/*

* Copyright (c) 2003 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the License "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: Appearance implementation

*

*/

/*!

 * \internal

 * \file

 * \brief Appearance implementation

 */

#ifndef M3G_CORE_INCLUDE

#   error included by m3g_core.c; do not compile separately.

#endif

#include "m3g_appearance.h"

#include "m3g_vertexbuffer.h"

/*----------------------------------------------------------------------

 * Private functions

 *--------------------------------------------------------------------*/

/*!

 * \internal

 * \brief Applies default appearance values to OpenGL.

 */

static void m3gApplyAppearanceDefaults(RenderContext *ctx)

{

    int i;

    m3gApplyCompositingMode(NULL, ctx);

    m3gApplyPolygonMode(NULL);

    m3gApplyMaterial(NULL, 0x10000);

	m3gApplyFog(NULL);

    for (i = 0; i < M3G_NUM_TEXTURE_UNITS; ++i) {

        glActiveTexture(GL_TEXTURE0 + i);

        glDisable(GL_TEXTURE_2D);

    }

}

/*!

 * \internal

 * \brief Generate a hash number for a pointer

 */

static M3Guint m3gGenPointerHash(const void *ptr)

{

    M3Guint p = ((M3Guint) ptr) >> 2;

    M3Guint key = p ^ (p >> 5) ^ (p >> 10) ^ (p >> 15) ^ (p >> 20) ^ (p >> 25);

    return key;

}

/*!

 * \internal

 * \brief Generate a quick hash bit pattern for the textures of this

 * appearance object

 */

static M3Guint m3gGen12BitTextureHash(const Appearance *app)

{

    M3Guint key = 0; 

    int i;

    for (i = 0; i < M3G_NUM_TEXTURE_UNITS; ++i) {

        const Texture *tex = app->texture[i];

        if (tex) {

            key ^= (m3gGenPointerHash(m3gGetTextureImage((M3GTexture)tex)) >> i) << 6;

            key ^= (m3gGenPointerHash(tex) >> i) & 0x3Fu;

        }

    }

    return key & ((1u<<12)-1);

}

/*!

 * \internal

 * \brief Generate the sorting key for render queue

 *

 * Sort key is a combination of user settable layer and

 * blending mode. Blended objects are always drawn last.

 *

 * \param appearance    Appearance object

 * \return              sort key

 */

static void m3gRegenerateSortKey(Appearance *appearance)

{

	M3Guint key = 0;

    M3G_VALIDATE_OBJECT(appearance);

    /*------------------------------------------------------------

     * First do the mandatory sorting by layer index and blending

     * state; this currently uses the top eight bits, 31..24

     *-----------------------------------------------------------*/

    key = (appearance->layer - M3G_APPEARANCE_MIN_LAYER)

        << (33 - M3G_APPEARANCE_HARD_SORT_BITS);

    /* NOTE the blending state bit is not set here, but dynamically in

     * m3gGetAppearanceSortKey; this way we do not need to implement

     * signaling from CompositingMode to Appearance when the blending

     * state changes */

    /*-----------------------------------------------------------------

     * The rest of the bits, 23..0, affect performance only; ideally,

     * these should be sorted so that the more expensive state is in the

     * higher bits, but this is largely dependent on the hardware

     *----------------------------------------------------------------*/

    /* Texturing changes are often expensive in graphics hardware, so

     * we put a hash of the texture objects into the top twelve

     * bits

     *

     * NOTE we do not currently update this if a texture image

     * changes, but that shouldn't happen too often and only has

     * relatively minor performance implications

     */

    key |= m3gGen12BitTextureHash(appearance) << 12;

    /* Use the rest of the bits for the various components; depth

     * function changes are another potentially costly operation, so

     * put that next */

    key |= (m3gGenPointerHash(appearance->compositingMode) & 0x0Fu) << 8;

    key |= (m3gGenPointerHash(appearance->material) & 0x07u) << 5;

    key |= (m3gGenPointerHash(appearance->polygonMode) & 0x07u) << 2;

    key |= (m3gGenPointerHash(appearance->fog) & 0x03u);

    /* Store the final value */

    appearance->sortKey = key;

}

/*----------------------------------------------------------------------

 * Internal functions

 *--------------------------------------------------------------------*/

/*!

