sl@0: /*
sl@0: * Copyright (c) 2003 Nokia Corporation and/or its subsidiary(-ies).
sl@0: * All rights reserved.
sl@0: * This component and the accompanying materials are made available
sl@0: * under the terms of the License "Eclipse Public License v1.0"
sl@0: * which accompanies this distribution, and is available
sl@0: * at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: *
sl@0: * Initial Contributors:
sl@0: * Nokia Corporation - initial contribution.
sl@0: *
sl@0: * Contributors:
sl@0: *
sl@0: * Description: Light manager implementation
sl@0: *
sl@0: */
sl@0: 
sl@0: 
sl@0: /*!
sl@0:  * \internal
sl@0:  * \file
sl@0:  * \brief Light manager implementation
sl@0:  */
sl@0: 
sl@0: #ifndef M3G_CORE_INCLUDE
sl@0: #   error included by m3g_core.c; do not compile separately.
sl@0: #endif
sl@0: 
sl@0: #include "m3g_lightmanager.h"
sl@0: #include "m3g_light.h"
sl@0: #include "m3g_rendercontext.h"
sl@0: #include "m3g_math.h"
sl@0: 
sl@0: /*!
sl@0:  * \internal
sl@0:  * \brief Light array element
sl@0:  */
sl@0: typedef struct
sl@0: {
sl@0:     /*! \internal \brief eye space spot direction */
sl@0:     Vec4 spotDir;
sl@0: 
sl@0:     /*! \internal \brief eye space position */
sl@0:     Vec4 position;
sl@0:     
sl@0:     /*! \internal \brief reference to the Light node */
sl@0:     Light *light;
sl@0: } LightRecord;
sl@0: 
sl@0: /*----------------------------------------------------------------------
sl@0:  * Private functions
sl@0:  *--------------------------------------------------------------------*/
sl@0:  
sl@0: /*!
sl@0:  * \internal
sl@0:  * \brief Update a single light record
sl@0:  *
sl@0:  * Light position and spot direction are transformed into world space,
sl@0:  * i.e. omitting the viewing transformation which is applied by OpenGL
sl@0:  * when rendering. Both transformations are special cases and
sl@0:  * accomplished by just reading a part of the matrix.
sl@0:  *
sl@0:  * \note We need to transform the spotlight direction even if the
sl@0:  * light is not a spotlight, since in immediate mode, it may change
sl@0:  * into a spotlight later on!
sl@0:  */
sl@0: static void m3gSetLightRecord(LightRecord *lrec,
sl@0:                               Light *light,
sl@0:                               const Matrix *tf)
sl@0: {
sl@0:     Vec4 v;
sl@0:     M3G_ASSIGN_REF(lrec->light, light);
sl@0: 
sl@0:     if (tf != NULL) {
sl@0:         m3gGetMatrixColumn(tf, 3, &lrec->position);
sl@0:         m3gGetMatrixColumn(tf, 2, &v);
sl@0:         lrec->spotDir.x = -v.x;
sl@0:         lrec->spotDir.y = -v.y;
sl@0:         lrec->spotDir.z = -v.z;
sl@0:         lrec->spotDir.w = 0.0f;
sl@0:     }
sl@0:     else {
sl@0:         lrec->spotDir.x = lrec->spotDir.y = lrec->spotDir.w = 0.0f;
sl@0:         lrec->spotDir.z = -1.0f;
sl@0:         lrec->position.x = lrec->position.y = lrec->position.z = 0.0f;
sl@0:         lrec->position.w = 1.0f;
sl@0:     }
sl@0: }
sl@0: 
sl@0: /*----------------------------------------------------------------------
sl@0:  * Internal functions
sl@0:  *--------------------------------------------------------------------*/
sl@0: 
sl@0: /*!
sl@0:  * \internal
sl@0:  * \brief Clears all lights in the current pool of lights
sl@0:  */
sl@0: static void m3gClearLights2(LightManager *mgr)
sl@0: {
sl@0:     LightRecord *lrec;
sl@0:     PointerArray *lights;
sl@0:     int i, n;
sl@0:     M3G_ASSERT_PTR(mgr);
sl@0: 
sl@0:     lights = &mgr->lights;
sl@0:     n = m3gArraySize(lights);
sl@0:     for (i = 0; i < n; ++i) {
sl@0:         lrec = m3gGetArrayElement(lights, i);
sl@0:         M3G_ASSIGN_REF(lrec->light, NULL);
sl@0:     }
sl@0: 
sl@0:     mgr->numActive = 0;
sl@0: }
sl@0: 
sl@0: /*!
