Use a VBO when drawing blurs

Until now, we were uploading the vertex and uv data for every draw call,
this is not great. This CL created a packed vertex buffer, uploads it
to the graphics card and reuses it.

Test: SurfaceFlinger_tests
Test: manual
Bug: 149792636
Change-Id: Iee72a9a815a8ea43880a21c1b4c61320dea20dff
diff --git a/libs/renderengine/gl/GLVertexBuffer.cpp b/libs/renderengine/gl/GLVertexBuffer.cpp
new file mode 100644
index 0000000..e50c471
--- /dev/null
+++ b/libs/renderengine/gl/GLVertexBuffer.cpp
@@ -0,0 +1,55 @@
+/*
+ * Copyright 2020 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.
+ */
+
+#define ATRACE_TAG ATRACE_TAG_GRAPHICS
+
+#include "GLVertexBuffer.h"
+
+#include <GLES/gl.h>
+#include <GLES2/gl2.h>
+#include <nativebase/nativebase.h>
+#include <utils/Trace.h>
+
+namespace android {
+namespace renderengine {
+namespace gl {
+
+GLVertexBuffer::GLVertexBuffer() {
+    glGenBuffers(1, &mBufferName);
+}
+
+GLVertexBuffer::~GLVertexBuffer() {
+    glDeleteBuffers(1, &mBufferName);
+}
+
+void GLVertexBuffer::allocateBuffers(const GLfloat data[], const GLuint size) {
+    ATRACE_CALL();
+    bind();
+    glBufferData(GL_ARRAY_BUFFER, size * sizeof(GLfloat), data, GL_STATIC_DRAW);
+    unbind();
+}
+
+void GLVertexBuffer::bind() const {
+    glBindBuffer(GL_ARRAY_BUFFER, mBufferName);
+}
+
+void GLVertexBuffer::unbind() const {
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+}
+
+} // namespace gl
+} // namespace renderengine
+} // namespace android