void R_SetupDecalTextureSpaceBasis( decal_t *pDecal, msurface_t *surf, int texture, vec3_t textureSpaceBasis[3], float decalWorldScale[2] )
{
float *sAxis = NULL;
int width, height;
if( pDecal->flags & FDECAL_USESAXIS )
sAxis = pDecal->saxis;
// Compute the non-scaled decal basis
R_DecalComputeBasis( surf, sAxis, textureSpaceBasis );
R_GetDecalDimensions( texture, &width, &height );
// world width of decal = ptexture->width / pDecal->scale
// world height of decal = ptexture->height / pDecal->scale
// scale is inverse, scales world space to decal u/v space [0,1]
// OPTIMIZE: Get rid of these divides
decalWorldScale[0] = (float)pDecal->scale / width;
decalWorldScale[1] = (float)pDecal->scale / height;
VectorScale( textureSpaceBasis[0], decalWorldScale[0], textureSpaceBasis[0] );
VectorScale( textureSpaceBasis[1], decalWorldScale[1], textureSpaceBasis[1] );
}
// Check for intersecting decals on this surface
static decal_t *R_DecalIntersect( decalinfo_t *decalinfo, msurface_t *surf, int *pcount )
{
int texture;
decal_t *plast, *pDecal;
vec3_t decalExtents[2];
float lastArea = 2;
int mapSize[2];
plast = NULL;
*pcount = 0;
// (Same as R_SetupDecalClip).
texture = decalinfo->m_iTexture;
// precalculate the extents of decalinfo's decal in world space.
R_GetDecalDimensions( texture, &mapSize[0], &mapSize[1] );
VectorScale( decalinfo->m_Basis[0], ((mapSize[0] / decalinfo->m_scale) * 0.5f), decalExtents[0] );
VectorScale( decalinfo->m_Basis[1], ((mapSize[1] / decalinfo->m_scale) * 0.5f), decalExtents[1] );
pDecal = surf->pdecals;
while( pDecal )
{
texture = pDecal->texture;
// Don't steal bigger decals and replace them with smaller decals
// Don't steal permanent decals
if(!( pDecal->flags & FDECAL_PERMANENT ))
{
vec3_t testBasis[3];
vec3_t testPosition[2];
float testWorldScale[2];
vec2_t vDecalMin, vDecalMax;
vec2_t vUnionMin, vUnionMax;
R_SetupDecalTextureSpaceBasis( pDecal, surf, texture, testBasis, testWorldScale );
VectorSubtract( decalinfo->m_Position, decalExtents[0], testPosition[0] );
VectorSubtract( decalinfo->m_Position, decalExtents[1], testPosition[1] );
// Here, we project the min and max extents of the decal that got passed in into
// this decal's (pDecal's) [0,0,1,1] clip space, just like we would if we were
// clipping a triangle into pDecal's clip space.
Vector2Set( vDecalMin,
DotProduct( testPosition[0], testBasis[0] ) - pDecal->dx + 0.5f,
DotProduct( testPosition[1], testBasis[1] ) - pDecal->dy + 0.5f );
VectorAdd( decalinfo->m_Position, decalExtents[0], testPosition[0] );
VectorAdd( decalinfo->m_Position, decalExtents[1], testPosition[1] );
Vector2Set( vDecalMax,
DotProduct( testPosition[0], testBasis[0] ) - pDecal->dx + 0.5f,
DotProduct( testPosition[1], testBasis[1] ) - pDecal->dy + 0.5f );
// Now figure out the part of the projection that intersects pDecal's
// clip box [0,0,1,1].
Vector2Set( vUnionMin, max( vDecalMin[0], 0 ), max( vDecalMin[1], 0 ));
Vector2Set( vUnionMax, min( vDecalMax[0], 1 ), min( vDecalMax[1], 1 ));
if( vUnionMin[0] < 1 && vUnionMin[1] < 1 && vUnionMax[0] > 0 && vUnionMax[1] > 0 )
{
// Figure out how much of this intersects the (0,0) - (1,1) bbox.
float flArea = (vUnionMax[0] - vUnionMin[1]) * (vUnionMax[1] - vUnionMin[1]);
if( flArea > 0.6f )
{
*pcount += 1;
if( !plast || flArea <= lastArea )
{
plast = pDecal;
lastArea = flArea;
}
}
}
}
pDecal = pDecal->pnext;
}
return plast;
}
// Shoots a decal onto the surface of the BSP. position is the center of the decal in world coords
void R_DecalShoot( int textureIndex, int entityIndex, int modelIndex, vec3_t pos, int flags, vec3_t saxis, float scale )
{
decalinfo_t decalInfo;
hull_t *hull;
cl_entity_t *ent = NULL;
model_t *model = NULL;
int width, height;
if( textureIndex <= 0 || textureIndex >= MAX_TEXTURES )
{
MsgDev( D_ERROR, "Decal has invalid texture!\n" );
return;
}
if( entityIndex > 0 )
{
ent = CL_GetEntityByIndex( entityIndex );
if( modelIndex > 0 ) model = Mod_Handle( modelIndex );
else if( ent != NULL ) model = Mod_Handle( ent->curstate.modelindex );
else return;
}
else if( modelIndex > 0 )
model = Mod_Handle( modelIndex );
else model = cl.worldmodel;
if( !model ) return;
if( model->type != mod_brush )
{
MsgDev( D_ERROR, "Decals must hit mod_brush!\n" );
return;
}
decalInfo.m_pModel = model;
hull = &model->hulls[0]; // always use #0 hull
if( ent && !( flags & FDECAL_LOCAL_SPACE ))
{
vec3_t pos_l;
// transform decal position in local bmodel space
if( !VectorIsNull( ent->angles ))
{
matrix4x4 matrix;
Matrix4x4_CreateFromEntity( matrix, ent->angles, ent->origin, 1.0f );
Matrix4x4_VectorITransform( matrix, pos, pos_l );
}
else
{
VectorSubtract( pos, ent->origin, pos_l );
}
VectorCopy( pos_l, decalInfo.m_Position );
flags |= FDECAL_LOCAL_SPACE; // decal position moved into local space
}
else
{
// pass position in global
VectorCopy( pos, decalInfo.m_Position );
}
// deal with the s axis if one was passed in
if( saxis )
{
flags |= FDECAL_USESAXIS;
VectorCopy( saxis, decalInfo.m_SAxis );
}
// this decal must use landmark for correct transition
if(!( model->flags & MODEL_HAS_ORIGIN ))
{
flags |= FDECAL_USE_LANDMARK;
}
// more state used by R_DecalNode()
decalInfo.m_iTexture = textureIndex;
decalInfo.m_Entity = entityIndex;
decalInfo.m_Flags = flags;
R_GetDecalDimensions( textureIndex, &width, &height );
decalInfo.m_Size = width >> 1;
if(( height >> 1 ) > decalInfo.m_Size )
decalInfo.m_Size = height >> 1;
decalInfo.m_scale = bound( MIN_DECAL_SCALE, scale, MAX_DECAL_SCALE );
// compute the decal dimensions in world space
decalInfo.m_decalWidth = width / decalInfo.m_scale;
decalInfo.m_decalHeight = height / decalInfo.m_scale;
R_DecalNode( model, &model->nodes[hull->firstclipnode], &decalInfo );
}