scons: Add support for GLES.

GLES can be enabled by running scons with

  $ scons gles=yes

When gles=yes is given, the build is changed in three ways.  First,
libmesa.a will be built with FEATURE_ES1 and FEATURE_ES2.  This makes
DRI drivers and libEGL support and advertise GLES support.  Second, GLES
libraries will be created.  They are libGLESv1_CM, libGLESv2, and
libglapi.  Last, libGL or opengl32 will link to libglapi.  This change
is required as _glapi_* will be declared as __declspec(dllimport) in
libmesa.a on windows.  libmesa.a expects those symbols to be defined in
another DLL.  Due to this change to GL, GLES support is marked
experimental.

Note that GLES requires libxml2-python to generate some of its sources.

1 files changed, 63 insertions, 0 deletions

diff --git a/src/mesa/SConscript b/src/mesa/SConscript
index cc4ad09fa3..7c7c7c37c8 100644
--- a/src/mesa/SConscript
+++ b/src/mesa/SConscript
@@ -12,11 +12,19 @@ env.Append(CPPPATH = [
     '#/src/mesa',
 ])
 
+env.Append(CPPDEFINES = [
+    'FEATURE_GL=1',
+])
+
 if env['platform'] == 'windows':
     env.Append(CPPDEFINES = [
         '_GDI32_', # prevent gl* being declared __declspec(dllimport) in MS headers
         'BUILD_GL32', # declare gl* as __declspec(dllexport) in Mesa headers
     ])
+    if not env['gles']:
+        # prevent _glapi_* from being declared __declspec(dllimport)
+        env.Append(CPPDEFINES = ['_GLAPI_NO_EXPORTS'])
+
     env.Prepend(CPPPATH = ['#src/talloc'])
 else:
     env.Append(CPPDEFINES = [
@@ -240,6 +248,61 @@ mesa_sources = (
     statetracker_sources
 )
 
+if env['gles']:
+    from sys import executable as python_cmd
+
+    env.Append(CPPDEFINES = ['FEATURE_ES1=1', 'FEATURE_ES2=1'])
+
+    # generate GLES sources
+    gles_sources = []
+    gles_sources += env.CodeGenerate(
+        target = 'main/api_exec_es1.c',
+        script = 'main/es_generator.py',
+        source = 'main/APIspec.xml',
+        command = python_cmd + ' $SCRIPT -S $SOURCE -V GLES1.1 > $TARGET'
+    )
+    gles_sources += env.CodeGenerate(
+        target = 'main/api_exec_es2.c',
+        script = 'main/es_generator.py',
+        source = 'main/APIspec.xml',
+        command = python_cmd + ' $SCRIPT -S $SOURCE -V GLES2.0 > $TARGET'
+    )
+
+    # generate GLES headers
+    GLAPI = '#src/mapi/glapi/'
+    gles_headers = []
+    gles_headers += env.CodeGenerate(
+        target = 'es1api/main/glapidispatch.h',
+        script = GLAPI + 'gen/gl_table.py',
+        source = GLAPI + 'gen-es/es1_API.xml',
+        command = python_cmd + ' $SCRIPT -c -m remap_table -f $SOURCE > $TARGET',
+    )
+    gles_headers += env.CodeGenerate(
+        target = 'es1api/main/remap_helper.h',
+        script = GLAPI + 'gen/remap_helper.py',
+        source = GLAPI + 'gen-es/es1_API.xml',
+        command = python_cmd + ' $SCRIPT -f $SOURCE > $TARGET',
+    )
+    gles_headers += env.CodeGenerate(
+        target = 'es2api/main/glapidispatch.h',
+        script = GLAPI + 'gen/gl_table.py',
+        source = GLAPI + 'gen-es/es2_API.xml',
+        command = python_cmd + ' $SCRIPT -c -m remap_table -f $SOURCE > $TARGET',
+    )
+    gles_headers += env.CodeGenerate(
+        target = 'es2api/main/remap_helper.h',
+        script = GLAPI + 'gen/remap_helper.py',
+        source = GLAPI + 'gen-es/es2_API.xml',
+        command = python_cmd + ' $SCRIPT -f $SOURCE > $TARGET',
+    )
+
+    env.Depends(gles_sources, gles_headers)
+
+    # gles_sources #include gles_headers with full path
+    env.Append(CPPPATH = [gles_headers[0].dir.up().up()])
+
+    mesa_sources += gles_sources
+
 #
 # Assembly sources
 #