From b42038826c2de8c24c61c409c845b3817119f85f Mon Sep 17 00:00:00 2001
From: Stephen Neilson <36410751+s-neilson@users.noreply.github.com>
Date: Wed, 24 Jun 2026 16:12:01 +1000
Subject: [PATCH 1/6] For lightcurve.f90, the render region can now be
 specified with the "xmin", "ymin", "xmax" and "ymax" flags. The render region
 bounds that are not specified are calculated automatically as they were
 before. The user can also now specify a constant tempature offset  with the
 "o_col" flag.

---
 src/lightcurve.f90 | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/lightcurve.f90 b/src/lightcurve.f90
index 472d1251..0a5b64be 100644
--- a/src/lightcurve.f90
+++ b/src/lightcurve.f90
@@ -83,7 +83,7 @@ subroutine get_lightcurve(ncolumns,dat,npartoftype,masstype,itype,ndim,ntypes,&
  real, dimension(:),   allocatable :: freq,spectrum,bb_spectrum
  real, dimension(:,:), allocatable :: img,taupix,flux_nu,v_on_c,badpix
  real, dimension(:,:,:), allocatable :: img_nu,img_tmp
- real :: zobs,dzobs,dx,dy,area,freqmin,freqmax,lam_max,freq_max,bb_scale,opacity_factor,f_col
+ real :: zobs,dzobs,dx,dy,area,freqmin,freqmax,lam_max,freq_max,bb_scale,opacity_factor,f_col,o_col
  real :: betaz,lorentz,doppler_factor,doppler_factor_max,tempi,badarea
  real :: rstar,lstar
  logical :: relativistic,nofits
@@ -127,8 +127,16 @@ subroutine get_lightcurve(ncolumns,dat,npartoftype,masstype,itype,ndim,ntypes,&
  if (f_col < 0.0) f_col = renvironment('f_col', 1.0)
  print "(/,a,f5.2,/,a,/)",' SPECTRAL HARDENING FACTOR f_col = ',f_col, &
                           ' (use --fcol=1.7 for radiation-pressure dominated flows; Shimura & Takahara 1995)'
+ o_col = renvironment('o_col')
+ print "(a,f8.2)"," Temperature offset: ",o_col
+
+ !If the user does not provide a limit for the render region it is calculated automatically.
  xmin(1:ndim) = lim(ix(1:ndim),1)
- xmax(1:ndim) = lim(ix(1:ndim),2)
+ xmax(1:ndim) = lim(ix(1:ndim),2)      
+ xmin(1) = renvironment('SPLASH_MARGIN_XMIN', xmin(1))
+ xmax(1) = renvironment('SPLASH_MARGIN_XMAX', xmax(1))
+ xmin(2) = renvironment('SPLASH_MARGIN_YMIN', xmin(2))
+ xmax(2) = renvironment('SPLASH_MARGIN_YMAX', xmax(2))
  !
  !--set number of particles to use in the interpolation routines
  !  and allocate memory for weights

From 6739bee179cf3091e273ce4347ae773c207e4965 Mon Sep 17 00:00:00 2001
From: Stephen Neilson <36410751+s-neilson@users.noreply.github.com>
Date: Wed, 24 Jun 2026 23:25:01 +1000
Subject: [PATCH 2/6] Fixed missing implementation of o_col in lightcurve.f90.

---
 src/lightcurve.f90 | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/lightcurve.f90 b/src/lightcurve.f90
index 0a5b64be..1b317cfa 100644
--- a/src/lightcurve.f90
+++ b/src/lightcurve.f90
@@ -222,7 +222,7 @@ subroutine get_lightcurve(ncolumns,dat,npartoftype,masstype,itype,ndim,ntypes,&
  doppler_factor_max = 0.
  !$omp parallel do default(none) &
  !$omp shared(n,nfreq,freq,flux,flux_nu,dat,h,weight,radkernel) &
- !$omp shared(opacity,relativistic,v_on_c,itemp,f_col) &
+ !$omp shared(opacity,relativistic,v_on_c,itemp,f_col,o_col) &
  !$omp private(i,betaz,lorentz,tempi,rstar,lstar) &
  !$omp firstprivate(opacity_factor,doppler_factor) &
  !$omp reduction(max:doppler_factor_max)
@@ -247,7 +247,7 @@ subroutine get_lightcurve(ncolumns,dat,npartoftype,masstype,itype,ndim,ntypes,&
        lstar = 4.*pi*rstar**2*steboltz*tempi**4
        print "(a,2(es10.3,a),/)",' Luminosity of sink = ',lstar,' erg/s = ',lstar/Lsun,' L_sun'
     else
-       tempi = dat(i,itemp)*f_col
+       tempi = (dat(i,itemp)*f_col)+o_col
     endif
     !call get_opacity_nongrey(nfreq,freq,dat(i,temp),dat(i,rho),opacity_nu(:,i))
     flux_nu(:,i) = B_nu(tempi,freq*doppler_factor)

From 55eb81de179082748521bc3b33a2bb322497355f Mon Sep 17 00:00:00 2001
From: Stephen Neilson <36410751+s-neilson@users.noreply.github.com>
Date: Wed, 24 Jun 2026 23:54:47 +1000
Subject: [PATCH 3/6] Fixed accidentally using "o_col" instead of "ocol" as the
 flag.