sl@0:  * \internal
sl@0:  * \brief Destroys the light manager, freeing allocated resources
sl@0:  */
sl@0: static void m3gDestroyLightManager(LightManager *mgr, Interface *m3g)
sl@0: {
sl@0:     int i, n;
sl@0:     M3G_ASSERT_PTR(mgr);
sl@0:     M3G_VALIDATE_INTERFACE(m3g);
sl@0: 
sl@0:     /* First remove all light references */
sl@0:     m3gClearLights2(mgr);
sl@0: 
sl@0:     /* Free the records currently in the light array */
sl@0:     n = m3gArraySize(&mgr->lights);
sl@0:     for (i = 0; i < n; ++i) {
sl@0:         m3gFree(m3g, m3gGetArrayElement(&mgr->lights, i));
sl@0:     }
sl@0:     m3gDestroyArray(&mgr->lights, m3g);
sl@0: }
sl@0: 
sl@0: /*!
sl@0:  * \internal
sl@0:  * \brief Appends a light at the end of the light manager array
sl@0:  */
sl@0: static M3Gint m3gInsertLight(LightManager *mgr,
sl@0:                              Light *light,
sl@0:                              const Matrix *tf,
sl@0:                              Interface *m3g)
sl@0: {
sl@0:     LightRecord *lrec;
sl@0:     PointerArray *lights;
sl@0:     M3Gint idx;
sl@0:     M3G_ASSERT_PTR(mgr);
sl@0:     M3G_VALIDATE_INTERFACE(m3g);
sl@0: 
sl@0:     lights = &mgr->lights;
sl@0:     
sl@0:     /* Get the first unused light record, or add a new one */
sl@0:     
sl@0:     if (mgr->numActive < m3gArraySize(lights)) {
sl@0:         lrec = m3gGetArrayElement(lights, mgr->numActive);
sl@0:     }
sl@0:     else {
sl@0:         M3G_ASSERT(mgr->numActive == m3gArraySize(lights));
sl@0:         lrec = m3gAllocZ(m3g, sizeof(LightRecord));
sl@0:         if (lrec == NULL) {
sl@0:             return -1;
sl@0:         }
sl@0:         if (m3gArrayAppend(lights, lrec, m3g) == -1) {
sl@0:             return -1;
sl@0:         }
sl@0:     }
sl@0:     idx = mgr->numActive++;
sl@0: 
sl@0:     m3gSetLightRecord(lrec, light, tf);
sl@0:     return idx;
sl@0: }
sl@0: 
sl@0: /*!
sl@0:  * \internal
sl@0:  * \brief
sl@0:  */
sl@0: static M3Gsizei m3gLightArraySize(const LightManager *mgr)
sl@0: {
sl@0:     M3G_ASSERT_PTR(mgr);
sl@0:     return mgr->numActive;
sl@0: }
sl@0: 
sl@0: /*!
sl@0:  * \internal
sl@0:  * \brief
sl@0:  */
sl@0: static Light *m3gGetLightTransformInternal(const LightManager *mgr, M3Gint idx, M3GMatrix *transform)
sl@0: {
sl@0:     M3Gfloat matrix[16];
sl@0:     LightRecord *lrec;
sl@0:     M3G_ASSERT_PTR(mgr);
sl@0:     M3G_ASSERT(m3gInRange(idx, 0, mgr->numActive - 1));
sl@0: 
sl@0:     lrec = m3gGetArrayElement(&mgr->lights, idx);
sl@0: 
sl@0:     if (transform != NULL) {
sl@0:         m3gZero(matrix, sizeof(matrix));
sl@0:     
sl@0:         matrix[0 * 4 + 0] = 1.f;
sl@0:         matrix[1 * 4 + 1] = 1.f;
sl@0:     
sl@0:         matrix[2 * 4 + 0] = -lrec->spotDir.x;
sl@0:         matrix[2 * 4 + 1] = -lrec->spotDir.y;
sl@0:         matrix[2 * 4 + 2] = -lrec->spotDir.z;
sl@0:     
sl@0:         matrix[3 * 4 + 0] = lrec->position.x;
sl@0:         matrix[3 * 4 + 1] = lrec->position.y;
sl@0:         matrix[3 * 4 + 2] = lrec->position.z;
sl@0:         matrix[3 * 4 + 3] = lrec->position.w;
sl@0:     
sl@0:         m3gSetMatrixColumns(transform, matrix);
sl@0:     }
sl@0: 
sl@0:     return lrec->light;
sl@0: }
sl@0: 
sl@0: /*!
