add pixman library.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@1320 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/external/pixman/SConscript

+Import('RTT_ROOT')
+Import('rtconfig')
+
+from building import *
+import os
+
+PIXMAN_VERSION = '0.21.6'
+PIXMAN_PATH = 'pixman-' + PIXMAN_VERSION
+
+if GetDepend('RT_USING_CAIRO') and not os.path.exists(PIXMAN_PATH):
+    print '================ERROR============================'
+    print 'Please get pixman dist and put them under pixman folder'
+    print '================================================='
+    exit(0)
+
+# core source files 
+src = Split('''
+pixman-access-accessors.c
+pixman-access.c
+pixman-arm-neon.c
+pixman-arm-simd.c
+pixman-bits-image.c
+pixman-combine32.c
+pixman-combine64.c
+pixman-conical-gradient.c
+pixman-cpu.c
+pixman-edge-accessors.c
+pixman-edge.c
+pixman-fast-path.c
+pixman-general.c
+pixman-gradient-walker.c
+pixman-image.c
+pixman-implementation.c
+pixman-linear-gradient.c
+pixman-matrix.c
+pixman-mmx.c
+pixman-radial-gradient.c
+pixman-region16.c
+pixman-region32.c
+pixman-solid-fill.c
+pixman-timer.c
+pixman-trap.c
+pixman-utils.c
+pixman.c
+''')
+
+for item in range(len(src)):
+    src[item] = PIXMAN_PATH + '/pixman/' + src[item]
+
+CPPDEFINES  = ['HAVE_PTHREAD_SETSPECIFIC', 'PACKAGE']
+CPPPATH = [RTT_ROOT + '/components/external/pixman/' + PIXMAN_PATH + '/pixman']
+
+group = DefineGroup('pixman', src, depend = ['RT_USING_CAIRO'], CPPDEFINES = CPPDEFINES, CPPPATH = CPPPATH)
+
+Return('group')