star-camera

commit a7f79ff6659a713e30e6bdb078ef5c1aab419e18
parent 0d14b485a39df890972eefccc985b05e4041412b
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Tue, 27 Jul 2021 08:41:35 +0200

Add the "field of view" <-> "focal length" conversions

Diffstat:
M
src/scam.h
 | 
12
++++++++++++
M
src/scam_perspective.c
 | 
26
++++++++++++++++++++++++++

2 files changed, 38 insertions(+), 0 deletions(-)
diff --git a/src/scam.h b/src/scam.h
@@ -123,6 +123,18 @@ SCAM_API res_T
 scam_ref_put
   (struct scam* camera);
 
+SCAM_API res_T
+scam_focal_length_to_field_of_view
+  (const double lens_radius,
+   const double focal_length,
+   double* field_of_view);
+
+SCAM_API res_T
+scam_field_of_view_to_focal_length
+  (const double lens_radius,
+   const double field_of_view,
+   double* focal_length);
+
 END_DECLS
 
 #endif /* SCAM_H */
diff --git a/src/scam_perspective.c b/src/scam_perspective.c
@@ -56,6 +56,8 @@ setup_perspective(struct scam* cam, const struct scam_perspective_args* args)
     log_err(cam,
       "perspective camera: invalid negative focal distance: %g\n",
       args->focal_distance);
+    res = RES_BAD_ARG;
+    goto error;
   }
 
   if(pinhole && (args->field_of_view <= 0 || args->field_of_view >= PI)) {
@@ -230,6 +232,30 @@ error:
   goto exit;
 }
 
+res_T
+scam_focal_length_to_field_of_view
+  (const double lens_radius,
+   const double focal_length,
+   double* field_of_view)
+{
+  if(lens_radius < 0 || focal_length <= 0 || !field_of_view)
+    return RES_BAD_ARG;
+  *field_of_view = 2 * atan(lens_radius /focal_length);
+  return RES_OK;
+}
+
+res_T
+scam_field_of_view_to_focal_length
+  (const double lens_radius,
+   const double field_of_view,
+   double* focal_length)
+{
+  if(lens_radius < 0 || field_of_view <= 0 || field_of_view >= PI || !focal_length)
+    return RES_BAD_ARG;
+  *focal_length = lens_radius / tan(field_of_view*0.5);
+  return RES_OK;
+}
+
 /*******************************************************************************
  * Local function
  ******************************************************************************/