---
 src/lightcurve.f90 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/lightcurve.f90 b/src/lightcurve.f90
index 1b317cfa..d2ee6572 100644
--- a/src/lightcurve.f90
+++ b/src/lightcurve.f90
@@ -127,7 +127,7 @@ subroutine get_lightcurve(ncolumns,dat,npartoftype,masstype,itype,ndim,ntypes,&
  if (f_col < 0.0) f_col = renvironment('f_col', 1.0)
  print "(/,a,f5.2,/,a,/)",' SPECTRAL HARDENING FACTOR f_col = ',f_col, &
                           ' (use --fcol=1.7 for radiation-pressure dominated flows; Shimura & Takahara 1995)'
- o_col = renvironment('o_col')
+ o_col = renvironment('ocol')
  print "(a,f8.2)"," Temperature offset: ",o_col
 
  !If the user does not provide a limit for the render region it is calculated automatically.

From 8b22db07e0236c9b615cbc1265ae40258435c647 Mon Sep 17 00:00:00 2001
From: Stephen Neilson <36410751+s-neilson@users.noreply.github.com>
Date: Thu, 25 Jun 2026 01:16:42 +1000
Subject: [PATCH 4/6] In lightcurve generation, prevented maximum render region
 bounds from being less than or equal to the minimum bounds, and also
 prevented the temperature offset making particle temperatures less than or
 equal to zero. Lightcurve generation will be aborted in both of these
 scenarios.

---
 src/lightcurve.f90 | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/src/lightcurve.f90 b/src/lightcurve.f90
index d2ee6572..f4f8eb08 100644
--- a/src/lightcurve.f90
+++ b/src/lightcurve.f90
@@ -137,6 +137,17 @@ subroutine get_lightcurve(ncolumns,dat,npartoftype,masstype,itype,ndim,ntypes,&
  xmax(1) = renvironment('SPLASH_MARGIN_XMAX', xmax(1))
  xmin(2) = renvironment('SPLASH_MARGIN_YMIN', xmin(2))
  xmax(2) = renvironment('SPLASH_MARGIN_YMAX', xmax(2))
+
+ if (xmax(1) <= xmin(1)) then
+    print *,"ERROR: maximum x axis render bound less than or equal to minimum x axis render region bound, aborting..."
+    ierr = 3
+    return
+ endif
+ if (xmax(2) <= xmin(2)) then
+    print *,"ERROR: maximum y axis render bound less than or equal to minimum y axis render region bound, aborting..."
+    ierr = 4
+    return
+ endif
  !
  !--set number of particles to use in the interpolation routines
  !  and allocate memory for weights
@@ -145,7 +156,7 @@ subroutine get_lightcurve(ncolumns,dat,npartoftype,masstype,itype,ndim,ntypes,&
  allocate(weight(n),x(n),y(n),z(n),flux(n),opacity(n),h(n),stat=ierr)
  if (ierr /= 0) then
     print*,' ERROR allocating memory for interpolation weights, aborting...'
-    ierr = 3
+    ierr = 5
     return
  endif
  x(1:n) = dat(1:n,ix(1))
@@ -221,7 +232,7 @@ subroutine get_lightcurve(ncolumns,dat,npartoftype,masstype,itype,ndim,ntypes,&
  opacity_factor = 1.
  doppler_factor_max = 0.
  !$omp parallel do default(none) &
- !$omp shared(n,nfreq,freq,flux,flux_nu,dat,h,weight,radkernel) &
+ !$omp shared(n,nfreq,freq,flux,flux_nu,dat,h,weight,radkernel,ierr) &
  !$omp shared(opacity,relativistic,v_on_c,itemp,f_col,o_col) &
  !$omp private(i,betaz,lorentz,tempi,rstar,lstar) &
  !$omp firstprivate(opacity_factor,doppler_factor) &
@@ -248,11 +259,19 @@ subroutine get_lightcurve(ncolumns,dat,npartoftype,masstype,itype,ndim,ntypes,&
        print "(a,2(es10.3,a),/)",' Luminosity of sink = ',lstar,' erg/s = ',lstar/Lsun,' L_sun'
     else
        tempi = (dat(i,itemp)*f_col)+o_col
+       if (tempi < =0.0) ierr = 6
+       
     endif
     !call get_opacity_nongrey(nfreq,freq,dat(i,temp),dat(i,rho),opacity_nu(:,i))
-    flux_nu(:,i) = B_nu(tempi,freq*doppler_factor)
+    if (ierr /= 6) flux_nu(:,i) = B_nu(tempi,freq*doppler_factor)
  enddo
  !$omp end parallel do
+
+ if (ierr = 6) then
+     print *,"ERROR: choice of temperature offset has resulted in a zero or negative temperature for at least one particle, aborting..."
+     return
+ endif
+ 
  if (relativistic) print*,' max relativistic correction=',doppler_factor_max
 
