source: trunk/src/gfx/mesh_creator.cc @ 294

// Copyright (C) 2012-2014 ChaosForge Ltd
// http://chaosforge.org/
//
// This file is part of NV Libraries.
// For conditions of distribution and use, see copyright notice in nv.hh

#include "nv/gfx/mesh_creator.hh"

struct nv_key_transform { nv::transform tform; };

void nv::mesh_nodes_creator::pre_transform_keys()
{
        if ( m_data->m_flat ) return;
        merge_keys();
        uint32 max_frames = 0;
        for ( size_t i = 0; i < m_data->get_count(); ++i )
        {
                sint16 parent_id = m_data->m_nodes[i].parent_id;
                key_data* keys   = m_data->m_nodes[i].data;
                key_data* pkeys  = ( parent_id != -1 ? m_data->m_nodes[parent_id].data : nullptr );
                size_t count     = ( keys ? keys->get_channel(0)->count : 0 );
                size_t pcount    = ( pkeys ? pkeys->get_channel(0)->count : 0 );
                max_frames = glm::max<uint32>( count, max_frames );
                if ( pkeys && pkeys->get_channel_count() > 0 && keys && keys->get_channel_count() > 0 )
                {
                        nv_key_transform*  channel = ((nv_key_transform*)(keys->get_channel(0)->data));
                        nv_key_transform* pchannel = ((nv_key_transform*)(pkeys->get_channel(0)->data));
                        for ( unsigned n = 0; n < count; ++n )
                        {
                                channel[n].tform = pchannel[ glm::min( n, pcount-1 ) ].tform * channel[n].tform;
                        }
                }
        }

        // DAE pre_transform hack
        if ( m_data->m_frame_rate == 1 )
        {
                m_data->m_frame_rate = 32;
                m_data->m_duration   = (float)max_frames;
        }

        m_data->m_flat = true;
}

// TODO: DELETE
struct assimp_key_p  { float time; nv::vec3 position; };
struct assimp_key_r  { float time; nv::quat rotation; };


void nv::mesh_nodes_creator::merge_keys()
{
        for ( size_t i = 0; i < m_data->get_count(); ++i )
        {
                key_data* old_keys = m_data->m_nodes[i].data;
                if ( old_keys && old_keys->get_channel_count() > 0 )
                {
                        size_t chan_count = old_keys->get_channel_count();
                        if ( chan_count == 1 
                                && old_keys->get_channel(0)->desc.count == 1 
                                && old_keys->get_channel(0)->desc.slots[0].etype == TRANSFORM ) continue;

                        size_t max_keys = 0;
                        for ( size_t c = 0; c < chan_count; ++c )
                        {
                                max_keys = glm::max( max_keys, old_keys->get_channel(c)->count );
                        }

                        key_raw_channel* raw_channel = key_raw_channel::create<nv_key_transform>( max_keys );
                        key_data* new_keys = new key_data;
                        new_keys->add_channel( raw_channel );
                        nv_key_transform* channel = ((nv_key_transform*)(raw_channel->data));
                        key_descriptor final_key = old_keys->get_final_key();

                        for ( unsigned n = 0; n < max_keys; ++n )
                        {
                                float key[ 16 ];
                                float* pkey = key;

                                for ( uint16 c = 0; c < chan_count; ++c )
                                {
                                        size_t idx = glm::min( old_keys->get_channel(c)->count - 1, n );
                                        pkey += old_keys->get_channel(c)->get_raw( idx, pkey );
                                }
                                channel[n].tform = extract_transform_raw( final_key, key );
                        }

                        delete old_keys;
                        m_data->m_nodes[i].data = new_keys;
                }
        }
}

void nv::mesh_nodes_creator::transform( float scale, const mat3& r33 )
{
        mat3 ri33 = glm::inverse( r33 );
        mat4 pre_transform ( scale * r33 );
        mat4 post_transform( 1.f/scale * ri33 ); 

        for ( size_t i = 0; i < m_data->get_count(); ++i )
        {
                mesh_node_data& node = m_data->m_nodes[i];
                node.transform = pre_transform * node.transform * post_transform;
                if ( node.data )
                {
                        key_data* kdata  = node.data;
                        for ( size_t c = 0; c < kdata->get_channel_count(); ++c )
                        {
                                const key_raw_channel* channel = kdata->get_channel(c);
                                size_t key_size = channel->desc.size;
                                for ( size_t n = 0; n < channel->count; ++n )
                                {
                                        transform_key_raw( channel->desc, (uint8*)(channel->data + n * key_size), scale, r33, ri33 );
                                }
                        }
                }
        }
}

void nv::mesh_data_creator::transform( float scale, const mat3& r33 )
{
        vec3 vertex_offset     = glm::vec3(); 
        mat3 vertex_transform  = scale * r33;
        mat3 normal_transform  = r33;

