Support max() and min().

8 files changed, 78 insertions, 2 deletions

diff --git a/dimension/common.nonterminals b/dimension/common.nonterminals
index c3b2b3f..2008290 100644
--- a/dimension/common.nonterminals
+++ b/dimension/common.nonterminals
@@ -73,6 +73,8 @@
 
 /* Generalized arithmetic expressions */
 %type <astnode> ARITH_EXPR
+%type <astnode> MAX_LIST
+%type <astnode> MIN_LIST
 
 /* Colors */
 %type <astnode> COLOR
diff --git a/dimension/common.rules b/dimension/common.rules
index e5b9e67..c8e0767 100644
--- a/dimension/common.rules
+++ b/dimension/common.rules
@@ -453,6 +453,12 @@ ARITH_EXPR: FLOAT_LITERAL
           | "log" "(" ARITH_EXPR ")" {
             $$ = dmnsn_new_astnode1(DMNSN_AST_LOG, @$, $3);
           }
+          | "max" "(" MAX_LIST ")" {
+            $$ = $3;
+          }
+          | "min" "(" MIN_LIST ")" {
+            $$ = $3;
+          }
           | "mod" "(" ARITH_EXPR "," ARITH_EXPR ")" {
             $$ = dmnsn_new_astnode2(DMNSN_AST_MOD, @$, $3, $5);
           }
@@ -501,6 +507,22 @@ ARITH_EXPR: FLOAT_LITERAL
           | "t" { $$ = dmnsn_new_ast_ivector(0, 0, 0, 1, 0); }
 ;
 
+MAX_LIST: ARITH_EXPR "," ARITH_EXPR {
+          $$ = dmnsn_new_astnode2(DMNSN_AST_MAX, @$, $1, $3);
+        }
+        | MAX_LIST "," ARITH_EXPR {
+          $$ = dmnsn_new_astnode2(DMNSN_AST_MAX, @$, $1, $3);
+        }
+;
+
+MIN_LIST: ARITH_EXPR "," ARITH_EXPR {
+          $$ = dmnsn_new_astnode2(DMNSN_AST_MIN, @$, $1, $3);
+        }
+        | MIN_LIST "," ARITH_EXPR {
+          $$ = dmnsn_new_astnode2(DMNSN_AST_MIN, @$, $1, $3);
+        }
+;
+
 /* Colors */
 
