/*
 *  This file is part of the Haven & Hearth game client.
 *  Copyright (C) 2009 Fredrik Tolf <fredrik@dolda2000.com>, and
 *                     Björn Johannessen <johannessen.bjorn@gmail.com>
 *
 *  Redistribution and/or modification of this file is subject to the
 *  terms of the GNU Lesser General Public License, version 3, as
 *  published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  Other parts of this source tree adhere to other copying
 *  rights. Please see the file `COPYING' in the root directory of the
 *  source tree for details.
 *
 *  A copy the GNU Lesser General Public License is distributed along
 *  with the source tree of which this file is a part in the file
 *  `doc/LPGL-3'. If it is missing for any reason, please see the Free
 *  Software Foundation's website at <http://www.fsf.org/>, or write
 *  to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 *  Boston, MA 02111-1307 USA
 */

package haven.resutil;

import java.util.*;
import haven.*;
import haven.glsl.*;
import static haven.glsl.Cons.*;
import static haven.glsl.Function.PDir.*;
import static haven.glsl.Type.*;
import haven.glsl.ValBlock.Value;

public class TexPal extends GLState {
    public static final Slot<TexPal> slot = new Slot<TexPal>(Slot.Type.DRAW, TexPal.class);
    public final TexGL tex;

    public TexPal(TexGL tex) {
	this.tex = tex;
    }

    private static final Uniform ctex = new Uniform(SAMPLER2D);
    private static final ShaderMacro[] shaders = {new ShaderMacro() {
	    public void modify(ProgramContext prog) {
		Tex2D.tex2d(prog.fctx).mod(new Macro1<Expression>() {
			public Expression expand(Expression in) {
			    return(texture2D(ctex.ref(), pick(in, "rg")));
			}
		    }, -100);
	    }
	}};

    public ShaderMacro[] shaders() {return(shaders);}
    public boolean reqshaders() {return(true);}

    private TexUnit sampler;

    public void reapply(GOut g) {
    }

    public void apply(GOut g) {
	sampler = TexGL.lbind(g, tex);
	reapply(g);
    }

    public void unapply(GOut g) {
	sampler.ufree(); sampler = null;
    }

    public void prep(Buffer buf) {
	buf.put(slot, this);
    }

    @Material.ResName("pal")
    public static class $res implements Material.ResCons2 {
	public void cons(final Resource res, List<GLState> states, List<Material.Res.Resolver> left, Object... args) {
	    final Resource tres;
	    final int tid;
	    int a = 0;
	    if(args[a] instanceof String) {
		tres = Resource.load((String)args[a], (Integer)args[a + 1]);
		tid = (Integer)args[a + 2];
		a += 3;
	    } else {
		tres = res;
		tid = (Integer)args[a];
		a += 1;
	    }
	    left.add(new Material.Res.Resolver() {
		    public void resolve(Collection<GLState> buf) {
			TexR rt = tres.layer(TexR.class, tid);
			if(rt == null)
			    throw(new RuntimeException(String.format("Specified texture %d for %s not found in %s", tid, res, tres)));
			buf.add(new TexPal((TexGL)rt.tex()));
		    }
		});
	}
    }
}