  if (allocated(img_nu)) deallocate(img_nu)

From 407c4120856440deabeca6154066b3216cad42c0 Mon Sep 17 00:00:00 2001
From: Stephen Neilson <36410751+s-neilson@users.noreply.github.com>
Date: Thu, 25 Jun 2026 01:23:28 +1000
Subject: [PATCH 5/6] Fixed incorrect "<=" and "==" in lightcurve.f90.

---
 src/lightcurve.f90 | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/lightcurve.f90 b/src/lightcurve.f90
index f4f8eb08..66a8f4a2 100644
--- a/src/lightcurve.f90
+++ b/src/lightcurve.f90
@@ -259,7 +259,7 @@ subroutine get_lightcurve(ncolumns,dat,npartoftype,masstype,itype,ndim,ntypes,&
        print "(a,2(es10.3,a),/)",' Luminosity of sink = ',lstar,' erg/s = ',lstar/Lsun,' L_sun'
     else
        tempi = (dat(i,itemp)*f_col)+o_col
-       if (tempi < =0.0) ierr = 6
+       if (tempi <= 0.0) ierr = 6
        
     endif
     !call get_opacity_nongrey(nfreq,freq,dat(i,temp),dat(i,rho),opacity_nu(:,i))
@@ -267,7 +267,7 @@ subroutine get_lightcurve(ncolumns,dat,npartoftype,masstype,itype,ndim,ntypes,&
  enddo
  !$omp end parallel do
 
- if (ierr = 6) then
+ if (ierr == 6) then
      print *,"ERROR: choice of temperature offset has resulted in a zero or negative temperature for at least one particle, aborting..."
      return
  endif

From 894ca5708044300e52ce1278b9b5b24b384d2050 Mon Sep 17 00:00:00 2001
From: Stephen Neilson <36410751+s-neilson@users.noreply.github.com>
Date: Fri, 26 Jun 2026 13:39:31 +1000
Subject: [PATCH 6/6] Added the following to the lightcurve generation
 documentation:  added references to the spectral hardening factor, constant
 temperature offset and the user defined render region bounds.

---
 docs/lightcurve.rst | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/docs/lightcurve.rst b/docs/lightcurve.rst
index 6f345173..805f5550 100755
--- a/docs/lightcurve.rst
+++ b/docs/lightcurve.rst
@@ -74,11 +74,14 @@ where the :math:`w_{\mathrm{col}, ij}` is the dimensionless column kernel.
 
 The spectra were then summed across the frequencies and pixels to produce the bolometric luminosity, listed in [02  Luminosity] in the outputted .out file.
 
+The bounds of the ray-traced region is by default equal to the extent of the particle positions in the dump file. Any number of these automatically calculated bounds can be overriden with the ``SPLASH_MARGIN_XMIN``, ``SPLASH_MARGIN_XMAX``, ``SPLASH_MARGIN_YMIN`` and ``SPLASH_MARGIN_YMAX`` environment variables or the ``--xmin``, ``--xmax``, ``--ymin`` and ``--ymax`` flags. The units of these bounds are the same as the units of the particle positions.
 
 When ``--temperature`` is set, temperature :math:`T` is computed at **read time** from density :math:`\rho` and
 specific internal energy :math:`u` using *get_temp_from_u()* in ``lightcurve_utils.f90``, assuming gas and
 radiation pressure in local thermodynamic equilibrium (see :ref:`sec:lckappa`).
 
+The temperature for each SPH particle can be altered with a scaling factor (called the spectral hardening factor) and constant offset. The scaling factor is set using the flag ``--fcol`` and the constant offset with the flag ``--ocol``. The scaling factor is applied first and the constant offset is added to the scaled temperature.
+
 Opacity :math:`\kappa` used in the ray trace is described in :ref:`sec:lckappa`.