diff options
Diffstat (limited to 'libdimension/geometry.c')
| -rw-r--r-- | libdimension/geometry.c | 72 |
1 files changed, 32 insertions, 40 deletions
diff --git a/libdimension/geometry.c b/libdimension/geometry.c index 1ec2801..c93dd11 100644 --- a/libdimension/geometry.c +++ b/libdimension/geometry.c @@ -1,5 +1,5 @@ /************************************************************************* - * Copyright (C) 2009-2011 Tavian Barnes <tavianator@tavianator.com> * + * Copyright (C) 2009-2014 Tavian Barnes <tavianator@tavianator.com> * * * * This file is part of The Dimension Library. * * * @@ -358,48 +358,40 @@ dmnsn_bounding_box dmnsn_transform_bounding_box(dmnsn_matrix trans, dmnsn_bounding_box box) { // Infinite/zero bounding box support - if (isinf(box.min.x)) + if (isinf(box.min.x)) { return box; + } + + // Taking the "absolute value" of the matrix saves some min/max calculations + for (int i = 0; i < 3; ++i) { + for (int j = 0; j < 3; ++j) { + trans.n[i][j] = fabs(trans.n[i][j]); + } + } + + dmnsn_vector Mx = dmnsn_matrix_column(trans, 0); + dmnsn_vector xmin = dmnsn_vector_mul(box.min.x, Mx); + dmnsn_vector xmax = dmnsn_vector_mul(box.max.x, Mx); + + dmnsn_vector My = dmnsn_matrix_column(trans, 1); + dmnsn_vector ymin = dmnsn_vector_mul(box.min.y, My); + dmnsn_vector ymax = dmnsn_vector_mul(box.max.y, My); + + dmnsn_vector Mz = dmnsn_matrix_column(trans, 2); + dmnsn_vector zmin = dmnsn_vector_mul(box.min.z, Mz); + dmnsn_vector zmax = dmnsn_vector_mul(box.max.z, Mz); + + dmnsn_vector Mt = dmnsn_matrix_column(trans, 3); - dmnsn_vector corner; dmnsn_bounding_box ret; - ret.min = dmnsn_transform_point(trans, box.min); - ret.max = ret.min; - - corner = dmnsn_new_vector(box.min.x, box.min.y, box.max.z); - corner = dmnsn_transform_point(trans, corner); - ret.min = dmnsn_vector_min(ret.min, corner); - ret.max = dmnsn_vector_max(ret.max, corner); - - corner = dmnsn_new_vector(box.min.x, box.max.y, box.min.z); - corner = dmnsn_transform_point(trans, corner); - ret.min = dmnsn_vector_min(ret.min, corner); - ret.max = dmnsn_vector_max(ret.max, corner); - - corner = dmnsn_new_vector(box.min.x, box.max.y, box.max.z); - corner = dmnsn_transform_point(trans, corner); - ret.min = dmnsn_vector_min(ret.min, corner); - ret.max = dmnsn_vector_max(ret.max, corner); - - corner = dmnsn_new_vector(box.max.x, box.min.y, box.min.z); - corner = dmnsn_transform_point(trans, corner); - ret.min = dmnsn_vector_min(ret.min, corner); - ret.max = dmnsn_vector_max(ret.max, corner); - - corner = dmnsn_new_vector(box.max.x, box.min.y, box.max.z); - corner = dmnsn_transform_point(trans, corner); - ret.min = dmnsn_vector_min(ret.min, corner); - ret.max = dmnsn_vector_max(ret.max, corner); - - corner = dmnsn_new_vector(box.max.x, box.max.y, box.min.z); - corner = dmnsn_transform_point(trans, corner); - ret.min = dmnsn_vector_min(ret.min, corner); - ret.max = dmnsn_vector_max(ret.max, corner); - - corner = dmnsn_new_vector(box.max.x, box.max.y, box.max.z); - corner = dmnsn_transform_point(trans, corner); - ret.min = dmnsn_vector_min(ret.min, corner); - ret.max = dmnsn_vector_max(ret.max, corner); + + ret.min = dmnsn_vector_add(xmin, ymin); + ret.min = dmnsn_vector_add(ret.min, zmin); + ret.min = dmnsn_vector_add(ret.min, Mt); + + ret.max = dmnsn_vector_add(xmax, ymax); + ret.max = dmnsn_vector_add(ret.max, zmax); + ret.max = dmnsn_vector_add(ret.max, Mt); return ret; } |