        for ( uint32 c = 0; c < m_data->get_channel_count(); ++c )
        {
                const mesh_raw_channel* channel = m_data->get_channel(c);
                const vertex_descriptor& desc   = channel->desc;
                uint8* raw_data = channel->data;
                int vtx_size = desc.size;
                int p_offset = -1;
                int n_offset = -1;
                int t_offset = -1;
                for ( uint32 i = 0; i < desc.count; ++i )
                        switch ( desc.slots[i].vslot )
                        {
                                case slot::POSITION : if ( desc.slots[i].etype == FLOAT_VECTOR_3 ) p_offset = desc.slots[i].offset; break;
                                case slot::NORMAL   : if ( desc.slots[i].etype == FLOAT_VECTOR_3 ) n_offset = desc.slots[i].offset; break;
                                case slot::TANGENT  : if ( desc.slots[i].etype == FLOAT_VECTOR_4 ) t_offset = desc.slots[i].offset; break;
                                default             : break;
                        }

                if ( p_offset != -1 )
                        for ( uint32 i = 0; i < channel->count; i++)
                        {
                                vec3& p = *((vec3*)(raw_data + vtx_size*i + p_offset ));
                                p = vertex_transform * p + vertex_offset;
                        }

                if ( n_offset != -1 )
                        for ( uint32 i = 0; i < channel->count; i++)
                        {
                                vec3& n = *((vec3*)(raw_data + vtx_size*i + n_offset ));
                                n = glm::normalize( normal_transform * n );
                        }
                if ( t_offset != -1 )
                        for ( uint32 i = 0; i < channel->count; i++)
                        {
                                vec4& t = *((vec4*)(raw_data + vtx_size*i + t_offset ));
                                t = vec4( glm::normalize( normal_transform * vec3(t) ), t[3] );
                        }
        }
}

struct vertex_g
{
        nv::vec4 tangent;
};

void nv::mesh_data_creator::generate_tangents()
{
        int p_offset = -1;
        int n_offset = -1;
        int t_offset = -1;
        datatype i_type = NONE;
        uint32 n_channel_index = 0;

        const mesh_raw_channel* p_channel = nullptr;
              mesh_raw_channel* n_channel = nullptr;
        const mesh_raw_channel* t_channel = nullptr;
        const mesh_raw_channel* i_channel = nullptr;

        for ( uint32 c = 0; c < m_data->get_channel_count(); ++c )
        {
                const mesh_raw_channel* channel = m_data->get_channel(c);
                const vertex_descriptor& desc   = channel->desc;
                for ( uint32 i = 0; i < desc.count; ++i )
                        switch ( desc.slots[i].vslot )
                {
                        case slot::POSITION : 
                                if ( desc.slots[i].etype == FLOAT_VECTOR_3 ) 
                                {
                                        p_offset  = desc.slots[i].offset; 
                                        p_channel = channel;
                                }
                                break;
                        case slot::NORMAL   : if ( desc.slots[i].etype == FLOAT_VECTOR_3 ) 
                                {
                                        n_offset  = desc.slots[i].offset; 
                                        n_channel = m_data->m_channels[ c ];
                                        n_channel_index = c;
                                }
                                break;
                        case slot::TEXCOORD : if ( desc.slots[i].etype == FLOAT_VECTOR_2 ) 
                                {
                                        t_offset  = desc.slots[i].offset; 
                                        t_channel = channel;
                                }
                                break;
                        case slot::INDEX    : 
                                {
                                        i_type    = desc.slots[i].etype;
                                        i_channel = channel;
                                }
                                break;
                        case slot::TANGENT  : return;
                        default             : break;
                }
        }
        if ( !p_channel || !n_channel || !t_channel ) return;

        if ( p_channel->count != n_channel->count || p_channel->count % t_channel->count != 0 || ( i_type != UINT && i_type != USHORT && i_type != NONE ) )
        {
                return;
        }

        mesh_raw_channel* g_channel = mesh_raw_channel::create<vertex_g>( p_channel->count );
        vec4* tangents              = (vec4*)g_channel->data;
        vec3* tangents2             = new vec3[ p_channel->count ];
        uint32 tri_count = i_channel ? i_channel->count / 3 : t_channel->count / 3;
        uint32 vtx_count = p_channel->count;
        uint32 sets      = p_channel->count / t_channel->count;