 * \internal

 * \brief Destroys this Appearance object.

 *

 * \param obj Appearance object

 */

static void m3gDestroyAppearance(Object *obj)

{

    int i;

    Appearance *appearance = (Appearance *) obj;

    M3G_VALIDATE_OBJECT(appearance);

    M3G_ASSIGN_REF(appearance->compositingMode, NULL);

    M3G_ASSIGN_REF(appearance->fog,             NULL);

    M3G_ASSIGN_REF(appearance->material,        NULL);

    M3G_ASSIGN_REF(appearance->polygonMode,     NULL);

    for (i = 0; i < M3G_NUM_TEXTURE_UNITS; ++i) {

        M3G_ASSIGN_REF(appearance->texture[i], NULL);

    }

    m3gDestroyObject(obj);

}

/*!

 * \internal

 * \brief Applies Apperance settings to current OpenGL state

 *

 * \note m3gReleaseTextures must be called when no longer using this,

 * to properly reset texture usage counters and unmap the texture

 * images.

 * 

 * \param appearance    Appearance object

 * \param alphaFactor   alpha factor as 1.16 fixed point

 */

static void m3gApplyAppearance(const Appearance *appearance,

							   RenderContext *ctx,

                               M3Gint alphaFactor)

{

    M3G_ASSERT_GL;

    if (appearance != NULL) {

        int i;

#       if defined(M3G_NGL_TEXTURE_API)

        m3gLockMemory(M3G_INTERFACE(appearance)); /* for textures */

#       endif

        m3gApplyCompositingMode(appearance->compositingMode, ctx);

        m3gApplyPolygonMode(appearance->polygonMode);

        m3gApplyMaterial(appearance->material, alphaFactor);

        m3gApplyFog(appearance->fog);

        for (i = 0; i < M3G_NUM_TEXTURE_UNITS; ++i) {

            Texture *tex = appearance->texture[i];

            glActiveTexture(GL_TEXTURE0 + i);

            if (tex != NULL) {

                glEnable(GL_TEXTURE_2D);

                m3gBindTexture(appearance->texture[i]);

            }

            else {

                glDisable(GL_TEXTURE_2D);

            }

        }

    }

    else {

        m3gApplyAppearanceDefaults(ctx);

    }

    M3G_ASSERT_GL;

}

/*!

 * \internal

 * \brief Release the textures bound for this appearance

 */

static void m3gReleaseTextures(const Appearance *appearance)

{

    if (appearance != NULL) {

        int i;

        for (i = 0; i < M3G_NUM_TEXTURE_UNITS; ++i) {

            Texture *tex = appearance->texture[i];

            if (tex != NULL) {

                m3gReleaseTexture(tex);

            }

        }

#       if defined(M3G_NGL_TEXTURE_API)

        m3gUnlockMemory(M3G_INTERFACE(appearance));

#       endif

    }

}

/*!

 * \internal

 * \brief Overloaded Object3D method.

 *

 * \param self Appearance object

 * \param time current world time

 * \return minimum validity

 */

static M3Gint m3gAppearanceApplyAnimation(Object *self, M3Gint time) {

    M3Gint i, validity, minValidity = 0x7fffffff;

    Appearance *appearance = (Appearance *)self;

    M3G_VALIDATE_OBJECT(appearance);

    if (appearance->compositingMode != NULL) {

        validity = M3G_VFUNC(Object, appearance->compositingMode, applyAnimation)((Object *)appearance->compositingMode, time);

        minValidity = (validity < minValidity ? validity : minValidity);

    }

    if (appearance->fog != NULL) {

        validity = M3G_VFUNC(Object, appearance->fog, applyAnimation)((Object *)appearance->fog, time);

        minValidity = (validity < minValidity ? validity : minValidity);

    }

    if (appearance->material != NULL) {

        validity = M3G_VFUNC(Object, appearance->material, applyAnimation)((Object *)appearance->material, time);

        minValidity = (validity < minValidity ? validity : minValidity);

    }

    for (i = 0; i < M3G_NUM_TEXTURE_UNITS; ++i) {

        if (appearance->texture[i] != NULL) {

            validity = M3G_VFUNC(Object, appearance->texture[i], applyAnimation)((Object *)appearance->texture[i], time);

            minValidity = (validity < minValidity ? validity : minValidity);

        }

    }

    /* no animations can target an Appearance directly, so we need

       not call super.applyAnimation() here. */

    return minValidity;

}    

/*!

