9 files changed, 44 insertions, 49 deletions
diff --git a/boltzgen/kernel/generator.py b/boltzgen/kernel/generator.py
index 92ceb72..4fd3c25 100644
--- a/boltzgen/kernel/generator.py
+++ b/boltzgen/kernel/generator.py
@@ -6,10 +6,9 @@ from pathlib import Path
 from . import memory
 
 class Generator:
-    def __init__(self, descriptor, moments, collision, target, precision, index, layout):
-        self.descriptor = descriptor
-        self.moments    = moments
-        self.collision  = collision
+    def __init__(self, model, target, precision, index, layout):
+        self.model      = model
+        self.descriptor = self.model.descriptor
         self.target     = target
         self.float_type = eval("memory.precision.%s" % target).get_float_type(precision)
 
@@ -30,14 +29,11 @@ class Generator:
 
         return Template(filename = str(template_path)).render(
             descriptor = self.descriptor,
+            model      = self.model,
             geometry   = geometry,
             index      = self.index_impl(geometry),
             layout     = self.layout_impl(self.descriptor, self.index_impl, geometry),
 
-            moments_subexpr    = self.moments[0],
-            moments_assignment = self.moments[1],
-            collision_subexpr    = self.collision[0],
-            collision_assignment = self.collision[1],
             ccode = sympy.ccode,
 
             float_type = self.float_type,
@@ -54,14 +50,11 @@ class Generator:
     def custom(self, geometry, source):
         return Template(text = source).render(
             descriptor = self.descriptor,
+            model      = self.model,
             geometry   = geometry,
             index      = self.index_impl(geometry),
             layout     = self.layout_impl(self.descriptor, self.index_impl, geometry),
 
-            moments_subexpr    = self.moments[0],
-            moments_assignment = self.moments[1],
-            collision_subexpr    = self.collision[0],
-            collision_assignment = self.collision[1],
             ccode = sympy.ccode,
 
             float_type = self.float_type,
diff --git a/boltzgen/kernel/template/bounce_back_boundary.cl.mako b/boltzgen/kernel/template/bounce_back_boundary.cl.mako
index cb59cbd..8bb4f6c 100644
--- a/boltzgen/kernel/template/bounce_back_boundary.cl.mako
+++ b/boltzgen/kernel/template/bounce_back_boundary.cl.mako
@@ -9,19 +9,15 @@ __kernel void bounce_back_boundary_gid(__global ${float_type}* f_next,
     const ${float_type} f_curr_${i} = preshifted_f_prev[${layout.pop_offset(i) + layout.neighbor_offset(-c_i)}];
 % endfor
 
-% for i, expr in enumerate(moments_subexpr):
-    const ${float_type} ${expr[0]} = ${ccode(expr[1])};
-% endfor
-
-% for i, expr in enumerate(moments_assignment):
-    ${float_type} ${ccode(expr)}
-% endfor
+<%
+    subexpr, assignment = model.bgk(f_eq = model.equilibrium(resolve_moments = True))
+%>
 
-% for i, expr in enumerate(collision_subexpr):
+% for i, expr in enumerate(subexpr):
     const ${float_type} ${expr[0]} = ${ccode(expr[1])};
 % endfor
 
-% for i, expr in enumerate(collision_assignment):
+% for i, expr in enumerate(assignment):
     const ${float_type} ${ccode(expr)}
 % endfor
 
diff --git a/boltzgen/kernel/template/bounce_back_boundary.cpp.mako b/boltzgen/kernel/template/bounce_back_boundary.cpp.mako
index c7abd2a..91dcfa0 100644
--- a/boltzgen/kernel/template/bounce_back_boundary.cpp.mako
+++ b/boltzgen/kernel/template/bounce_back_boundary.cpp.mako
@@ -9,19 +9,15 @@ void bounce_back_boundary(      ${float_type}* f_next,
     const ${float_type} f_curr_${i} = preshifted_f_prev[${layout.pop_offset(i) + layout.neighbor_offset(-c_i)}];
 % endfor
 
-% for i, expr in enumerate(moments_subexpr):
-    const ${float_type} ${expr[0]} = ${ccode(expr[1])};
-% endfor
-
-% for i, expr in enumerate(moments_assignment):
-    ${float_type} ${ccode(expr)}
-% endfor
+<%
+    subexpr, assignment = model.bgk(f_eq = model.equilibrium(resolve_moments = True))
+%>
 
-% for i, expr in enumerate(collision_subexpr):
+% for i, expr in enumerate(subexpr):
     const ${float_type} ${expr[0]} = ${ccode(expr[1])};
 % endfor
 
-% for i, expr in enumerate(collision_assignment):
+% for i, expr in enumerate(assignment):
     const ${float_type} ${ccode(expr)}
 % endfor
 
diff --git a/boltzgen/kernel/template/collect_moments.cl.mako b/boltzgen/kernel/template/collect_moments.cl.mako
index ddf5102..587f58a 100644
--- a/boltzgen/kernel/template/collect_moments.cl.mako
+++ b/boltzgen/kernel/template/collect_moments.cl.mako
@@ -9,6 +9,10 @@ __kernel void collect_moments_gid(__global ${float_type}* f,
     const ${float_type} f_curr_${i} = preshifted_f[${layout.pop_offset(i)}];
 % endfor
 
