emulator: opengl: Back-port GLES emulation from the master tree.

The modules here are only built when BUILD_EMULATOR_OPENGL is defined to true
in your environment or your BoardConfig.mk (see tools/emulator/opengl/Android.mk)

Change-Id: I5f32c35b4452fb5a7b4d5f9fc5870ec1da6032e6

tools/emulator/opengl/host/libs/libOpenglRender/RenderContext.cpp

@@ -0,0 +1,76 @@
+/*
+* Copyright (C) 2011 The Android Open Source Project
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+#include "RenderContext.h"
+#include "FBConfig.h"
+#include "FrameBuffer.h"
+#include "EGLDispatch.h"
+#include "GLDispatch.h"
+
+RenderContext *RenderContext::create(int p_config,
+                                     RenderContextPtr p_shareContext,
+                                     bool p_isGL2)
+{
+    const FBConfig *fbconf = FBConfig::get(p_config);
+    if (!fbconf) {
+        return NULL;
+    }
+
+    RenderContext *c = new RenderContext();
+    if (!c) {
+        return NULL;
+    }
+
+    EGLContext share = EGL_NO_CONTEXT;
+    if (p_shareContext.Ptr() != NULL) {
+        share = p_shareContext->getEGLContext();
+    }
+
+    GLint glContextAttribs[] = {
+        EGL_CONTEXT_CLIENT_VERSION, 1,
+        EGL_NONE
+    };
+
+    if (p_isGL2) {
+        glContextAttribs[1] = 2;
+        c->m_isGL2 = true;
+    }
+
+    c->m_ctx = s_egl.eglCreateContext(FrameBuffer::getFB()->getDisplay(),
+                                      fbconf->getEGLConfig(), share,
+                                      glContextAttribs);
+
+    if (c->m_ctx == EGL_NO_CONTEXT) {
+        delete c;
+        return NULL;
+    }
+
+    c->m_config = p_config;
+    return c;
+}
+
+RenderContext::RenderContext() :
+    m_ctx(EGL_NO_CONTEXT),
+    m_config(0),
+    m_isGL2(false)
+{
+}
+
+RenderContext::~RenderContext()
+{
+    if (m_ctx != EGL_NO_CONTEXT) {
+        s_egl.eglDestroyContext(FrameBuffer::getFB()->getDisplay(), m_ctx);
+    }
+}