/* Copyright (c) 2014 Google Inc.

*

* 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 "GLDrawer.h"

GLDrawer::GLDrawer() {

increasing_ = true;

red_ = 0.0f;

}

void GLDrawer::onSurfaceCreated() {

glClearColor(red_, 0.5f, 0.5f, 1.0f);

}

void GLDrawer::onSurfaceChanged() {

// No-op

}

void GLDrawer::onDrawFrame() {

glClearColor(red_, 0.5f, 0.5f, 1.0f);

glClear(GL_COLOR_BUFFER_BIT);

}

void GLDrawer::onUpdate() {

// Increment red if increasing, decrement otherwise

float diff = increasing_ ? 0.01f : -0.01f;

// Increment red up to 1.0, then back down to 0.0, repeat.

red_ += diff;

if (red_ >= 1.0f) {

increasing_ = false;

} else if (red_ <= 0.0f) {

increasing_ = true;

}

}