tr_turboshadow.cpp

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/*
===========================================================================

Doom 3 GPL Source Code
Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company. 

This file is part of the Doom 3 GPL Source Code (?Doom 3 Source Code?).  

Doom 3 Source Code is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Doom 3 Source Code 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.

You should have received a copy of the GNU General Public License
along with Doom 3 Source Code.  If not, see <http://www.gnu.org/licenses/>.

In addition, the Doom 3 Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 Source Code.  If not, please request a copy in writing from id Software at the address below.

If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.

===========================================================================
*/

#include "../idlib/precompiled.h"
#pragma hdrstop

#include "tr_local.h"

int     c_turboUsedVerts;
int c_turboUnusedVerts;


/*
=====================
R_CreateVertexProgramTurboShadowVolume

are dangling edges that are outside the light frustum still making planes?
=====================
*/
srfTriangles_t *R_CreateVertexProgramTurboShadowVolume( const idRenderEntityLocal *ent, 
                                                                                                                const srfTriangles_t *tri, const idRenderLightLocal *light,
                                                                                                                srfCullInfo_t &cullInfo ) {
        int             i, j;
        srfTriangles_t  *newTri;
        silEdge_t       *sil;
        const glIndex_t *indexes;
        const byte *facing;

        R_CalcInteractionFacing( ent, tri, light, cullInfo );
        if ( r_useShadowProjectedCull.GetBool() ) {
                R_CalcInteractionCullBits( ent, tri, light, cullInfo );
        }

        int numFaces = tri->numIndexes / 3;
        int     numShadowingFaces = 0;
        facing = cullInfo.facing;

        // if all the triangles are inside the light frustum
        if ( cullInfo.cullBits == LIGHT_CULL_ALL_FRONT || !r_useShadowProjectedCull.GetBool() ) {

                // count the number of shadowing faces
                for ( i = 0; i < numFaces; i++ ) {
                        numShadowingFaces += facing[i];
                }
                numShadowingFaces = numFaces - numShadowingFaces;

        } else {

                // make all triangles that are outside the light frustum "facing", so they won't cast shadows
                indexes = tri->indexes;
                byte *modifyFacing = cullInfo.facing;
                const byte *cullBits = cullInfo.cullBits;
                for ( j = i = 0; i < tri->numIndexes; i += 3, j++ ) {
                        if ( !modifyFacing[j] ) {
                                int     i1 = indexes[i+0];
                                int     i2 = indexes[i+1];
                                int     i3 = indexes[i+2];
                                if ( cullBits[i1] & cullBits[i2] & cullBits[i3] ) {
                                        modifyFacing[j] = 1;
                                } else {
                                        numShadowingFaces++;
                                }
                        }
                }
        }

        if ( !numShadowingFaces ) {
                // no faces are inside the light frustum and still facing the right way
                return NULL;
        }

        // shadowVerts will be NULL on these surfaces, so the shadowVerts will be taken from the ambient surface
        newTri = R_AllocStaticTriSurf();

        newTri->numVerts = tri->numVerts * 2;

        // alloc the max possible size
#ifdef USE_TRI_DATA_ALLOCATOR
        R_AllocStaticTriSurfIndexes( newTri, ( numShadowingFaces + tri->numSilEdges ) * 6 );
        glIndex_t *tempIndexes = newTri->indexes;
        glIndex_t *shadowIndexes = newTri->indexes;
#else
        glIndex_t *tempIndexes = (glIndex_t *)_alloca16( tri->numSilEdges * 6 * sizeof( tempIndexes[0] ) );
        glIndex_t *shadowIndexes = tempIndexes;
#endif

        // create new triangles along sil planes
        for ( sil = tri->silEdges, i = tri->numSilEdges; i > 0; i--, sil++ ) {

                int f1 = facing[sil->p1];
                int f2 = facing[sil->p2];

                if ( !( f1 ^ f2 ) ) {
                        continue;
                }

                int v1 = sil->v1 << 1;
                int v2 = sil->v2 << 1;

                // set the two triangle winding orders based on facing
                // without using a poorly-predictable branch

                shadowIndexes[0] = v1;
                shadowIndexes[1] = v2 ^ f1;
                shadowIndexes[2] = v2 ^ f2;
                shadowIndexes[3] = v1 ^ f2;
                shadowIndexes[4] = v1 ^ f1;
                shadowIndexes[5] = v2 ^ 1;

                shadowIndexes += 6;
        }

        int     numShadowIndexes = shadowIndexes - tempIndexes;

