/*
 * Copyright (c) 2016, Metron, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of Metron, Inc. nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL METRON, INC. BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package com.metsci.glimpse.dnc;

import static com.metsci.glimpse.gl.shader.GLShaderUtils.createProgram;
import static com.metsci.glimpse.gl.shader.GLShaderUtils.requireResourceText;

import javax.media.opengl.GL2ES2;

public class DncLabelProgram
{

    public static final String dncLabelVertShader_GLSL = requireResourceText( "shaders/DncPainter/label.vs" );
    public static final String dncLabelGeomShader_GLSL = requireResourceText( "shaders/DncPainter/label.gs" );
    public static final String dncLabelFragShader_GLSL = requireResourceText( "shaders/DncPainter/label.fs" );


    public static class DncLabelProgramHandles
    {
        public final int program;

        public final int AXIS_RECT;
        public final int VIEWPORT_SIZE_PX;

        public final int ATLAS;
        public final int ATLAS_SIZE_PX;

        public final int HIGHLIGHT_SET;
        public final int HIGHLIGHT_SCALE;

        public final int inLabelVertex;
        public final int inImageAlign;
        public final int inImageBounds;

        public DncLabelProgramHandles( GL2ES2 gl )
        {
            this.program = createProgram( gl, dncLabelVertShader_GLSL, dncLabelGeomShader_GLSL, dncLabelFragShader_GLSL );

            this.AXIS_RECT = gl.glGetUniformLocation( program, "AXIS_RECT" );
            this.VIEWPORT_SIZE_PX = gl.glGetUniformLocation( program, "VIEWPORT_SIZE_PX" );

            this.ATLAS = gl.glGetUniformLocation( program, "ATLAS" );
            this.ATLAS_SIZE_PX = gl.glGetUniformLocation( program, "ATLAS_SIZE_PX" );

            this.HIGHLIGHT_SET = gl.glGetUniformLocation( program, "HIGHLIGHT_SET" );
            this.HIGHLIGHT_SCALE = gl.glGetUniformLocation( program, "HIGHLIGHT_SCALE" );

            this.inLabelVertex = gl.glGetAttribLocation( program, "inLabelVertex" );
            this.inImageAlign = gl.glGetAttribLocation( program, "inImageAlign" );
            this.inImageBounds = gl.glGetAttribLocation( program, "inImageBounds" );
        }
    }


    protected DncLabelProgramHandles handles;


    public DncLabelProgram( )
    {
        this.handles = null;
    }

    /**
     * Returns the raw GL handles for the shader program, uniforms, and attributes. Compiles and
     * links the program, if necessary.
     */
    public DncLabelProgramHandles handles( GL2ES2 gl )
    {
        if ( this.handles == null )
        {
            this.handles = new DncLabelProgramHandles( gl );
        }

        return this.handles;
    }

    /**
     * Deletes the program, and resets this object to the way it was before {@link #handles(GL2ES2)}
     * was first called.
     * <p>
     * This object can be safely reused after being disposed, but in most cases there is no
     * significant advantage to doing so.
     */
    public void dispose( GL2ES2 gl )
    {
        if ( this.handles != null )
        {
            gl.glDeleteProgram( this.handles.program );
            this.handles = null;
        }
    }

}