ir_constant_expression: Add support for "atan" builtins.

1 files changed, 9 insertions, 1 deletions

diff --git a/src/glsl/ir_constant_expression.cpp b/src/glsl/ir_constant_expression.cpp
index 301bfa80251..a6ce339e3e0 100644
--- a/src/glsl/ir_constant_expression.cpp
+++ b/src/glsl/ir_constant_expression.cpp
@@ -826,7 +826,15 @@ ir_call::constant_expression_value()
       for (unsigned c = 0; c < op[0]->type->components(); c++)
 	 data.f[c] = asinf(op[0]->value.f[c]);
    } else if (strcmp(callee, "atan") == 0) {
-      return NULL; /* FINISHME: implement this */
+      assert(op[0]->type->is_float());
+      if (num_parameters == 2) {
+	 assert(op[1]->type->is_float());
+	 for (unsigned c = 0; c < op[0]->type->components(); c++)
+	    data.f[c] = atan2f(op[0]->value.f[c], op[1]->value.f[c]);
+      } else {
+	 for (unsigned c = 0; c < op[0]->type->components(); c++)
+	    data.f[c] = atanf(op[0]->value.f[c]);
+      }
    } else if (strcmp(callee, "dFdx") == 0 || strcmp(callee, "dFdy") == 0) {
       return ir_constant::zero(mem_ctx, this->type);
    } else if (strcmp(callee, "ceil") == 0) {