        // we aren't bothering to separate front and back caps on these
        newTri->numIndexes = newTri->numShadowIndexesNoFrontCaps = numShadowIndexes + numShadowingFaces * 6;
        newTri->numShadowIndexesNoCaps = numShadowIndexes;
        newTri->shadowCapPlaneBits = SHADOW_CAP_INFINITE;

#ifdef USE_TRI_DATA_ALLOCATOR
        // decrease the size of the memory block to only store the used indexes
        R_ResizeStaticTriSurfIndexes( newTri, newTri->numIndexes );
#else
        // allocate memory for the indexes
        R_AllocStaticTriSurfIndexes( newTri, newTri->numIndexes );
        // copy the indexes we created for the sil planes
        SIMDProcessor->Memcpy( newTri->indexes, tempIndexes, numShadowIndexes * sizeof( tempIndexes[0] ) );
#endif

        // these have no effect, because they extend to infinity
        newTri->bounds.Clear();

        // put some faces on the model and some on the distant projection
        indexes = tri->indexes;
        shadowIndexes = newTri->indexes + numShadowIndexes;
        for ( i = 0, j = 0; i < tri->numIndexes; i += 3, j++ ) {
                if ( facing[j] ) {
                        continue;
                }

                int i0 = indexes[i+0] << 1;
                shadowIndexes[2] = i0;
                shadowIndexes[3] = i0 ^ 1;
                int i1 = indexes[i+1] << 1;
                shadowIndexes[1] = i1;
                shadowIndexes[4] = i1 ^ 1;
                int i2 = indexes[i+2] << 1;
                shadowIndexes[0] = i2;
                shadowIndexes[5] = i2 ^ 1;

                shadowIndexes += 6;
        }

        return newTri;
}

/*
=====================
R_CreateTurboShadowVolume
=====================
*/
srfTriangles_t *R_CreateTurboShadowVolume( const idRenderEntityLocal *ent,
                                                                                        const srfTriangles_t *tri, const idRenderLightLocal *light,
                                                                                        srfCullInfo_t &cullInfo ) {
        int             i, j;
        idVec3  localLightOrigin;
        srfTriangles_t  *newTri;
        silEdge_t       *sil;
        const glIndex_t *indexes;
        const byte *facing;

        R_CalcInteractionFacing( ent, tri, light, cullInfo );
        if ( r_useShadowProjectedCull.GetBool() ) {
                R_CalcInteractionCullBits( ent, tri, light, cullInfo );
        }

        int numFaces = tri->numIndexes / 3;
        int     numShadowingFaces = 0;
        facing = cullInfo.facing;

        // if all the triangles are inside the light frustum
        if ( cullInfo.cullBits == LIGHT_CULL_ALL_FRONT || !r_useShadowProjectedCull.GetBool() ) {

                // count the number of shadowing faces
                for ( i = 0; i < numFaces; i++ ) {
                        numShadowingFaces += facing[i];
                }
                numShadowingFaces = numFaces - numShadowingFaces;

        } else {

                // make all triangles that are outside the light frustum "facing", so they won't cast shadows
                indexes = tri->indexes;
                byte *modifyFacing = cullInfo.facing;
                const byte *cullBits = cullInfo.cullBits;
                for ( j = i = 0; i < tri->numIndexes; i += 3, j++ ) {
                        if ( !modifyFacing[j] ) {
                                int     i1 = indexes[i+0];
                                int     i2 = indexes[i+1];
                                int     i3 = indexes[i+2];
                                if ( cullBits[i1] & cullBits[i2] & cullBits[i3] ) {
                                        modifyFacing[j] = 1;
                                } else {
                                        numShadowingFaces++;
                                }
                        }
                }
        }

        if ( !numShadowingFaces ) {
                // no faces are inside the light frustum and still facing the right way
                return NULL;
        }

        newTri = R_AllocStaticTriSurf();

#ifdef USE_TRI_DATA_ALLOCATOR
        R_AllocStaticTriSurfShadowVerts( newTri, tri->numVerts * 2 );
        shadowCache_t *shadowVerts = newTri->shadowVertexes;
#else
        shadowCache_t *shadowVerts = (shadowCache_t *)_alloca16( tri->numVerts * 2 * sizeof( shadowVerts[0] ) );
#endif

        R_GlobalPointToLocal( ent->modelMatrix, light->globalLightOrigin, localLightOrigin );

        int     *vertRemap = (int *)_alloca16( tri->numVerts * sizeof( vertRemap[0] ) );

