/*******************************************************************************
* Copyright 2012 Geoscience Australia
*
* 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.
******************************************************************************/
package au.gov.ga.earthsci.worldwind.common.effects.edge;
import gov.nasa.worldwind.render.DrawContext;
import java.awt.Dimension;
import javax.media.opengl.GL2;
import au.gov.ga.earthsci.worldwind.common.effects.Effect;
import au.gov.ga.earthsci.worldwind.common.effects.EffectBase;
import au.gov.ga.earthsci.worldwind.common.render.FrameBuffer;
/**
* Example {@link Effect} that convolves the input with a kernel matrix,
* producing different filter effects like blurring, edge detection, sharpening,
* embossing, etc.
*
* @author Michael de Hoog (michael.dehoog@ga.gov.au)
*/
public class EdgeDetectionEffect extends EffectBase
{
private final EdgeShader edgeShader = new EdgeShader();
@Override
protected void drawFrameBufferWithEffect(DrawContext dc, Dimension dimensions, FrameBuffer frameBuffer)
{
GL2 gl = dc.getGL().getGL2();
if (!edgeShader.createIfRequired(gl))
{
FrameBuffer.renderTexturedQuad(gl, frameBuffer.getTexture().getId(), frameBuffer.getDepth().getId());
return;
}
try
{
edgeShader.use(gl, dimensions.width, dimensions.height);
FrameBuffer.renderTexturedQuad(gl, frameBuffer.getTexture().getId(), frameBuffer.getDepth().getId());
}
finally
{
edgeShader.unuse(gl);
}
}
@Override
protected void releaseEffect(DrawContext dc)
{
edgeShader.deleteIfCreated(dc.getGL().getGL2());
}
}