+<%
+    moments_subexpr, moments_assignment = model.moments()
+%>
+
 % for i, expr in enumerate(moments_subexpr):
     const ${float_type} ${expr[0]} = ${ccode(expr[1])};
 % endfor
diff --git a/boltzgen/kernel/template/collect_moments.cpp.mako b/boltzgen/kernel/template/collect_moments.cpp.mako
index d72ff5d..1605084 100644
--- a/boltzgen/kernel/template/collect_moments.cpp.mako
+++ b/boltzgen/kernel/template/collect_moments.cpp.mako
@@ -9,6 +9,10 @@ void collect_moments(const ${float_type}* f,
     const ${float_type} f_curr_${i} = preshifted_f[${layout.pop_offset(i)}];
 % endfor
 
+<%
+    moments_subexpr, moments_assignment = model.moments()
+%>
+
 % for i, expr in enumerate(moments_subexpr):
     const ${float_type} ${expr[0]} = ${ccode(expr[1])};
 % endfor
diff --git a/boltzgen/kernel/template/collide_and_stream.cl.mako b/boltzgen/kernel/template/collide_and_stream.cl.mako
index c586884..303b21b 100644
--- a/boltzgen/kernel/template/collide_and_stream.cl.mako
+++ b/boltzgen/kernel/template/collide_and_stream.cl.mako
@@ -9,19 +9,15 @@ __kernel void collide_and_stream_gid(__global ${float_type}* f_next,
     const ${float_type} f_curr_${i} = preshifted_f_prev[${layout.pop_offset(i) + layout.neighbor_offset(-c_i)}];
 % endfor
 
-% for i, expr in enumerate(moments_subexpr):
-    const ${float_type} ${expr[0]} = ${ccode(expr[1])};
-% endfor
-
-% for i, expr in enumerate(moments_assignment):
-    ${float_type} ${ccode(expr)}
-% endfor
+<%
+    subexpr, assignment = model.bgk(f_eq = model.equilibrium(resolve_moments = True))
+%>
 
-% for i, expr in enumerate(collision_subexpr):
+% for i, expr in enumerate(subexpr):
     const ${float_type} ${expr[0]} = ${ccode(expr[1])};
 % endfor
 
-% for i, expr in enumerate(collision_assignment):
+% for i, expr in enumerate(assignment):
     const ${float_type} ${ccode(expr)}
 % endfor
 
diff --git a/boltzgen/kernel/template/collide_and_stream.cpp.mako b/boltzgen/kernel/template/collide_and_stream.cpp.mako
index 20fc529..47dd6dd 100644
--- a/boltzgen/kernel/template/collide_and_stream.cpp.mako
+++ b/boltzgen/kernel/template/collide_and_stream.cpp.mako
@@ -9,23 +9,19 @@ void collide_and_stream(      ${float_type}* f_next,
     const ${float_type} f_curr_${i} = preshifted_f_prev[${layout.pop_offset(i) + layout.neighbor_offset(-c_i)}];
 % endfor
 
-% for i, expr in enumerate(moments_subexpr):
-    const ${float_type} ${expr[0]} = ${ccode(expr[1])};
-% endfor
-
-% for i, expr in enumerate(moments_assignment):
-    ${float_type} ${ccode(expr)}
-% endfor
+<%
+    subexpr, assignment = model.bgk(f_eq = model.equilibrium(resolve_moments = True))
+%>
 
-% for i, expr in enumerate(collision_subexpr):
+% for i, expr in enumerate(subexpr):
     const ${float_type} ${expr[0]} = ${ccode(expr[1])};
 % endfor
 
-% for i, expr in enumerate(collision_assignment):
+% for i, expr in enumerate(assignment):
     const ${float_type} ${ccode(expr)}
 % endfor
 
-% for i, expr in enumerate(collision_assignment):
+% for i, expr in enumerate(assignment):
     preshifted_f_next[${layout.pop_offset(i)}] = f_next_${i};
 % endfor
 }
diff --git a/boltzgen/kernel/template/momenta_boundary.cl.mako b/boltzgen/kernel/template/momenta_boundary.cl.mako
index f5edb61..4e29601 100644
--- a/boltzgen/kernel/template/momenta_boundary.cl.mako
+++ b/boltzgen/kernel/template/momenta_boundary.cl.mako
@@ -1,3 +1,8 @@
+<%
+moments_subexpr, moments_assignment = model.moments()
+collision_subexpr, collision_assignment = model.bgk(f_eq = model.equilibrium(resolve_moments = False))
+%>
+
 <%def name="momenta_boundary(name, param)">
 __kernel void ${name}_momenta_boundary_gid(
    __global ${float_type}* f_next,
diff --git a/boltzgen/kernel/template/momenta_boundary.cpp.mako b/boltzgen/kernel/template/momenta_boundary.cpp.mako
index 3f51087..6d05288 100644
--- a/boltzgen/kernel/template/momenta_boundary.cpp.mako
+++ b/boltzgen/kernel/template/momenta_boundary.cpp.mako
@@ -1,3 +1,8 @@
+<%
+moments_subexpr, moments_assignment = model.moments()
+collision_subexpr, collision_assignment = model.bgk(f_eq = model.equilibrium(resolve_moments = False))
+%>
+
 <%def name="momenta_boundary(name, param)">
 void ${name}_momenta_boundary(
           ${float_type}* f_next,