        SIMDProcessor->Memset( vertRemap, -1, tri->numVerts * sizeof( vertRemap[0] ) );

        for ( i = 0, j = 0; i < tri->numIndexes; i += 3, j++ ) {
                if ( facing[j] ) {
                        continue;
                }
                // this may pull in some vertexes that are outside
                // the frustum, because they connect to vertexes inside
                vertRemap[tri->silIndexes[i+0]] = 0;
                vertRemap[tri->silIndexes[i+1]] = 0;
                vertRemap[tri->silIndexes[i+2]] = 0;
        }

        newTri->numVerts = SIMDProcessor->CreateShadowCache( &shadowVerts->xyz, vertRemap, localLightOrigin, tri->verts, tri->numVerts );

        c_turboUsedVerts += newTri->numVerts;
        c_turboUnusedVerts += tri->numVerts * 2 - newTri->numVerts;

#ifdef USE_TRI_DATA_ALLOCATOR
        R_ResizeStaticTriSurfShadowVerts( newTri, newTri->numVerts );
#else
        R_AllocStaticTriSurfShadowVerts( newTri, newTri->numVerts );
        SIMDProcessor->Memcpy( newTri->shadowVertexes, shadowVerts, newTri->numVerts * sizeof( shadowVerts[0] ) );
#endif

        // alloc the max possible size
#ifdef USE_TRI_DATA_ALLOCATOR
        R_AllocStaticTriSurfIndexes( newTri, ( numShadowingFaces + tri->numSilEdges ) * 6 );
        glIndex_t *tempIndexes = newTri->indexes;
        glIndex_t *shadowIndexes = newTri->indexes;
#else
        glIndex_t *tempIndexes = (glIndex_t *)_alloca16( tri->numSilEdges * 6 * sizeof( tempIndexes[0] ) );
        glIndex_t *shadowIndexes = tempIndexes;
#endif

        // create new triangles along sil planes
        for ( sil = tri->silEdges, i = tri->numSilEdges; i > 0; i--, sil++ ) {

                int f1 = facing[sil->p1];
                int f2 = facing[sil->p2];

                if ( !( f1 ^ f2 ) ) {
                        continue;
                }

                int v1 = vertRemap[sil->v1];
                int v2 = vertRemap[sil->v2];

                // set the two triangle winding orders based on facing
                // without using a poorly-predictable branch

                shadowIndexes[0] = v1;
                shadowIndexes[1] = v2 ^ f1;
                shadowIndexes[2] = v2 ^ f2;
                shadowIndexes[3] = v1 ^ f2;
                shadowIndexes[4] = v1 ^ f1;
                shadowIndexes[5] = v2 ^ 1;

                shadowIndexes += 6;
        }

        int numShadowIndexes = shadowIndexes - tempIndexes;

        // we aren't bothering to separate front and back caps on these
        newTri->numIndexes = newTri->numShadowIndexesNoFrontCaps = numShadowIndexes + numShadowingFaces * 6;
        newTri->numShadowIndexesNoCaps = numShadowIndexes;
        newTri->shadowCapPlaneBits = SHADOW_CAP_INFINITE;

#ifdef USE_TRI_DATA_ALLOCATOR
        // decrease the size of the memory block to only store the used indexes
        R_ResizeStaticTriSurfIndexes( newTri, newTri->numIndexes );
#else
        // allocate memory for the indexes
        R_AllocStaticTriSurfIndexes( newTri, newTri->numIndexes );
        // copy the indexes we created for the sil planes
        SIMDProcessor->Memcpy( newTri->indexes, tempIndexes, numShadowIndexes * sizeof( tempIndexes[0] ) );
#endif

        // these have no effect, because they extend to infinity
        newTri->bounds.Clear();

        // put some faces on the model and some on the distant projection
        indexes = tri->silIndexes;
        shadowIndexes = newTri->indexes + numShadowIndexes;
        for ( i = 0, j = 0; i < tri->numIndexes; i += 3, j++ ) {
                if ( facing[j] ) {
                        continue;
                }

                int i0 = vertRemap[indexes[i+0]];
                shadowIndexes[2] = i0;
                shadowIndexes[3] = i0 ^ 1;
                int i1 = vertRemap[indexes[i+1]];
                shadowIndexes[1] = i1;
                shadowIndexes[4] = i1 ^ 1;
                int i2 = vertRemap[indexes[i+2]];
                shadowIndexes[0] = i2;
                shadowIndexes[5] = i2 ^ 1;

                shadowIndexes += 6;
        }

        return newTri;
}