From 0c20db39bdbfbedb2ae55be466724272cc8462f3 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Mario=20H=C3=BCttel?= Date: Sat, 16 Nov 2019 15:54:56 +0100 Subject: [PATCH] Update documentation and implementations of bounding box calculations. Rename functions to fit their behavior --- geometric/bounding-box.c | 46 ++++++++++----- geometric/cell-geometrics.c | 2 +- include/gds-render/geometric/bounding-box.h | 65 ++++++++++++++++++++- 3 files changed, 96 insertions(+), 17 deletions(-) diff --git a/geometric/bounding-box.c b/geometric/bounding-box.c index 32fb5b5..a37dda4 100644 --- a/geometric/bounding-box.c +++ b/geometric/bounding-box.c @@ -145,7 +145,7 @@ static void calculate_path_miter_points(struct vector_2d *a, struct vector_2d *b vector_2d_subtract(m2, m2, &v_vec); } -void bounding_box_calculate_path_box(GList *vertices, double thickness, +void bounding_box_update_with_path(GList *vertices, double thickness, conv_generic_to_vector_2d_t conv_func, union bounding_box *box) { GList *vertex_iterator; @@ -191,24 +191,40 @@ void bounding_box_update_point(union bounding_box *destination, conv_generic_to_ destination->vectors.upper_right.y = MAX(destination->vectors.upper_right.y, point.y); } -/** - * @brief Apply transformations onto bounding box. - * @param scale Scaling factor - * @param rotation_deg Roation of bounding box around the origin in degrees (counterclockwise) - * @param flip_at_x Flip the boundig box on the x axis before rotating. - * @param box Bounding box the operations should be applied to. - */ +void bounding_box_get_all_points(struct vector_2d *points, union bounding_box *box) +{ + if (!points || !box) + return; + + points[0].x = box->vectors.lower_left.x; + points[0].y = box->vectors.lower_left.y; + points[1].x = box->vectors.upper_right.x; + points[1].y = box->vectors.lower_left.y; + points[2].x = box->vectors.upper_right.x; + points[2].y = box->vectors.upper_right.y; + points[3].x = box->vectors.lower_left.x; + points[3].y = box->vectors.upper_right.y; +} + void bounding_box_apply_transform(double scale, double rotation_deg, bool flip_at_x, union bounding_box *box) { int i; + struct vector_2d input_points[4]; - /* Due to linearity, the order of the operations does not matter. - * flip must be applied before rotation as defined by the GDS format - */ - for (i = 0; i < 2; i++) { - box->vector_array[i].y *= (flip_at_x ? -1 : 1); - vector_2d_rotate(&box->vector_array[i], rotation_deg * M_PI / 180); - vector_2d_scale(&box->vector_array[i], scale); + if (!box) + return; + + bounding_box_get_all_points(input_points, box); + + /* Reset box */ + bounding_box_prepare_empty(box); + + for (i = 0; i < 4; i++) { + input_points[i].y *= (flip_at_x ? -1 : 1); + vector_2d_rotate(&input_points[i], rotation_deg * M_PI / 180.0); + vector_2d_scale(&input_points[i], scale); + + bounding_box_update_point(box, NULL, &input_points[i]); } } diff --git a/geometric/cell-geometrics.c b/geometric/cell-geometrics.c index 0d7ac71..ee86ae2 100644 --- a/geometric/cell-geometrics.c +++ b/geometric/cell-geometrics.c @@ -63,7 +63,7 @@ static void update_box_with_gfx(union bounding_box *box, struct gds_graphics *gf * Please be aware if paths are the outmost elements of your cell. * You might end up with a completely wrong calculated cell size. */ - bounding_box_calculate_path_box(gfx->vertices, gfx->width_absolute, + bounding_box_update_with_path(gfx->vertices, gfx->width_absolute, (conv_generic_to_vector_2d_t)&convert_gds_point_to_2d_vector, ¤t_box); break; diff --git a/include/gds-render/geometric/bounding-box.h b/include/gds-render/geometric/bounding-box.h index b68bec7..c12030a 100644 --- a/include/gds-render/geometric/bounding-box.h +++ b/include/gds-render/geometric/bounding-box.h @@ -46,12 +46,75 @@ union bounding_box { typedef void (*conv_generic_to_vector_2d_t)(void *, struct vector_2d *); +/** + * @brief Calculate bounding box of polygon + * @param vertices List of vertices that describe the polygon + * @param conv_func Conversion function to convert vertices to vector_2d structs. + * @param box Box to write to. This box is not updated! All previous data is discarded + */ void bounding_box_calculate_polygon(GList *vertices, conv_generic_to_vector_2d_t conv_func, union bounding_box *box); + +/** + * @brief Update an exisitng bounding box with another one. + * @param destination Target box to update + * @param update Box to update the target with + */ void bounding_box_update_box(union bounding_box *destination, union bounding_box *update); + +/** + * @brief Prepare an empty bounding box. + * + * Updating this specially prepared box, results in a bounding box that is the same size as the update + * + * @param box Box to preapre + */ void bounding_box_prepare_empty(union bounding_box *box); + +/** + * @brief Update bounding box with a point + * @param destination Bounding box to update + * @param conv_func Conversion function to convert \p pt to a vector_2d. May be NULL + * @param pt Point to update bounding box with + */ void bounding_box_update_point(union bounding_box *destination, conv_generic_to_vector_2d_t conv_func, void *pt); + +/** + * @brief Return all four corner points of a bounding box + * @param[out] points Array of 4 vector_2d structs that has to be allocated by the caller + * @param box Bounding box + */ +void bounding_box_get_all_points(struct vector_2d *points, union bounding_box *box); + +/** + * @brief Apply transformations onto bounding box. + * + * All corner points of the bounding \f$ \vec{P_i} \f$ box are transformed to output points \f$ \vec{P_o} \f$ by: + * + * \f$ \vec{P_o} = s \cdot \begin{pmatrix}\cos\left(\phi\right) & -\sin\left(\phi\right)\\ \sin\left(\phi\right) & \cos\left(\phi\right)\end{pmatrix} \cdot \begin{pmatrix} 1 & 0 \\ 0 & -1^{m} \end{pmatrix} \cdot \vec{P_i} \f$, with: + * + * * \f$s\f$: Scale + * * \f$m\f$: 1, if flipped_at_x is True, else 0 + * * \f$\phi\f$: Rotation angle in radians. The conversion degrees => radians is done internally + * + * The result is the bounding box generated around all output points + * + * @param scale Scaling factor + * @param rotation_deg Rotation of bounding box around the origin in degrees (counterclockwise) + * @param flip_at_x Flip the boundig box on the x axis before rotating. + * @param box Bounding box the operations should be applied to. + * @note Keep in mind, that this bounding boxy is actually the bounding box of the rotated boundig box and not the object itself. + * It might be too big. + */ void bounding_box_apply_transform(double scale, double rotation_deg, bool flip_at_x, union bounding_box *box); -void bounding_box_calculate_path_box(GList *vertices, double thickness, conv_generic_to_vector_2d_t conv_func, union bounding_box *box); + +/** + * @brief Calculate the bounding box of a path and update the given bounding box + * @param vertices Vertices the path is made up of + * @param thickness Thisckness of the path + * @param conv_func Conversion function for vertices to vector_2d structs + * @param box Bounding box to write results in. + */ +void bounding_box_update_with_path(GList *vertices, double thickness, conv_generic_to_vector_2d_t conv_func, union bounding_box *box); #endif /* _BOUNDING_BOX_H_ */