commit ac68ce2c111dee51d62210aae42cf4c203be61e8
parent d1cf0e76c3c0a0af8402fbe59fca14a24b2d2ff0
Author: Vincent Forest <vincent.forest@meso-star.com>
Date: Wed, 22 Jul 2020 14:21:09 +0200
Add the s2d_scene_view_closest_point function
Diffstat:
3 files changed, 237 insertions(+), 5 deletions(-)
diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
@@ -36,7 +36,7 @@ option(NO_TEST "Disable the test" OFF)
################################################################################
# Check dependencies
################################################################################
-find_package(Embree 3 REQUIRED)
+find_package(Embree 3.6 REQUIRED)
find_package(RCMake 0.2.2 REQUIRED)
find_package(RSys 0.6 REQUIRED)
@@ -67,6 +67,7 @@ set(S2D_FILES_SRC
s2d_primitive.c
s2d_scene.c
s2d_scene_view.c
+ s2d_scene_view_closest_point.c
s2d_shape.c)
set(S2D_FILES_INC_API s2d.h)
set(S2D_FILES_INC
diff --git a/src/s2d.h b/src/s2d.h
@@ -148,9 +148,10 @@ enum s2d_scene_view_flag {
};
/* Filter function data type. One can define such function to discard
- * intersections along a ray with respect to user defined criteria, e.g.:
- * masked/transparent primitive, etc. Return 0 or the intersection is not
- * discarded and a value not equal to zero otherwise. */
+ * intersections along a ray or the result of a closest point query with
+ * respect to user defined criteria, e.g.: masked/transparent primitive, etc.
+ * Return 0 if the intersection is not discarded and a value not equal to zero
+ * otherwise. */
typedef int
(*s2d_hit_filter_function_T)
(const struct s2d_hit* hit,
@@ -289,8 +290,26 @@ s2d_scene_view_trace_ray_3d
void* ray_data,
struct s2d_hit* hit);
+/* Return the point onto the scene segments that is the closest of the
+ * submitted `pos'. Note that even though only one point is returned, several
+ * position can have the same minimal distance to the queried position. The
+ * `radius' parameter defines the maximum search distance around `pos'. Each
+ * candidate position are internally filtered by the hit_filter_function
+ * attached to the corresponding shape; the user can thus reject a candidate
+ * position according to its own criteria. This function can be called only if
+ * the scnview was created with the S2D_TRACE flag which is actually the flag
+ * used to tell Star-2D to internally build an acceleration structure on which
+ * this function relies. */
+S2D_API res_T
+s2d_scene_view_closest_point
+ (struct s2d_scene_view* scnview,
+ const float pos[2], /* Position to query */
+ const float radius, /* Search distance in ]0, radius[ */
+ void* query_data, /* User data sent to the hit filter func. May be NULL */
+ struct s2d_hit* hit);
+
/* Uniformly sample the scene and returned the sampled primitive and its sample
- * position. CCan be called only if the scnview was created with the
+ * position. Can be called only if the scnview was created with the
* S2D_SAMPLE flag */
S2D_API res_T
s2d_scene_view_sample
diff --git a/src/s2d_scene_view_closest_point.c b/src/s2d_scene_view_closest_point.c
@@ -0,0 +1,212 @@
+/* Copyright (C) 2016-2019 |Meso|Star> (contact@meso-star.com)
+ *
+ * This software is governed by the CeCILL license under French law and
+ * abiding by the rules of distribution of free software. You can use,
+ * modify and/or redistribute the software under the terms of the CeCILL
+ * license as circulated by CEA, CNRS and INRIA at the following URL
+ * "http://www.cecill.info".
+ *
+ * As a counterpart to the access to the source code and rights to copy,
+ * modify and redistribute granted by the license, users are provided only
+ * with a limited warranty and the software's author, the holder of the
+ * economic rights, and the successive licensors have only limited
+ * liability.
+ *
+ * In this respect, the user's attention is drawn to the risks associated
+ * with loading, using, modifying and/or developing or reproducing the
+ * software by the user in light of its specific status of free software,
+ * that may mean that it is complicated to manipulate, and that also
+ * therefore means that it is reserved for developers and experienced
+ * professionals having in-depth computer knowledge. Users are therefore
+ * encouraged to load and test the software's suitability as regards their
+ * requirements in conditions enabling the security of their systems and/or
+ * data to be ensured and, more generally, to use and operate it in the
+ * same conditions as regards security.
