gl: Add support for OpenGL ES 3.0

This improves the OpenGL ES support to extend it to version 3.0.
A number of new features are available in glesv3 including creation of
multi-sampled renderbuffers.  These renderbuffers can be blitted to
single sample textures (but not the other way around).  Other features
such as PBO for image uploading, are left as followon work.

For this preliminary implementation, glesv3 backends always create
renderbuffers, which can be set as single sample or multisample.  The
renderbuffer's content is blitted to the texture only when used as a
source or a mask.

Images uploaded to a texture stay there until the surface is used as a
rendering target, at which point its painted to the renderbuffer.

This patch is heavily based off of Henry Song's initial GLESv3 patch
6f7f3795 from his cairogles fork of Cairo, and incorporates subsequent
fixes and pertinent refactorings from his trunk and review feedback from
Uli.

This implements the *functional* support for glesv3, excluding the
various optimization work to utilize its features.  Rendering and
performance should not be expected to improve notably from pure glesv2.
As the GL backend for Cairo remains "experimental", these changes should
likewise be considered as such.

Signed-off-by: Bryce Harrington <bryce@osg.samsung.com>

2 files changed, 34 insertions, 8 deletions

diff --git a/boilerplate/Makefile.win32.features b/boilerplate/Makefile.win32.features
index e60a95ba6..abb198dee 100644
--- a/boilerplate/Makefile.win32.features
+++ b/boilerplate/Makefile.win32.features
@@ -247,6 +247,18 @@ enabled_cairo_boilerplate_cxx_sources += $(cairo_boilerplate_glesv2_cxx_sources)
 enabled_cairo_boilerplate_sources += $(cairo_boilerplate_glesv2_sources)
 endif
 
+unsupported_cairo_boilerplate_headers += $(cairo_boilerplate_glesv3_headers)
+all_cairo_boilerplate_headers += $(cairo_boilerplate_glesv3_headers)
+all_cairo_boilerplate_private += $(cairo_boilerplate_glesv3_private)
+all_cairo_boilerplate_cxx_sources += $(cairo_boilerplate_glesv3_cxx_sources)
+all_cairo_boilerplate_sources += $(cairo_boilerplate_glesv3_sources)
+ifeq ($(CAIRO_HAS_GLESV3_SURFACE),1)
+enabled_cairo_boilerplate_headers += $(cairo_boilerplate_glesv3_headers)
+enabled_cairo_boilerplate_private += $(cairo_boilerplate_glesv3_private)
+enabled_cairo_boilerplate_cxx_sources += $(cairo_boilerplate_glesv3_cxx_sources)
+enabled_cairo_boilerplate_sources += $(cairo_boilerplate_glesv3_sources)
+endif
+
 unsupported_cairo_boilerplate_headers += $(cairo_boilerplate_cogl_headers)
 all_cairo_boilerplate_headers += $(cairo_boilerplate_cogl_headers)
 all_cairo_boilerplate_private += $(cairo_boilerplate_cogl_private)
diff --git a/boilerplate/cairo-boilerplate-egl.c b/boilerplate/cairo-boilerplate-egl.c
index 99bee64cf..c44441cc5 100644
--- a/boilerplate/cairo-boilerplate-egl.c
+++ b/boilerplate/cairo-boilerplate-egl.c
@@ -33,10 +33,13 @@
 #include "cairo-boilerplate-private.h"
 
 #include <cairo-gl.h>
-#if CAIRO_HAS_GL_SURFACE
-#include <GL/gl.h>
+#if CAIRO_HAS_GLESV3_SURFACE
+#include <GLES3/gl3.h>
+#include <EGL/eglext.h>
 #elif CAIRO_HAS_GLESV2_SURFACE
 #include <GLES2/gl2.h>
+#elif CAIRO_HAS_GL_SURFACE
+#include <GL/gl.h>
 #endif
 
 static const cairo_user_data_key_t gl_closure_key;
@@ -85,15 +88,19 @@ _cairo_boilerplate_egl_create_surface (const char		 *name,
 	EGL_BLUE_SIZE, 8,
 	EGL_ALPHA_SIZE, 8,
 	EGL_SURFACE_TYPE, EGL_PBUFFER_BIT,
-#if CAIRO_HAS_GL_SURFACE
-	EGL_RENDERABLE_TYPE, EGL_OPENGL_BIT,
+#if CAIRO_HAS_GLESV3_SURFACE
+	EGL_RENDERABLE_TYPE, EGL_OPENGL_ES3_BIT_KHR,
 #elif CAIRO_HAS_GLESV2_SURFACE
 	EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
+#elif CAIRO_HAS_GL_SURFACE
+	EGL_RENDERABLE_TYPE, EGL_OPENGL_BIT,
 #endif
 	EGL_NONE
     };
     const EGLint ctx_attribs[] = {
-#if CAIRO_HAS_GLESV2_SURFACE
+#if CAIRO_HAS_GLESV3_SURFACE
+	EGL_CONTEXT_CLIENT_VERSION, 3,
+#elif CAIRO_HAS_GLESV2_SURFACE
 	EGL_CONTEXT_CLIENT_VERSION, 2,
 #endif
 	EGL_NONE
@@ -110,15 +117,22 @@ _cairo_boilerplate_egl_create_surface (const char		 *name,
     }
 
     eglChooseConfig (gltc->dpy, config_attribs, &config, 1, &numConfigs);
+#if CAIRO_HAS_GLESV3_SURFACE && CAIRO_HAS_GLESV2_SURFACE
+    if (numConfigs == 0) {
+        /* retry with ES2_BIT */
+        config_attribs[11] = ES2_BIT;  /* FIXME: Ick */
+        eglChooseConfig (gltc->dpy, config_attribs, &config, 1, &numConfigs);
+    }
+#endif
     if (numConfigs == 0) {
 	free (gltc);
 	return NULL;
     }
 
-#if CAIRO_HAS_GL_SURFACE
-    eglBindAPI (EGL_OPENGL_API);
-#elif CAIRO_HAS_GLESV2_SURFACE
+#if CAIRO_HAS_GLESV3_SURFACE || CAIRO_HAS_GLESV2_SURFACE
     eglBindAPI (EGL_OPENGL_ES_API);
+#elif CAIRO_HAS_GL_SURFACE
+    eglBindAPI (EGL_OPENGL_API);
 #endif
 
     gltc->ctx = eglCreateContext (gltc->dpy, config, EGL_NO_CONTEXT,