 COLOR: COLOR_BODY {
diff --git a/dimension/common.terminals b/dimension/common.terminals
index a877ac1..b5308e4 100644
--- a/dimension/common.terminals
+++ b/dimension/common.terminals
@@ -270,7 +270,7 @@
 %token DMNSN_T_MATERIAL
 %token DMNSN_T_MATERIAL_MAP
 %token DMNSN_T_MATRIX
-%token DMNSN_T_MAX
+%token DMNSN_T_MAX                      "max"
 %token DMNSN_T_MAX_EXTENT
 %token DMNSN_T_MAX_GRADIENT
 %token DMNSN_T_MAX_INTERSECTIONS
@@ -287,7 +287,7 @@
 %token DMNSN_T_METALLIC
 %token DMNSN_T_METHOD
 %token DMNSN_T_METRIC
-%token DMNSN_T_MIN
+%token DMNSN_T_MIN                      "min"
 %token DMNSN_T_MIN_EXTENT
 %token DMNSN_T_MINIMUM_REUSE
 %token DMNSN_T_MOD                      "mod"
diff --git a/dimension/grammar.epilogue b/dimension/grammar.epilogue
index 05e9741..6a4a85f 100644
--- a/dimension/grammar.epilogue
+++ b/dimension/grammar.epilogue
@@ -197,6 +197,8 @@ dmnsn_astnode_string(dmnsn_astnode_type astnode_type)
   dmnsn_astnode_map(DMNSN_AST_INT,     "int"    );
   dmnsn_astnode_map(DMNSN_AST_LN,      "ln"     );
   dmnsn_astnode_map(DMNSN_AST_LOG,     "log"    );
+  dmnsn_astnode_map(DMNSN_AST_MAX,     "max"    );
+  dmnsn_astnode_map(DMNSN_AST_MIN,     "min"    );
   dmnsn_astnode_map(DMNSN_AST_MOD,     "mod"    );
   dmnsn_astnode_map(DMNSN_AST_POW,     "pow"    );
   dmnsn_astnode_map(DMNSN_AST_RADIANS, "radians");
diff --git a/dimension/lexer.l b/dimension/lexer.l
index 79d0a51..a2cf342 100644
--- a/dimension/lexer.l
+++ b/dimension/lexer.l
@@ -214,7 +214,9 @@ unsigned long wchar;
 "log"                   RETURN_TOKEN(DMNSN_T_LOG);
 "look_at"               RETURN_TOKEN(DMNSN_T_LOOK_AT);
 "light_source"          RETURN_TOKEN(DMNSN_T_LIGHT_SOURCE);
+"max"                   RETURN_TOKEN(DMNSN_T_MAX);
 "max_trace_level"       RETURN_TOKEN(DMNSN_T_MAX_TRACE_LEVEL);
+"min"                   RETURN_TOKEN(DMNSN_T_MIN);
 "mod"                   RETURN_TOKEN(DMNSN_T_MOD);
 "perspective"           RETURN_TOKEN(DMNSN_T_PERSPECTIVE);
 "phong"                 RETURN_TOKEN(DMNSN_T_PHONG);
diff --git a/dimension/parse.c b/dimension/parse.c
index fb9de1c..177a96c 100644
--- a/dimension/parse.c
+++ b/dimension/parse.c
@@ -1184,6 +1184,12 @@ dmnsn_eval_binary(dmnsn_astnode astnode, dmnsn_symbol_table *symtable)
     case DMNSN_AST_INT_DIV:
       dmnsn_make_ast_integer(&ret, l/r);
       break;
+    case DMNSN_AST_MAX:
+      dmnsn_make_ast_integer(&ret, l > r ? l : r);
+      break;
+    case DMNSN_AST_MIN:
+      dmnsn_make_ast_integer(&ret, l < r ? l : r);
+      break;
     case DMNSN_AST_MOD:
       dmnsn_make_ast_float(&ret, fmod(l, r));
       break;
@@ -1287,6 +1293,36 @@ dmnsn_eval_binary(dmnsn_astnode astnode, dmnsn_symbol_table *symtable)
     case DMNSN_AST_INT_DIV:
       dmnsn_make_ast_float(&ret, trunc(l/r));
       break;
+    case DMNSN_AST_MAX:
+      if (l > r) {
+        if (lhs.type == DMNSN_AST_INTEGER) {
+          dmnsn_make_ast_maybe_integer(&ret, l);
+        } else {
+          dmnsn_make_ast_float(&ret, l);
+        }
+      } else {
+        if (rhs.type == DMNSN_AST_INTEGER) {
+          dmnsn_make_ast_maybe_integer(&ret, r);
+        } else {
+          dmnsn_make_ast_float(&ret, r);
+        }
+      }
+      break;
+    case DMNSN_AST_MIN:
+      if (l < r) {
+        if (lhs.type == DMNSN_AST_INTEGER) {
+          dmnsn_make_ast_maybe_integer(&ret, l);
+        } else {
+          dmnsn_make_ast_float(&ret, l);
+        }
+      } else {
+        if (rhs.type == DMNSN_AST_INTEGER) {
+          dmnsn_make_ast_maybe_integer(&ret, r);
+        } else {
+          dmnsn_make_ast_float(&ret, r);
+        }
+      }
+      break;
     case DMNSN_AST_MOD:
       dmnsn_make_ast_float(&ret, fmod(l, r));
       break;
@@ -1395,6 +1431,8 @@ dmnsn_eval(dmnsn_astnode astnode, dmnsn_symbol_table *symtable)
   case DMNSN_AST_OR:
   case DMNSN_AST_ATAN2:
   case DMNSN_AST_INT_DIV:
+  case DMNSN_AST_MAX:
+  case DMNSN_AST_MIN:
   case DMNSN_AST_MOD:
   case DMNSN_AST_POW:
   case DMNSN_AST_STRCMP:
diff --git a/dimension/parse.h b/dimension/parse.h
index 4648c87..ddd5e7a 100644
--- a/dimension/parse.h
+++ b/dimension/parse.h
@@ -109,6 +109,8 @@ typedef enum {
   DMNSN_AST_INT,
   DMNSN_AST_LN,
   DMNSN_AST_LOG,
+  DMNSN_AST_MAX,
+  DMNSN_AST_MIN,
   DMNSN_AST_MOD,
   DMNSN_AST_POW,
   DMNSN_AST_RADIANS,
diff --git a/tests/dimension/arithexp.pov b/tests/dimension/arithexp.pov
index c891b1c..d25be7d 100644
--- a/tests/dimension/arithexp.pov
+++ b/tests/dimension/arithexp.pov
@@ -100,6 +100,14 @@ sphere {
   #error "log"
 #end
 
+#if (max(-1.5, 0, 1) != 1)
+  #error "max"
+#end
+
+#if (min(-1.5, 0, 1) != -1.5)
+  #error "min"
+#end
+
 #if (mod(3.5, 2) != 1.5)
   #error "mod"
 #end