+ *
+ * The fact that you are presently reading this means that you have had
+ * knowledge of the CeCILL license and that you accept its terms. */
+
+#include "s2d.h"
+#include "s2d_device_c.h"
+#include "s2d_geometry.h"
+#include "s2d_line_segments.h"
+#include "s2d_scene_view_c.h"
+
+#include <rsys/float2.h>
+
+struct point_query_context {
+ struct RTCPointQueryContext rtc;
+ struct s2d_scene_view* scnview;
+ void* data; /* Per point query defined data */
+};
+
+/*******************************************************************************
+ * Helper functions
+ ******************************************************************************/
+static INLINE float*
+closest_point_segment
+ (const float p[2], /* Position */
+ const float v0[2], /* 1st segment vertex */
+ const float v1[2], /* 2nd segment vertex */
+ const float E[2], /* v0 -> v1 vector */
+ float closest_pt[2], /* Closest position */
+ float* s) /* Parametric coordinate of the closest point onto [v0, v1] */
+{
+ float v[2]; /* Vector from v0 to p */
+ float segment_len; /* Length of the [v0, v1] */
+ float dst; /* Dst from v0 to the orthogonal projection of p onto [v0, v1] */
+ ASSERT(p && v0 && v1);
+ ASSERT(f2_eq(f2_sub(v, v1, v0), E));
+
+ /* Orthogonally project the point onto the segment */
+ f2_sub(v, p, v0);
+ segment_len = f2_len(E);
+ dst = f2_dot(v, E);
+
+ /* Check if the closest point is the segment vertex 'v0' */
+ if(dst <= 0) {
+ *s = 0;
+ return f2_set(closest_pt, v0);
+ }
+ /* Check if the closest point is the segment vertex 'v1' */
+ if(dst >= segment_len) {
+ *s = 1;
+ return f2_set(closest_pt, v1);
+ }
+
+ /* The closest point is on the segment */
+ *s = CLAMP(dst / segment_len, 0, 1);
+ return f2_add(closest_pt, f2_mulf(closest_pt, E, dst/segment_len), v0);
+}
+
+static bool
+closest_point_line_segments
+ (struct RTCPointQueryFunctionArguments* args,
+ struct geometry* geom,
+ void* query_data)
+{
+ struct s2d_hit hit = S2D_HIT_NULL;
+ struct s2d_hit* out_hit = NULL;
+ struct hit_filter* filter = NULL;
+ const uint32_t* ids = NULL;
+ float v0[2], v1[2]; /* Segment vertices */
+ float E[2]; /* Segment vector */
+ float N[2]; /* Segment normal */
+ float query_pos[2]; /* Submitted position */
+ float closest_point[2]; /* Computed closest point */
+ float vec[2]; /* Vector from query pos to the closest point */
+ float dst; /* Distance to the closest point */
+ float s; /* Parametric coordinate of the closest point */
+ ASSERT(args && geom);
+ ASSERT(args->primID < line_segments_get_nsegments(geom->lines));
+
+ /* Fetch the line segments indices */
+ ids = line_segments_get_ids(geom->lines) + args->primID*2/*#indices per segment*/;
+
+ /* Fetch segments vertices */
+ ASSERT(geom->lines->attribs_type[S2D_POSITION] == S2D_FLOAT2);
+ f2_set(v0, line_segments_get_pos(geom->lines)+ids[0]*2/*#coords per vertex */);
+ f2_set(v1, line_segments_get_pos(geom->lines)+ids[1]*2/*#coords per vertex */);
+ f2_sub(E, v1, v0);
+
+ query_pos[0] = args->query->x;
+ query_pos[1] = args->query->y;
+
+ /* Compute the closest point ont the segment from the sumbitted query_pos */
+ closest_point_segment(query_pos, v0, v1, E, closest_point, &s);
+
+ f2_sub(vec, closest_point, query_pos);
+ dst = f2_len(vec);
+ if(dst >= args->query->radius) return 0;
+
+ /* Compute the segment normal */
+ N[0] = E[1];
+ N[1] = E[0];
+
+ /* Flip the geometry normal wrt the flip line_segments flag */
+ if(geom->flip_contour) f2_minus(N, N);
+
+ /* Setup the hit */
+ hit.prim.mesh__ = geom;
+ hit.prim.prim_id = args->primID;
+ hit.prim.geom_id = geom->name;
+ hit.prim.scene_prim_id = hit.prim.prim_id + geom->scene_prim_id_offset;
+ hit.normal[0] = N[0];
+ hit.normal[1] = N[1];
+ hit.u = s;
+ hit.distance = dst;
+
+ /* `vec' is the direction along which the closest point was found. Submit it
+ * to the filter function as the direction of the computed hit. */
+ filter = &geom->lines->filter;
+ if(filter->func
+ && filter->func(&hit, query_pos, vec, query_data, filter->data)) {
+ return 0; /* This point is filtered. Discard it! */
+ }
+
+ /* Update output data */
+ out_hit = args->userPtr;
+ *out_hit = hit;
+ args->query->radius = dst; /* Shrink the query radius */
+
+ return 1; /* Notify that the query radius was updated */
+}
+
+static bool
+closest_point(struct RTCPointQueryFunctionArguments* args)
+{
+ struct point_query_context* ctx = NULL;
+ struct geometry* geom = NULL;
+ ASSERT(args);
+
+ ctx = CONTAINER_OF(args->context, struct point_query_context, rtc);
+
+ /* Instance are not supported by Star-2D */
+ ASSERT(args->context->instStackSize == 0);
+
+ geom = scene_view_geometry_from_embree_id(ctx->scnview, args->geomID);
+ return closest_point_line_segments(args, geom, ctx->data);
+}
+
+/*******************************************************************************
+ * Exported functions
+ ******************************************************************************/
+res_T
+s2d_scene_view_closest_point
+ (struct s2d_scene_view* scnview,
+ const float pos[2],
+ const float radius,
+ void* query_data,
+ struct s2d_hit* hit)
+{
+ struct RTCPointQuery query;
+ struct point_query_context query_ctx;
+
+ if(!scnview || !pos || radius <= 0 || !hit)
+ return RES_BAD_ARG;
+
+ if((scnview->mask & S2D_TRACE) == 0) {
+ log_error(scnview->scn->dev,
+ "%s: the S2D_TRACE flag is not active onto the submitted scene view.\n",
+ FUNC_NAME);
+ return RES_BAD_OP;
+ }
+
+ *hit = S2D_HIT_NULL;
+
+ /* Initialise the point query */
+ query.x = pos[0];
+ query.y = pos[1];
+ query.z = 0;
+ query.radius = radius;
+ query.time = FLT_MAX; /* Invalid fields */
+
+ /* Initialise the point query context */
+ rtcInitPointQueryContext(&query_ctx.rtc);
+ query_ctx.scnview = scnview;
+ query_ctx.data = query_data;
+
+ /* Here we go! */
+ rtcPointQuery(scnview->rtc_scn, &query, &query_ctx.rtc, closest_point, hit);
+ return RES_OK;
+}