 * \internal

 * \brief Overloaded Object3D method.

 */

static Object *m3gAppearanceFindID(Object *self, M3Gint userID)

{

    int i;

    Appearance *app = (Appearance *)self;

    Object *found = m3gObjectFindID(self, userID);

    if (!found && app->compositingMode) {

        found = m3gFindID((Object*) app->compositingMode, userID);

    }

    if (!found && app->polygonMode) {

        found = m3gFindID((Object*) app->polygonMode, userID);

    }

    if (!found && app->fog) {

        found = m3gFindID((Object*) app->fog, userID);

    }

    if (!found && app->material) {

        found = m3gFindID((Object*) app->material, userID);

    }

    for (i = 0; !found && i < M3G_NUM_TEXTURE_UNITS; ++i) {

        if (app->texture[i]) {

            found = m3gFindID((Object*) app->texture[i], userID);

        }

    }

    return found;

}

/*!

 * \internal

 * \brief Overloaded Object3D method.

 *

 * \param self Appearance object

 * \param references array of reference objects

 * \return number of references

 */

static M3Gint m3gAppearanceDoGetReferences(Object *self, Object **references)

{

    Appearance *app = (Appearance *)self;

    M3Gint i, num = m3gObjectDoGetReferences(self, references);

    if (app->compositingMode != NULL) {

        if (references != NULL)

            references[num] = (Object *)app->compositingMode;

        num++;

    }

    if (app->polygonMode != NULL) {

        if (references != NULL)

            references[num] = (Object *)app->polygonMode;

        num++;

    }

    if (app->fog != NULL) {

        if (references != NULL)

            references[num] = (Object *)app->fog;

        num++;

    }

    if (app->material != NULL) {

        if (references != NULL)

            references[num] = (Object *)app->material;

        num++;

    }

    for (i = 0; i < M3G_NUM_TEXTURE_UNITS; i++) {

        if (app->texture[i] != NULL) {

            if (references != NULL)

                references[num] = (Object *)app->texture[i];

            num++;

        }

    }

    return num;

}

/*!

 * \internal

 * \brief Overloaded Object3D method.

 *

 * \param originalObj original Appearance object

 * \param cloneObj pointer to cloned Appearance object

 * \param pairs array for all object-duplicate pairs

 * \param numPairs number of pairs

 */

static M3Gbool m3gAppearanceDuplicate(const Object *originalObj,

                                      Object **cloneObj,

                                      Object **pairs,

                                      M3Gint *numPairs)

{

    M3Gint i;

    Appearance *original = (Appearance *)originalObj;

    Appearance *clone = (Appearance *)m3gCreateAppearance(originalObj->interface);

    *cloneObj = (Object *)clone;

    if (*cloneObj == NULL) {

        return M3G_FALSE;

    }

    if (m3gObjectDuplicate(originalObj, cloneObj, pairs, numPairs)) {

        clone->layer = original->layer;

        M3G_ASSIGN_REF(clone->compositingMode, original->compositingMode);

        M3G_ASSIGN_REF(clone->fog, original->fog);

        M3G_ASSIGN_REF(clone->polygonMode, original->polygonMode);

        M3G_ASSIGN_REF(clone->material, original->material);

        for (i = 0; i < M3G_NUM_TEXTURE_UNITS; i++) {

            M3G_ASSIGN_REF(clone->texture[i], original->texture[i]);

        }

        m3gRegenerateSortKey(clone);

        return M3G_TRUE;

    }

    else {

        return M3G_FALSE;

    }

}

/*----------------------------------------------------------------------

 * Virtual function table

 *--------------------------------------------------------------------*/

static const ObjectVFTable m3gvf_Appearance = {

    m3gAppearanceApplyAnimation,

    m3gObjectIsCompatible,

    m3gObjectUpdateProperty,

    m3gAppearanceDoGetReferences,

    m3gAppearanceFindID,

    m3gAppearanceDuplicate,

    m3gDestroyAppearance

};

/*----------------------------------------------------------------------

 * Public API functions

 *--------------------------------------------------------------------*/

/*!

