GUI/GUI_PolygonNormalShade.h

/*
 * Copyright (c) 2024
 *    Side Effects Software Inc.  All rights reserved.
 *
 * Redistribution and use of Houdini Development Kit samples in source and
 * binary forms, with or without modification, are permitted provided that the
 * following conditions are met:
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. The name of Side Effects Software may not be used to endorse or
 *    promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY SIDE EFFECTS SOFTWARE `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 SIDE EFFECTS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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/*
 * COMMENTS:
 *      Example of a filter hook.
 *      Replaces Cd in a GT polygon mesh with false N color, mapped from
 *      normalized [-1,1] to [0,1].
 */

#ifndef GUI_PolygonNormalShade_h
#define GUI_PolygonNormalShade_h

#include <GUI/GUI_PrimitiveHook.h>

namespace HDK_Sample
{

/// Render hook which visualizes normals by painting a normal map on 
/// polygon geometry with Cd.
class GUI_PolygonNormalShade : public GUI_PrimitiveHook
{
public:
             GUI_PolygonNormalShade();
            ~GUI_PolygonNormalShade() override;

    /// The main virtual for filtering GT or GEO primitives. If the hook is
    /// interested in the primitive, it should set 'processed' to  GR_PROCESSED,
    /// even if it is not actively modifying the primitive (in which case
    /// return a NULL primitive handle). This ensures that the primitive will
    /// be updated when its display option is toggled. If not interested in the
    /// primitive at all, set 'processed' to GR_NOT_PROCESSED.
    GT_PrimitiveHandle filterPrimitive(
                            const GT_PrimitiveHandle    &gt_prm,
                            const GEO_Primitive         *geo_prm,
                            const GR_RenderInfo         *info,
                            GR_PrimAcceptResult         &processed) override;
};

}
#endif