htrdr

commit 3b41b51414d6c35391566df8b2473fbd83b7bd25
parent 422896aee475f12df5f234d5f6008690b578c71a
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Wed, 14 Oct 2020 13:22:43 +0200

Implement the htrdr_ground_closest_point function

Diffstat:
M
src/htrdr_ground.c
 | 
58
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
M
src/htrdr_ground.h
 | 
7
+++++++

2 files changed, 65 insertions(+), 0 deletions(-)
diff --git a/src/htrdr_ground.c b/src/htrdr_ground.c
@@ -672,3 +672,61 @@ error:
   goto exit;
 }
 
+res_T
+htrdr_ground_find_closest_point
+  (struct htrdr_ground* ground,
+   const double pos[3],
+   const double radius,
+   struct s3d_hit* hit)
+{
+  float query_pos[3];
+  float query_radius;
+  float ground_sz[3];
+  res_T res = RES_OK;
+  ASSERT(ground && pos && hit);
+
+  if(!ground->view) { /* No ground geometry */
+    *hit = S3D_HIT_NULL;
+    goto exit;
+  }
+
+  query_radius = (float)radius;
+  f3_set_d3(query_pos, pos);
+
+  if(ground->repeat) {
+    float translation[2] = {0, 0};
+    int64_t xy[2];
+    ground_sz[0] = ground->upper[0] - ground->lower[0];
+    ground_sz[1] = ground->upper[1] - ground->lower[1];
+    ground_sz[2] = ground->upper[2] - ground->lower[2];
+
+    /* Define the 2D index of the current ground instance. (0,0) is the index
+     * of the non instantiated ground */
+    xy[0] = (int64_t)floor((query_pos[0] - ground->lower[0]) / ground_sz[0]);
+    xy[1] = (int64_t)floor((query_pos[1] - ground->lower[1]) / ground_sz[1]);
+
+    /* Define the translation along the X and Y axis from world space to local
+     * ground geometry space */
+    translation[0] = -(float)xy[0] * ground_sz[0];
+    translation[1] = -(float)xy[1] * ground_sz[1];
+
+    /* Transform the query pos in local ground geometry space */
+    query_pos[0] += translation[0];
+    query_pos[1] += translation[1];
+  }
+
+  /* Closest point query */
+  res = s3d_scene_view_closest_point
+    (ground->view, query_pos, query_radius, NULL, hit);
+  if(res != RES_OK) {
+    htrdr_log_err(ground->htrdr,
+      "%s: could not query the closest point to the ground geometry -- %s.\n",
+      FUNC_NAME, res_to_cstr(res));
+    goto error;
+  }
+
+exit:
+  return res;
+error:
+  goto exit;
+}
diff --git a/src/htrdr_ground.h b/src/htrdr_ground.h
@@ -67,5 +67,12 @@ htrdr_ground_trace_ray
    const struct s3d_hit* prev_hit,/* Previous hit. Avoid self hit. May be NULL*/
    struct s3d_hit* hit);
 
+extern LOCAL_SYM res_T
+htrdr_ground_find_closest_point
+  (struct htrdr_ground* ground,
+   const double position[3],
+   const double radius,
+   struct s3d_hit* hit);
+
 #endif /* HTRDR_GROUND_H */