Tex2D.java

/*
 *  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.glsl;

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

public class Tex2D {
    public static final Uniform tex2d = new Uniform(Type.SAMPLER2D);
    public Varying.Interpol ipol = Varying.Interpol.NORMAL;

    public static final AutoVarying texcoord = new AutoVarying(VEC2, "s_tex2d") {
	    protected Expression root(VertexContext vctx) {
		return(pick(vctx.gl_MultiTexCoord[0].ref(), "st"));
	    }

	    protected Interpol ipol(Context ctx) {
		Tex2D mod;
		if((ctx instanceof ShaderContext) && ((mod = ((ShaderContext)ctx).prog.getmod(Tex2D.class)) != null))
		    return(mod.ipol);
		return(super.ipol(ctx));
	    }
	};

    public static Value tex2d(FragmentContext fctx) {
	return(fctx.uniform.ext(tex2d, new ValBlock.Factory() {
		public Value make(ValBlock vals) {
		    return(vals.new Value(VEC4) {
			    public Expression root() {
				return(texture2D(tex2d.ref(), texcoord.ref()));
			    }
			});
		}
	    }));
    }

    public Tex2D(ProgramContext prog) {
	prog.module(this);
    }

    public static Tex2D get(ProgramContext prog) {
	Tex2D t = prog.getmod(Tex2D.class);
	if(t == null)
	    t = new Tex2D(prog);
	return(t);
    }

    public static final ShaderMacro mod = new ShaderMacro() {
	    public void modify(ProgramContext prog) {
		final Value tex2d = tex2d(prog.fctx);
		tex2d.force();
		prog.fctx.fragcol.mod(new Macro1<Expression>() {
			public Expression expand(Expression in) {
			    return(mul(in, tex2d.ref()));
			}
		    }, 0);
	    }
	};

    public static final ShaderMacro clip = new ShaderMacro() {
	    public void modify(ProgramContext prog) {
		final Value tex2d = tex2d(prog.fctx);
		tex2d.force();
		prog.fctx.mainmod(new CodeMacro() {
			public void expand(Block blk) {
			    blk.add(new If(lt(pick(tex2d.ref(), "a"), l(0.5)),
					   new Discard()));
			}
		    }, -100);
	    }
	};
}