 * \brief Creates a new Appearance with default values

 *

 * \param hInterface            M3G interface

 * \retval Appearance new Appearance object

 * \retval NULL Appearance creating failed

 */

/*@access M3GInterface@*/

/*@access M3GAppearance@*/

M3G_API M3GAppearance m3gCreateAppearance(M3GInterface hInterface)

{

    Interface *m3g = (Interface *) hInterface;

    M3G_VALIDATE_INTERFACE(m3g);

    {

        Appearance *appearance = m3gAllocZ(m3g, sizeof(Appearance));

        if (appearance != NULL) {

    		m3gInitObject(&appearance->object, m3g, M3G_CLASS_APPEARANCE);

        }

        return (M3GAppearance) appearance;

    }

}

/*!

 * \brief Get compositing mode

 *

 * \param hAppearance Appearance object

 * \return CompositingMode object

 */

M3G_API M3GCompositingMode m3gGetCompositingMode(M3GAppearance hAppearance)

{

    const Appearance *appearance = (const Appearance *) hAppearance;

    M3G_VALIDATE_OBJECT(appearance);

    return (M3GCompositingMode)(appearance->compositingMode);

}

/*!

 * \brief Get fog

 *

 * \param hAppearance Appearance object

 * \return Fog object

 */

M3G_API M3GFog m3gGetFog(M3GAppearance hAppearance)

{

    const Appearance *appearance = (const Appearance *) hAppearance;

    M3G_VALIDATE_OBJECT(appearance);

    return (M3GFog)(appearance->fog);

}

/*!

 * \brief Get material

 *

 * \param hAppearance Appearance object

 * \return Material object

 */

M3G_API M3GMaterial m3gGetMaterial(M3GAppearance hAppearance)

{

    const Appearance *appearance = (const Appearance *) hAppearance;

    M3G_VALIDATE_OBJECT(appearance);

    return (M3GMaterial)(appearance->material);

}

/*!

 * \brief Get polygon mode

 *

 * \param hAppearance Appearance object

 * \return PolygonMode object

 */

M3G_API M3GPolygonMode m3gGetPolygonMode(M3GAppearance hAppearance)

{

    const Appearance *appearance = (const Appearance *) hAppearance;

    M3G_VALIDATE_OBJECT(appearance);

    return (M3GPolygonMode)(appearance->polygonMode);

}

/*!

 * \brief Get texture

 *

 * \param hAppearance Appearance object

 * \param unit texturing unit

 * \return Texture2D object

 */

M3G_API M3GTexture m3gGetTexture(M3GAppearance hAppearance, M3Gint unit)

{

    const Appearance *appearance = (const Appearance *) hAppearance;

    M3G_VALIDATE_OBJECT(appearance);

    if (!m3gInRange(unit, 0, M3G_NUM_TEXTURE_UNITS - 1)) {

        m3gRaiseError(M3G_INTERFACE(appearance), M3G_INVALID_INDEX);

        return (M3GTexture) NULL;

    }

    return (M3GTexture)(appearance->texture[unit]);

}

/*!

 * \brief Get layer

 *

 * \param hAppearance Appearance object

 * \return layer number

 */

M3G_API M3Gint m3gGetLayer(M3GAppearance hAppearance)

{

    const Appearance *appearance = (const Appearance *) hAppearance;

    M3G_VALIDATE_OBJECT(appearance);

    return appearance->layer;

}

/*!

 * \brief Set compositing mode

 *

 * \param hAppearance Appearance object

 * \param hMode CompositingMode object

 */

M3G_API void m3gSetCompositingMode(M3GAppearance hAppearance,

                                   M3GCompositingMode hMode)

{