        for ( unsigned int i = 0; i < tri_count; ++i )
        {
                uint32 ti0 = 0;
                uint32 ti1 = 0;
                uint32 ti2 = 0;
                if ( i_type == UINT )
                {
                        const uint32* idata = (const uint32*)i_channel->data;
                        ti0 = idata[ i * 3 ];
                        ti1 = idata[ i * 3 + 1 ];
                        ti2 = idata[ i * 3 + 2 ];
                }
                else if ( i_type == USHORT )
                {
                        const uint16* idata = (const uint16*)i_channel->data;
                        ti0 = idata[ i * 3 ];
                        ti1 = idata[ i * 3 + 1 ];
                        ti2 = idata[ i * 3 + 2 ];
                }
                else // if ( i_type == NONE )
                {
                        ti0 = i * 3;
                        ti1 = i * 3 + 1;
                        ti2 = i * 3 + 2;
                }

                const vec2& w1 = *((vec2*)(t_channel->data + t_channel->desc.size*ti0 + t_offset ));
                const vec2& w2 = *((vec2*)(t_channel->data + t_channel->desc.size*ti1 + t_offset ));
                const vec2& w3 = *((vec2*)(t_channel->data + t_channel->desc.size*ti2 + t_offset ));
                vec2 st1 = w3 - w1;
                vec2 st2 = w2 - w1;
                float stst = (st1.x * st2.y - st2.x * st1.y);
                float coef = ( stst != 0.0f ? 1.0f / stst : 0.0f );

                for ( uint32 set = 0; set < sets; ++set )
                {
                        uint32 nti0 = t_channel->count * set + ti0;
                        uint32 nti1 = t_channel->count * set + ti1;
                        uint32 nti2 = t_channel->count * set + ti2;
                        vec3 v1 = *((vec3*)(p_channel->data + p_channel->desc.size*nti0 + p_offset ));
                        vec3 v2 = *((vec3*)(p_channel->data + p_channel->desc.size*nti1 + p_offset ));
                        vec3 v3 = *((vec3*)(p_channel->data + p_channel->desc.size*nti2 + p_offset ));
                        vec3 xyz1 = v3 - v1;
                        vec3 xyz2 = v2 - v1;

                        //glm::vec3 normal = glm::cross( xyz1, xyz2 );
                        //
                        //vtcs[ ti0 ].normal += normal;
                        //vtcs[ ti1 ].normal += normal;
                        //vtcs[ ti2 ].normal += normal;
                        vec3 tangent  = (( xyz1 * st2.y ) - ( xyz2 * st1.y )) * coef;
                        vec3 tangent2 = (( xyz2 * st1.x ) - ( xyz1 * st2.x )) * coef;

                        tangents[nti0] = vec4( vec3( tangents[nti0] ) + tangent, 0 );
                        tangents[nti1] = vec4( vec3( tangents[nti1] ) + tangent, 0 );
                        tangents[nti2] = vec4( vec3( tangents[nti2] ) + tangent, 0 );

                        tangents2[nti0] += tangent2;
                        tangents2[nti1] += tangent2;
                        tangents2[nti2] += tangent2;
                }
        }

        for ( unsigned int i = 0; i < vtx_count; ++i )
        {
                const vec3 n = *((vec3*)(n_channel->data + n_channel->desc.size*i + n_offset ));
                const vec3 t = vec3(tangents[i]);
                if ( ! ( t.x == 0.0f && t.y == 0.0f && t.z == 0.0f ) )
                {
                        tangents[i]    = vec4( glm::normalize(t - n * glm::dot( n, t )), 0.0f ); 
                        tangents[i][3] = (glm::dot(glm::cross(n, t), tangents2[i]) < 0.0f) ? -1.0f : 1.0f;
                }
        }
        delete tangents2;

        m_data->m_channels[ n_channel_index ] = merge_channels( n_channel, g_channel );
        delete n_channel;
        delete g_channel;
}

nv::mesh_raw_channel* nv::mesh_data_creator::merge_channels( mesh_raw_channel* a, mesh_raw_channel* b )
{
        NV_ASSERT( a->count == b->count, "merge_channel - bad channels!" );
        vertex_descriptor adesc = a->desc;
        vertex_descriptor bdesc = b->desc;
        uint32            count = a->count;

        vertex_descriptor desc  = a->desc;
        for ( uint32 i = 0; i < bdesc.count; i++ )
        {
                desc.slots[desc.count+i] = bdesc.slots[i];
                desc.slots[desc.count+i].offset += desc.size;
        }
        desc.size  += bdesc.size;
        desc.count += bdesc.count;
        uint8* data = new uint8[ count * desc.size ];
        for ( uint32 i = 0; i < count; ++i )
        {
                std::copy_n( a->data + i * adesc.size, adesc.size, data + i*desc.size );
                std::copy_n( b->data + i * bdesc.size, bdesc.size, data + i*desc.size + adesc.size );
        }
        mesh_raw_channel* result = new mesh_raw_channel;
        result->count = count;
        result->desc  = desc;
        result->data  = data;
        return result;
}