sl@0:  * \internal
sl@0:  * \brief Replaces an existing light in the light array
sl@0:  */
sl@0: static void m3gReplaceLight(LightManager *mgr,
sl@0:                             M3Gint idx,
sl@0:                             Light *light,
sl@0:                             const Matrix *tf)
sl@0: {
sl@0:     LightRecord *lrec;
sl@0:     M3G_ASSERT_PTR(mgr);
sl@0:     M3G_ASSERT(m3gInRange(idx, 0, mgr->numActive - 1));
sl@0: 
sl@0:     lrec = m3gGetArrayElement(&mgr->lights, idx);
sl@0:     m3gSetLightRecord(lrec, light, tf);
sl@0: }
sl@0: 
sl@0: /*!
sl@0:  * \internal
sl@0:  * \brief Selects a set of lights from the current light array for OpenGL
sl@0:  *
sl@0:  * Selects a maximum on \c maxNum lights from the array matching the
sl@0:  * given scope, sets those into the current OpenGL context, and
sl@0:  * disables the rest of the OpenGL lights GL_LIGHT0..GL_LIGHT7. A
sl@0:  * maximum of 8 lights is ever used.
sl@0:  *
sl@0:  */
sl@0: static void m3gSelectGLLights(const LightManager *mgr,
sl@0:                               M3Gsizei maxNum,
sl@0:                               M3Guint scope,
sl@0:                               M3Gfloat x, M3Gfloat y, M3Gfloat z)
sl@0: {
sl@0:     const PointerArray *lights;
sl@0:     int i, required, total;
sl@0:     GLenum glIndex = GL_LIGHT0;
sl@0:     M3G_ASSERT_PTR(mgr);
sl@0: 
sl@0:     M3G_UNREF(x);
sl@0:     M3G_UNREF(y);
sl@0:     M3G_UNREF(z);
sl@0: 
sl@0:     lights = &mgr->lights;
sl@0:     required = m3gClampInt(maxNum, 0, 8);
sl@0:     total = mgr->numActive;
sl@0: 
sl@0:     /* Select the first n lights that match the scope */
sl@0:     
sl@0:     for (i = 0; required > 0 && i < total; ++i) {
sl@0:         const LightRecord *lrec;
sl@0:         const Light *light;
sl@0:         
sl@0:         lrec = (const LightRecord *) m3gGetArrayElement(lights, i);
sl@0:         M3G_ASSERT(lrec != NULL);
sl@0:         light = lrec->light;
sl@0:         
sl@0:         if (light != NULL && (light->node.scope & scope) != 0) {
sl@0:             m3gApplyLight(light, glIndex++, &lrec->position, &lrec->spotDir);
sl@0:             --required;
sl@0:         }
sl@0:     }
sl@0: 
sl@0:     /* Disable the leftover lights */
sl@0:     
sl@0:     while (glIndex <= GL_LIGHT7) {
sl@0:         glDisable(glIndex++);
sl@0:     }
sl@0: }
sl@0: 
sl@0: /*!
sl@0:  * \internal
sl@0:  * \brief Transforms all lights with the given matrix
sl@0:  */
sl@0: static void m3gTransformLights(LightManager *mgr, const Matrix *mtx)
sl@0: {
sl@0:     const PointerArray *lights;
sl@0:     M3Gint i, n;
sl@0: 
sl@0:     lights = &mgr->lights;
sl@0:     n = mgr->numActive;
sl@0:     
sl@0:     for (i = 0; i < n; ++i) {
sl@0:         LightRecord *lrec = (LightRecord*) m3gGetArrayElement(lights, i);
sl@0:         m3gTransformVec4(mtx, &lrec->position);
sl@0:         m3gTransformVec4(mtx, &lrec->spotDir);
sl@0:     }
sl@0: }
sl@0: