\n' % (variables_filename(bits)))

    for component in component_names:
        #fp.write('\nREM Shader component "%s"\n' % (component))
        fp.write(single_shader_commands(component, bits=bits, link=False))
    fp.close()


# Check shader and component inventory files:

def check_file(filename, description):
    if not os.path.exists(filename):
        print '''
This script expects %s to be found in a file called "%s"
in the current directory.
''' % (description, filename)
        sys.exit(1)


# Make batch files:

check_file(shader_inventory_file, 'shader names')
check_file(component_inventory_file, 'component names')

shader_names = open(shader_inventory_file).read().split()
component_names = open(component_inventory_file).read().split()

write_set_variables_file()
write_set_variables_file(bits=64)

individual_shader_batchfiles(shader_names)
individual_shader_batchfiles(shader_names, bits=64)

component_batchfile(component_names)
component_batchfile(component_names, bits=64)

all_shader_batchfile(shader_names, component_names)
all_shader_batchfile(shader_names, component_names, bits=64)